technetium-tc-99m-tetrofosmin and Myocardial-Infarction

(18)F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) is assumed to be the most useful method for evaluating the viability of the myocardium. However, there are few reports regarding serial changes in (18)F-FDG-PET images of acute myocardial infarction (AMI). We evaluated serial changes in glucose-loaded (18)F-FDG-PET, (123)I-β-methyl-p-iodophenyl-penta-decanoic acid (BMIPP) single-photon emission computed tomography (SPECT) and (99m)Tc-Tetrofosmin (TF) gated SPECT images in patients with AMI.. We enrolled 7 consecutive patients with first anterior AMI who successfully underwent percutaneous coronary intervention (PCI). (18)F-FDG-PET images were obtained in the acute, subacute, chronic, mid-term and long-term phases. (123)I-BMIPP and (99m)Tc-TF SPECT images were obtained in the subacute, chronic, mid-term and long-term phases. We determined the total defect score (TDS) for each image. The TDS of the glucose-loaded (18)F-FDG-PET, (123)I-BMIPP and( 99m)Tc-TF SPECT images indicated significant serial decrease (P<0.001). Comparing these images, the TDS of the glucose-loaded (18)F-FDG-PET images was larger than that of the (123)I-BMIPP and (99m)Tc-TF SPECT images, and the TDS indicated (18)F-FDG-PET>(123)I-BMIPP>(99m)Tc-TF in all phases.. The defect areas of glucose-loaded (18)F-FDG-PET images were significantly larger than those of (123)I-BMIPP and( 99m)Tc-TF SPECT images during 9 months follow-up of patients with successful PCI for anterior AMI. Additionally, the impairment of glucose metabolism was prolonged.

Topics: Aged; Fatty Acids; Female; Fluorodeoxyglucose F18; Follow-Up Studies; Humans; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Percutaneous Coronary Intervention; Positron-Emission Tomography; Radiography; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Magnetic resonance imaging (MRI) is often considered to be the gold standard in measuring left ventricular function and volumes. The aim of this study was to assess the agreements between standard echocardiography (standard echo), contrast echocardiography (contrast echo), single-photon emission computed tomography (SPECT), and MRI in the determination of left ventricular ejection fraction (EF) and end-diastolic volumes (EDV) in patients treated for acute ST-elevation myocardial infarction (STEMI).. Standard echo, contrast echo, SPECT and MRI were performed on the same day, 3 months after STEMI in 150 patients participating in the NORwegian Study on District Treatment of ST-Elevation Myocardial Infarction (NORDISTEMI). Bland-Altman analysis of EF measured by all four imaging modalities showed generally low mean differences but wide limits of agreement. The mean EDV difference, however, was consistently higher when MRI was compared with standard echo (54.9 mL), contrast echo (41.7 mL) and SPECT (54.6 mL), and the limits of agreement were wider. The mean EDV differences between contrast echo vs. standard echo, SPECT vs. standard echo and contrast echo vs. SPECT were small.. Our data suggest that all four imaging modalities measured EF closely similar after STEMI as demonstrated by a very small bias. The limits of agreement were however wide. EDV measured by MRI was consistently higher when compared with the other methods which may be caused by different tracing-methods and imaging principles. As echocardiography is preferable from a cost-benefit point of view, further analysis would be needed to clarify the nature of such differences.

Topics: Contrast Media; Echocardiography; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Statistics, Nonparametric; Thrombolytic Therapy; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Disturbances of autonomic function after infarction are associated with both total mortality and sudden death. Although many imaging techniques for assessing the cardiac autonomic nervous system have been studied, the clinical usefulness of these techniques remains uncertain. This exploratory pilot study examined the relationship between abnormalities of ventricular sympathetic innervation delineated by scintigraphic imaging with (123)I-mIBG and inducible ventricular tachyarrhythmias in patients with left ventricular dysfunction and previous myocardial infarction.. Fifty patients underwent electrophysiological (EP) testing and 15-minute and 4-hour planar and single photon emission computed tomography (SPECT) imaging with (123)I-mIBG and SPECT imaging with (99m)Tc-tetrofosmin. The primary efficacy variables were the 4-hour heart:mediastinum ratio (H/M) and the (123)I-mIBG/(99m)Tc-tetrofosmin SPECT mismatch score. EP studies were categorized as positive (EP(+)) or negative (EP(-)) for inducibility of sustained (>30 seconds) ventricular tachyarrhythmias. Thirty patients were EP(+), and 20 were EP(-). There were no significant differences in the 4-hour H/M ratios or (123)I-mIBG/(99m)Tc-tetrofosmin SPECT mismatch scores between the two groups. In a multivariable analysis using all (123)I-mIBG and (99m)Tc-tetrofosmin SPECT measurements, the only variable that showed a significant difference between EP(+) and EP(-) patients was the 4-hour (123)I-mIBG SPECT defect score. A 4-hour (123)I-mIBG SPECT defect score of > or =37 yielded a sensitivity of 77% and specificity of 75% for predicting EP results.. The standard indices of (123)I-mIBG imaging (H/M and innervation-perfusion mismatch score) are not predictive of EP test results. The association of (123)I-mIBG SPECT defect severity with EP test inducibility in this exploratory study will require confirmation in a larger cohort of patients.

Topics: 3-Iodobenzylguanidine; Aged; Arrhythmias, Cardiac; Autonomic Nervous System; Electrophysiologic Techniques, Cardiac; Female; Heart; Humans; Iodine Radioisotopes; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Sympathetic Nervous System; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

To investigate whether a significant number of normal 1-day stress-rest 99mTc-tetrofosmin myocardial perfusion scintigraphy (MPS) studies can be identified from the low-dose stress acquisition alone, and whether technical staff can find such studies reliably.. The supervising consultant and four technologists independently graded the stress acquisitions from 200 consecutive MPS studies using a five-point scale. Studies were classified as normal or abnormal according to the final clinical report based on the completed stress-rest protocol.. Between 31 and 62 studies (16-31%) were classified as definitely normal from the stress acquisition alone, of which 0-4 (0-9%) proved abnormal on the final report. Of stress studies graded definitely normal by each technologist, the consultant disagreed in 13-34% of cases. Of 78 stress studies graded definitely normal by at least one technologist, 6% turned out to be abnormal and the consultant disagreed in 33%. When there was agreement between at least two technologists (57 studies), the rates fell to 4% and 21% respectively.. Technologists could make the decision to avoid a resting study in up to 30% of patients following a normal low-dose stress acquisition. The supervising nuclear cardiologist would disagree in perhaps one in five cases, even when there was consensus between two or more technologists. These patients would suffer minor inconvenience by being recalled for a rest acquisition on a second day, but there would be important savings in time and radiation exposure for the majority.

Topics: Adenosine; Allied Health Personnel; Exercise Test; Female; Humans; Male; Myocardial Infarction; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; United Kingdom

Although preserved glucose metabolism is considered to be a marker of myocardial viability in the chronic stage, it has not been fully elucidated whether this is also true with regard to reperfused acute myocardial infarction (AMI). The aim of this study was to compare the diagnostic performance of(99m)Tc-tetrofosmin SPECT and(18)F-fluorodeoxyglucose (FDG) PET for the prediction of functional recovery in reperfused AMI.. The study population comprised 28 patients. Both tetrofosmin SPECT and FDG PET were performed in all 28 patients at ca. 2 weeks and in 23 at 6 months. The tetrofosmin and FDG findings in infarct-related segments were compared with the regional wall motion score assessed by left ventriculography over 6 months to determine the predictive value for functional recovery.. Of 120 infarct-related segments, 83 had preserved flow (tetrofosmin uptake >/=50%) and 81 had preserved glucose metabolism (FDG uptake >/=40%). The sensitivity and specificity of tetrofosmin SPECT for the prediction of functional recovery tended to be superior to those of FDG PET (90.0% and 72.5% vs 85.0% and 67.5%, respectively). Thirteen segments with preserved flow and decreased glucose metabolism demonstrated marked recovery of contractile function from 2.5+/-1.0 to 1.4+/-1.4 (p<0.01), with restoration of glucose metabolism at 6 months. In contrast, 11 segments with decreased flow and preserved glucose metabolism demonstrated incomplete functional improvement from 3.0+/-0.8 to 2.2+/-1.2.. In the subacute phase, preserved myocardial blood flow is more reliable than glucose metabolism in predicting functional recovery in reperfused myocardium.

Topics: Aged; Aged, 80 and over; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Prognosis; Radiopharmaceuticals; Recovery of Function; Reproducibility of Results; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Ventricular Dysfunction, Left

To assess if myocardial perfusion scintigraphy (MPS) at rest can be of value in elucidating myocardial perfusion, ischaemia and perioperative myocardial infarction (PMI) associated with coronary artery bypass graft (CABG) surgery.. This was a prospective randomized study of patients undergoing elective CABG. Forty-eight patients in the control group underwent serial ECG recordings and measurements of CK-MB and cTnT. Fifty-four patients in the study group were additionally examined with MPS preoperatively and 2-4 days and 6 weeks postoperatively.. The study showed a highly significant (p < 0.001) improvement in myocardial radionuclide uptake from preoperatively to 2-4 days postoperatively. Judged from ECG and enzymatic changes, two control patients and one study patient only had PMI and no additional cases of PMI were demonstrated by MPS.. MPS at rest showed that CABG significantly improved myocardial perfusion, by demonstrating an increase in radionuclide uptake. In diagnosing PMI, we found that MPS provided no additional information beyond cardiac biochemical markers and ECG changes.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Coronary Artery Bypass; Coronary Circulation; Creatine Kinase, MB Form; Elective Surgical Procedures; Electrocardiography; Female; Follow-Up Studies; Gamma Cameras; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Time Factors; Treatment Outcome; Troponin T

Information on the prognostic value of noninvasive stress imaging techniques in the elderly is relatively scarce. This study assessed the prognostic value of dobutamine stress (99m)Tc-tetrofosmin SPECT for the prediction of mortality and cardiac events in elderly patients.. Clinical information and SPECT results were analyzed for 272 consecutive patients > or = 65 y old (mean age, 71 +/- 5 y; range, 65-87 y) with limited exercise capacity. Follow-up was complete in 270 patients (99.3%); 23 underwent revascularization within 60 d of the scintigraphy and were excluded. Abnormal findings were defined as the presence of a fixed or reversible perfusion defect. A summed stress score was obtained to estimate the extent and severity of perfusion defects. The incremental prognostic value of SPECT over clinical data was evaluated according to 3 multivariate models, which included any SPECT abnormality, the presence of a fixed or reversible defect, and the summed stress score.. During the follow-up (3.3 +/- 1.4 y), 59 patients died (29 cardiac deaths), 16 had a nonfatal infarction, and 49 underwent late revascularization. Abnormal scan findings were present for 140 patients (57%). The annual event rates for total mortality, cardiac death, and cardiac death or nonfatal infarction were, respectively, 3.2%, 0.2%, and 0.7% when scan findings were normal and, respectively, 9.5%, 4.3%, and 8% when scan findings were abnormal (all P < 0.0001). Multivariate analysis showed that abnormal scan findings, the presence of a fixed or reversible defect, and the summed stress score provided incremental prognostic information over clinical data. The presence of abnormal scan findings was independently associated with an increased risk for total mortality, cardiac death, and cardiac death or nonfatal infarction (respectively, hazard ratio 3.4 [95% CI, 1.8-6.5], 12.1 [95% CI, 2.9-51.5], and 9.0 [95% CI, 2.8-29.6]).. Dobutamine stress (99m)Tc-tetrofosmin SPECT provides incremental prognostic information for the prediction of total mortality and cardiac events in elderly patients.

Topics: Aged; Aged, 80 and over; Causality; Comorbidity; Coronary Artery Disease; Dobutamine; Exercise Test; Female; Geriatric Assessment; Humans; Male; Myocardial Infarction; Netherlands; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Reproducibility of Results; Risk Assessment; Risk Factors; Sensitivity and Specificity; Survival Analysis; Tomography, Emission-Computed, Single-Photon

(18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET) is assumed to be the most useful method of evaluating the viability of the myocardium, but its use is limited by the need for a cyclotron. In the present study, the ability of a combination of (99m)Tc-tetrofosmin (TF) and (123)I-beta-methyliodophenyl pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT), a combination of (18)F-FDG PET and (123)I-BMIPP SPECT, and a combination of (18)F-FDG PET and (99m)Tc-TF SPECT were compared to predict functional improvement of ischemic myocardium after a large acute myocardial infarction (AMI).. Ten patients with large AMI were studied by (99m)Tc-TF SPECT, (123)I-BMIPP SPECT and (18)F-FDG PET within 3 weeks. Six months later, (99m)Tc-TF imaging was performed. All patients underwent successful revascularization, and had no restenosis. Regional tracer uptake was scored using a 4-point scale in 20 segments of the SPECT and PET images. When the defect score of (123)I-BMIPP SPECT exceeded the defect score of (99m)Tc-TF SPECT or (18)F-FDG PET by 1 point or more, and when the defect score of (99m)Tc-TF SPECT exceeded the defect score of (18)F-FDG PET by 1 point or more, the segment was considered to show mismatching. When the defect score was the same in 2 tracers, the segment was considered to show matching. (99m)Tc-TF imaging at 3 weeks and 6 months used quantitative gated SPECT (QGS) to score wall motion using a 6-point scale (-1= dyskinesis, 0= akinesis, 1= severe hypokinesis, 2= moderate hypokinesis, 3= mild hypokinesis, and 4= normokinesis). The sensitivity of the combination of (123)I-BMIPP and (99m)Tc-TF imaging in predicting functional improvement was 61%, that of (18)F-FDG PET and (123)I-BMIPP SPECT was 94%, and that of (18)F-FDG PET and (99m)Tc-TF SPECT was 76%. The specificity of the combination of (123)I-BMIPP and (99m)Tc-TF imaging in predicting functional improvement was 83%, that of (18)F-FDG PET and (123)I-BMIPP SPECT was 40%, and that of (18)F-FDG PET and (99m)Tc-TF SPECT was 49%. The accuracy of the combination of (123)I-BMIPP and (99m)Tc-TF imaging in predicting functional improvement was 70%, that of (18)F-FDG PET and (123)I-BMIPP SPECT was 71%, and that of (18)F-FDG PET and (99m)Tc-TF SPECT was 63%.. The combination of (123)I-BMIPP and (99m)Tc-TF imaging is a practical modality for predicting the functional improvement of ischemic myocardium after a large AMI.

Topics: Aged; Drug Combinations; Fatty Acids; Female; Humans; Iodine Radioisotopes; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Sensitivity and Specificity; Severity of Illness Index; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

This study was carried out to assess the repeatability of left ventricular ejection fraction (EF) and volume values obtained using Cedars-Sinai quantitative gated single photon emission computed tomography (SPECT) (QGS) software and relatively low doses of 400-600 MBq of 99mTc-tetrofosmin.. Repeatability was assessed in a group of 75 patients, with both normal and reduced EF, who underwent repeat 99mTc-tetrofosmin gated SPECT studies and showed no clinical change in cardiac status. Gated SPECT data were acquired 1 h after injection at rest of 400-600 MBq of 99mTc-tetrofosmin. The standard patient dose was 400 MBq; however, some patients with a weight of >90 kg were given increased doses up to a maximum of 600 MBq.. There was good correlation of EF and volumes between the first and repeat measurements, and no significant difference between the mean EF and volumes for both the initial and repeat measurements. Background-corrected counts in the left ventricle were calculated and patients were divided into two groups: one with low counts and one with high counts. The mean difference in EF between the first and repeat measurements was significantly higher for patients in the low count group compared with those in the high count group, but there was no significant change in volume. Similarly, the mean sequential difference in EF was significantly higher for patients with normal EF, but there was no significant difference in volume.. We have demonstrated that EF measured using 99mTc-tetrofosmin gated SPECT is repeatable, particularly for patients with low EF, provided that adequate left ventricular counts are obtained. This will require doses greater than 400 MBq in larger patients. Ventricular volumes calculated using QGS may not be sufficiently repeatable for clinical use.

Topics: Algorithms; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Software Validation; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

The clinical usefulness of characterizing reperfused myocardium by perfusion/thickening assessment using electrocardiographic gated single photon emission computed tomography (SPECT) has not been investigated. We evaluated whether single-injection gated SPECT with 99mTc tetrofosmin early after primary percutaneous coronary intervention (PCI) can predict left ventricular (LV) functional recovery.. Gated SPECT was performed 3 days after primary PCI in 45 patients with acute myocardial infarction and revascularized segments were classified into perfusion/thickening mismatched segments, matched normal and matched abnormal segments. Gated SPECT was repeated 3 months later to evaluate the changes in LV ejection fraction (deltaLVEF).. Among 332 revascularized segments, there were 83 mismatched segments, 163 matched abnormal segments and 86 matched normal segments. In all the patients, LVEF increased significantly from 3 days to 3 months after primary PCI (52+/-13 to 57+/-14%, P<0.0001). Patients were divided into two groups according to deltaLVEF: 24 patients with LV functional recovery (deltaLVEF > or = 5%) and 21 patients without LV functional recovery. The number of mismatched segments in patients with LV functional recovery was significantly greater than that in patients without (2.7+/-1.7 vs. 0.8+/-1.4, P<0.0003) despite no differences in the number of matched abnormal and matched normal segments. There was a significant correlation between deltaLVEF and the number of mismatched segments (r=0.56, P<0.0001) and LVEF at 3 months after primary PCI was related to the number of matched abnormal segments (r=-0.78, P<0.0001).. Single-injection gated SPECT early after primary PCI can predict LV functional recovery.

Topics: Angioplasty, Balloon, Coronary; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Recovery of Function; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Stroke Volume; Treatment Outcome; Ventricular Dysfunction, Left

The aim of this study was to compare (99m)Tc-tetrofosmin SPECT with contrast-enhanced MRI (ceMRI), a new direct sign of myocardial fibrosis.. We studied 21 patients (age, 60 +/- 11 y; 19 male) with previous myocardial infarction and severe left ventricular dysfunction (ceMRI EF, 29% +/- 6%). All patients underwent resting and postnitrate (intravenous isosorbide dinitrate) (99m)Tc-tetrofosmin gated SPECT as well as ceMRI. Scintigraphic analysis was performed using quantitative perfusion SPECT (QPS), providing the percentage radiotracer uptake and defect severity in a 20-segment model. Hyperenhancement was defined by the increase of ceMRI signal intensity 20 min after intravenous injection of gadolinium-diethylenetriaminepentaacetic acid and its regional extension as the percentage of the total segment area.. In ceMRI dysfunctional segments, the correlation between the extent of hyperenhancement and both (99m)Tc-tetrofosmin uptake and defect severity was significantly better after nitrate administration rather than at rest (P < 0.0001). Using a ceMRI cutoff below 40%, 102 of 196 (52%) segments were viable, whereas 94 (48%) segments were not viable. According to receiver-operating characteristic curve analysis, diagnostic accuracies were higher for postnitrate (99m)Tc-tetrofosmin uptake as well as perfusion defect severity than using resting data (0.84 vs. 0.71, P < 0.001; 0.89 vs. 0.76, P < 0.001, respectively).. After nitrate administration, (99m)Tc-tetrofosmin uptake and perfusion defect severity were closely related to ceMRI, demonstrating, in vivo, the existence of an inverse correlation between the transmural distribution of fibrosis and tracer delivery to the myocardium.

Topics: Adult; Aged; Aged, 80 and over; Contrast Media; Exercise Test; Female; Gadolinium DTPA; Heart; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Infarction; Myocardium; Nitrates; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

We compared Takotsubo cardiomyopathy (transient left ventricular apical ballooning) with acute myocardial infarction (AMI) using two-dimensional echocardiography, 99mTc-tetrofosmin, 99mTc-PYP, 123I-BMIPP and 123I-MIBG myocardial SPECT.. We examined 7 patients with Takotsubo cardiomyopathy and 7 with AMI at the time of emergency admission (acute phase), and 2-14 days (subacute phase), one month (chronic phase), and 3 months (chronic II phase) after the attack. The left ventricle was divided into nine regions on echocardiograms and SPECT images, and the degree of abnormalities in each region was scored according to five grades from normal (0) to severely abnormal (4).. Coronary angiography showed the absence of stenotic regions in patients with Takotsubo cardiomyopathy, and severely stenotic and/or occlusive lesions in patients with AMI. The total ST segment elevation on electrocardiograms (mm) was 7.8 +/- 3.7 in those with Takotsubo cardiomyopathy, and 7.3 +/- 3.9 in patients with AMI. Abnormal wall motion scores on echocardiograms were 14.2 +/- 4.6, 4.7 +/- 4.0, 1.7 +/- 2.0 and 0.5 +/- 0.4 during the acute, subacute, chronic and chronic II phases, respectively, in patients with Takotsubo cardiomyopathy, and 14.0 +/- 4.3, 11.4 +/- 3.9, 8.8 +/- 3.6 and 5.2 +/- 4.8 in those with AMI. Abnormal myocardial perfusion scores on 99mTc-tetrofosmin images were 11.8 +/- 3.5, 3.2 +/- 3.0, 0.5 +/- 1.2 and 0.2 +/- 0.4 during the acute, subacute, chronic and chronic II phases, in patients with Takotsubo cardiomyopathy, and 16.2 +/- 4.3, 13.9 +/- 4.6, 7.9 +/- 4.6 and 5.0 +/- 4.5, respectively, in those with AMI. Abnormal myocardial fatty acid scores on 123I-BMIPP images were 12.6 +/- 3.7, 6.8 +/- 3.2 and 0.4 +/- 0.6 during the subacute, chronic and chronic II phases, respectively, in patients with Takotsubo cardiomyopathy, and 16.5 +/- 5.1, 14.7 +/- 4.8 and 7.5 +/- 4.5 in those with AMI. Abnormal myocardial sympathetic nerve function scores on 123I-MIBG images were 14.8 +/- 4.0, 8.8 +/- 4.0 and 0.4 +/- 0.6 during the subacute, chronic, chronic II phases, respectively, in patients with Takotsubo cardiomyopathy, and 18.6 +/- 6.5, 16.8 +/- 6.8 and 12.9 +/- 5.2 in those with AMI. Myocardial 99mTc-PYP uptake was abnormal not only in patients with AMI but also in those with Takotsubo cardiomyopathy during the acute phase.. Takotsubo cardiomyopathy might represent a stunned myocardium caused by a disturbance of the coronary microcirculation.

Topics: 3-Iodobenzylguanidine; Aged; Aged, 80 and over; Cardiomyopathies; Diagnosis, Differential; Fatty Acids; Female; Humans; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Syndrome; Technetium Tc 99m Pyrophosphate; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

The accuracy of viability and defect size detection by Tc-tetrofosmin has been discussed by several authors. The lower myocardial extraction fraction of the latter compared with Tc-sestamibi or Tl has often been emphasized. We hypothesized that the intracoronary (i.c.) injection of tracer activity, i.e. higher than that theoretically achievable in the case of intravenous (i.v.) administration, could demonstrate the clinical relevance of this finding intra-individually. In this study, myocardial perfusion images obtained after tracer injection down the infarct-related artery were compared with i.v. injection images in the same patients. The trial also provided us with the opportunity to compare the wall motion values calculated using conventional Tc-tetrofosmin gated single-photon emission computed tomography (SPECT) studies with those obtained using optimal target/background ratios after i.c. injection.. Fourteen patients with acute myocardial infarction, no history of previous cardiac events, single vessel disease and no visible collaterals in the coronary arteriogram were included in the study. Electrocardiogram gated SPECT was carried out separately after i.c. and i.v. injections of the tracer within 5-7 days following thrombolytic therapy. Myocardial perfusion patterns were compared by contingency table analysis after semi-quantitative visual scoring. Segmental wall motion was compared using quantified polar map data in a subset of patients (eight of 14) with normal to moderately hypoperfused myocardium supplied by the left coronary artery.. Visual perfusion scores of both studies showed good concordance (kappa, 0.70), with complete agreement in 94 of 119 segments. Nearly all of the discordant segments (24 of 25) were mildly better scored in i.c. studies than in i.v. studies. The mean wall motion values calculated on polar maps of 78 segments for i.c. and i.v. studies were 8.4 +/- 1.2 mm and 8.2 +/- 1.3 mm (mean Delta wall motion=0.23 mm), respectively. High segmental wall motion correlation was observed (R=0.90; P<0.0001).. It can be concluded that infarct-related myocardial perfusion scores obtained after i.c. and i.v. injections of Tc-tetrofosmin compare favourably, with a total agreement rate of 79%. However, the additional information obtained in 21% of the total number of myocardial segments by i.c. injection may indicate a mild underestimation of myocardial viability by i.v. injection. Conventional gated SPECT using i.v. Tc-tetrofosmin was demonstrated to be a reliable technique in the detection of true wall motion.

Topics: Arteries; Coronary Vessels; Female; Humans; Injections, Intra-Arterial; Injections, Intravenous; Male; Middle Aged; Movement; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Ventricular Dysfunction, Left

This study evaluated the ability of low-dose dobutamine stress 99mTc tetrofosmin (DSTF) quantitative gated single photon emission computed tomography (QGS) performed during the acute phase of myocardial infarction to predict subsequent myocardial viability and detect stunned myocardium. Twenty-four patients suffering their first acute myocardial infarction (AMI) underwent coronary angioplasty after coronary angiography (CAG) immediately following admission. Follow-up CAG and left ventriculography (LVG) were performed 10 days and 6 months later. All patients underwent DSTF QGS to measure left ventricular ejection fraction (LVEF) at rest and during dobutamine infusion (10 microg.kg(-1).min(-1)) 14 days after angioplasty. No patient suffered coronary restenosis. After 6 months, the LVEF measured by LVG improved >5% in 12 patients (group A), and did not improve in the remaining 12 patients (group B). The culprit coronary artery, the peak serum creatine phosphokinase concentration, the recanalization time, and the LVEF during the acute phase were similar in the two groups. However, the increase in the LVEF was greater in group A than in group B during dobutamine infusion (deltaLVEF) as measured by DSTF QGS (11.2+/-3.8% vs 2.9+/-4.7%, P <0.001). If a cut-off value of 6.5% for the deltaLVEF was used to predict the improvement in LVEF during the chronic phase, then the sensitivity of this test was 83.3% and its specificity was 83.3%. It is concluded that DSTF QGS during AMI can be used to predict myocardial viability and detect stunned myocardium.

Topics: Acute Disease; Aged; Aged, 80 and over; Dobutamine; Female; Follow-Up Studies; Gated Blood-Pool Imaging; Heart Ventricles; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Stress, Physiological; Stroke Volume; Tissue Survival; Ventricular Dysfunction, Left

Because of damage to cardiomyocytes and the contractile apparatus, contractile reserve may be observed less frequently in hibernating than in stunned myocardium. The aim of this study was to assess the presence of contractile reserve in response to dobutamine infusion in a large group of patients with stunned and hibernating myocardium.. A total of 198 consecutive patients with ischemic cardiomyopathy (left ventricular ejection fraction < or = 40%) underwent resting 2-dimensional echocardiography to assess regional contractile dysfunction. On the basis of assessment of perfusion (with (99m)Tc-tetrofosmin SPECT) and glucose use (with (18)F-FDG SPECT), dysfunctional segments were grouped. Dysfunctional segments with normal perfusion were classified as stunned. Dysfunctional segments with a perfusion defect were classified as hibernating when a perfusion-(18)F-FDG mismatch was present. Dysfunctional segments with a perfusion defect were classified as scar tissue when a perfusion-(18)F-FDG match was present; these segments were subdivided into nontransmural and transmural scars. Contractile reserve was evaluated by dobutamine stress echocardiography.. Dobutamine-induced contractile reserve was more frequently found in stunned than in hibernating myocardium (61% vs. 51%, respectively; P < 0.01). Only 14% of the scarred segments improved in wall motion during dobutamine infusion, significantly less than stunned or hibernating myocardium (P < 0.001). Nontransmural scars exhibited contractile reserve more frequently than did transmural scars.. The progressive reduction of contractile reserve in stunned, hibernating, and scarred myocardium supports the hypothesis that stunning, hibernation, and scarring are not circumscript pathophysiologic entities but represent gradual ultrastructural damage on the myocyte level.

Topics: Dobutamine; Echocardiography; Female; Fluorodeoxyglucose F18; Heart; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Myocardial Ischemia; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Single-Blind Method; Stress, Physiological; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Angiographic Thrombolysis in Myocardial Infarction (TIMI) flow grade

Topics: Angioplasty, Balloon, Coronary; Coronary Angiography; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion Injury; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Ventricular Dysfunction, Left

The calculation of ejection fraction using gated single photon emission computed tomography (SPECT) has been widely validated against a range of other techniques. There have been fewer studies validating left ventricular volumes. We compared quantitative gated SPECT (QGS) with magnetic resonance imaging (MRI) measurements of left ventricular ejection fraction and end diastolic volume in 50 patients with a large range of ventricular dimensions. MRI data were obtained using a turbo gradient echo pulse sequence (TGE) in 17 patients and a steady state free precession pulse sequence (SSFP) in 33 patients. There was good correlation between ejection fraction and end diastolic volume measurements from SPECT and MRI (r=0.82, r=0.90, respectively) but the mean SPECT values were significantly lower (ejection fraction, 6.6+/-6.4% points; end diastolic volume, 18.4+/-25.4 ml) than those obtained from MRI. Bland-Altman analysis showed some large differences in individual patients but no trends in the data either in ejection fraction over a range from 15% to 70% or in end diastolic volume, range 75-400 ml. SSFP gave a larger difference for end diastolic volume measurement compared to SPECT than did TGE, although this difference did not reach significance. Both SSFP and TGE gave similar values for the difference between MRI and SPECT for the measurement of ejection fraction. We suggest that the difference in EF may be a result of 8 frames being used for gating in QGS but 12-18 for MR. Differences in volumes may be related to the different spatial resolution and the exclusion or inclusion of trabeculation and papillary muscles between SPECT and MRI. Differences between SSFP and TGE may be caused by differing delineation of the endocardial border, dependent on the particular acquisition sequence. In conclusion, QGS values correlated well with MRI, but a correction factor may be needed if direct comparison is made.

Topics: Female; Gated Blood-Pool Imaging; Heart Ventricles; Humans; Magnetic Resonance Imaging, Cine; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Statistics as Topic; Stroke Volume; Tomography, Emission-Computed, Single-Photon

The aim of this study was to assess the influence of incremental nitroglycerin infusion (NTG+Inf) on the myocardial uptake of 99mTc-tetrofosmin (TF) in order to determine whether nitrates enhance the detection of viable myocardium with TF in patients with coronary artery disease (CAD) and left ventricular dysfunction. Fifty patients (39 males, 11 females; 54 +/- 11 years) with previous myocardial infarction and left ventricular dysfunction, who had been referred for coronary revascularization procedures, were studied. Myocardial single-photon emission tomography (SPET) images were obtained 1 h after injection of 750 MBq TF at baseline and after NTG+Inf, using a 2 day protocol. NTG+Inf was performed starting at 0.4 microg x kg(-1) x min(-1), with equal increments every 5 min up to 2 microg x kg(-1) x min(-1). Within 1 week of the TF study, rest-redistribution (R-RD) 201Tl SPET was performed after the injection of 111 MBq 201Tl. For each study, quantitative analysis was performed in 17 segments. Viability was defined as the presence of tracer uptake of > 50% of the peak activity on baseline studies or reversibility. There was significant correlation between quantitative regional RD 201Tl activity and TF activity after NTG+Inf (r = 0.90, P < 0.001). Of the 131 segments with severely reduced tracer uptake on resting TF images, 34 (26%) were reversible, showing increased tracer uptake after NTG+Inf (from 41%+/-7% to 57%+/-12% of peak activity; P < 0.001). All reversible segments after NTG+Inf had viability criteria on 201Tl studies. There was 95% concordance between TF with NTG+Inf and RD 201Tl imaging with regard to the presence of myocardial viability. We conclude that TF imaging with incremental NTG+Inf improves the detection of ischaemic but viable myocardium, correlating with the viability criteria observed on 201Tl studies. When the advantages of TF imaging are considered, rest TF imaging with NTG+Inf may be a practical diagnostic protocol in patients with CAD and left ventricular dysfunction who are being considered for revascularization.

Topics: Adult; Aged; Coronary Artery Disease; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Statistics as Topic; Thallium; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

The purpose of this study was to validate a new quantitative index of salvaged myocardial mass calculated from Tc-99m tetrofosmin SPECT for evaluating the therapeutic effect of emergent reperfusion therapy in acute myocardial infarction (AMI).. Tc-99m tetrofosmin SPECT was performed before and after emergent percutaneous transluminal coronary angioplasty (PTCA) in eight patients with AMI. In the pre-PTCA study, Tc-99m tetrofosmin was injected before emergent PTCA. Two weeks after the PTCA, post-PTCA study was performed. As a quantitative index of salvaged myocardial mass, salvaged myocardial volume (SMV) was defined as the difference of myocardial functional volume between the SPECT studies before and after the PTCA. To investigate the clinical significance of SMV, SMV was compared with the grade of therapeutic efficacy determined visually from pre- and post-PTCA SPECT images and clinical parameters, namely peak creatine phosphokinase level (pCK) and the time from the onset of the AMI to reperfusion (RPT).. SMV showed a significant correlation with the visual grade of therapeutic efficacy (r = 0.737, p < 0.037) and a trend toward significant correlation with pCK (r = -0.622, p < 0.1). SMVs in early- and late-reperfusion groups (RPT < or = 6 hr and RPT > 6 hr) were 30.0 +/- 14.0 and -6.2 +/- 25.5 ml, showing a greater mean SMV value in the early-reperfusion group (p < 0.07).. SMV could be used as a quantitative index of salvaged myocardial mass for evaluating the therapeutic effect of emergent reperfusion therapy.

Topics: Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Statistics as Topic; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

The detection of viable myocardium is important for the prediction of functional recovery after revascularisation. However, a fixed perfusion defect often includes viable myocardium, and perfusion imaging then underestimates myocardial viability. We previously reported that low-dose dobutamine stress gated single-photon emission tomography (SPET) provides similar findings to dobutamine stress echocardiography in the assessment of myocardial viability. The present study investigated whether low-dose dobutamine stress gated SPET is of additional value as compared with stress-rest technetium-99m tetrofosmin SPET for the detection of myocardial viability. Standard stress-rest perfusion SPET, low-dose dobutamine stress gated SPET and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) were studied in 23 patients (mean age 67+/-7.6 years) with previous myocardial infarction. Twenty-one of them were successfully studied with each technique. FDG PET viability (FDG uptake >/=50%) was employed as the gold standard. One-day stress-rest (99m)Tc-tetrofosmin myocardial SPET was performed. After the resting study, gated SPET was acquired following infusion of 7.5 microg kg(-1) min(-1) of dobutamine. Left ventricular wall motion in 16 segments was assessed by cine mode display using a four-point scale. Myocardial viability was considered present when there was improvement by one point. Of a total of 336 segments analysed, 53 had persistent defects on stress-rest perfusion SPET. FDG viability was seen in 16 of 17 dobutamine-responsive segments, but in only 11 of 36 dobutamine non-responsive segments ( P<0.01). Thus, in the segments with persistent defects, viability findings on low-dose dobutamine stress gated SPET were concordant with those on FDG PET in 77% of segments (kappa value =0.55). For the detection of FDG-viable myocardium, the combination of stress-rest perfusion SPET and low-dose dobutamine stress gated SPET achieved a better sensitivity than stress-rest perfusion SPET alone (35/46, 76% vs 19/46, 41.3%, P<0.001), with a similar specificity (25/29, 86% vs 26/29, 90%, P=NS). We conclude that in the identification of viable myocardium, low-dose dobutamine stress gated SPET may provide additional information missed on a routine stress-rest perfusion scan. Dobutamine stress gated SPET may provide new insights into myocardial viability on the basis of ischaemia and contractile reserve.

Topics: Aged; Dobutamine; Exercise Test; Female; Fluorodeoxyglucose F18; Gated Blood-Pool Imaging; Heart; Humans; Male; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Ultrasonography

The present study evaluates left ventricular performance during exercise by ECG-gated myocardial perfusion SPECT with short-time data collection.. The study population consisted of 10 healthy volunteers (Group N) and 9 patients with ischemic heart disease (Group I). Seven patients in Group I had a history of prior myocardial infarction. Rest ECG-gated SPECT was performed 40 min after an injection of Tc-99m-tetrofosmin (555-740 MBq). After resting data acquisition, Group N underwent up to two 5-min stages of exercise (75 and 125 watts) on a detachable bicycle ergometer. The Group I patients all underwent symptom-limited, maximal testing on the ergometer. ECG-gated SPECT data were acquired from both groups for 3 min at rest and during the last 3 min of each exercise stage.. Significant increases occurred in LVEF from rest to peak stress in both groups (from 55.4 +/- 5.8 to 66.6 +/- 4.1% in group N, p < 0.0001; from 49.0 +/- 12.8 to 56.7 +/- 13.8% in Group I, p < 0.001). The LVESV values significantly decreased to peak stress in Group N (from 49.9 +/- 13.1 to 37.8 +/- 10.0 ml, p < 0.0001), whereas LVEDV did not change (from 110.6 +/- 18.9 to 112.0 +/- 19.0 ml). In contrast, the LVESV values at rest and under peak stress were similar in Group I (from 52.6 +/- 23.9 to 51.7 +/- 31.4 ml) and LVEDV in Group I at peak exercise tended to increase (from 102.8 +/- 36.7 to 111.3 +/- 39.0 ml). The changes in LVESV from rest to peak stress were significantly different between Groups N and I (-12.1 +/- 6.3 vs. -0.9 +/- 11.6 ml, p < 0.02).. ECG-gated SPECT with short-time data collection can assess left ventricular function during exercise and may offer useful information for evaluating patients with ischemic heart disease.

Topics: Adult; Aged; Exercise Test; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Rest; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Reverse redistribution (RR) of technetium-99m tetrofosmin (TF) in patients with acute myocardial infarction (AMI) has been considered a sign of salvaged myocardium. We examined the time evolution of the RR pattern during a 6-month period and the clinical implications of RR. TF myocardial SPET was performed in 22 patients 1 week, 1 month and 3-6 months after AMI. Myocardial images were obtained 30 min and 180 min after the injection of TF. Regional uptake of TF was rated using a four-point scoring system. RR was defined as an increase of more than 1 point in the regional score on images obtained at 180 min. Echocardiography was performed to assess regional wall motion at the same time as TF imaging. RR observed at 1 week tended to disappear after 1 month and 3-6 months. The incidence of regional wall motion abnormality was reduced in patients with RR compared with that in patients with fixed defects. Recovery of abnormal regional wall motion occurred earlier in segments with disappearance of RR than in those without disappearance of RR. It is concluded that RR may reflect salvaged myocardium and that disappearance of RR may indicate earlier recovery of salvaged myocardium.

Topics: Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Female; Follow-Up Studies; Heart Ventricles; Humans; Male; Metabolic Clearance Rate; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Single-Blind Method; Tissue Distribution; Tissue Survival; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Ultrasonography

The state of no-reflow (i.e. inadequate myocardial tissue perfusion despite normal arterial flow proven in angiography after pharmacological or mechanical interventions) is considered to be a marker of a poor prognosis. Although the Thrombolysis in Myocardial Infarction (TIMI) flow grade is a valuable and widely used qualitative measure in angiography trials, it is limited by its subjective and categorical nature. Recently, the TIMI frame count method (TFC) was proposed for detecting no-reflow. In our study we aimed to compare TFC values with myocardial perfusion single photon emission computed tomography (SPECT) findings to investigate the additional role of the former method in the evaluation of no-reflow. Twenty patients (16 men and four women; mean age 58+/-9 years) with first acute myocardial infarction were included in the study after thrombolytic therapy. Coronary angiography (CAG) was performed 5-7 days later. The TIMI flow grade and TFC values were determined in angiography examinations. A TIMI flow of less than grade 3 and a TFC value >27 were considered to be pathologically decreased for coronary artery blood flow. Tc tetrofosmin myocardial rest SPECT was carried out 24 h after coronary angiography. SPECT images were scored on a four-point scale in 20 myocardial segments and the total defect score was calculated from the sum of defect scores in 20 segments. Wall motion was assessed using the wall motion score index in echocardiography (ECWSI). The occurrence rates of angiographic no-reflow, pathological TFC and perfusion defects in SPECT were calculated as 40% (8/20), 47% (8/17; non-measurable in three patients with TIMI grade 0), and 55% (11/20), respectively. Perfusion defects were present and the TIMI frame count value was increased in all patients with angiographic no-reflow (TIMI grade <3). The occurrence rate of perfusion defects and increased TFC was equal (42%) in all 12 patients having TIMI grade 3 flow. Increased TFC was demonstrated in four of five patients having perfusion defects and TIMI grade 3 flow (80% compatibility with SPECT). TIMI frame count and ECWSI values were significantly higher in patients having perfusion defects than in patients with normal perfusion ( <0.05). It is concluded that the TIMI frame count is a valuable method in the detection of patients with TIMI grade 3 flow, with no-reflow, and increases the specificity of coronary angiography in the evaluation of the response to thrombolytic therapy. A pathologicall

Topics: Acute Disease; Aged; Coronary Angiography; Coronary Circulation; Creatine Kinase; Echocardiography; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion Injury; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thrombolytic Therapy; Tissue Plasminogen Activator; Tomography, Emission-Computed, Single-Photon

By evaluating concordant or discordant perfusion and systolic wall thickening patterns, resting quantitative electrocardiographic (ECG) gated single-photon emission tomography (SPET) can identify various myocardial pathological conditions with different functional recovery after revascularisation therapy. However, no data are available on the ability of this methodology to predict regional functional recovery after primary percutaneous transluminal coronary angioplasty (PTCA). This study evaluated whether single-injection ECG gated SPET imaging performed at rest with 99mTc-tetrofosmin early after successful PTCA can predict recovery of regional wall motion. ECG gated SPET was performed 3 days and 3 weeks after successful PTCA in 26 patients. Regional functional parameters were automatically calculated with a 20-segment model on the day 3 image, and segments with perfusion/thickening mismatch were defined as showing preserved perfusion (>55% uptake on the end-diastolic image: mean-standard deviation of the normal value) without systolic wall thickening (mean-standard deviation of the normal value). On the third day, the regional wall motion score of 37 mismatched segments (3.8+/-2.1) was significantly lower than that of 41 matched normal segments (6.0+/-2.9), but was significantly higher than that of 108 matched abnormal segments (1.4+/-1.9, both P<0.01). At 3 weeks after acute MI, the regional wall motion score of mismatched segments (6.4+/-3.9) improved to the level of matched normal segments (7.1+/-3.0) and was significantly higher than that of matched abnormal segments (2.5+/-3.0, P<0.01). Absolute change in the regional wall motion score (3 days to 3 weeks) of mismatched segments (2.6+/-3.5) was significantly greater than that in the regional wall motion score of matched normal segments and matched abnormal segments (1.1+/-1.3 and 1.2+/-2.6, respectively, both P<0.05). Twenty-seven of 37 segments (73%) with perfusion/thickening mismatch showed significant improvement in regional wall motion, whereas improvement in regional wall motion was observed in 22 of 108 segments (20%) with matched abnormal segments and 6 of 41 segments (15%) with matched normal segments. Segments with perfusion/thickening mismatch had a significantly higher incidence of regional functional improvement than did matched abnormal or matched normal segments (chi2=42.3, P<0.01). Thus, by estimating both perfusion and wall thickening, single-injection resting ECG gated SPET imaging w

Topics: Analysis of Variance; Angioplasty, Balloon, Coronary; Coronary Artery Disease; Coronary Circulation; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity; Systole

Reconstruction of gated single-photon emission tomography (gSPET) is intrinsically a four-dimensional (4D) problem. In practice, the time frames are reconstructed independently as a sequence of frame-by-frame reconstructions. This approach is not optimal since the strong signal correlations among the individual time frames are not exploited. In this study we propose a simple but efficient algorithm to improve the image quality of myocardial perfusion gSPET by incorporating the cyclic temporal information within the reconstruction using Fourier filtering. The gSPET images were reconstructed using the Ordered Subsets Expectation Maximisation (OSEM) algorithm employing six iterations with eight subsets. Temporal filtering was applied either before (PreOSEM) or after image reconstruction (PostOSEM) or was incorporated within the OSEM algorithm (OSEM4D). The effect of temporal filtering was compared with conventional frame-by-frame OSEM using clinical data. Image quality was evaluated by estimating the systematic and statistical error. The results indicated that temporal filtering introduces a small (<1%) systematic error, while the statistical error was reduced from 15.0%+/-3.1% when conventional frame-by-frame OSEM was applied to 12.6%+/-2.7%, 12.0%+/-2.5% and 9.3%+/-2.4% when PreOSEM, PostOSEM and OSEM4D were used, respectively. It is concluded that temporal filtering incorporated within OSEM reconstruction dramatically reduces noise in gated SPET myocardial images.

Topics: Adult; Algorithms; Female; Fourier Analysis; Gated Blood-Pool Imaging; Humans; Image Processing, Computer-Assisted; Male; Models, Cardiovascular; Models, Statistical; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Signal Processing, Computer-Assisted; Statistics as Topic; Stochastic Processes; Stroke Volume; Time Factors; Ventricular Function, Left

This study was designed to assess the value of gated SPECT Tc-99m-tetrofosmin (TF) wall thickening (WT) in addition to TF exercise (Ex)/rest myocardial SPECT, in comparison with F-18 fluorodeoxyglucose (FDG)-PET.. The study population consisted of 33 patients with old myocardial infarction (27 men and 6 women; mean age, 62 +/- 8 years old). All patients underwent Ex/rest TF SPECT and glucose loading FDG-PET. Polar map images of Ex/rest TF were generated and divided into 24 segments for further analysis. We classified LV segments according to the exercise-rest perfusion scintigraphy. LV segments with less than 70% of the maximum TF activity on the exercise image were defined as stress-induced defects. Among these, the segments whose TF activity increased by 10% from exercise to rest images or exceeded 70% of the maximum uptake were defined as reversible (viable) defects. The remaining defects on the rest image were irreversible (non-viable) defect segments, and were considered for viability study on the basis of %WT. %WT was calculated according to the standard method: [(counts ES - counts ED)/counts ED] x 100. A viable segment on gated SPECT was defined as a segment whose %WT exceeded the lower limit of the normal value (mean - SD). PET viability was defined as FDG uptake exceeding 50% of the maximum count.. Among the 792 segments evaluated in the 33 patients studied, there were 689 PET viable segments. Of the 689 segments analyzed, 198 (29%) were identified as having defects on Ex images. Among these defects, 55 (8%) were reversible or partially reversible, as evidenced by rest images, and 143 (21%) were irreversible. Of the irreversible segments on Ex/rest images, 106 (15%) demonstrated no apparent WT by gated TF SPECT, whereas 37 (6%) segments with irreversible defects did have apparent WT. Overall, the sensitivity of Ex/rest TF perfusion imaging was 79%. Sensitivity was improved from 79% to 85% by combining %WT and perfusion data, but specificity was reduced from 70% to 56%.. %WT evaluated from gated TF imaging enhanced myocardial viability assessment in comparison with FDG-PET.

Topics: Aged; Cell Survival; Coronary Artery Disease; Exercise Test; Female; Fluorodeoxyglucose F18; Gated Blood-Pool Imaging; Heart; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity

Left ventricular (LV) volume, and not only ejection fraction (EF), is a crucial parameter for assessing the severity of cardiac disease and determining the patient's prognosis. The purpose of this study was to compare LV volumes and EF computed automatically from gated blood pool tomography (gBPT), using QUBE, and from gated myocardial perfusion tomography (gMPT), using QGS, in the same patients with a known history of myocardial infarction. The effects of the extent and severity of the myocardial perfusion defects were investigated. Thirty-seven patients were injected in a random sequence with 740 MBq of technetium-99m human serum albumin and 925 MBq of (99m)Tc-tetrofosmin, within an interval of 2 days. gBPT and gMPT were acquired on the same triple-head gamma camera using the following acquisition parameters: 360 degrees step-and shoot rotation, 32 stops (96 projections), 30 s per stop, 64x64 matrix (pixel size 5.8 mm), 8 time bins (75% forward/backward framing). Projection data were reconstructed by filtered back-projection using a Butterworth filter. LV volumes calculated from gBPT correlated well with LV volumes measured on gMPT ( r=0.93 for end-diastolic volume and 0.95 for end-systolic volume). Volumes above 200 ml, however, were substantially higher with gMPT than with gBPT. These discrepancies were related to the severity, but not the extent, of the perfusion defects. There was also good agreement between gBPT and gMPT for the LVEF ( r=0.91). On the Bland-Altman plot, no trend but a systematic error of 5.57% and a random error of 6.85% could be found. For the LVEF, the differences between the gated tomographic techniques were related neither to the extent nor to the severity of the perfusion defects. In conclusion, LV volumes and EF computed on gMPT correlated well with those measured on gBPT. Discrepancies were observed for large volumes presumably because of inaccuracies of gMPT in patients with severe perfusion defects.

Topics: Aged; Aged, 80 and over; Algorithms; Coronary Circulation; Female; Gated Blood-Pool Imaging; Heart Ventricles; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Statistics as Topic; Stroke Volume; Technetium Tc 99m Aggregated Albumin

In myocardial perfusion scintigraphy, the clinical significance of fixed defects presents some difficulty. In this study, we evaluated whether additional information on left ventricular function assessed by quantitative gated single-photon emission computed tomography (gated SPET) would increase the diagnostic yield of the study in such patients. We studied 55 patients with a previous myocardial infarction and 20 patients without a previous myocardial infarction using gated SPET 99Tc(m)-tetrofosmin myocardial perfusion imaging. Each patient had to have a persistent perfusion defect consisting of at least three contiguous segments in the same vascular territory. The left ventricle was divided into 20 segments which were analysed for perfusion and wall thickening on a 4-point severity scale. Of the 55 patients with myocardial infarction, 19 (35%) patients showed preserved wall thickening in the region of the previous infarction with fixed perfusion abnormalities, which suggested residual myocardial viability. In the 20 patients without myocardial infarction, preserved wall thickening was seen in 10 (50%) patients with fixed perfusion defects, suggesting an attenuation artefact. Conversely, in 16 (29%) patients in the myocardial infarction group and two (10%) patients in the non-myocardial infarction group normal perfusion was associated with severely diminished wall thickening possibly due to stunning. We found an excellent correlation between wall thickening and left ventricular ejection fraction both for the patients with myocardial infarction and the patients without myocardial infarction (r = 0.86 and r = 0.82, respectively, both P<0.0001). A reasonable correlation between perfusion and left ventricular ejection fraction was found for the patients with myocardial infarction (r = 0.41, P = 0.002), and a non-significant correlation for the patients without myocardial infarction (r = 0.37, P = 0.1). Quantitative gated SPET myocardial imaging allows the detection of residual wall thickening in patients with a previous myocardial infarction who show severe fixed perfusion defects. In patients without myocardial infarction, gated SPET imaging allows differentiation between an attenuation artefact and a fixed perfusion defect due to coronary artery disease. In addition, gated SPET may show diminished ventricular function in normally perfused segments possibly due to myocardial stunning. The addition of gated SPET myocardial perfusion imaging increases diagnost

Topics: Aged; Coronary Circulation; Coronary Disease; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

The differentiation of residual viability from necrotic myocardium in patients with a previously sustained myocardial infarction is important in deciding indications for revascularization. Myocardial viability can be assessed by studying perfusion and regional wall motion. With gated single photon emission computed tomography (SPECT), it is possible to augment SPECT perfusion data with ventricular functional data both at a global and regional level. The aim of the study was to analyse the concordance between wall motion score derived by gated SPECT and echocardiography. Furthermore, the agreement between myocardial perfusion and left ventricular wall motion was analysed with both techniques. We studied a homogenous group of 25 consecutive patients with a previous myocardial infarction (MI) using both gated SPECT 99Tcm-tetrofosmin myocardial perfusion imaging and two-dimensional echocardiography. Echocardiography was performed within 2 weeks of the gated SPECT study. Both for gated SPECT and for echocardiography the left ventricle was divided into seven regions per patient. For comparison, the gated SPECT regions were matched to the echocardiographic regions, resulting in a total of 175 regions. Prevalence of abnormal wall motion (akinetic or dyskinetic) was 23% (39/171) for echocardiography and 21% (36/175) for gated SPECT (P = NS). There was a high agreement in wall motion score between echocardiography and gated SPECT of 80% (136/171). The agreement between myocardial perfusion and myocardial wall motion was 82% (143/175) for gated SPECT and 76% (130/171) for echocardiography (P = NS). Nineteen (34%) of the 56 regions with severely diminished or absent myocardial perfusion showed normal or hypokinetic wall motion both by gated SPECT and echocardiography suggesting residual myocardial viability in malperfused regions. Our results suggest that, gated SPECT imaging is a reliable tool for the assessment of regional wall motion in post myocardial infarction patients. Furthermore, in patients with a previous myocardial infarction gated SPECT imaging has the potential to detect preserved wall motion in regions with fixed perfusion defects, which might be indicative of residual myocardial viability.

Topics: Adult; Aged; Aged, 80 and over; Coronary Circulation; Echocardiography; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

To avoid the haemorrhagic risk of unnecessary thrombolysis in acute myocardial infarction (MI), early and precise diagnosis of spontaneous recanalization (SR) of the infarct-related artery is required. To clarify the accuracy of technetium-99m tetrofosmin myocardial single-photon emission tomography (SPET) in the detection of SR in patients with acute anterior MI, electrocardiography (ECG), echocardiography and 99mTc-tetrofosmin SPET imaging were performed in 49 patients with acute anterior MI before emergency coronary angiography. Defect score was calculated as the sum of the perfusion defects of each segment: from 3 (complete defect) to 0 (normal perfusion). Echocardiographic asynergic score (the sum of asynergic grades) and the greatest ST elevation of the 12-lead ECG on admission were also measured. SR was defined as Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow on emergency coronary angiography. Defect score in 11 patients with SR (9.2 +/- 3.7) was significantly lower than that in 38 patients without SR (18.5 +/- 5.0) (P < 0.001), whereas there were no significant differences in asynergic score and ST elevation between the two groups. From the receiver operating characteristic curves, the optimal cut-off points of defect score, asynergic score and ST elevation for the detection of SR were calculated to be 12, 13 and 3.5, respectively. The sensitivity and specificity of the scintigraphic defect score (91% and 89%) were significantly higher than those of the asynergic score (64% and 68%) and ST elevation (73% and 71%). Thus, 99mTc-tetrofosmin SPET imaging on admission is a very accurate method for the detection of SR in patients with acute anterior MI.

Topics: Acute Disease; Aged; Aged, 80 and over; Coronary Angiography; Echocardiography; Electrocardiography; Female; Follow-Up Studies; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Neovascularization, Physiologic; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

201Tl and 99mTc-pyrophosphate (PYP) dual scintigraphy is daily used in the detection of acute myocardial infarction (AMI). However, 201Tl is not available on emergent situation. We proposed a new method for detection of AMI combined 99mTc-PYP with 99mTc-tetrofosmin (TF).. 99mTc-PYP (740 MBq) was administered to 25 patients with AMI, and 3.5 hours later, planar imaging (PYP planar) and SPECT were performed (PYP-SPECT). Immediately after cessation of PYP-SPECT, 99mTc-TF (370-740 MBq) was injected and 5 minutes later SPECT was performed in the same position (TF-SPECT). PYP-SPECT and TF-SPECT were reconstructed in the same geometric status to permit superimpose of PYP-SPECT and TF-SPECT images. Two experts and 2 beginners of nuclear medicine physician interpreted the images in three ways; PYP planar image only, PYP-SPECT, and PYP-SPECT with TF-SPECT.. PYP-SPECT combined with TF-SPECT shows 100% detectability of the AMI lesions, which is significantly higher than other two methods in both experts and beginners.. PYP-SPECT combined with TF-SPECT is a powerful method for detection of AMI.

Topics: Aged; Female; Humans; Male; Myocardial Infarction; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Pyrophosphate; Tomography, Emission-Computed, Single-Photon

We studied the effects of glucose, insulin, and KCl infusion (GIK), on regional myocardial perfusion and function by 99m-Tc-tetrofosmin-gated SPECT.. We studied 21 male patients with their first uncomplicated acute myocardial infarction (AMI). All patients underwent a rest and submaximal stress before and after 24-hour infusion of GIK-solution (group A) or saline solution (group B).. Group A showed better stress tolerance and ischaemic threshold improvement after GIK infusion whilst no statistical differences were found between basal and post-infusion test in group B. At first the stress test in group A, of the 192 segments analysed, 52 (27%) showed reversible perfusion defect. In group B, of 144 segments analysed, 31 (21%) showed reversible perfusion defect. A post-infusion analysis in group A showed a post-GIK end-diastolic significant count improvement in 21 segments, and a post-GIK end-systolic count improvement in 22 segments. In group B, perfusion increase was observed only in 4 segments, whilst systolic thickening increase was observed only in 1 segment.. These data demonstrate the efficacy of GIK infusion to improve regional myocardial perfusion and function mainly in segments adjacent to the recently infarcted area.

Topics: Adult; Aged; Cardioplegic Solutions; Chi-Square Distribution; Coronary Angiography; Double-Blind Method; Electrocardiography; Exercise Test; Glucose; Heart; Humans; Insulin; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Potassium; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

This study assessed the effect of sublingual nitroglycerin administered before rest imaging in the technetium-99m (99mTc) tetrofosmin exercise and rest same day protocols to determine whether the use of nitroglycerin improved the detection of fill-in the rest single photon emission computed tomography (SPECT) images 3 hours after peak exercise. Twenty-one patients with old myocardial infarction underwent repeated 99mTc-tetrofosmin exercise/rest same day protocols with and without the administration of sublingual nitroglycerin (0.3 mg) 5 min before the second injection of 99mTc-tetrofosmin for rest SPECT imaging. Twelve of these patients also underwent ordinary exercise/redistribution 201T1 SPECT imaging. The control study protocol images showed decreased uptake of 99mTc-tetrofosmin on exercise in 157 of 420 segments and the presence of fill-in at rest in 58 segments. Images obtained with administration of nitroglycerin showed decreased uptake of 99mTc-tetrofosmin on exercise in 163 of 420 segments and fill-in in 74 segments at rest. The frequency of fill-in was greater in the nitroglycerin protocol than in the control protocol (p < 0.05). The segments were scored as different grades according to 99mTc-tetrofosmin uptake between 2 protocols. Fill-in was only present or more remarkable in 31 segments in the nitroglycerin protocol than in the control protocol. Fill-in was only present or more remarkable in 10 segments in the control protocol than in the nitroglycerin protocol. In the nitroglycerin protocol, the mean defect score of the exercise images, calculated from the bull's eye image automatically, was higher than that of the rest images (121 +/- 40 vs 94 +/- 53, p < 0.01). The mean severity score of the exercise images, also calculated from the bull's eye image automatically, was likewise higher than that of the rest images (691 +/- 382 vs 524 +/- 431, p < 0.01), whereas the mean severity score of the stress images and rest images in the control protocol was not significantly different. Moreover, the mean defect score and severity score of the rest images from the nitroglycerin protocol were significantly lower than those obtained from the control protocol (p < 0.05). Sublingual nitroglycerin administration before the injection of 99mTc-tetrofosmin at the rest study in the one day exercise/rest studies enhanced fill-in, so may enhance the detection of viable myocardium, allowing more informed decisions regarding cardiac revascularization in patients wi

Topics: Administration, Sublingual; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Infarction; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rest; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to compare 2 different techniques--dobutamine-atropine stress echocardiography (DSE) and dual-isotope simultaneous acquisition (technetium-99-m-tetrofosmin/fluorine 18-fluorodeoxyglucose) single-photon emission computed tomography (DISA-SPECT)--for assessment of viable myocardium. One hundred ten patients (mean age 55 +/- 9 years) with left ventricular (LV) dysfunction (mean LV ejection fraction 27 +/- 13%) underwent both DISA-SPECT and DSE. A 16-segment scoring model was adopted for both techniques. Four types of wall motion during DSE were assessed: (1) biphasic, improvement at low dose (10 microg/kg/min) with worsening at high dose; (2) worsening, deterioration without initial improvement; (3) sustained, persistent or late improvement; and (4) no change. Viability criteria were biphasic, worsening, and sustained improvement with DSE. Viability criteria with DISA-SPECT were normal perfusion and metabolism (normal), concordantly mildly reduced perfusion and metabolism (subendocardial scar), or severely reduced perfusion and increased metabolism (mismatch). Myocardium was considered nonviable with DSE in case of unchanged wall motion, or moderate reduction or absence in both technetium-99m-tetrofosmin perfusion and fluorodeoxyglucose uptake with DISA-SPECT. Of 1,756 of 1,760 analyzable LV segments, 1,373 (78%) had severe wall motion abnormalities at baseline (severe hypokinesia, akinesia, or dyskinesia). Of these abnormal segments, 282 (21%) were considered viable during DSE (63 [5%] with biphasic response, 47 [3%] with ischemia, and 172 [13%]) with sustained improvement, whereas 1,091 (79%) were considered nonviable. With DISA-SPECT, 396 (29%) segments were considered viable (312 [23%] with matched perfusion/metabolism and 84 [6%] with mismatch), whereas 977 segments (71%) were considered nonviable. Both techniques showed agreement for viability in 201 segments and 896 were concordantly classified as nonviable. Disagreement was present in 276 segments of which 195 (71%) were nonviable with DSE and viable with DISA-SPECT. Overall agreement between the 2 techniques was 81% (kappa 0.46) in a subgroup of patients with an ejection fraction <25% 78% (kappa 0.39). Thus, DSE and DISA-SPECT show good agreement for assessing viable myocardium not influenced by resting ejection fraction. DSE underestimated the amount of viable tissue compared with DISA-SPECT.

Topics: Blood Pressure; Cardiotonic Agents; Dobutamine; Echocardiography; Exercise Test; Fluorodeoxyglucose F18; Heart; Heart Rate; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

We developed a new diagnostic method for simultaneously evaluating myocardial ischemia, myocardial viability and ventricular function in less than 90 minutes by combined use of rest thallium-201 (Tl) SPECT and exercise Tc-99m tetrofosmin (TF) first pass and SPECT. The subjects were 9 healthy controls, 19 angina pectoris patients, and 19 old myocardial infarction patients, in all of whom coronary angiography had been performed. Rest Tl myocardial SPECT was performed first, and was followed by exercise TF myocardial SPECT. We also performed first pass radionuclide angiography by TF during maximum exercise on a bicycle ergometer to assess the left ventricular ejection fraction (LVEF). The total examination time was less than 90 minutes. SPECT diagnosis was performed by semi-quantitative analysis. LVEF below 55% was regarded as abnormal. In the patients with angina pectoris, analysis according to the coronary artery showed that the diagnostic accuracy of SPECT was 85.0% for ischemia in the region of the left anterior descending branch (LAD), 87.5% for the left circumflex branch (LCX) and 77.8% for the right coronary artery (RCA). The accuracy of diagnosis for angina pectoris was 82.1%, as determined by SPECT alone, and rose to 89.3% when the LVEF levels were also taken into consideration. In the patients with old myocardial infarction, the diagnostic accuracy of SPECT was 84.2% for the LAD, 92.3% for the LCX and 85.0% for the RCA. Analysis by patients showed that the accuracy of diagnosis for myocardial infarction was 85.7%, as determined by SPECT alone. The diagnostic accuracy, however, rose to 89.3% when the LVEF levels also were taken into consideration. In conclusion, it was demonstrated that this combined diagnostic method was highly reliable for evaluating ischemic heart disease within a short time.

Topics: Aged; Coronary Angiography; Exercise; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Ventriculography; Reproducibility of Results; Sensitivity and Specificity; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

A one-hour protocol for stress myocardial scintigraphy using technetium-99m-tetrofosmin (Tc-tetrofosmin) was compared with coronary arteriography for the detection of coronary artery stenosis in 90 consecutive patients without prior myocardial infarction, revascularization procedure or vasospastic angina. Tc-tetrofosmin stress myocardial scintigraphy acquired a rest image 20 min after intravenous administration of Tc-tetrofosmin (185 MBq, 1/5 vial) using a three-head gamma camera collecting 20-sec views over 360 degrees. The stress test using bicycle ergometer was performed and administration of Tc-tetrofosmin (740 MBq, 4/5 vial) was repeated at the peak stress point. The stress image was acquired 15 min after the second injection with 5-sec views over 360 degrees. Coronary arteriography revealed the presence of significant coronary artery stenosis (> 75%) in 56 vessels of 45 patients, including 35 patients with single-vessel disease, 5 with two-vessel disease, 2 with three-vessel disease, and 3 with left main trunk disease. The overall sensitivity and specificity for the detection of coronary artery disease by visual analysis were 91.1% and 77.8%, respectively, and by quantitative analyses (using bull's-eye method) were 95.6% and 91.1%, respectively. The individual stenotic vessel sensitivities in the right coronary artery, left anterior descending artery, and left circumflex artery were 84.6%, 90.9%, and 78.6%, respectively. The specificities were 97.3%, 95.9%, and 100.0%, respectively. These results suggest that stress myocardial scintigraphy using the present new protocol is a promising approach for the detection of coronary artery stenosis.

Topics: Angina Pectoris; Coronary Angiography; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity

Previous studies have indicated that iodine-123 labelled beta-methyliodophenyl pentadecanoic acid (BMIPP), an iodinated fatty acid analogue, can identify persistent alteration of fatty acid metabolism after restoration of blood flow. To assess whether fatty acid imaging can delineate areas at risk following successful revascularization in patients with acute myocardial infarction (AMI), BMIPP findings at 1 week post AMI were compared with perfusion imaging before and after revascularization therapy. Sixty-five patients with AMI underwent technetium-99m tetrofosmin single-photon emission tomography (SPET) before m (TF0) and 1 week (TF1) after successful revascularization therapy. BMIPP SPET was also performed under a fasting state at 1 week (BM1) post AMI. The extent scores were calculated from the defect scores in 20 segments. The BM1 score (7.7 +/- 3.9) was similar to the TF0 score (8.8 +/- 4.2) (r = 0.86, P < 0.0001), but significantly higher than the TF1 score (5.8 +/- 3.9) (P < 0.0001). A significant correlation was observed between the BM1 score and TF0 score (r = 0.86, P < 0.0001). Among a total of 1300 segments, the BM1 score was identical to the TF0 score in 1156 (88.9%). These data indicate that the ability of BMIPP imaging at 1 week post AMI to identify areas at risk is similar to that of tetrofosmin perfusion imaging in the acute phase. This may be due to the impairment of fatty acid uptake and metabolism reflecting prior severe ischaemic insult which persists at least 1 week after recovery of perfusion in the acute phase of AMI.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Coronary Circulation; Fatty Acids; Female; Humans; Image Processing, Computer-Assisted; Iodine Radioisotopes; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Risk Assessment; Tomography, Emission-Computed, Single-Photon

To assess clinical performance of coronary perfusion in patients with acute myocardial infarction following successful PTCA, various 99mTc-tetrofosmin (TF) SPECT were obtained. Twenty-eight patients with acute myocardial infarction underwent TF SPECT before emergent PTCA (acute phase), after 7 days (subacute phase) and 4 weeks (chronic phase) later. Twenty-eight patients divided into 2 groups. Early group; time lug from onset of AMI till PTCA is 6 hours or shorter (n = 17), delayed group; time lug is more than 6 hrs (n = 11). The defect scores were graded by 4 points grading system (0 as normal to 3 as defect) in 14 myocardial segments. In early group, the mean defect score was 13 +/- 7 at acute phase, 6 +/- 5 at subacute phase, and 3 +/- 4 at chronic phase. In delayed group, the mean value of defect score at each phases were 18 +/- 7, 14 +/- 7, and 13 +/- 7. The improvement of defect score of early group was significantly larger than that of delayed group (p < 0.005). These data indicate that PTCA therapy for acute MI patients is useful particularly in the early stage following acute MI.

Topics: Aged; Angioplasty, Balloon, Coronary; Coronary Circulation; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

The clinical usefulness of a new myocardial perfusion imaging agent, 99mTc-1,2-bis[bis(2-ethoxyethyl)phosphino]ethane (99mTc-Tetrofosmin, (PPN1011) was evaluated in 355 patients with various heart diseases. Both 1 and 2 day protocols resulted in images that were significantly clearer than those of 201Tl. The absence of significant drug related adverse reaction supported the safety of the agent for clinical use. Regional abnormalities detected by CAG agreed with 99mTc-Tetrofosmin SPECT findings in 74% and with 201Tl SPECT in 78% of this study. Eighty-four percent of an abnormalities were detected with 99mTc-Tetrofosmin SPECT, as compared with those detected with 201Tl SPECT (88.4%). The complete concordance ratio between 99mTc-Tetrofosmin and 201Tl images in segmental analysis was 87-89% at rest and stress. Since 99mTc-Tetrofosmin SPECT was judged clinically useful in 93.2% (331/355) of the patients studied, it is concluded that 99mTc-Tetrofosmin is a promising agent for myocardial perfusion imaging. The simple labeling procedure without heating and cooling is suitable for emergency administration. Reconditioning of myocardial perfusion could be evaluated with 99mTc-Tetrofosmin injection before and after interventional therapy. These are additional features of the agent for clinical use.

Topics: Adult; Aged; Aged, 80 and over; Angina Pectoris; Cardiomyopathies; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

Topics: Cadmium; Fatty Acids; Feasibility Studies; Humans; Iodine Radioisotopes; Iodobenzenes; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Tellurium; Zinc

The use of cadmium-zinc-telluride-based scanners may increase the clinical feasibility of simultaneous dual-isotope imaging. In the current study, we sought to investigate a potential acquisition time in simultaneous Tc-tetrofosmin/I-β-methyl-p-iodophenyl pentadecanoic acid dual-isotope imaging using a Discovery NM/CT 670 cadmium-zinc-telluride.. Simultaneous Tc-tetrofosmin/I-β-methyl-p-iodophenyl pentadecanoic acid dual-isotope imaging was performed in 29 patients who had undergone primary percutaneous coronary intervention for acute myocardial infarction. Referenced images with an acquisition time of 65 s/view (16.25 min) were reframed to produce images with acquisition times of 33, 16, and 8 s/view. The values for the quantitative-gated single-photon emission computed tomography (SPECT) and the quantitative perfusion SPECT were compared.. The quantitative-gated SPECT values for images with 33, 16, and 8 s/views showed good consistency with those for 65 s/view (the lower 95% confidence intervals for the intraclass correlation were ≥0.80). The quantitative perfusion SPECT values for Tc-tetrofosmin images with 33, 16, and 8 s/views also showed good consistency with those for 65 s/view; however, the quantitative perfusion SPECT values for I-β-methyl-p-iodophenyl pentadecanoic acid images with an acquisition time of 8 s/view were not consistent with the reference acquisition time of 65 s/view.. The quantitative-gated SPECT and quantitative perfusion SPECT values obtained from images with shorter acquisition times correlated with the values obtained from images with a reference acquisition time of 65 s/view; however, tracer-specific predisposition should be considered. These findings suggest that it is possible to reduce acquisition time when performing simultaneous Tc-tetrofosmin/I-β-methyl-p-iodophenyl pentadecanoic acid dual-tracer imaging with the novel cadmium-zinc-telluride scanner.

Topics: Acute Disease; Cadmium; Fatty Acids; Female; Humans; Image Processing, Computer-Assisted; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Percutaneous Coronary Intervention; Tellurium; Time Factors; Tomography, Emission-Computed, Single-Photon; Zinc

After a primary transluminal coronary angioplasty (PTCA) following AMI (acute myocardial infarction), the perfusion defect and LV (left ventricular) function recover/change over a period of time. The analysis immediately after the procedure may not be true depiction of the exact success of the procedure. There is varying and scanty information available on the natural course of changes in these parameters after a successful PTCA. We hypothesized that majority of change occurs at 3-4 month period. Hence, we undertook this study on the natural course of recovery/changes occurring in perfusion defect size and LV function in first 3 months after primary angioplasty MATERIAL AND METHODS: 30 consecutive cases of first AMI who were taken up for Primary angioplasty were enrolled into the study. Resting MPI(Myocardial perfusion imaging) was done within 24-72 hrs of admission using Tc-99m-Tetrofosmin and after 10-14 weeks. Analysis of LVEF (left ventricular ejection fraction), summed segmental score and extent of perfusion defect was done. Images were processed using autocardiac software of emory tool box and quantification was done using QPS (quantitative perfusion SPECT) and QGS (qualitative perfusion SPECT) softwares. 20 segment scoring method was used for quantification on bull's eye images. Student t test (two tailed, dependent) was used to find the significance of study parameters on continuous scale within each group. Effect size was computed to find the effect. Pearson correlation between perfusion defect and LVEF was performed at acute stage and after 10-14 weeks.. The average acute perfusion defect extent was 19.76 ± 12.89% which after 3months became 16.79 ± 12.61%. The summed segmental score changed from 14.31 ± 10.58 to 11.38 ± 10.03 and LVEF improved from 48.40 ± 13.15% to 53.37 ± 12.8%. There was significant improvement in LVEF from acute setting to 10-14 weeks (p = 0.001). There was significant lowering of summed score (p = 0.007). Perfusion defect size showed significant reduction (p = 0.030). Three patients showed deterioration in perfusion defect size and in summed score with reduction in LVEF. Four patients had no change in any of the parameters. Correlation between perfusion defect and LVEF was strong both at baseline (r = -0.705, p < 0.001) and after 10-18 weeks (r = -0.766, p < 0.001).. The changes we found in 3 months are similar to earlier studies and also to studies using follow up at 6 months to 1 year. We feel that 3 months is a good enough time to accurately assess the success of primary angioplasty.

Topics: Angioplasty; Coronary Circulation; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Time Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Dobutamine stress myocardial perfusion imaging (MPI) is a useful alternative for the evaluation of coronary artery disease (CAD) in elderly patients who are unable to perform an exercise stress test. However, data on the long-term prognostic value of stress MPI in elderly patients are lacking. Therefore, this study evaluated the long-term prognostic value of dobutamine stress MPI in elderly patients unable to perform an exercise test.. The study population consisted of 247 elderly patients (mean age 71 ± 5 years) who underwent dobutamine stress single-photon emission computed tomography (SPECT) MPI. An abnormal SPECT study was defined as the presence of fixed and/or reversible perfusion defects. A summed stress score (SSS) was obtained to estimate the extent and severity of perfusion defects. End points during follow-up were all-cause mortality, cardiac mortality, and nonfatal myocardial infarction (MI).. During a median follow-up of 14 years (range 12-16), 168 (68%) patients died (all-cause mortality), of which 56 (23%) were due to cardiac causes. Nonfatal MI occurred in 19 (8%) patients. Kaplan-Meier survival curves showed that MPI provided optimal risk stratification in patients with normal and abnormal MPI. Multivariable analysis identified an abnormal MPI as a strong significant predictor of all-cause mortality and cardiac events. A multivariable analysis also revealed that a reversible defect and SSS were strong long-term predictors of cardiac mortality and hard cardiac events.. Dobutamine stress

Topics: Aged; Aged, 80 and over; Coronary Artery Disease; Disease Progression; Dobutamine; Exercise Test; Female; Follow-Up Studies; Humans; Kaplan-Meier Estimate; Male; Myocardial Infarction; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Retrospective Studies; Risk Assessment; Risk Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Two-dimensional echocardiographic left ventricular (LV) global longitudinal strain (GLS) after ST-segment elevation myocardial infarction (STEMI) is moderately correlated with infarct size and reflects the residual LV systolic function. This correlation may be influenced by the presence of myocardial ischemia. The present study investigated how myocardial ischemia modulates the correlation between LV GLS and infarct size determined with single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in patients with first STEMI treated with primary coronary intervention. A total of 1,128 patients (age 60 ± 11 years) who underwent SPECT MPI for the evaluation of infarct size and residual ischemia were evaluated. LV GLS was measured on transthoracic echocardiography. The time interval between echocardiography and SPECT MPI was 1 ± 1 month. A moderate correlation between echocardiographic LV GLS and infarct size on SPECT MPI was observed (r = 0.58, p <0.001). This correlation was weakened by the presence or extent of ischemia; in the group of patients without ischemia, the correlation between LV GLS and infarct size on SPECT MPI was r = 0.66 (p <0.001), whereas in patients with mild or moderate-to-severe ischemia, the correlations were r = 0.56 and 0.38, respectively (both p <0.001). Moderate-to-severe myocardial ischemia was independently associated with more impaired LV GLS after adjusting for infarct size, age, diabetes mellitus, and hypertension (β 0.60, 95% confidence interval 013 to 1.06). In conclusion, the presence of myocardial ischemia after STEMI impacts on the correlation between echocardiographic LV GLS and infarct size measured on SPECT MPI. Residual ischemia is independently associated with more impaired LV GLS.

Topics: Echocardiography; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Retrospective Studies; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Direct ischemia imaging with F18-FDG can potentially overcome many limitations of SPECT-MPS inherent to "cold imaging". We compared SPECT-MPS with exercise F18-FDG PET in detection of ischemia in patients with suspected CAD.. 45 patients with clinical suspicion of CAD without the history of myocardial infarction were prospectively included. All patients underwent Tc-99m tetrofosmin SPECT-MPS and exercise F18-FDG PET imaging within 7 days of SPECT-MPS, and both modalities were compared with coronary angiography for detecting ischemia.. 27 patients had an abnormal coronary angiography (at least one coronary artery with stenosis >50%). Exercise F18-FDG performed better than SPECT-MPS in LAD and LCX territory with comparably good performance in RCA territory. Exercise F18-FDG performed better in single-vessel disease and equally good in multi-vessel disease compared to SPECT-MPS. Performance of exercise 18F-FDG study was significantly better than SPECT-MPS (P = .0014) in the analysis of the 81 vascular territories in the 27 patients with abnormal coronary angiography. Performance of exercise F18-FDG was significantly better than SPECT-MPS in detecting ischemia in suspected CAD patients.. Exercise F18-FDG imaging is a potentially useful ischemia imaging modality which offers the advantages of direct ischemia imaging in CAD patients.

Topics: Adult; Aged; Constriction, Pathologic; Coronary Angiography; Coronary Artery Disease; Female; Fluorodeoxyglucose F18; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Young Adult

Prone imaging has been demonstrated to minimize diaphragmatic and breast tissue attenuation.. To determine the role of prone imaging on the reduction of unnecessary rest perfusion studies and coronary angiographies performed, thus decreasing investigation time and radiation exposure.. We examined 139 patients, 120 with an inferior wall and 19 with an anterior wall perfusion defect that might represented attenuation artifact. Post-stress images were acquired in both the supine and prone position. Coronary angiography was used as the "gold standard" for evaluating coronary artery patency. The study was terminated and rest imaging was obviated in the presence of complete improvement of the defect in the prone position. Quantitative interpretation was performed. Results were compared with clinical data and coronary angiographic findings.. Prone acquisition correctly revealed defect improvement in 89 patients (89/120) with inferior wall and 12 patients (12/19) with anterior wall attenuation artifact. Quantitative analysis demonstrated statistically significant difference in the mean summed stress scores (SSS) of supine and mean SSS of prone studies in patients with disappearing inferior wall defect in the prone position and patent right coronary artery (true negative results). The mean difference between SSS in supine and in prone position was higher with disappearing than with remaining defects.. Technetium-99m (Tc-99m) tetrofosmin myocardial perfusion imaging with the patient in the prone position overcomes soft tissue attenuation; moreover it provides an inexpensive, accurate approach to limit the number of unnecessary rest perfusion studies and coronary angiographies performed.

Topics: Aged; Artifacts; Coronary Angiography; Coronary Artery Disease; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Patient Positioning; Prone Position; Radiation Exposure; Radiopharmaceuticals; Risk Assessment; Sensitivity and Specificity; Statistics, Nonparametric; Time Factors; Tomography, Emission-Computed, Single-Photon

Left ventricular function is altered during and after AMI. Regional function can be determined by cardiac magnetic resonance (CMR) wall thickening, and velocity encoded (VE) strain analysis. The aims of this study were to investigate how regional myocardial wall function, assessed by CMR VE-strain and regional wall thickening, changes after acute myocardial infarction, and to determine if we could differentiate between ischemic, adjacent and remote segments of the left ventricle.. Ten pigs underwent baseline CMR study for assessment of wall thickening and VE-strain. Ischemia was then induced for 40-minutes by intracoronary balloon inflation in the left anterior descending coronary artery. During occlusion, (99m)Tc tetrofosmin was administered intravenously and myocardial perfusion SPECT (MPS) was performed for determination of the ischemic area, followed by a second CMR study. Based on ischemia seen on MPS, the 17 AHA segments of the left ventricle was divided into 3 different categories (ischemic, adjacent and remote). Regional wall function measured by wall thickening and VE-strain analysis was determined before and after ischemia.. Mean wall thickening decreased significantly in the ischemic (from 2.7 mm to 0.65 mm, p < 0.001) and adjacent segments (from 2.4 to 1.5 mm p < 0.001). In remote segments, wall thickening increased significantly (from 2.4 mm to 2.8 mm, p < 0.01). In ischemic and adjacent segments, both radial and longitudinal strain was significantly decreased after ischemia (p < 0.001). In remote segments there was a significant increase in radial strain (p = 0.002) while there was no difference in longitudinal strain (p = 0.69). ROC analysis was performed to determine thresholds distinguishing between the different regions. Sensitivity for determining ischemic segments ranged from 70-80%, and specificity from 72%-77%. There was a 9% increase in left ventricular mass after ischemia.. Differentiation thresholds for wall thickening and VE-strain could be established to distinguish between ischemic, adjacent and remote segments but will, have limited applicability due to low sensitivity and specificity. There is a slight increase in radial strain in remote segments after ischemia. Edema was present mainly in the ischemic region but also in the combined adjacent and remote segments.

Topics: Animals; Biomechanical Phenomena; Disease Models, Animal; Edema, Cardiac; Heart Ventricles; Magnetic Resonance Imaging; Myocardial Contraction; Myocardial Infarction; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Sus scrofa; Time Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

The aim was to determine the sensitivity and specificity of gated myocardial perfusion SPECT (MPS) with a technetium-labelled (Tc) perfusion tracer to detect myocardial infarction (MI) in a clinical population referred for assessment of stress-induced ischemia using late gadolinium enhancement cardiac magnetic resonance (CMR) as reference method.. 119 patients referred for evaluation of stress-induced ischemia with MPS were included. 108 patients (age 62 ± 10 years, 39% females) completed MPS and CMR. A 2-day protocol for MPS was used for most patients (n = 105).. MI was found in 31 patients (29%) using MPS and in 30 patients using CMR (28%). The sensitivity and specificity on a patient basis were 93% and 96%, respectively. Positive predictive value (PPV) was 90% and negative predictive value (NPV) was 97%. Per territory, the sensitivity and specificity for LAD infarcts were 83% and 97%, respectively. PPV was 77% and NPV was 98% for LAD infarcts. The sensitivity and specificity for RCA/LCx infarcts were 95% and 95%, respectively. PPV was 84% and NPV was 99% for RCA/LCx infarcts. The MI size on CMR was 12.0 ± 7.3% of the LV and mean transmurality was 66.3 ± 12.0%. All MI > 3% were detected on gated SPECT.. This study has demonstrated high sensitivity and specificity for gated Tc-MPS detecting subendocardial and transmural MI.

Topics: Aged; Contrast Media; Female; Gadolinium; Heart; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Infarction; Myocardial Perfusion Imaging; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Risk; Sensitivity and Specificity; Time Factors; Tomography, Emission-Computed, Single-Photon

Topics: Angioplasty, Balloon; Coronary Angiography; Diagnosis, Differential; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stents; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

Myocardial perfusion single-photon emission computed tomography (MPS) can be used to assess myocardium at risk in occlusive coronary ischaemia. The aim was to develop a method to quantify myocardium at risk as perfusion defect size on ex vivo MPS using co-registration and fusion with ex vivo magnetic resonance imaging (MRI).. Pigs (n = 19) were injected 99mTc-tetrofosmin prior to concluding 40 min of coronary artery occlusion, followed by reperfusion and MRI contrast injection. The excised heart was imaged with T1-weighted MRI and MPS, and images were co-registered using freely available software (Segment v1.8, http://segment.heiberg.se). The left ventricle was semi-automatically delineated in MRI and copied to MPS. The threshold for a MPS perfusion defect was defined as the mean counts in the MPS image at the MRI-determined border between remote myocardium and air. The threshold was measured using count maxima set to the 100th-95th percentile of counts within the myocardium. The count maximum that gave the lowest threshold variability (SD) was considered the most robust.. A count maximum using the 100th percentile yielded a threshold of (mean ± SD) 55 ± 6·2%. This method showed the lowest SD compared to 99th-95th percentile count maxima (6·6-7·2%).. We describe a method for objective quantification of myocardium at risk as perfusion defect size on MPS using knowledge of the anatomy of the myocardium from co-registered MRI. This enables simultaneous quantification of myocardium at risk by MPS and infarct size by MRI for the evaluation of treatments for myocardial infarction.

Topics: Animals; Contrast Media; Coronary Circulation; Coronary Occlusion; Disease Models, Animal; Female; Magnetic Resonance Imaging; Male; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Swine; Tomography, Emission-Computed, Single-Photon

To assess the significance of a paradoxical pattern (PP) (greater tracer uptake during stress than at rest) on gated myocardial perfusion SPECT in myocardial regions with myocardial necrosis.. A review of 1,764 consecutive stress-rest myocardial perfusion SPECT studies in patients with prior myocardial infarction (MI) was conducted. Of these, 117 patients (6.6%) with a PP corresponding to a region with myocardial necrosis were identified. An assessment of perfusion, contractility, wall thickening, scintigraphic criteria for viability, and the characteristics of the culprit artery in regions with a PP was performed.. Of the 160 regions with necrosis, 125 (75%) had a PP: 67 in the anterior region and 58 in the inferior-lateral region. In the PP group, the average tracer activity of defects during stress was significantly higher than at rest (P < .0001). Ninety-three (86.6%) out of 110 PP segments without scintigraphic criteria of viability at rest met viability criteria on stress imaging. The artery supplying regions with a PP was patent in 88% of cases. In the remaining patients it was occluded, although collateral circulation was always present.. In scintigraphic segments corresponding to regions with infarction and PP, a mixture of viable and well perfused myocardium was observed. In most cases, the vessel that supplied the region with PP was either patent, or when the artery was occluded, there was evident collateral circulation.

Topics: Aged; Cardiac-Gated Imaging Techniques; Comorbidity; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Perfusion Imaging; Necrosis; Organophosphorus Compounds; Organotechnetium Compounds; Prevalence; Radiopharmaceuticals; Reproducibility of Results; Risk Assessment; Risk Factors; Sensitivity and Specificity; Spain; Tomography, Emission-Computed, Single-Photon

Of various nuclear medicine techniques, F-18/flourodeoxyglucose (FDG) positron emission tomography (PET) is considered as the best modality for the assessment of viable myocardium (VM). In this study, we compared the diagnostic accuracy of nitrate augmented Tc-99m tetrofosmin gated G-single-photon emission computed tomography (SPECT) with FDG PET.. 54 consecutive cases of angiographically proven CAD with severe LV dysfunction were enrolled in the study. The patients underwent Tc-99m tetrofosmin G-SPECT and FDG PET as per the standard protocols and were compared.. SPECT data analysis indicated functional abnormalities in 661/918 myocardial segments. F-18 FDG PET revealed VM in 496/661 segments. The diagnostic accuracy of baseline NAC, postnitrate NAC, baseline AC, and postnitrate AC Tc-99m tetrofosmin SPECT was 84%, 87%, 90%, and 94%, respectively. κ values for NAC baseline, NAC postnitrate, AC baseline, and AC postnitrate Tc-99m tetrofosmin G-SPECT were 0.65, 0.70, 0.77, and 0.85, respectively. Attenuation correction revealed viability additionally in 46 segments which were non-viable on NAC postnitrate study (P < .001). Nitrate augmentation showed viability additionally in 25 segments which were non-viable on AC baseline scan (P = .004). On patient-based analysis FDG PET changes the management only in 13% (7/54) of patients.. Nitrate augmented AC Tc-99m tetrofosmin G-SPECT shows excellent (κ = .85) agreement with FDG PET. FDG PET changes management only in 13% of the patients. Tc-99m tetrofosmin G-SPECT being more widely available and cheaper imaging modality can be reliably used to detect VM where FDG PET is not available.

Topics: Adult; Aged; Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; Coronary Artery Disease; Female; Fluorodeoxyglucose F18; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Nitrates; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Predictive Value of Tests; Prospective Studies; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Ventricular Dysfunction, Left

The aim of this study was to determine the impact of attenuation correction with CT (CT-AC) on the prognostic value of SPECT myocardial perfusion imaging (SPECT MPI).. The summed stress score (SSS; 20-segment model) was obtained from filtered backprojection (FBP) and iterative reconstruction with CT-AC in 876 consecutive patients undergoing a 1-d stress-rest (99m)Tc-tetrofosmin SPECT MPI study for the evaluation of known or suspected coronary artery disease. Survival free of major adverse cardiac events (MACEs; cardiac death or nonfatal myocardial infarction) and survival free of any adverse cardiac events (including cardiac hospitalization, unstable angina, and late coronary revascularization) were analyzed by Kaplan-Meier analysis.. At a mean follow-up of 2.3 ± 0.6 y, a total of 184 adverse events occurred in 145 patients, including 35 MACEs (16 cardiac deaths [rate, 1.8%] and 19 nonfatal myocardial infarctions [rate, 2.2%]). With FBP, an SSS of 0-3 best distinguished patients with a low MACE rate (0.6%), followed by an SSS of 4-8 (4.3%), with increased MACE rate, and an SSS of 9-13 (3.8%), which was comparable. By contrast, with CT-AC the discrimination of low from intermediate MACE rate was best observed between an SSS of 0 (0%) and an SSS of 1-3 (3.7%), with a plateau at an SSS of 4-8 (3.2%).. CT-AC for SPECT MPI allows improved risk stratification. The prognostically relevant SSS cutoff is shifted toward lower values.

Topics: Adenosine; Aged; Death, Sudden, Cardiac; Disease-Free Survival; Electrocardiography; Endpoint Determination; Female; Follow-Up Studies; Heart; Heart Diseases; Humans; Image Interpretation, Computer-Assisted; Kaplan-Meier Estimate; Male; Middle Aged; Myocardial Infarction; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prognosis; Radiopharmaceuticals; Risk Factors; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Aims Although cardiac hybrid imaging, fusing single-photon emission computed tomography (SPECT) myocardial perfusion imaging with coronary computed tomography angiography (CCTA), provides important complementary diagnostic information for coronary artery disease (CAD) assessment, no prognostic data exist on the predictive value of cardiac hybrid imaging. Hence, the aim of this study was to assess the prognostic value of hybrid SPECT/CCTA images. Methods and results Of 335 consecutive patients undergoing a 1-day stress/rest (99m)Tc-tetrofosmin SPECT and a CCTA, acquired on stand-alone scanners and fused to obtain cardiac hybrid images, follow-up was obtained in 324 patients (97%). Survival free of all-cause death or non-fatal myocardial infarction (MI) and free of major adverse cardiac events (MACE: death, MI, unstable angina requiring hospitalization, coronary revascularizations) was determined using the Kaplan-Meier method for the following groups: (i) stenosis by CCTA and matching reversible SPECT defect; (ii) unmatched CCTA and SPECT finding; and (iii) normal finding by CCTA and SPECT. Cox's proportional hazard regression was used to identify independent predictors for cardiac events. At a median follow-up of 2.8 years (25th-75th percentile: 1.9-3.6), 69 MACE occurred in 47 patients, including 20 death/MI. A corresponding matched hybrid image finding was associated with a significantly higher death/MI incidence (P < 0.005) and proved to be an independent predictor for MACE. The annual death/MI rate was 6.0, 2.8, and 1.3% for patients with matched, unmatched, and normal findings. Conclusion Cardiac hybrid imaging allows risk stratification in patients with known or suspected CAD. A matched defect on hybrid image is a strong predictor of MACE.

Topics: Aged; Angina, Unstable; Cause of Death; Coronary Angiography; Coronary Artery Disease; Death, Sudden, Cardiac; Female; Hospitalization; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiation Dosage; Radiopharmaceuticals; Risk Factors; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Assessment of small-animal cardiac data acquired using SPECT requires an accurate understanding of the reproducibility and the uncertainties associated with the technique. Furthermore, it is also useful to have a baseline of reference data against which to compare the outcome of a particular study.. We scanned both healthy and post-myocardial infarction rats injected with (99m)Tc-tetrofosmin in a multidetector, multipinhole small-animal SPECT scanner. In this paper, we report on the creation of a reference database of the relative myocardial blood perfusion of rats. We also evaluated the reproducibility of perfusion measurements and measurements of left ventricle volume and ejection fraction, defined as the SD of a particular measurement repeated on the same animal or over multiple animals.. For the healthy rats, interscan reproducibility of volume measurements was 4%-7% of the total volume, and intersubject reproducibility was 9%-12% of the volume being measured. Interscan reproducibility remained unaffected after infarction (6%-8%), but intersubject reproducibility was much poorer (15%-26%). Ejection fraction in healthy animals was highly reproducible between scans and between rats: 3.1% and 3.3%, respectively. Interscan reproducibility of the postinfarction ejection fraction was 3.6%; intersubject reproducibility after infarction was 8.1%.. We have created a reference database for small-animal SPECT perfusion measurements in healthy male Sprague-Dawley rats and quantified the reproducibility of perfusion and functional measurement made with small-animal SPECT in healthy and postinfarction rats.

Topics: Animals; Diagnostic Imaging; Gated Blood-Pool Imaging; Heart Ventricles; Humans; Male; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

We aimed to compare two-dimensional global longitudinal strain (GS) with different non-invasive imaging modalities for the assessment of left ventricular function in an ST-elevation myocardial infarction population.. GS was compared with ejection fraction (EF) determined by magnetic resonance imaging (MRI), standard echocardiography (echo), contrast echo, and electrocardiography-gated single-photon emission computed tomography (SPECT), as well as with MRI-determined relative infarct size and echo-determined wall motion score index (WMSI), in 163 patients participating in the NORwegian Study on District Treatment of ST-Elevation Myocardial Infarction (NORDISTEMI). The linear relation between GS and standard echo (r(2)= 0.43, P <0.001), contrast echo (r(2)= 0.38, P <0.001), and SPECT-determined EF (r(2)= 0.52, P <0.001) was almost identical as that between GS and the gold standard MRI-determined EF (r(2)= 0.47, P <0.001). GS was best associated with WMSI by echo (r(2)= 0.55, P <0.001), while the associations between GS and relative infarct size were weaker (r = 0.43, P <0.001). Receiver operator characteristics curves, used to analyse the ability of GS to discriminate low EF (≤ 40%) measured by the four different modalities, large myocardial infarction (MI ≥ 15.7%), and high WMSI (≥ 1.5), were significant for all. GS was shown to be the best predictor of low EF measured by MRI [area under the curve (AUC) 0.965], while the lowest AUC was found between GS and large MI (0.814).. Global strain is associated well with EF measured by all modalities. Global strain was found to be the best predictor of low EF measured by the gold standard MRI. Since global strain is an inexpensive test, these data may be of health economic interest.

Topics: Adult; Aged; Contrast Media; Echocardiography; Electrocardiography; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Phospholipids; Radiopharmaceuticals; Randomized Controlled Trials as Topic; Stroke Volume; Sulfur Hexafluoride; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left; Young Adult

The aim of this study was to determine the long-term prognostic value of early poststress lung/heart ratio (LHR) of (99m)Tc-tetrofosmin radioactivity.. We studied 276 patients (aged 62.2 + or - 8.9 years, 168 men) with stress/rest (99m)Tc-tetrofosmin myocardial gated-SPECT and coronary angiography. To evaluate myocardial ischaemia, we calculated the summed stress score, summed rest score and summed difference score indices. For the eLHR calculation, an anterior image was acquired, 4-6 min after radiotracer injection at stress (eLHR was defined as mean counts per pixel in the lung region of interest divided by the mean counts per pixel in the myocardial region of interest). Cardiovascular death and nonfatal myocardial infarction were considered as hard cardiac events, and late revascularization procedures as soft cardiac events. The Cox proportional hazards model in a stepwise method was used to determine the independent predictors for hard and soft cardiac events.. During the follow-up period hard cardiac events occurred in 28 patients (10.1%) and soft cardiac events in 32 patients (11.6%). Implying multiple Cox regression analysis, eLHR was found to be a significant independent predictor for both soft and hard cardiac events. The hazard ratio (for a 0.1 unit increase) was 4.41 (95% CI 1.52-12.73, p=0.006) for soft cardiac events and 4.22 (95% CI 2.07-8.62, p<0.001) for hard cardiac events. The other significant prognostic factors were use of beta-blockers, the summed stress score and the use of nitrates for soft events, and exercise duration and the summed stress score for hard cardiac events.. Early poststress (99m)Tc-tetrofosmin LHR has an independent and powerful value in predicting hard and soft cardiac events.

Topics: Aged; Cardiac Catheterization; Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; Cardiovascular Diseases; Comorbidity; Coronary Angiography; Coronary Disease; Exercise; Exercise Test; Female; Humans; Kaplan-Meier Estimate; Lung; Male; Middle Aged; Myocardial Infarction; Myocardial Perfusion Imaging; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Proportional Hazards Models; Radiopharmaceuticals; Single-Blind Method; Smoking

Our goal was to validate myocardium at risk on T2-weighted short tau inversion recovery (T2-STIR) cardiac magnetic resonance (CMR) over time, compared with that seen with perfusion single-photon emission computed tomography (SPECT) in patients with ST-segment elevation myocardial infarction, and to assess the amount of salvaged myocardium after 1 week.. To assess reperfusion therapy, it is necessary to determine how much myocardium is salvaged by measuring the final infarct size in relation to the initial myocardium at risk of the left ventricle (LV).. Sixteen patients with first-time ST-segment elevation myocardial infarction received (99m)Tc tetrofosmin before primary percutaneous coronary intervention. SPECT was performed within 4 h and T2-STIR CMR within 1 day, 1 week, 6 weeks, and 6 months. At 1 week, patients were injected with a gadolinium-based contrast agent for quantification of infarct size.. Myocardium at risk at occlusion on SPECT was 33 +/- 10% of the LV. Myocardium at risk on T2-STIR did not differ from SPECT, at day 1 (29 +/- 7%, p = 0.49) or week 1 (31 +/- 6%, p = 0.16) but declined at week 6 (10 +/- 12%, p = 0.0096 vs. 1 week) and month 6 (4 +/- 11%, p = 0.0013 vs. 1 week). There was a correlation between myocardium at risk demonstrated by T2-STIR at week 1 and myocardium at risk by SPECT (r(2) = 0.70, p < 0.001), and the difference between the methods on Bland-Altman analysis was not significant (-2.3 +/- 5.7%, p = 0.16). Both modalities identified myocardium at risk in the same perfusion territory and in concordance with angiography. Final infarct size was 8 +/- 7%, and salvage was 75 +/- 19% of myocardium at risk.. This study demonstrates that T2-STIR performed up to 1 week after reperfusion can accurately determine myocardium at risk as it was before opening of the occluded artery. CMR can also quantify salvaged myocardium as myocardium at risk minus final infarct size.

Topics: Aged; Angioplasty, Balloon, Coronary; Contrast Media; Coronary Angiography; Female; Follow-Up Studies; Heart Ventricles; Heterocyclic Compounds; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Myocardium; Organometallic Compounds; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Risk Assessment; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Topics: Angioplasty, Balloon, Coronary; Contrast Media; Coronary Angiography; Heart Ventricles; Heterocyclic Compounds; Humans; Magnetic Resonance Imaging; Myocardial Infarction; Myocardial Ischemia; Myocardium; Organometallic Compounds; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Risk Assessment; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Images of myocardial perfusion taken during an episode of chest pain have been used for patients in the emergency department.. To evaluate the operating characteristics of 99mTc-Tetrofosmin scintigraphy during an episode of chest pain to exclude the diagnosis of acute myocardial infarction.. One hundred and eight patients admitted with chest pain, or up to four hours after the end of symptoms and nondiagnostic electrocardiogram, underwent resting scintigraphy and measurement of troponin I concentrations. Patients with a history of myocardial infarction (MI) were not excluded (24 patients). Troponin I concentrations were determined at admission and 6 hours later. Nuclear physicians performed a blind analysis of the images, and myocardial infarction was confirmed whenever troponin I level increase was three times that of the control.. Resting perfusion image was abnormal in all 6 patients with MI. Only 1 patient had a normal image and increased troponin levels. Fifty-five patients had positive images without MI, and 46 patients had normal images and troponin levels. The prevalence of the disease was 6.5%. The sensitivity and specificity of the resting images during an episode of chest pain to diagnose MI was 85.7% and 45.5%, respectively. The negative predictive value was 97.7%.. Patients undergoing chest pain protocol with SPECT showed an excellent negative predictive value to exclude diagnosis of myocardial infarction. These results suggest that resting perfusion image is an important tool at the chest pain unit.

Topics: Biomarkers; Brazil; Chest Pain; Diagnosis, Differential; Epidemiologic Methods; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Rest; Troponin I

(123)I-beta-methyl-iodophenyl pentadecanoic acid (BMIPP) and (99m)Tc-Tetrofosmin (TF) mismatch designated as stunned myocardium having both systolic and diastolic components. The degree of mismatch might reflect subsequent functional improvement, and this study was designed to unravel the impact of mismatched defect score (MMDS) on recovery of both systolic and diastolic function following acute myocardial infarction (AMI). Forty patients with recent AMI were recruited, and all of them underwent emergency percutaneous coronary intervention. Echocardiography and BMIPP and TF cardiac scintigraphy were performed on 7 +/- 3 days of admission. Follow up echocardiography was performed after 3 months. MMDS were compared with the systolic [ejection fraction (EF) and wall motion score index (WMSI)] and diastolic [peak velocity of early diastolic filling of mitral inflow/peak early diastolic velocity of the mitral annulus(E/E') and left atrial volume index(LAVI)] parameters. BMIPP defect score was significantly higher than the TF defect score and there was a strong positive correlation between them (r = 0.90, P < 0.00001). Thirty-two (80%) patients showed mismatched defect and rest 8(20%) showed matched defect. Of 32 patients 24(75%), 22(69%), 19(59%), and 20(62.5%) showed improved EF, WMSI, E/E' and LAVI respectively. Conversely out of 8 only 2(25%), 1(12.5%), and 2(25%) patients showed improvement of EF, WMSI and LAVI, respectively. E/E' was not improved in patients with matched defect. MMDS were significantly correlated with the improvement of EF (r = -0.46, P = 0.002), WMSI (r = 0.41, P = 0.007), E/E' (r = 0.56, P < 0.0002), and LAVI (r = 0.44, P = 0.004). Mismatched defect score could predict the approximate amount of viable dysfunctional myocardium, and the degree of mismatch showed a significant correlation with the improvement of both systolic and diastolic function.

Topics: Aged; Angioplasty, Balloon, Coronary; Cross-Sectional Studies; Echocardiography, Doppler; Fatty Acids; Female; Humans; Iodine Radioisotopes; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Myocardial Perfusion Imaging; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prospective Studies; Radiopharmaceuticals; Recovery of Function; Stroke Volume; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Ventricular Dysfunction, Left; Ventricular Function, Left

The purpose of this study was to clarify the relationship between reverse redistribution (RRD) of (99m)Tc-tetrofosmin ((99m)Tc-TF) and left ventricular functional recovery in patients with acute myocardial infarction (AMI).. We studied 21 patients with AMI who underwent direct percutaneous coronary intervention (PCI). (99m)Tc-TF-gated single-photon emission computed tomography (SPECT) was performed at rest in the sub-acute and chronic phases. Imaging data were acquired at 30 min (early images) and 3 h (delayed images) after injection. Defect score, regional relative uptakes of (99m)Tc-TF (%uptake), and regional wall thickening (WT) were calculated using the 20-segment model. We measured left ventricular ejection fraction (LVEF) and defined DeltaLVEF as change in LVEF. Summed defect score was calculated by adding the scores of 20 segments on early and delayed images. Summed washout score (SWS) was derived as the difference between early and delayed scores. We defined that SWS was more than 1 point as individual RRD (I-RRD). In each segment, regional RRD (R-RRD) in the sub-acute phase was calculated as %uptake on early images minus %uptake on delayed images in the sub-acute phase. DeltaWT was defined as change in WT from the sub-acute phase to chronic phase. We defined that R-RRD and DeltaWT were higher than 1SD on the control map as R-RRD (+) and change of WT (+).. All patients were divided into two groups according to the presence of I-RRD. DeltaLVEF was significantly higher in I-RRD (+) than in I-RRD (-) (14.5 +/- 12.1 vs. 0.0 +/- 3.9%, p < 0.01). We analyzed 162 segments as at-risk areas among a total of 420 segments. In total of R-RRD (+), 75 of 96 segments (78%) had change of WT (+), while this was observed in only 13 of 66 segments (20%) in total of R-RRD (-) (p < 0.0001). In addition, there was a significant correlation between R-RRD in the sub-acute phase and change in %uptake on delayed images from the sub-acute phase to chronic phase in at-risk areas (r = 0.584, p < 0.001).. These findings suggested that quantitative evaluation of RRD by gated (99m)Tc-tetrofosmin SPECT in the sub-acute phase can predict recovery of left ventricular function in the chronic phase with higher accuracy in patients with AMI who underwent direct PCI.

Topics: Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Recovery of Function; Time Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

To compare the myocardial kinetics of three (99m)technetium-labeled monocationic tracers [methoxy-isobutylisonitrile (MIBI), tetrofosmin, and Q12] in a model of ischemia-reperfusion (IR) to determine their abilities to assess myocardial viability.. Isolated perfused rat hearts (n = 30) were studied in control and IR groups for each tracer. IR hearts were treated with 120 min global no-flow followed by 5 min reflow, then 60 min tracer uptake/clearance. Tracer kinetics were monitored using a scintillation detector.. This model produced significant myocardial injury, without significant differences in the percentage of injured myocardium by triphenyltetrazolium chloride (TTC) staining and creatine kinase (CK) assay. Transmission electron microscopy analysis also confirmed necrosis with abundant mitochondrial damage in the IR hearts. All three IR groups exhibited significantly less mean (+/-standard error of the mean) tracer retention than matched controls (MIBI 73.4 +/- 4.9% vs. 96.9 +/- 1.76%, tetrofosmin 38.7 +/- 4.6% vs. 82.2 +/- 3.5%, and Q12 23.0 +/- 2.5% vs. 43.8 +/- 1.8%, respectively; P < 0.05). Tetrofosmin IR hearts exhibited 54 +/- 9% of control myocardial retention, which was significantly less than either MIBI (86 +/- 5%, P < 0.05) or Q12 (63 +/- 6%, P < 0.05); thus, tetrofosmin provided the best differentiation between nonviable and normal myocardium. Furthermore, tetrofosmin end activity (%id/g) in controls was significantly higher than Q12 (4.09 +/- 0.04 vs. 1.71 +/- 0.06, respectively, P < 0.05), and tetrofosmin end activity (%id/g) in IR hearts was significantly higher than Q12 (2.19 +/- 0.37 vs. 1.06 +/- 0.12, respectively, P < 0.05). The correlation between end activity and viable myocardium determined by TTC staining was r = 0.66 (P < 0.05) for MIBI, r = 0.94 (P < 0.05) for tetrofosmin, and r = 0.91 (P < 0.05) for Q12. The correlation between myocardial end activity and myocardial CK leak was r = -0.62 (P < 0.05) for MIBI, r = -0.87 (P < 0.05) for tetrofosmin, and r = -0.89 (P < 0.05) for Q12.. Nonviable myocardium can be distinguished from normal myocardium by the retention kinetics of all three monocationic tracers studied. Tetrofosmin and Q12 end activities demonstrate the best correlation with infarct size. However, tetrofosmin kinetics may combine the greatest differentiation between nonviable and normal myocardium, while still retaining adequate activity for imaging.

Topics: Animals; Creatine Kinase; Furans; Heart; In Vitro Techniques; Kinetics; Male; Mitochondria, Heart; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Necrosis; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Technetium Tc 99m Sestamibi; Tetrazolium Salts

To investigate the cardioprotective effect of intravenous nicorandil before primary percutaneous coronary intervention (PCI) on preservation of myocardial viability, we studied 199 consecutive patients with acute myocardial infarction.. Nicorandil was given intravenously on admission (before primary PCI). Echocardiography and technetium-99m tetrofosmin perfusion imaging were performed before and 1 month after primary PCI. Echocardiographic asynergic score before primary PCI was used to define the size of risk area, whereas the sum of scintigraphic defect grade before primary PCI was used to estimate myocardial viability within the area at risk. The change (before primary PCI and 1 month after primary PCI) in asynergic score and scintigraphic salvage index were calculated.. Patients were divided into nicorandil (n=101) and control (n=98) groups. Although asynergic score before primary PCI was not different between the two groups (nicorandil=3.5+/-2.1 and control=3.9+/-1.5), myocardial viability was preserved in nicorandil group (defect score=11.0+/-4.0) than that in control group (defect score=14.0+/-4.7, P<0.0001). Multivariate analysis revealed that the presence of antegrade flow (P=0.015) and nicorandil (P<0.0001) were independently associated with preserved myocardial viability before primary PCI. Moreover, the greater reduction in asynergic score (66+/-41 vs. 49+/-23%, P=0.0006) and larger salvage index (65+/-25 vs. 53+/-26%, P=0.0015) were observed in nicorandil group compared with the control group.. Intravenous administration of nicorandil before primary PCI preserved myocardial viability within the risk area, which leads to greater myocardial salvage and better functional recovery after primary PCI.

Topics: Acute Disease; Aged; Angioplasty, Balloon, Coronary; Female; Humans; Male; Middle Aged; Multivariate Analysis; Myocardial Infarction; Myocardium; Nicorandil; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

To evaluate the long-term prognostic value of Tc-99m tetrofosmin myocardial gated-SPECT in asymptomatic patients after coronary artery stenting.. We included 246 consecutive patients in the study. All patients underwent exercise gated-single photon emission computed tomography (SPECT) myocardial imaging 5 to 7 months after percutaneous coronary intervention (PCI) and were followed for a mean period of 8.3 years (SD = 2.9). Myocardial scintigrams were evaluated calculating the summed stress score (SSS), summed rest score, and summed difference score (SDS) indexes. Cardiovascular death and nonfatal myocardial infarction were considered hard cardiac events, whereas late revascularization (>3 months after myocardial SPECT) procedures were considered to be soft events. Cox proportional hazard models were applied to evaluate the association between several variables and the investigated outcome.. During the follow-up period, hard cardiac events occurred in 32 (13%) patients (cardiac death occurred in 12 patients and nonfatal myocardial infarction in 20 patients). In addition, 60 (24.4%) patients underwent a late revascularization procedure. When multiple Cox regression analysis was implied, the factors that remained significant in the final model for soft events were SSS, SDS, and angina during exercise testing. In addition, SSS, SDS, and left ventricular dilatation were independently associated with hard cardiac events as defined from the results of multiple analysis. However, SSS and SDS were the only independent predictors for both hard and soft events.. Tc-99m tetrofosmin myocardial perfusion imaging (MPI), performed 6 months post-percutaneous coronary intervention, has an independent and powerful clinical value to predict hard and soft cardiac events in asymptomatic patients after PCI.

Topics: Angioplasty, Balloon, Coronary; Coronary Artery Disease; Coronary Circulation; Coronary Restenosis; Coronary Vessels; Exercise Test; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Acute myocardial infarction (MI) can occur in patients with previously normal stress myocardial perfusion imaging (MPI). It is not known whether the prognosis of these patients differ from those with MI who had an abnormal MPI on an earlier testing. The aim of this study was to compare the outcome of patients who sustained a MI during follow-up after stress MPI based on the presence or absence of perfusion abnormalities on the earlier test.. We studied 109 patients (age 62 +/- 11 years, 73 men) who developed MI 2.1 +/- 2.7 years after exercise or dobutamine stress Tc-99m tetrofosmin MPI. Subsequently, a follow-up was done for the occurrence of death during or after the acute event.. Myocardial perfusion was normal in 31 patients and was abnormal in 78 (45 had reversible defects). During a mean follow-up of 3.1 +/- 2.4 years after MI, death occurred in 35 (32%) patients. The death rate was 19% in patients with previously normal versus 33% in patients with abnormal perfusion (P < 0.01). In a Cox model, independent predictors of death were age (risk ratio (RR) 1.06, 95% CI: 1.02-1.10), heart failure (RR 2.7, CI: 1.3-5.5), and abnormal MPI (RR 2.5, CI: 1.3-4.5).. Patients with a previously normal stress MPI are less likely to die after acute MI than patients who had an abnormal MPI.

Topics: Aged; Exercise Test; Female; Humans; Male; Myocardial Infarction; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Proportional Hazards Models; Survival Analysis; Treatment Outcome

This prospective study evaluated the relationship between preinfarction angina (2 months before a 1st acute myocardial infarction) and the extent of postinfarction myocardial injury, myocardial perfusion, contractile function, and late recovery of global left ventricular contractile function. We enrolled 46 patients who had been admitted for a 1st, single-vessel-disease, acute myocardial infarction. Low-dose dobutamine echocardiography and technetium-99m-tetrofosmin scintigraphy were performed on all patients 7 to 10 days after acute myocardial infarction; and resting echocardiography was performed 7 to 12 months later. Twenty-seven of 46 (58.7%) patients had experienced angina before acute myocardial infarction, and 19 of 46 (41.3%) had not. There was no difference between the 2 groups in acute basal left ventricular ejection fraction (P=0.17) or in basal wall motion score index (P=0.521). The maximal creatine kinase-MB level was lower in the preinfarction-angina group (P=0.039). Patients with preinfarction angina had significantly more myocardial segments with preserved regional contractile function (P <0.0001) and significantly fewer segments with less than 50% perfusion (P=0.008). Stepwise regression analysis identified preinfarction angina (r2=0.317, P=0.032) as a significant predictor of the percentage of left ventricular ejection fraction recovery after the follow-up period. In our study, preinfarction angina was associated with decreased infarct size and with better protection of global and regional left ventricular contractility and improved preservation of the microvasculature. A history of preinfarction angina should be of value in predicting the late clinical outcomes of patients after a 1st acute myocardial infarction.

Topics: Adult; Aged; Aged, 80 and over; Angina Pectoris; Cardiotonic Agents; Collateral Circulation; Dobutamine; Female; Humans; Ischemic Preconditioning, Myocardial; Male; Middle Aged; Multivariate Analysis; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Regression Analysis; Stroke Volume; Time Factors; Treatment Outcome; Ultrasonography

N-terminal pro-b-type natriuretic peptide (NT pro-BNP) is a neurohormone synthesized predominantly in ventricular myocardium. In patients with symptoms of heart failure, elevation in NT pro-BNP accurately identifies ventricular dysfunction. However, NT pro-BNP levels are not specific for ventricular dysfunction in patients who do not have overt symptoms of heart failure, suggesting that other cardiac processes such as myocardial ischemia may also cause elevation in NT pro-BNP. The study was aimed to determine whether NT pro-BNP elevations are associated with myocardial ischemia.. One hundred and thirty patients (104 males, 26 females, mean age 61+12 years), with ST elevation acute myocardial infarction (STEMI) and preserved left ventricular ejection fraction (>45%) at echocardiography performed at entry, from February 2003 and February 2004 were enrolled. In all patients NT pro-BNP plasma levels were checked at entry and 4-5 days after symptoms onset. In addition, maximal or symptom-limited exercise treadmill test (Bruce protocol), and myocardial perfusion scintigraphy using [(99m)Tc]Tetrofosmin single photon emission computed tomography (SPECT) imaging were performed within 30 days of STEMI. Ischemia was defined as reversible perfusion abnormalities.. Of the 130 participants, 66 (51%) had inducible ischemia. Compared with patients in the lowest tertile, those in the highest tertile of NT pro-BNP had a greater significant risk of residual ischemia (odds ratio: 8.66; 95% CI, 3.90 to 19.24). Nevertheless patients in the highest tertile were older (64.19+/-10.80 years versus 55.90+/-9.67 years, P = 0.0001), had a lower left ventricular ejection fraction (49.70+13.46% versus 59.49+/-6.58%, P = 0.0001) and had a great rate of acute myocardial infarction (anterior acute myocardial infarction = 40.63% versus 25%).. Elevated levels of NT pro-BNP are associated with residual myocardial ischemia among patients with STEMI and preserved left ventricular ejection fraction, as demonstrated by perfusion defect on SPECT imaging, suggesting that these patients may need further evaluation for stratification of the future risk of fatal events. The observed association between NT pro-BNP levels and ischemia may explain because tests for NT pro-BNP are not specific for ventricular dysfunction among patients with coronary artery disease.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Echocardiography, Stress; Electrocardiography; Exercise Test; Female; Humans; Logistic Models; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Natriuretic Peptide, Brain; Odds Ratio; Organophosphorus Compounds; Organotechnetium Compounds; Peptide Fragments; Predictive Value of Tests; Radiopharmaceuticals; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Previous studies have shown a good outcome for patients who present with normal findings on stress myocardial perfusion imaging. Currently, the prognostic implications of a normal study in patients who have a history of coronary artery disease (CAD) are not clear. This study investigated the long-term prognosis after a normal finding on stress technetium-99m (Tc-99m)-tetrofosmin single-photon emission computed tomography in patients with a history of CAD. The study included 147 consecutive patients with a history of CAD (previous myocardial infarction and/or myocardial revascularization), who underwent exercise bicycle or high-dose dobutamine-atropine stress Tc-99m-tetrofosmin single-photon emission computed tomography, and had normal perfusion results during stress and at rest. Follow-up was completed in all patients. During a follow-up of 6.5 +/- 1.9 years, 20 patients (14%) died, 10 (7%) of whom died due to cardiac causes, and 12 (8%) had a nonfatal myocardial infarction. Annual cardiac death rates were 0.5% during the first 3 years of follow-up and 1.3% in the subsequent 3 years. Independent predictors of cardiac death were male gender, rate-pressure product at rest, and rate-pressure product at peak stress. In conclusion, patients who have a history of CAD have a very low cardiac death rate during the 3 years after a normal finding on stress Tc-99m-tetrofosmin single-photon emission computed tomography. Repeated testing should be reconsidered 3 years after the initial evaluation and when a change in symptoms or clinical condition occurs.

Topics: Aged; Blood Pressure; Coronary Artery Disease; Coronary Circulation; Echocardiography, Stress; Exercise Test; Female; Follow-Up Studies; Heart Rate; Humans; Male; Middle Aged; Multivariate Analysis; Myocardial Infarction; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Sex Factors; Tomography, Emission-Computed, Single-Photon

The aim of this prospective study was to evaluate the prognostic value of exercise myocardial scintigraphy in patients who undergo incomplete revascularization with percutaneous coronary stenting. In 322 consecutive patients (mean age 61 +/- 10 years), exercise technetium-99m-tetrofosmin single-photon emission computed tomography scintigraphy was prospectively performed 4 to 6 months after an incomplete revascularization procedure. Follow-up lasted < or = 84 months (median 33). Patients with normal findings were at low risk of cardiac events compared with patients with mildly abnormal and severely abnormal findings (yearly event rate 1.5% vs 5.1% and 8.5%, respectively, p < 0.01). A significant difference was observed in hard, soft, and composite event-free survival among patients with normal, mildly abnormal, and severely abnormal findings (p < 0.01, p < 0.03, and p < 0.01, respectively). Nuclear data provided significant incremental prognostic value for cardiac events compared with the clinical, angiographic, and exercise test findings. In conclusion, in patients with incomplete revascularization procedures, exercise myocardial scintigraphy provides significant independent information concerning the subsequent risk of cardiac events, with an annualized event rate of < 2% for patients with normal scan findings. Myocardial scintigraphy is able to provide incremental prognostic information after adjusting for clinical, angiographic, and exercise variables.

Topics: Aged; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Prospective Studies; Radiopharmaceuticals; Stents; Tomography, Emission-Computed, Single-Photon

Evaluation of myocardial blood flow from collateral vessels into the infarct area has been estimated by coronary angiography. In patients with acute myocardial infarction with Thrombolysis in Myocardial Infarction (TIMI) 0 flow, myocardial tracer uptake on single photon emission computed tomography (SPECT) images can predict the collateral blood flow in the infarct area if technetium (Tc)-99m-tetrofosmin was administered before recanalization. The present study investigated whether collateral blood flow evaluated by myocardial scintigraphy is a good predictor of myocardial salvage in patients with acute myocardial infarction.. The study group consisted of 30 patients (mean age 65 +/- 14 years, 23 males, 7 females) with first acute myocardial infarction and coronary angiography evidence of total occlusion (TIMI 0) within 12 hr after the onset. All patients had one vessel disease related to infarction and TIMI 3 flow after percutaneous coronary intervention (PCI). Tc-99m-tetrofosmin was injected intravenously before the PCI. The regional severity score index (RSSI) was obtained from SPECT using the 17 segment method with the four-point scoring system. Myocardial viability was evaluated by the RSSI obtained from thallium-glucose-insulin infusion SPECT after 1 week and regional wall motion score index obtained from echocardiography during the chronic phase.. The patients were divided into two groups according to the angiographic collateral finding. There were no differences in RSSI on thallium-glucose-insulin SPECT and regional wall motion score between the good collateral group (n = 8) and poor collateral group (n = 22). Myocardial Tc-99m-tetrofosmin RSSI was similar in these groups. On the other hand, the patients were divided according to Tc-99m-tetrofosmin scintigraphic evaluation before PCI. RSSI on thallium-glucose-insulin SPECT was significantly greater (0.7 +/- 0.5 vs 1.5 +/- 0.4, p < 0.01) and regional wall motion score was significantly less (1.46 +/- 0.50 vs 2.08 +/- 0.78, p < 0.05) in the lower Tc-99m-tetrofosmin RSSI (< 1.9) group (n = 22) compared with the higher RSSI (> or = 1.9) group (n = 8). In addition, a significant correlation was obtained between Tc-99 m-tetrofosmin RSSI and regional wall motion score index (r = 0.53, p < 0.01).. The collateral flow evaluated by scintigraphy was significantly correlated with myocardial viability.

Topics: Aged; Collateral Circulation; Coronary Angiography; Coronary Circulation; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

To assess the value of ECG-gating for the diagnosis of myocardial infarction using myocardial perfusion scintigraphy (MPS) and an artificial neural network. A total of 422 patients referred for MPS were studied using a one day (99m)Tc-tetrofosmin protocol. Adenosine stress combined with submaximal dynamic exercise was used. The images were interpreted by one of three experienced clinicians and these interpretations regarding the presence or absence of myocardial infarction were used as the standard. A fully automated method using artificial neural networks was compared with the clinical interpretation. Either perfusion data alone or a combination of perfusion and function from ECG-gated images were used as input to different artificial neural networks. After a training session, the two types of neural networks were evaluated in separate test groups using an eightfold cross-validation procedure. The neural networks trained with both perfusion and ECG-gated images had a 4-7% higher specificity compared with the corresponding networks using perfusion data only, in four of five segments compared at the same level of sensitivity. The greatest improvement in specificity, from 70% to 77%, was seen in the inferior segment. In the septal and lateral segments the specificity rose from 73% to 77% and from 81% to 85%, respectively. In the anterior segment, the increase in specificity from 93% to 94% by adding functional data was not significant. The addition of functional information from ECG-gated MPS is of value for the diagnosis of myocardial infarction using an automated method of interpreting myocardial perfusion images.

Topics: Adenosine; Automation; Diagnosis, Computer-Assisted; Electrocardiography; Humans; Myocardial Infarction; Myocardium; Neural Networks, Computer; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radiographic Image Interpretation, Computer-Assisted; Radionuclide Angiography; Radiopharmaceuticals; Sensitivity and Specificity

Laryngopharyngoesophagectomy and reconstruction by using stomach roll with retrocardiac anastomosis were performed in a 60-year-old man with hypopharyngeal cancer. Postoperative electrocardiogram showed marked ST-segment elevation in leads I and aVL and depression in leads II, III, aVF, and V1-6. However, the patient did not present with abnormal findings on physical examination and vital signs were normal. Further, the laboratory data were normal. Echocardiography was a poor technique, but the stomach roll was observed to be expanded due to wall edema with exudates and exerted pressure on the posterior side of the heart. These findings were also ascertained by contrast-enhanced chest computed tomography scanning. Technetium-99m-tetrofosmin myocardial scintigraphy clearly showed that coronary blood perfusion and left ventricular wall motion were quite normal. The characteristic electrocardiogram returned to a near-normal state, and the expanded stomach roll shrank back to its ordinary size after one week. Coronary angiography showed neither organic stenoses nor vasospasm. The physical pressure of the expanded stomach roll might have influenced the electrocardiogram findings.

Topics: Contrast Media; Coronary Angiography; Echocardiography; Electrocardiography; Esophagus; Humans; Middle Aged; Movement; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Stomach; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

We compared acute and late myocardial perfusion imaging using technetium-99m isotopes in 69 patients who had non-ST-elevation myocardial infarction. Among these patients, we found that the ischemic risk area was often large (19% of the left ventricle), and that 67% had significant myocardial salvage, defined as a >25% decrease in risk area, which was associated with an improved ejection fraction.

Topics: Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Ventricular arrhythmias have been shown to originate in the myocardial peri-infarct region due to irregular heterotopic conduction. Hypoperfused but viable myocardium is often localised in those areas and may be involved in the pathogenesis of arrhythmias. We tested the hypothesis that these myocardial perfusion/metabolism mismatches (MM) are significantly associated with ventricular arrhythmias in the chronic post infarction state.. 47 post infarction patients were included in the study. 33 suffered from ventricular arrhythmia whereas 14 did not. All patients underwent (99m)Tc tetrofosmin SPECT and (18)F-FDG PET. A region-of-interest(ROI)-analysis was used to assess viable myocardium based on predefined MM-criteria. Univariate analyses as well as a logistic regression model for the multivariate analysis were carried out.. 94% of the arrhythmic patients displayed at least one MM-segment as compared to 64% of the non-arrhythmic patients. MM-segments and arrhythmia showed a statistically significant relation (p = 0.018). The logistic regression model predicted the occurrence or absence of arrhythmia in 85% of all cases. Multivariate analysis gave consistent results, after adjusting for symptomatic chronic heart failure (CHF), aneurysms and age.. Our results support the hypothesis that hypoperfused but viable myocardium represents an arrhythmogenic substrate and is a relevant risk factor for developing ventricular arrhythmias following myocardial infarction. Therefore, the detection of MM-segments allows the identification of patients with a higher risk for future cardiac events.

Topics: Coronary Disease; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left; Ventricular Fibrillation

Evaluation of myocardial ischemia and viability is very important for the management of patients with a history of Kawasaki disease (KD). (99m)Tc-tetrofosmin myocardial perfusion scintigraphy combined with quantitative gated single photon computed emission tomography (QGS) gives us information, not only about perfusion, but also the percentage change in left ventricular wall thickness (%WT) and relative changes in left ventricular wall motion (LVM).. The subjects were 27 patients with a history of KD followed as outpatients at the National Cardiovascular Center, Osaka, Japan. Exercise-loaded QGS was performed on 21 patients, and dipyridamole- loaded QGS was performed in six patients younger than 7 years old.. Perfusion defects (PD) were observed in 12 patients. Of the 12 patients, four with old myocardial infarction (OMI) had decreased %WT. All patients with OMI showed a decrease in %WT in the areas where PD was seen on the image. The other eight patients without OMI showed no decrease in %WT. In non-infarcted cases, the %WT was normal in the PD-positive area.. It is possible to evaluate myocardial ischemia and viability in KD patients by comparing PD on the image with %WT determined by QGS using exercise or drug-loaded myocardial scintigraphy alone.

Topics: Adolescent; Adult; Child; Child, Preschool; Coronary Stenosis; Dipyridamole; Exercise Test; Female; Humans; Male; Mucocutaneous Lymph Node Syndrome; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tissue Survival; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Cardiac systolic (left ventricular ejection fraction) and diastolic (mitral inflow velocity pattern and/or mitral deceleration time) function were reported as predictors of clinical outcome or left ventricular remodeling in patients with acute myocardial infarction (AMI). Recently, a new index (Doppler-derived index combining systolic and diastolic myocardial performance; Tei index) for combined systolic and diastolic ventricular function has been reported to be a useful and convenient method for evaluation of global ventricular function. We therefore investigated the usefulness of the Tei index by echocardiography for evaluation of infarct size and clinical outcome in patients with AMI treated by successful primary angioplasty. We analyzed 10 age-matched control subjects and 43 consecutive patients with first AMI treated by successful primary angioplasty. The Tei index of the AMI patients was significantly greater than that of the control subjects (0.630 +/- 0.106 vs 0.375 +/- 0.036, P << 0.0001). Also, the Tei index showed a significant positive correlation with peak creatine kinase values and (99m)Tc-tetrofosmin scores. Moreover, multiple logistic regression analysis showed that the Tei index >>0.70 ( P = 0.0313, odds ratio = 14.14) was the only significant explanatory factor for cardiac death or developed congestive heart failure. The Tei index combining systolic and diastolic myocardial performance reflects infarct size and might be a predictor of clinical outcome in patients with AMI treated by successful primary angioplasty.

Topics: Angioplasty, Balloon, Coronary; Case-Control Studies; Echocardiography, Doppler; Female; Heart; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Prospective Studies; Radiopharmaceuticals; Regression Analysis; Stents; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

To assess whether quantification of myocardial systolic velocities by pulsed wave tissue Doppler imaging can differentiate between stunned, hibernating, and scarred myocardium.. Observational study.. Tertiary referral centre.. 70 patients with reduced left ventricular function caused by chronic coronary artery disease.. Pulsed wave tissue Doppler imaging was done close to the mitral annulus at rest and during low dose dobutamine; systolic ejection velocity (Vs) and the difference in Vs between low dose dobutamine and the resting value (DeltaVs) were assessed using a six segment model. Assessment of perfusion (with Tc-99m-tetrofosmin SPECT) and glucose utilisation (by 18F-fluorodeoxyglucose SPECT) was used to classify dysfunctional regions (by resting cross sectional echocardiography) as stunned, hibernating, or scarred.. 253 of 420 regions (60%) were dysfunctional. Of these, 132 (52%) were classified as stunned, 25 (10%) as hibernating, and 96 (38%) as scarred. At rest, Vs in stunned, hibernating, and scar tissue was, respectively, 6.3 (1.8), 6.6 (2.2), and 5.5 (1.5) cm/s (p = 0.001 by ANOVA). There was a gradual decline in Vs during low dose dobutamine infusion between stunned, hibernating, and scar tissue (8.3 (2.6) v 7.8 (1.5) v 6.8 (1.9) cm/s, p < 0.001 by ANOVA). DeltaVs was higher in stunned (2.1 (1.9) cm/s) than in hibernating (1.2 (1.4) cm/s, p < 0.05) or scarred regions (1.3 (1.2) cm/s, p = 0.001).. Quantitative tissue Doppler imaging showed a gradual reduction in regional velocities between stunned, hibernating, and scarred myocardium. Dobutamine induced contractile reserve was higher in stunned regions than in hibernating and scarred myocardium, reflecting different severities of myocardial damage.

Topics: Cicatrix; Coronary Disease; Diagnosis, Differential; Echocardiography; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

In the present study, we evaluated whether stenting is useful for cardiac overloading, using ANP, BNP, and (99m)Tc-tetrofosmin myocardial scintigraphy. It has been reported that coronary artery stenting is useful for cardiac functions for acute myocardial infarction (AMI). The subjects were 110 patients with AMI successfully treated by direct angioplasty. These patients were subgrouped into two groups: the S group (underwent stenting; 54 patients) and the P group (underwent POBA alone; 56 patients). Extent scores reflecting decreased myocardial blood flow were calculated at myocardial areas showing a radioactivity count of less than (-)2 x standard deviations compared to the database of normal subjects.The ratio of extent scores to defect scores (extent/defect ratio) was compared between the P and S groups. Both ANP and BNP levels in the S group were lower than in the P group at the chronic stage (1 and 3 months after reperfusion therapy). Moreover, the end-diastolic volume index from the left ventriculography 3 months after reperfusion therapy was significantly larger in the P than the S group. The extent/defect ratio was significantly lower in the P group (2.8 +/- 0.2) than the S group (3.5 +/- 0.3), suggestive of a microcirculation disorder. These results suggest that cardiac overloading and left ventricular remodeling are decreased more by stenting than by POBA alone, probably because stenting prevents decreased myocardial blood flow around the infarct myocardium.

Topics: Aged; Angioplasty, Balloon; Angioplasty, Balloon, Coronary; Coronary Vessels; Female; Heart; Hemodynamics; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Stents; Stroke Volume; Ventricular Function, Left

Increased lung uptake of thallium-201 in exercise myocardial perfusion imaging is a reliable marker of multivessel disease in patients with ischemic heart disease. This study investigated whether the lung-to-heart uptake ratio with techenetium-99m(99mTc)-tetrofosmin also provides valuable information to detect patients with multivessel disease.. Fifty-three consecutive patients (35 men, 18 women, mean age 66 +/- 11 years; single-vessel disease: 29, double-vessel disease: 16, triple-vessel disease: 8) with stable effort angina pectoris without prior myocardial infarction and 17 control subjects (12 men, 5 women, mean age 62 +/- 9 years) underwent exercise myocardial perfusion imaging with 99mTc-tetrofosmin and coronary angiography in January 2000 to December 2002. The lung-to-heart uptake ratio was calculated on an anterior projection before reconstruction of the exercise single photon emission computed tomographic images.. The mean lung-to-heart uptake ratio was 0.34 +/- 0.04, 0.38 +/- 0.07, 0.41 +/- 0.05, and 0.46 +/- 0.09, in patients with normal coronary, single-vessel disease, double-vessel disease, and triple-vessel disease, respectively. Significantly higher lung-to-heart uptake ratio was associated with more diseased vessels (p < 0.05). Multivessel disease could be detected with a sensitivity of 67% and a specificity of 74% if the cut-off point of the lung-to-heart uptake ratio was set as 0.4. Combining lung-to-heart uptake ratio with conventional myocardial perfusion imaging improved the sensitivity to detect multivessel disease to 83% and the specificity to 74%.. Lung-to-heart uptake ratio measured by exercise myocardial scintigraphy with 99mTc-tetrofosmin can provide clinically useful information to detect multivessel disease in patients with ischemic heart disease.

Topics: Angina Pectoris; Coronary Vessels; Exercise Test; Female; Heart; Humans; Lung; Male; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Soft-tissue attenuation artifacts generally appear as fixed perfusion-scan defects. Gated (99m)Tc-tetrofosmin SPECT may help differentiate myocardial infarction (MI) from artifacts, as fixed defects with decreased function (wall motion and thickening) probably represent MI, whereas attenuation artifacts represent preserved function.. Ungated stress and gated rest (99m)Tc-tetrofosmin SPECT was performed on 153 consecutive patients referred for evaluation of coronary artery disease. From stress and summed gated rest images, 107 patients (70%) were identified with isolated fixed defects. The function of the defects was assessed semiquantitatively from gated stress images. The findings were correlated with clinical (history or electrocardiographic Q waves) evidence of MI.. Of 62 patients with fixed defects and clinical MI, 60 (97%) had an abnormal defect function. Of 45 patients with no clinical MI, 16 (36%) had decreased function of the defect, possibly indicating silent MI. In 29 of the 45 patients (64%) with no clinical MI, defect function was normal. Because most (90%) fixed defects with normal systolic function occurred in men with inferior fixed defects (87%) or women with anterior fixed defects (3%), these were most likely attenuation artifacts. By reclassifying the condition of patients with fixed defects and normal function as normal, patients with unexplained fixed defects (no clinical MI) decreased from 29% to 10%.. Gating adds considerable value to (99m)Tc-tetrofosmin SPECT myocardial perfusion imaging in characterizing fixed defects and potentially improves test specificity.

Topics: Adenosine; Artifacts; Echocardiography; Electrocardiography; Exercise Test; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Myocardial Contraction; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

The relationship between the visual scores for wall motion (WM) and wall thickening (WT) of different left ventricular regions in patients with anterior and infero-lateral myocardial infarctions was evaluated using gated SPECT.. Ninety consecutive patients (79 men and 11 women; mean age 56 +/- 9 years) with previous myocardial infarction (33 anterior and 57 infero-lateral) were included. Left ventricular volumes and ejection fractions (EFs) were calculated from quantitative rest gated SPECT 99mTc tetrofosmin images by using the QGS automatic algorithm. Global and regional (anterior, septal, inferior and lateral) wall motion and wall thickening scores were calculated by consensus of three experienced observers.. The correlation between EFs and wall motion and wall thickening scores was better for WM scores in anterior (r=0.904, P<0.0001) than infero-lateral infarctions (r=0.674, P<0.0001). Correlation between wall motion and wall thickening scores was also better for anterior (r=0.898, P<0.0001) than for infero-lateral infarctions (r=0.750, P<0.0001). Except in septal regions, WT scores of the different regions were higher than WM scores (P<0.05) but the statistical significance was higher (P<0.001) in inferior and lateral regions of infero-lateral infarctions.. Visual global wall motion and wall thickening scores obtained by gated SPECT showed good correlation between them and with the EF, but differences were observed between regional wall motion and wall thickening, especially in inferior and lateral regions of patients with infero-lateral infarctions.

Topics: Aged; Electrocardiography; Female; Heart; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon

Topics: Aged; Aged, 80 and over; Female; Follow-Up Studies; Heart Ventricles; Humans; Male; Metabolic Clearance Rate; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Tissue Distribution; Ventricular Dysfunction, Left

The diagnostic value of myocardial perfusion scintigraphy in patients with left bundle branch block (LBBB) and previous acute myocardial infarction has not been evaluated.. To determine the utility of single photon emission computed tomography (SPECT) in patients with LBBB and previous acute myocardial infarction.. Seventy two consecutive patients with permanent LBBB and previous acute myocardial infarction were studied with stress-rest SPECT using 99mTc compounds. The same stress procedures were followed in all patients: (1) exercise alone when it was sufficient; (2) exercise plus simultaneous administration of dipyridamole if exercise was insufficient.. In 26 of 28 patients (93%) who had a Q wave acute myocardial infarct before the development of LBBB, there was concordance between abnormal Q waves and rest SPECT in the localisation of myocardial necrosis (kappa = 0.836; p = 0.0001). In 48 patients who had coronary angiography, the positive predictive value of exercise (+dipyridamole) myocardial SPECT for the diagnosis of left anterior descending coronary artery stenosis was 93%, for left circumflex coronary artery stenosis, 96%, and for right coronary artery stenosis, 89%. Specificity values were 83%, 91%, and 69%, respectively. However, sensitivity (69%, 64%, and 89%) and negative predictive values (48%, 46%, and 82%) were suboptimal.. Rest myocardial perfusion SPECT with technetium compounds is useful for localising healed myocardial infarction in patients with LBBB, and exercise (+dipyridamole) SPECT has a high positive predictive value and specificity for the diagnosis of coronary stenosis in these patients.

Topics: Aged; Analysis of Variance; Bundle-Branch Block; Coronary Stenosis; Dipyridamole; Exercise Test; Female; Humans; Male; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

The purpose of this study was to investigate the clinical significance of the reverse redistribution (RR) phenomenon on technetium-99m ((99m)Tc)-tetrofosmin myocardial single photon emission computed tomography (SPECT) performed at rest. Twenty-five patients underwent myocardial SPECT 3 weeks after the onset of acute myocardial infarction. Myocardial images were acquired at 40 min (early) and 4 h (delayed) after the injection of 740 MBq of (99m)Tc-tetrofosmin. The regional myocardial uptake of the tracer in 26 segments of the left ventricular (LV) wall was visually scored from 0 (no activity) to 3 (normal activity), and then the RR was defined as a decrease of more than 1 point in the activity score on the delayed image compared with that on the early image. Regions with an activity score of 3 on both the early and delayed images were defined as normal, and those with a score of 0 or 1 on the early image were considered to have a fixed defect. The regional myocardial (99m)Tc-tetrofosmin uptake and washout rate were also quantitatively assessed in each region. In addition, exercise stress electrocardiograph-gated SPECT with (99m)Tc-tetrofosmin was performed within 1 week of the rest study, and the percent count increase (%CI) during myocardial contraction in each corresponding region was studied. RR was observed in 18 of the 25 patients. The regional washout rate of (99m)Tc-tetrofosmin was significantly higher in the RR regions (45.0+/-3.8%) than in either the normal regions (36.4+/-4.1%, p<0.001) or in those with a fixed defect (39.7+/-3.9%, p<0.001). The %CI in the RR regions (10.4+/-10.4%) was significantly less than that in the normal regions (23.5+/-10.1%, p<0.001); however, no significant difference was found between the RR regions and those with a fixed defect (8.0+/-7.2%). In patients with acute myocardial infarction, the regions showing the RR phenomenon on (99m)Tc-tetrofosmin SPECT have severely impaired LV wall contraction after exercise.

Topics: Aged; Aged, 80 and over; Electrocardiography; Exercise; Female; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Angiography; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

High-risk patients with acute coronary syndrome are difficult to distinguish from low-risk patients with chest pain in the emergency room. Technetium-99m (99mTc) tetrofosmin single-photon emission computed tomography (SPECT) was investigated to exclude high-risk patients with chest pain in the emergency room.. 99mTc-tetrofosmin SPECT was evaluated using a four-point scoring system in 228 patients (144 men, 84 women, mean age 68 +/- 12 years) with chest pain. Negative was defined as the myocardial segments with a defect score (DS) of < 2. The patients were divided into two groups; the negative group with DS < 2 (n = 78) and the positive group with DS > or = 2 (n = 150). Cardiac events (cardiac death, acute myocardial infarction and refractory angina) were evaluated within 30 days of onset. ST-segment elevation or depression > or = 0.1 mV was defined as positive in electrocardiography. The results of SPECT were compared with those of electrocardiography, transthoracic echocardiography and serum cardiac markers (troponin T and creatine kinase-MB) in 95 patients.. The negative group had very few cardiac events (three patients with refractory angina) (3.8%). The negative predictive value of cardiac events evaluated by electrocardiography was calculated as 83.1%, whereas the negative predictive value by SPECT was 96.2% (p < 0.01). In addition, the negative predictive value of acute myocardial infarction by SPECT was 100%. The negative predictive values of cardiac events evaluated by SPECT, electrocardiography, transthoracic echocardiography and serum cardiac markers were 95.8%, 81.5% (vs 99mTc-tetrofosmin; NS), 84.9% (NS) and 60.4% (p < 0.05), respectively.. 99mTc-tetrofosmin SPECT is a useful method to exclude high-risk patients among patients with chest pain in the emergency room.

Topics: Aged; Aged, 80 and over; Chest Pain; Echocardiography, Transesophageal; Electrocardiography; Emergency Service, Hospital; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Troponin T

Topics: Coronary Angiography; Coronary Vessels; Humans; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

There are no published data in the literature on the scintigraphic perfusion pattern in patients with myocardial infarction (MI) and normal coronary arteries (NCA).. To evaluate myocardial perfusion imaging in a series of patients with MI and NCA.. Twenty-seven patients who had developed a MI and had NCA were studied. As a control group we included 27 patients with a recent MI and coronary artery disease (CAD). All patients underwent stress/rest tetrofosmin myocardial perfusion SPECT within 6 months from MI.. In patients with NCA tetrofosmin stress images revealed 41 hypoperfused segments in 17 patients (63%). On rest images, 13 segments remained unchanged, 4 showed partial reperfusion, 10 normalized and 14 worsened. Additionally, there were 18 new hypoperfused segments in nine patients. Therefore, perfusion worsened at rest in 18 patients (67%) (32 segments). Overall, at rest there were 49 hypoperfused segments in 22 patients (81%). In patients with CAD, stress images revealed 71 hypoperfused segments. On rest images, 39 segments remained unchanged, 16 showed partial reperfusion and 12 normalized. Four segments worsened at rest and only four patients (15%) showed new perfusion defects at rest.. Myocardial perfusion with tetrofosmin might appear considerably worse at rest than at stress in patients with MI and NCA. Specifically, a reverse perfusion pattern in the infarct area is a frequent finding and is likely to be due to residual tissue viability. We postulate that in these patients the hyperemic response to exercise may mask resting underperfusion areas.

Topics: Adult; Aged; Case-Control Studies; Coronary Angiography; Coronary Circulation; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Infarction; Necrosis; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

This study evaluated the influence of extra-cardiac accumulation in technetium-99m-tetrofosmin myocardial single photon emission computed tomography (SPECT) imaging.. Technetium-99m-tetrofosmin myocardial SPECT was performed in 247 patients from 1997 to 1999. To evaluate the sensitivity, 42 patients with inferior infarction were selected. To evaluate the specificity, 32 patients with no significant perfusion defect and low pretest likelihood (< 15%) of coronary artery disease and 13 patients with normal coronary angiography were selected. Firstly, the SPECT raw data were evaluated according to the effects of diaphragm and breast, the position and the degree of accumulation of the liver, gall bladder and intestine. Then, the myocardial tracer uptake was scored semiquantitatively from 0 (normal) to 4 (perfusion defect) in the 13 segments of the left ventricle.. The specificity was 86.7% and the sensitivity was 92.8%. Perfusion abnormality of the inferior wall was observed in 6 of 45 patients with a low pretest likelihood of coronary artery disease. These 6 patients were classified into the false positive group, and the other 39 patients were classified into the true negative group. The liver position and the liver accumulation on the stress images were significantly higher in the false positive group than in the true negative group (p < 0.001), but only the liver position on the rest images was significantly higher in the false positive group (p < 0.001). By estimating the defect 1 point lower for the high-positioned liver patients, specificity improved from 86.7% to 100% and sensitivity did not change.. Inferior perfusion defect on technetium-99m-tetrofosmin myocardial SPECT of high-positioned liver patients needs to be evaluated with special caution.

Topics: Aged; False Negative Reactions; False Positive Reactions; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

We report the estimation of left ventricular systolic pressure (LVSP) by a left ventricular (LV) volume-time curve obtained from electrocardiogram (ECG) gated 99mTc-tetrofosmin single photon emission computed tomography (SPECT) using quantitative gated SPECT (QGS). LVSP was calculated based on the following parameters: LV volumes, velocity and acceleration of LV contraction, aortic valve area and density of blood. The first three parameters can be derived from ECG gated SPECT. In 16 patients, the LV volume-time curve was obtained from ECG gated SPECT by using QGS. LVSP was estimated by the above-mentioned theory. The values of estimated peak LVSP were compared with those measured from a pressure transducer. There was a correlation between the values of peak LVSP estimated by the LV volume-time curve and those measured by pressure transducer (r=0.69, P<0.01). Using QGS, LVSP and the systolic LV pressure-volume relationship could be estimated by the LV volume-time curve.

Topics: Algorithms; Angina Pectoris; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Models, Cardiovascular; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Ventricular Function, Left; Ventricular Pressure

This patient was a 70-year-old man had acute subendocardial infarction in the inferior wall. 123I-BMIPP myocardial scintigraphy showed no accumulation in the myocardium. 123I-MIBG myocardial scintigraphy on the early and delay images and 99mTc-tetrofosmin myocardial scintigraphy at rest showed slightly decreased accumulation of the tracer in the apical region and in middle inferior wall of the left ventricle, indicating subendocardial infracted area. In the examinations of CD36 in platelets and monocytes, the patient had negative CD36 in platelets and monocytes, and type I CD36 deficiency was diagnosed. We supposed that no 123I-BMIPP accumulation may be related closely to type I CD36 deficiency.

Topics: 3-Iodobenzylguanidine; Aged; CD36 Antigens; Endocardium; Fatty Acids; Heart; Humans; Iodine Radioisotopes; Iodobenzenes; Male; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

Both 2-dimensional echocardiography and myocardial perfusion imaging (MPI) with technetium-99m based agents have been used to identify patients in the emergency department with myocardial infarction (MI). However, the inclusion of small numbers of patients in prior studies limits the accurate assessment of sensitivity of the 2 techniques.. Gated MPI was used as part of the initial triage process in patients initially considered at low to moderate risk for acute coronary syndromes (no ST elevation or depression). Patients diagnosed with MI also underwent echocardiography. MPI results were considered positive if there was a perfusion defect associated with abnormal wall motion or thickening, and echocardiographic results were considered positive if there were segmental wall motion abnormalities or ejection fraction of less than 40%.. Both tests were performed on 141 patients. The sensitivities for MI for echocardiography (91%; 95% CI, 86%-95%) and MPI (89%; 95% CI, 83%-94%) were similar. Patients who had either negative echocardiographic results (peak creatine kinase level [CK], 325 +/- 206 vs 582 +/- 614 U/L; P =.003) or negative MPI results (peak CK, 313 +/- 227 vs 590 +/- 620 U/L; P =.001) had smaller MIs as estimated with peak CK values. Ejection fraction was highly correlated between the 2 techniques (r = 0.82; P <.001).. Both echocardiography and MPI have a high sensitivity for identifying patients in the emergency department who have MI. False negative studies with either technique were associated with small MIs.

Topics: Biomarkers; Cardiology Service, Hospital; Clinical Enzyme Tests; Creatine Kinase; Echocardiography; Emergency Service, Hospital; False Negative Reactions; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Sestamibi

Left ventricular (LV) volume and ejection fraction (LVEF) derived from ECG-gated myocardial SPECT data are reproducible and objective. Those quantitative values, however, interacted according to varied factors such as a frame number per R-R interval, tracers, and processing-algorisms. A decrease of frame number per R-R interval yields underestimation of end-diastolic volume and overestimation of end-systolic volume, resulting in underestimation of LVEF. Thus, it is important to change a frame number per R-R interval by the examination purpose. A good correlation of LVEF is usually obtained, independent of a combination of tracer and processing-algorism. On the other hand, LV volume does not always show linearity between combinations of tracer and processing-algorism. An extraction of myocardial edge using QGS program is deteriorating in patients with small LV below 20 ml. It is crucial to assess LV functional values derived from ECG-gated SPECT data as clinical indices, taking the varied effects into consideration.

Topics: Algorithms; Cardiac Volume; Gated Blood-Pool Imaging; Humans; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Administration of dipyridamole produces angina and ST depression in 20%-30% and 6%-34% of patients, respectively. This study aimed to evaluate the clinical implications of the presentation of angina and/or ST depression during the administration of dipyridamole in the study of coronary heart disease by myocardial perfusion SPECT (MPS).. The study population is constituted by 593 consecutive patients without left branch block or ventricular pacemaker rhythm who were referred to our service to undergo MPS with dipyridamole. A SPECT was performed after the administration of 99mTc-tetrosfosmine and drug stimulation with dipyridamole (0.142 mg/kg/min for 4 minutes). A coronariography was performed in 338 patients (57%). The frequency of clinical and electrical positivity and their relationship with the MPS and the coronariography were studied.. The rate of angina and ST depression was 32% (n = 190) and 10% (n = 58), respectively. Myocardial perfusion defects were observed in 465 patients (78%), and signs of scintigraphic ischemia in 311 (52%). The patients with ST depression presented a higher frequency of perfusion defects (93% vs 76%, p = 0.0012) and scintigraphic ischemia (89% vs 49%, p < 0.0001). In addition, perfusion defects in more than one territory were observed in these patients in a higher percentage (53% vs 34%, p = 0.0036). Among the patients who underwent cardiac catheterization, those who had a ST depression had a greater extension of coronary heart disease (1.8 +/- 1.2 vs 1.3 +/- 1.0 diseased vessels, respectively. p = 0.0100) and a higher frequency of multivessel disease (61% vs 43%, p = 0.0380). Those patients who had clinical positivity showed a scintigraphic ischemia more frequently (66% vs 47%, p < 0.0001), however no statistically significant differences were observed between the presence of patients with perfusion defects or in the extension of these defects as well as in the number of diseased vessels in the coronariographic study.. During the administration of dipyridamole, the ST depression is associated with more frequent scintigraphic ischemia, larger extension of perfusion defects and more diseased vessels. The appearance of angina is associated with scintigraphic ischemia, but it is not necessarily associated with the extension of perfusion defects or greater number of diseased vessels.

Topics: Angina Pectoris; Convalescence; Coronary Angiography; Coronary Circulation; Coronary Disease; Dipyridamole; Electrocardiography; False Negative Reactions; False Positive Reactions; Heart; Humans; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Patients with permanent ventricular pacemakers (PP) are a difficult subgroup to assess in the study of coronary artery disease. The objective of this study was to evaluate the diagnostic value of the myocardial perfusion scintigraphy with 99mTC-Tetrofosmin (Tc-Tf) and stimulus with dipyridamole in patients with PP and suspected coronary artery disease.. Fourteen patients with suspected coronary artery disease and without structural cardiopathy, who underwent Tc-Tf and cardiac catheterization, were studied retrospectively. Sensitivity, specificity, predictive values and Kappa index were calculated for the diagnosis of coronary artery disease, multivessel disease, and for each one of the coronary arteries (left anterior descending, right coronary, and circumflex). In addition, the correlation between the number of territories with perfusion defects and the number of diseased vessels was studied.. In regards to the diagnosis of coronary artery disease, sensitivity, specificity, positive predictive value, negative predictive value and the Kappa index were 100%, 50%, 83%, 100% and 0.55, respectively. For multi-vessel disease, these values were 83%, 64%, 64%, 83% and 0.43 respectively. The correlation coefficient between the number of territories with perfusion defects and the number of diseased vessels was 0.61 (p = 0.02). In the diagnosis of anterior descending disease, sensitivity and specificity were 83% and 88% respectively. For the right coronary artery, these values were 100% and 44% and for the circumflex artery 38% and 83%, respectively.. In patients with PP and suspected coronary artery disease, myocardial perfusion scintigraphy with Tc-Tf and stimulus with dipyridamole is of great value in the diagnosis of coronary artery disease and in the assessment of its extension.

Topics: Aged; Aged, 80 and over; Angina Pectoris; Arrhythmias, Cardiac; Cardiac Catheterization; Comorbidity; Coronary Angiography; Coronary Circulation; Dipyridamole; Female; Humans; Male; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Pacemaker, Artificial; Predictive Value of Tests; Radiopharmaceuticals; Risk Factors; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

The identification of severely dysfunctional but viable myocardium is of particular importance for the selection of patients with depressed left ventricular function who will benefit from coronary revascularization. Assessment of inotropic reserve with dobutamine has recently been used for this purpose. This study compared the accuracy of low-dose dobutamine stress gated myocardial SPECT (DS SPECT) with the accuracy of dobutamine stress echocardiography (DSE) and resting perfusion SPECT for the identification of viable myocardium in patients with previous myocardial infarction.. Resting and low-dose dobutamine (7.5 microg/kg/min) gated (99m)Tc-tetrofosmin SPECT and echocardiography and resting (18)F-FDG PET were prospectively studied in 23 patients with previous myocardial infarction and severely depressed regional function. Twenty-one of them were successfully studied with each technique. The left ventricular wall was divided into 14 segments to assess wall motion using a 5-point scale. PET viability was defined as FDG uptake >/= 50% of the maximum uptake in a region with normal wall motion. For DS SPECT and DSE studies, viable myocardium was defined as hypokinetic areas with > or = 1 point improvement in wall motion. For resting perfusion SPECT, viable myocardium was defined as hypokinetic areas with a relative uptake > or = 50% of the maximum uptake.. Of a total of 294 segments, 55 had severe resting dyskinesis. Thirty-four segments were identified as viable on FDG PET, and 21 segments were identified as nonviable. Eleven segments were inadequately visualized with DSE, including 5 segments in the apex. Sensitivities (78% vs. 76%) and specificities (94% vs. 100%) were similar for DSE and DS SPECT, with a concordance of 86% (kappa = 0.72). DS SPECT and perfusion SPECT did not significantly differ with respect to sensitivities (76% vs. 85%, respectively). However, specificity was significantly higher for DS SPECT than for perfusion SPECT (100% vs. 52%, respectively, P < 0.05).. This study indicated that DS SPECT correlates well with DSE in the assessment of viability. In addition, gated SPECT can evaluate regional wall motion, even in areas inadequately assessed by echocardiography. DS SPECT may also provide additional information for identifying viable myocardium, which is often overestimated by routine perfusion scans.

Topics: Aged; Dobutamine; Echocardiography; Electrocardiography; Exercise Test; Female; Fluorodeoxyglucose F18; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prospective Studies; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents; Ventricular Function, Left

Myocardial perfusion imaging with 99mTc-labeled agents immediately after reperfusion therapy can underestimate myocardial salvage. It is also conceivable that delayed imaging is useful for assessing the risk area. However, to our knowledge, very few studies have sequentially evaluated these image changes. We conducted 99mTc-tetrofosmin (TF) and 123I-beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) SPECT before and after reperfusion to treat acute myocardial infarction and quantified changes in TF myocardial accumulation and reverse redistribution.. Seventeen patients with a first myocardial infarction underwent successful reperfusion. We examined SPECT images obtained at the onset (preimage), those acquired 30 min (early image) and 6 h (delayed image) after TF injection, and images acquired 1, 4, 7, and 20 d after reperfusion (post-1-d, post-4-d, post-7-d, and post-20-d image, respectively). We also examined BMIPP SPECT images after 7 +/- 1.8 d (BMIPP image). Polar maps were divided into 48 segments to calculate percentage uptake, and time course changes in segment numbers below 60% were observed as abnormal area. Moreover, cardiac function was analyzed by gated TF SPECT on 1 and 20 d after reperfusion.. In reference to the abnormal area on the early images, the post-1-d image was significantly improved compared with the preimage (P < 0.01) as was the post-7-d image compared with the post-1-d and post-4-d images (P < 0.05, respectively). However, post-20-d and post-7-d images did not significantly differ. Therefore, the improvement in myocardial accumulation reached a plateau 7 d after reperfusion. On the other hand, the abnormal area on the delayed images was significantly greater (P < 0.01) compared with that on the early images from 4 to 20 d after reperfusion, as the value was essentially constant. The correlations of the abnormal area between the preimage and the post-7-d delayed image, the preimage and the BMIPP image, and the post-7-d delayed image and the BMIPP image were very close (r = 0.963, r = 0.981, and r = 0.975, respectively). Gated TF SPECT revealed that the left ventricular ejection fraction was not significantly different (P = not significant) between 1 and 20 d after reperfusion, but regional wall motion was significantly different after reperfusion (P < 0.05).. These results suggest that the interval between reperfusion therapy and TF SPECT should be 7 d to evaluate the salvage effect and that TF delayed and BMIPP images are both useful in estimation of risk area.

Topics: Aged; Angioplasty, Balloon, Coronary; Fatty Acids; Female; Humans; Iodine Radioisotopes; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

We investigated the prognostic value of 99mTc-Tetrofosmin myocardial SPECT (99mTc-TF) in dysfunctional multivessel coronary disease patients who underwent revascularization (RV) or only medical treatment (MT).. In 78 coronary patients with 2-3 diseased vessels and left ventricular ejection fraction (EF) <= 40% (24 10%), we have assessed the extension of the stress perfusion defect, and percent of reversibility (R) by quantification of stress-rest myocardial SPECT 99mTc-TF bull's eyes (2 days-protocol), lung/heart ratio (LH) calculated in the original stress SPECT images, and EF by equilibrium radionuclide ventriculography obtained at 24 h. A R value >= 8% was used to identify viable (V) patients. A total of 28 patients underwent RV and 50 only received MT. After a mean follow-up of 22.9 20 months (3-60), they were considered as coronary events (CE): cardiac death, non-fatal infarction and heart transplant. CE rate was 20.5% (16/78).. No significant differences were found in the pre-revascularization study characteristics, except a significantly higher mean R value in RV (10.6 9.5%) than in MT patients (6.4 7.8%) p: 0.03, and the main difference was that RV patients showed less CE 2/28 (7%) than the MT group 14/50 (28%) p: 0.02. The CE rate was lower in V patients who underwent RV (6%) than in V patients with MT (45%) p: 0.03, but no significant difference was obtained in non-V patients between RV (7%) and MT (16%) groups. In viable patients, the corresponding survival curves (Kaplan-Meier) showed a CE-free survival at 5 years of 79% in patients RV and of 42% in MT patients, p: 0.03, without significant difference in non-V patients.. Patients with viable myocardium by myocardial SPECT have a good prognosis after revascularization, and show higher risk of CE if they are only medically treated. Myocardial viability is an indispensable assessment in prognosis evaluation and, above all, in therapeutic decision making in dysfunctional multivessel coronary disease patients.

Topics: Adult; Aged; Cell Survival; Coronary Circulation; Coronary Disease; Death, Sudden, Cardiac; Exercise Test; Female; Follow-Up Studies; Gated Blood-Pool Imaging; Heart; Heart Transplantation; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

To evaluate the relation between ST-segment analysis and microvascular reperfusion in patients with acute myocardial infarction (AMI), we studied 51 patients with first AMI who were successfully treated by percutaneous transluminal coronary angioplasty (PTCA). The lead showing the greatest ST-segment elevation on the 12-lead electrocardiogram (ECG) was serially investigated until 24 hours after PTCA. Successful reperfusion was determined by technetium-99m tetrofosmin single-photon emission computed tomography. Impaired reperfusion (group 1: < 4 change in the sum of the defect score from before to immediately after PTCA) was observed in 24 patients, and successful reperfusion (group 2) was observed in 27 patients. Although ST-segment elevation was reduced significantly at 30 minutes after PTCA in group 2 (2.2 +/- 1.4 to 1.7 +/- 1.3 mm, p = 0.01), there was no significant change in group 1 (1.9 +/- 1.9 to 2.4 +/- 1.7 mm). Ten of 14 patients (71%) with persistent ST-segment elevation (DeltaST > 0 mm change in ST segment from before to 30 minutes after PTCA > 0) were in group 1, whereas 23 of 37 patients (62%) with ST-segment resolution (DeltaST < or = 0) were in group 2. The sensitivity and specificity of persistent ST-segment elevation for predicting impaired microvascular reperfusion were 42% and 85%, respectively. Thus, persistent ST-segment elevation 30 minutes after primary PTCA was a highly specific electrocardiographic marker of impaired reperfusion in patients with AMI.

Topics: Aged; Angioplasty, Balloon, Coronary; Coronary Angiography; Electrocardiography; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Resting (99m)Tc-tetrofosmin (TF) uptake was compared with thallium ((201)Tl) rest-redistribution (R-RD) uptake in patients with previous myocardial infarction (MI) and significant coronary artery disease (CAD) to assess the ability of TF to detect viable myocardium. We studied 30 patients (21 males and nine females, mean age 53.9+/-12.5 years) with prior MI and left ventricular dysfunction who had been referred for coronary revascularization procedures. Myocardial single photon emission computed tomography (SPECT) images were obtained 1 h after injection of 750 MBq of TF. Within 1 week of the TF study, R-RD (201)Tl SPECT imaging was performed after injection of 111 MBq of (201)Tl . Quantitative analysis was performed in 21 segments. Viability was defined as the presence of tracer uptake greater than 50% of the peak activity on baseline studies or after reversibility. There was significant correlation between the quantitative regional R-RD (201)Tl activity and the resting TF activity (r=0.88, P<0.001). Quantitative analysis showed that the uptake of the two tracers was comparable in normal segments as well as in segments with fixed (201)Tl defects. In contrast, in segments with reversible (201)Tl defects, TF uptake was significantly greater than resting (201)Tl uptake, but lower than R-RD (201)Tl uptake. There were 52 segments (47% of the severely reduced segments on TF images) that showed no viability with TF, but were viable on the redistribution (201)Tl studies. We conclude that quantitative resting TF SPECT underestimates the presence of viable myocardium compared with R-RD (201)Tl imaging on the basis of using 50% of the peak activity as the viability threshold.

Topics: Adult; Aged; Biological Transport; Coronary Disease; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left; Wound Healing

To assess whether 15-(p-[iodine-123] iodophenyl)-3-(R,S) methylpentadecanoic acid (BMIPP) imaging can identify previous ischemic areas, BMIPP SPECT was performed in patients with acute chest pain to compare its findings with those of technetium-99m-tetrofosmin (tetrofosmin) SPECT and coronary angiography.. Basic studies indicate that BMIPP can identify previous ischemia as reduced tracer uptake.. This study prospectively enrolled 111 consecutive patients with acute chest pain without myocardial infarction. Tetrofosmin SPECT was performed at rest within 24 h after the last episode of chest pain. Coronary angiography and BMIPP SPECT were also performed on the following day.. Sixty-four of the 87 patients with coronary stenosis or spasm showed BMIPP abnormalities corresponding to the areas of coronary abnormalities (sensitivity 74%), whereas only 33 of them showed perfusion abnormalities (sensitivity 38%) (p < 0.001). Of 24 patients [corrected] without coronary stenosis or spasm, 22 showed normal BMIPP SPECT (specificity = 92%) [corrected] and 23 showed normal tetrofosmin SPECT (sensitivity = 96%) [corrected]. Coronary stenosis was more often seen in the group with abnormal tetrofosmin/abnormal BMIPP (82%) and with normal tetrofosmin/abnormal BMIPP (69%) than in the group with normal tetrofosmin/normal BMIPP (36%) (p < 0.05). Coronary spasm was observed more often in the group with abnormal tetrofosmin/abnormal BMIPP (83%) and with normal tetrofosmin/abnormal BMIPP (90%) than in the group with normal tetrofosmin/normal BMIPP (27%) (p < 0.05). The extent and severity scores of tetrofosmin and BMIPP in the patients with organic stenosis were significantly higher than those of patients with no organic stenosis or spasm (p < 0.0001).. These data indicate that BMIPP SPECT may specifically identify previous ischemic lesions due to coronary stenosis or spasm in patients with acute chest pain.

Topics: Aged; Angina Pectoris; Chest Pain; Coronary Angiography; Coronary Stenosis; Coronary Vasospasm; Diagnosis, Differential; Fatty Acids; Female; Humans; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Tomography, Emission-Computed, Single-Photon

To study changes in left ventricular function and infarct size during long-term follow-up after acute myocardial infarction treated with primary angioplasty.. From 1996 to 1998, 100 consecutive patients were treated with primary angioplasty for acute ST-elevation myocardial infarction. Angioplasty was successful in 95% of the patients. Global left ventricular ejection fraction (LVEF) was determined by radionuclide ventriculography before discharge, after 6 weeks and after a mean follow-up time of 20 months. Infarct size was assessed by technetium 99m-tetrofosmin myocardial perfusion tomography (SPECT) at rest, performed at the same time intervals.. Mean LVEF was 56% at discharge, 55% after 6 weeks and 57% after 20 months of follow-up. No significant improvement in LVEF was observed. Only 8% of the patients at follow-up had LVEF lower than 40%. After 1 week, a mean perfusion defect of 19% was measured by SPECT. After 6 weeks and 20 months of follow-up, the mean perfusion defects were reduced to 14% (p < 0.001) and 15%, respectively.. Left ventricular function was well preserved with a mean LVEF of 57% 20 months after primary angioplasty for acute myocardial infarction. No significant change in LVEF was observed from 1 week after angioplasty to follow-up. Infarct sizes as assessed by SPECT imaging with tetrofosmin were reduced from 1 to 6 weeks, but did not change further during long-term follow-up. The reduction in the perfusion defects over time was probably due to gradual relief of stunning.

Topics: Angioplasty, Balloon, Coronary; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Postoperative Period; Radionuclide Ventriculography; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

This study was designed to elucidate the usefulness of crosstalk correction for dual-isotope simultaneous acquisition (DISA) with 99mTc-tetrofosmin and FDG in estimating myocardial perfusion and viability.. Eighteen patients with coronary artery disease were studied. First, SPECT was performed with a low-energy high-resolution collimator after a single injection of 99mTc-tetrofosmin (single 99mTc-tetrofosmin). Second, PET and DISA with an ultra-high-energy collimator were performed after glucose loading and an injection of FDG. DISA was designed to operate with simultaneous 3-channel acquisition, and weighted scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak was performed by modification of an existing dual-window technique. The FDG SPECT images were compared with the images obtained by PET. Both crosstalk-corrected and uncorrected 99mTc-tetrofosmin images were generated and compared with the single 99mTc-tetrofosmin images.. Regional percentage uptake of FDG agreed well between DISA and PET. However, regional percentage uptake of 99mTc-tetrofosmin was generally higher on the uncorrected 99mTc-tetrofosmin images than on the single 99mTc-tetrofosmin images, especially in areas of low flow (percentage count of 99mTc-tetrofosmin > or = 50%). The crosstalk correction contributed to improving the agreement between regional percentage uptakes and significantly improved the detectability of myocardial perfusion-metabolism mismatching.. With 3-channel acquisition and weighted-scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak, DISA with 99mTc-tetrofosmin and FDG is feasible for assessing regional myocardial perfusion and viability.

Topics: Aged; Coronary Disease; Female; Fluorodeoxyglucose F18; Gamma Cameras; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Regression Analysis; Tomography, Emission-Computed, Single-Photon

In-vivo visualisation and quantification of the extent and time-frame of cell death after acute myocardial infarction would be of great interest. We studied in-vivo cell death in the hearts of patients with an acute myocardial infarction using imaging with technetium-99m-labelled annexin-V-a protein that binds to cells undergoing apoptosis.. Seven patients with an acute myocardial infarction and one control were studied. All patients were treated by percutaneous transluminal coronary angioplasty (six primary and one rescue), resulting in thrombolysis in myocardial infarction (TIMI) III flow of the infarct-related artery. 2 h after reperfusion, 1 mg annexin-V labelled with 584 MBq Tc-99m was injected intravenously. Early (mean 3.4 h) and late (mean 20.5 h) single-photon-emission computed tomographic (SPECT) images of the heart were obtained. Routine myocardial resting-perfusion imaging was also done to verify infarct localisation.. In six of the seven patients, increased uptake of Tc-99m-labelled annexin-V was seen in the infarct area of the heart on early and late SPECT images. No increased uptake was seen in the heart outside the infarct area. All patients with increased Tc-99m-labelled annexin-V uptake in the infarct area showed a matching perfusion defect. In a control individual, no increased uptake in the heart was seen.. Increased uptake of Tc-99m-labelled annexin-V is present in the infarct area of patients with an acute myocardial infarction, suggesting that programmed cell death occurs in that area. The annexin-V imaging protocol might allow us to study the dynamics of reperfusion-induced cell death in the area at risk and may help to assess interventions that inhibit cell death in patients with an acute myocardial infarction.

Topics: Aged; Angioplasty, Balloon, Coronary; Annexin A5; Apoptosis; Cell Death; Coronary Circulation; Coronary Vessels; Female; Follow-Up Studies; Heart; Humans; Image Processing, Computer-Assisted; Injections, Intravenous; Male; Middle Aged; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Protein Binding; Radiopharmaceuticals; Reperfusion Injury; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

The relationship between myocardial perfusion, fatty acid metabolism, and cardiac functional recovery were investigated by using single photon emission computed tomography (SPECT) with 99mTc-1,2-bis[bis(2-ethoxyethyl)phosphino]ethane (tetrofosmin: TF) and lodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) in patients with myocardial infarction. We examined myocardial SPECT in 18 patients with acute myocardial infarction (AMI) underwent successful reperfusion therapy within 24 hours from onset. TF myocardial SPECT (early and delayed images) and BMIPP (early image) SPECT were performed 2 weeks after onset of AMI, and regional TF and BMIPP defect scores of the infarct area were scored visually by a 4-point system. There was a significant correlation between the defect score of the TF delayed image, BMIPP image and SD/chord (indicator of regional wall motion abnormalities on left ventriculograms) at subacute phase (TF: r = -0.592, p = 0.011, BMIPP: r = -0.643, p = 0.004). Good correlations were also found between the defect score of the TF delayed image, the BMIPP image and the SD/chord at chronic phase (TF: r = -0.491, p = 0.037, BMIPP: r = -0.599, p = 0.007). Furthermore, there was a significant correlation between the improvement of SD/chord (acute to chronic phase) and the degree of reverse redistribution score of TF (r = 0.735, p = 0.022), and discordance score between TF and BMIPP (r = 0.691, p = 0.037). In conclusion, resting BMIPP and TF myocardial SPECT performed in patients with subacute phase AMI were shown to be useful in predicting improvement of left ventricular function at chronic phase.

Topics: Aged; Fatty Acids; Female; Humans; Iodine Radioisotopes; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

This study assessed a dual-head coincidence gamma camera (hybrid PET) equipped with single-photon transmission for myocardial fluorine-18 fluorodeoxyglucose (FDG) imaging by comparing this technique with conventional positron emission tomography (PET) using a dedicated ring PET scanner. Twenty-one patients were studied with dedicated FDG ring PET and FDG hybrid PET for evaluation of myocardial glucose metabolism, as well as technetium-99m tetrofosmin single-photon emission tomography (SPET) to estimate myocardial perfusion. All patients underwent transmitted attenuation correction using germanium-68 rod sources for ring PET and caesium-137 point sources for hybrid PET. Ring PET and hybrid PET emission scans were started 61+/-12 and 98+/-15 min, respectively, after administration of 154+/-31 MBq FDG. Attenuation-corrected images were reconstructed iteratively for ring PET and hybrid PET (ac-hybrid PET), and non-attenuation-corrected images for hybrid PET (non-ac-hybrid PET) only. Tracer distribution was analysed semiquantitatively using a volumetric vector sampling method dividing the left ventricular wall into 13 segments. FDG distribution in non-ac-hybrid PET and ring PET correlated with r=0.36 (P<0.0001), and in ac-hybrid PET and ring PET with r=0.79 (P<0.0001). Non-ac-hybrid PET significantly overestimated FDG uptake in the apical and supra-apical segments, and underestimated FDG uptake in the remaining segments, with the exception of one lateral segment. Ac-hybrid PET significantly overestimated FDG uptake in the apical segment, and underestimated FDG uptake in only three posteroseptal segments. A three-grade score was used to classify diagnosis of viability by FDG PET in 136 segments with reduced perfusion as assessed by SPET. Compared with ring PET, non-ac-hybrid PET showed concordant diagnoses in 80 segments (59%) and ac-hybrid PET in 101 segments (74%) (P<0.001). Agreement between ring PET and non-ac-hybrid PET was best in the basal lateral wall and in the apical-septal segment (80%-100%), and lowest in the apical, supra-apical and posteroseptal segments (41%-55%). Ac-hybrid PET showed highest agreement in the lateral wall (89%-100%), and lowest agreement in the apical and the basal septal segments (59%-67%). In conclusion, non-uniform attenuation correction with singles transmission significantly improves the diagnostic accuracy of myocardial dual-head gamma camera coincidence imaging with FDG. However, results equivalent to those obtained with r

Topics: Adult; Aged; Female; Fluorodeoxyglucose F18; Gamma Cameras; Glucose; Heart Ventricles; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardium; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed

To investigate the role of the cardiac sympathetic nervous system in left ventricular remodelling, 50 patients with first-time acute myocardial infarction (AMI) and patency of the infarct-related artery after reperfusion underwent quantitative iodine-123 metaiodobenzylguanidine (MIBG) imaging at 4 days and 4 weeks (n=42), and quantitative technetium-99m tetrofosmin imaging at 2 days after AMI. They also underwent both ventriculography and coronary angiography on admission and about 4 weeks after AMI. On the basis of left ventricular end-systolic volume (LVESV), patients were divided into two groups. Patients with LVESV dilatation (n=20) had a significantly lower ejection fraction (P<0.003) and a significantly higher severity score of 99mTc-tetrofosmin (P<0.04), and total severity (P<0.01), delta extent (P<0.007) and delta severity (P<0.0008) scores of MIBG than patients without LVESV dilatation (n=30). delta severity score of MIBG was directly correlated with change in LVESV at 4 weeks (r=0.63, P<0.0001). Stepwise linear discriminant function analysis showed that delta severity score of MIBG (P<0.0002) was the only discriminator of LVESV dilatation. Patients with LVESV dilatation had higher regional washout rates in both the infarct and the non-infarct zones than patients without such dilatation. Furthermore, no MIBG parameters changed significantly between 4 days and 4 weeks after AMI. In reperfused AMI, delta severity score of MIBG was related to the degree of ventricular dilatation and was the only powerful discriminator of ventricular dilatation. These results suggest that cardiac sympathetic nervous abnormality might contribute to left ventricular remodelling in reperfused AMI. MIBG imaging may allow identification of reperfused AMI patients at high risk for left ventricular remodelling.

Topics: 3-Iodobenzylguanidine; Adult; Aged; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Reproducibility of Results; Sympathetic Nervous System; Ventricular Function, Left

Evaluation of myocardial perfusion in the early stage of acute myocardial infarction (MI) is clinically important for adjunctive therapies to minimize infarct size. To determine the role of early scintigraphic detection of impaired myocardial reperfusion after primary coronary angioplasty (PTCA) in patients with acute MI, semiquantitative technetium-99m tetrofosmin single-photon emission tomographic (SPET) imaging was performed before primary PTCA (before; area at risk), 60 min after PTCA (after) and at 1 month (1 M; final infarct) in 35 patients with acute MI. The left ventricle was divided into 13 segments and the defect score was calculated as the sum of the perfusion defect of each segment, from 3 (complete defect) to 0 (normal perfusion). A significant myocardial perfusion change after PTCA was defined as a change in the defect score (before minus after PTCA) of >/=4. The echocardiographic asynergic score was defined as the number of asynergic (severe hypokinetic or akinetic) segments corresponding to the analogous segments on SPET images, and recovery of wall motion was calculated as absolute change in the asynergic score (before PTCA minus 1 M). Among the 35 patients, 15 (43%) had a change in the defect score of <4 (no reflow: group 1) while 20 had a change in the defect score of >/=4 (reflow: group 2). There were no significant differences between the two groups with respect to the time between admission to PTCA, revascularization time, collateral grade or Thrombolysis in Myocardial Infarction (TIMI) flow grade before PTCA. Despite the lack of a difference in area at risk between the two groups (group 1 = 12.8+/-4.3 and group 2 = 15.1+/-4.7), final infarct size in group 1 was significantly larger compared with that in group 2 (8.1+/-4.3 vs 4.9+/-3.0, P<0.001). Recovery of wall motion was significantly smaller in group 1 than in group 2 (4.3+/-1.7 to 3.5+/-1.5 vs 4. 1+/-2.1 to 1.6+/-1.6, P<0.001). In conclusion, a small change (<4) in defect score (scintigraphic no-reflow phenomenon) after primary PTCA indicates persisting impaired myocardial perfusion or irreversible cellular damage just after PTCA which is associated with poor recovery of wall motion, as compared with that observed in cases of reflow (>/=4 in defect score).

Topics: Aged; Angioplasty, Balloon, Coronary; Female; Humans; Male; Myocardial Contraction; Myocardial Infarction; Myocardial Reperfusion Injury; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Time Factors; Tomography, Emission-Computed, Single-Photon

We examined reverse redistribution (RR) of Tc-99m-tetrofosmin after a single injection in patients with acute myocardial infarction (AMI). Tc-99m-tetrofosmin myocardial SPECT was performed in 28 patients with AMI 10-14 days after the onset. Myocardial images were obtained 30 min and 180 min after the injection of 740 MBq of Tc-99m-tetrofosmin. The left ventricular wall was divided into 9 segments. Regional myocardial uptakes of Tc-99m-tetrofosmin were scored by 4-point scoring (0 = normal, 1 = mildly reduced, 2 = moderately reduced, and 3 = defect). RR was defined as an increase of more than 1 in the regional score in images at 180 min. RR of Tc-99m-tetrofosmin was observed in 17 of 20 patients with direct PTCA and 3 of 8 patients without reperfused therapy. RR was observed in 61 of all 252 segments. Coronary angiography performed 1 month later revealed that the infarct-related artery was patent in 19 of 20 patients (95%) with RR and in 3 of 8 patients (37.5%) with persistent defects (PD) (p < 0.05). In segment-by-segment analysis, the incidence of regional wall motion abnormality I month later was reduced in regions with RR compared to those with PD (p < 0.0001). In conclusion, RR of Tc-99m-tetrofosmin was frequently observed in patients with successful direct PTCA. As the segments with RR showed signs of preserved function 1 month later, this phenomenon may reflect a salvaged myocardium in AMI.

Topics: Adult; Aged; Coronary Angiography; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

We present a modified (non-segmental) method for quantification of regional left ventricular dysfunction using gated myocardial perfusion SPET. Gated SPET is increasingly used to obtain complementary information on local perfusion and to assess the relevance of deficits in segmental count densities (attenuation vs perfusion deficit). The non-segmental approach was motivated by a hypothetical limitation regarding the validity of commonly used methods of quantitative wall thickening (WT) analysis. These methods are all based on segmental analysis, which could cause underestimation of 'true' contractile dysfunction in perfusion defects that do not have a strict segmental distribution. SPET images gated in eight time bins 60 min after the injection of 740 MBq 99Tcm-tetrofosmin or 99Tcm-sestamibi were recorded on a triple-headed camera in 20 normal subjects and in 16 patients within 2 weeks and again 3 months after myocardial infarction. Normal limits of wall thickening, calculated from pooled wall thickening profiles obtained in normal subjects, were used to identify and quantify areas with abnormal wall thickening in patients with coronary artery disease. The method was validated against data obtained from contrast ventriculography (CVG) and tested for reproducibility. The reproducibility of the method was excellent: r = 0.98 (WTsev measure 1 = 1.03WTsev measure 2 - 0.01). The localization of wall thickening abnormalities detected by gated SPET correlated well with the localization of regions with abnormal wall motion (WM) identified by CVG. The severity of the regional myocardial dysfunction assessed by gated SPET was closely correlated with the severity of the regional myocardial dysfunction derived from CVG: r = 0.85 (WMsev = 2.55WTsev + 2.30). Furthermore, a good correlation between the total wall thickening severity score and the global left ventricular ejection fraction (LVEF) was observed early and late after myocardial infarction: r = 0.80 (WTsev = -0.4LVEF + 0.46). We conclude that quantitative analysis of regional wall thickening assessed from gated SPET myocardial perfusion scintigraphy is a reliable parameter for regional ventricular function. Categorizing wall thickening abnormalities quantitatively may be helpful in assessing small changes in regional function that may occur between sequential gated SPET images.

Topics: Adult; Aged; Case-Control Studies; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

This study qualified the severity and localization of reverse redistribution of technetium-99 m (Tc)-tetrofosmin rest imaging. Both Tc-tetrofosmin and thallium-201 (Tl) rest imaging with early images and delayed images were obtained in the subacute phase of myocardial infarction in 21 patients with first anterior myocardial infarction and with successful transluminal angioplasty (including stenting). Relative myocardial uptake (%uptake), degree of reverse redistribution (%), and washout rate (%) were evaluated quantitatively in 6 left ventricular segments (inferoseptal, anteroseptal, anterior, anterolateral, lateral, inferolateral and inferior) by circumferential profile analysis. The percentage reverse redistribution in the infarct area was larger in Tc-tetrofosmin imaging than in Tl imaging (p = 0.013). Reverse redistribution was most prominent in the anterior wall (anterior > anteroseptal > inferoseptal, p = 0.020). This suggests that infradiaphragmatic scatter is unlikely as the mechanism of reverse redistribution. The washout rate of Tc-tetrofosmin in the infarct area (reverse redistribution area) was higher than that in the normal area (non-reverse redistribution area), and was also higher than the washout rate of Tl imaging in the infarct area. The %uptake of delayed images in the infarct area was larger in Tc-tetrofosmin than that in Tl imaging, whereas %uptake of early images did not differ. The percentage reverse redistribution did not correlate with the degree of collateral circulation and the residual stenosis. In conclusion, reverse redistribution of Tc-tetrofosmin was more prominent in the infarct area, and this was due to the relatively lower uptake of reverse redistribution of Tc-tetrofosmin than delayed Tl images.

Topics: Angioplasty, Balloon, Coronary; Collateral Circulation; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Thallium Radioisotopes

To evaluate segmentary reverse defects (RD) (uptake higher in exercise than in rest) in 99mTc-tetrofosmin SPECT.. 1,124 consecutive SPECT studies were reviewed and 80 (7%) segmentary RD were identified. Thirty-eight patients with RD attributed to artifact (extra cardiac uptake) were excluded. Thus, 42 patients (3.6%), 21 with and 21 without previous infarct, were studied. Thirteen out of 21 RD in patients without previous infarct corresponded to inferior region and 8 to the anterior region. In three out of 8 patients in whom the coronary angiography was performed, the coronary arteries were angiographically normal and 5 had stenosis of between 50% to 70% of coronary arteries corresponding to RD. Of the 21 RD in patients with previous infarct, the RD site corresponded to the same region of the necrosis (15 inferior and 6 anterior). All had viability criteria (uptake higher than 40% in more than 50% of the region) in rest uptake SPECT quantification. In nine out of 11 patients in whom a coronary angiography was carried out, patency of the artery responsible for the infarct was verified.. 3.6% of segmentary RD, which were not attributed to the artifact, were observed in myocardial perfusion 99mTc-tetrofosmin SPECT studies. Half of these cases corresponded to regions without previous infarct and with normal coronary arteries or non-severe coronary stenosis. The remaining corresponded to regions with previous infarct and with viability criteria.

Topics: Convalescence; Coronary Angiography; Coronary Disease; Evaluation Studies as Topic; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

The aim of this study was to determine the utility of 99Tcm-tetrofosmin cardiac imaging in patients with previous myocardial infarction and with significant coronary artery disease (CAD) compared with that of 201Tl cardiac imaging. Sixteen patients (14 males, 2 females) were studied by same-day exercise-rest 99Tcm-tetrofosmin imaging and exercise, rest and reinjection 201Tl cardiac imaging. For each study, semi-quantitative visual analysis was performed in 20 segments using a 4-point scale. The regional distribution and defect reversibility with the two tracers were compared with the results of coronary angiography. A total of 320 segments were analysed. There was a statistically significant concordance between the numbers of fixed and reversible segments in both studies in myocardial segments supplied by totally occluded coronary arteries (Group 1), as well as in segments supplied by significantly stenosed coronary vessels (Group 2). The exercise and rest uptake of both 99Tcm-tetrofosmin and 201Tl in myocardial segments supplied by totally occluded coronary arteries with poor collateral flow was significantly lower compared with segments supplied by totally occluded coronary arteries with efficient collateral flow (P < or = 0.05). When the uptake of both tracers was analysed according to each major vascular territory, the mean exercise and rest uptake grades of 99Tcm-tetrofosmin and 201Tl were similar. There was also no significant difference in defect reversibility between the two tracers. Discordant results were observed in the territory of the right coronary artery in Group 1 (mean exercise grade of 99Tcm-tetrofosmin = 2.26 +/- 0.7 and of 201Tl = 1.92 +/- 0.8; P < or = 0.001) and in Group 2 (mean grade of 99Tcm-tetrofosmin = 0.79 +/- 0.65 and of 201Tl = 0.95 +/- 0.65; P < or = 0.05). The results of the present study indicate that the overall diagnostic utility of 99Tcm-tetrofosmin in the identification of individual stenosed vessels is comparable with 201Tl in both patients with totally occluded coronary arteries and those with significantly stenosed vessels. The regional distribution of both tracers was lower in myocardial segments supplied by totally occluded coronary arteries with poor collateral flow.

Topics: Adult; Aged; Coronary Disease; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

We sought to evaluate the clinical use and cost-analysis of acute rest technetium-99m (Tc-99m) tetrofosmin single-photon emission computed tomographic (SPECT) myocardial perfusion imaging in patients with chest pain and a normal electrocardiogram (ECG).. Current approaches used in emergency departments (EDs) for treating patients presenting with chest pain and a nondiagnostic ECG result in poor resource utilization.. Three hundred fifty-seven patients presenting to six centers with symptoms suggestive of myocardial ischemia and a nondiagnostic ECG underwent Tc-99m tetrofosmin SPECT during or within 6 h of symptoms. Follow-up evaluation was performed during the hospital period and 30 days after discharge. All entry ECGs, SPECT images and cardiac events were reviewed in blinded manner and were not available to the admitting physicians.. By consensus interpretation, 204 images (57%) were normal, and 153 were abnormal (43%). Of 20 patients (6%) with an acute myocardial infarction (MI) during the hospital period, 18 had abnormal images (sensitivity 90%), whereas only 2 had normal images (negative predictive value 99%). Multiple logistic regression analysis demonstrated abnormal SPECT imaging to be the best predictor of MI and significantly better than clinical data. Using a normal SPECT image as a criterion not to admit patients would result in a 57% reduction in hospital admissions, with a mean cost savings per patient of $4,258.. Abnormal rest Tc-99m tetrofosmin SPECT imaging accurately predicts acute MI in patients with symptoms and a nondiagnostic ECG, whereas a normal study is associated with a very low cardiac event rate. The use of acute rest SPECT imaging in the ED can substantially and safely reduce the number of unnecessary hospital admissions.

Topics: Electrocardiography; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; ROC Curve; Tomography, Emission-Computed, Single-Photon

We measured the uptake of technetium-99m tetrofosmin (99m Tc) and thallium-201 (201 TI) in areas of healed transmural myocardial infarction and in the regions of acute peri-infarction ischemia.. Anesthetised pigs with a 1-month old transmural infarction elicited by permanent ligature of the left anterior descending (LAD) coronary artery below the first branch underwent one hour of proximal LAD occlusion followed by injection of 99m Tc-tetrofosmin and 201TI either in the left atrium (GI, n= 19) or in the jugular vein (GII, n = 6). Twelve other pigs (GIII) with similar acute peri-infarction ischemia received 99m Tc-tetrofosmin and 201Tl into the left ventricle during cardiocirculatory arrest to rule out the effect of coronary collaterals. Radiotracer counting was determined in samples from normal, acute ischemic and necrotic regions.. Uptake of 99m Tc-tetrofosmin and 201 Tl was greater in the infarct scar (median % of normal tissue: 20 for 99m Tc and 8.6 for 201 Tl in GI; 22 and 15 in GII) than in acute ischemic myocardium (3.2 and 2.5 in GI; 6.4 and 3.3 in GII). Radiotracer injection in arrested hearts (GIII) depicted a similar pattern (median % of injected dose: 6.2 for 99m Tc and 10 for 201Tl in the scar; 2.3 and 4.0 in acute ischemia; 2.9 and 3.5 in normal tissue). The infarcted region showed connective tissue and lack of viable myocardium.. A 1-month old infarct scar with no viable myocardial tissue can take up significant fractions of 99mTc-tetrofosmin and 201Tl even in the absence of coronary collateral perfusion. Data suggest that the infarct scar can extract these radiotracers from the intraventricular blood.

Topics: Animals; Myocardial Infarction; Myocardial Ischemia; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radioisotopes; Radionuclide Imaging; Radiopharmaceuticals; Swine; Thallium Radioisotopes

99Tcm-tetrofosmin is a new myocardial perfusion agent with the advantage that it can be reconstituted at room temperature. Because two separate injections are required for rest and stress images, a separate-day imaging protocol with one injection each day would be optimal in terms of image quality. From the logistical point of view, a 1 day protocol may be more convenient for the majority of those referred as outpatients. The main aim of this study was to determine whether the detection of myocardial ischaemia would be impeded by the use of a 1 day protocol instead of a 2 day protocol. A secondary aim was to establish the relative diagnostic accuracy of the two imaging strategies. 99Tcm-tetrofosmin SPET imaging was performed in 157 patients. Sixty-nine (44%) patients were administered 250 MBq (7 mCi) 99Tcm-tetrofosmin at rest followed 4 h later by 750 MBq (21 mCi) during stress (the 1 day protocol), whereas 88 (56%) patients had rest and stress imaging studies on two separate days, receiving a 500 MBq (14 mCi) dose of 99Tcm-tetrofosmin on each occasion (the 2 day protocol). With the 1 day protocol, 135 of 621 (22%) abnormal segments (i.e. both reversible and persistent defects) were observed, compared with 195 of 792 (25%) segments with the 2 day protocol. Also, the occurrence of reversible defects only did not differ between the two protocols (both 9%). The sensitivity for the detection of coronary artery disease was 83 and 90% for the 1 and 2 day protocols respectively. We conclude that the 1 and 2 day protocols provide similar scintigraphic information and are equally sensitive and specific for the detection of coronary artery disease. Therefore, the imaging protocol can be adjusted as appropriate for the patient in question.

Topics: Adult; Aged; Aged, 80 and over; Angina Pectoris; Chest Pain; Coronary Angiography; Coronary Vessels; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radiopharmaceuticals; Rest; Sensitivity and Specificity; Time Factors; Tomography, Emission-Computed, Single-Photon

In patients with coronary artery disease (CAD), differentiation between severely ischemic but potentially viable myocardium and irreversibly infarcted tissue is clinically important, particularly when revascularization procedures are considered. Although thallium (TI) cardiac imaging has been shown to be a good tool for investigating myocardial viability in CAD, this tracer shows physical limitations, such as a low photon energy and long half-life. We assessed the results of a rest TI-201/stress Tc-99m tetrofosmin protocol in subjects with prior anterior myocardial infarction. All of the patients had an akinetic or dyskinetic area and more than 75% stenosis in the left anterior descending artery. All of the patients underwent revascularization after the examination. We evaluated the improvement in wall motion after revascularization using the centerline method with contrast left ventricular angiography. Fourteen patients showed reversible defects with the rest TI-201/stress Tc-99m tetrofosmin protocol or in additional TI-201 24 h redistribution images. All 14 patients showed a significant improvement in wall motion after revascularization. Dual-isotope rest TI-201/stress Tc-99m tetrofosmin single photon emission tomography data, acquired separately, may give fast and complete information about myocardial perfusion during stress and at rest, and on about myocardial viability.

Topics: Aged; Coronary Artery Bypass; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Myocardial Ischemia; Myocardial Reperfusion; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Thallium Radioisotopes; Tissue Survival; Tomography, Emission-Computed, Single-Photon

Standard exercise thallium-201 (201Tl)-redistribution protocols for the detection of coronary artery disease take about 4 h to complete. This is inconvenient for both patients and staff. The higher energy technetium-99m (99Tcm) emissions permit immediate imaging after 201Tl with minimal crosstalk. This study assessed exercise gated planar 201Tl scintigraphy (55 MBq) followed by rest gated planar 99Tcm-tetrofosmin scintigraphy (250 MBq) in 32 patients. The results showed a high sensitivity for the detection of coronary disease (100%) in this highly selective group of patients. In order to diagnose myocardial infarction accurately, it was necessary to view the gated 201Tl images and assess regional wall motion in a defect zone. This gave a specificity of 88% and a sensitivity of 71% for the prediction of myocardial infarction on the angiographic ventriculogram. Stress 201Tl/rest 99Tcm-tetrofosmin is a useful short protocol for patients unable to complete the full 4-h exercise 201Tl-redistribution study.

Topics: Adult; Aged; Clinical Protocols; Coronary Angiography; Coronary Disease; Evaluation Studies as Topic; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Sensitivity and Specificity; Thallium Radioisotopes

The aim of this study was to assess the potential role of 99mTc-tetrofosmin cardiac tomography in detecting totally occluded or severely stenosed coronary arteries.. Thirty-three patients (32 men, 1 woman; mean age, 52 +/- 9 yr) with chronic coronary artery disease (CAD) and left ventricular dysfunction (ejection fraction 40% +/- 12%) underwent resting 99mTc-tetrofosmin SPECT and coronary arteriography within 2 wk. Regional distribution of 99mTc-tetrofosmin activity was compared with the coronary anatomy. Tracer uptake was quantitatively analyzed in 22 segments for each patient. The activity in each segment was expressed as a percent of the peak activity.. A significant relationship between the degree of coronary artery stenosis and 99mTc-tetrofosmin uptake was observed (p = -0.64, p < 0.001). Technetium-99m-tetrofosmin uptake was lower (p < 0.001) in segments with 100% coronary occlusion with poor collateral flow (53% +/- 17%) compared to segments supplied by a vessel with 50%-99% coronary stenosis (75% +/- 20%) or a normal noncritically stenosed artery (85% +/- 10%). Furthermore, 99mTc-tetrofosmin uptake was lower (p < 0.01) in segments with 100% coronary occlusion with poor (53% +/- 17%) compared to those with good collateral flow (70% +/- 20%).. These results demonstrate that quantitative analysis of resting 99mTc-tetrofosmin regional uptake detects the majority of segments supplied by occluded coronary arteries with poor collateral flow and suggest that this tracer may be helpful in the diagnosis of acute myocardial infarction.

Topics: Adult; Coronary Angiography; Coronary Disease; Coronary Vessels; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

The determination of the myocardium at risk before intervention and the change in that region after intervention constitute a promising measurement tool for the assessment of acute therapy. A new 99mTc labeled myocardial blood flow tracer, 99mTc tetrofosmin, is expected to enable the evaluation of myocardium at risk because of the absence of redistribution. This preliminary study was performed in 9 patients with acute coronary syndrome (4 unstable angina and 5 acute myocardial infarction) to investigate whether recovery of perfusion by tetrofosmin imaging parallels mechanical improvement. Tetrofosmin imaging was performed acutely and 3-30 days later. Visual analysis of defect severity was assessed in both studies. Segments with improvement in perfusion were accompanied by significant wall motion recovery compared with normal and unimproved segments (delta WMI: normal segments 0.40 +/- 0.67, improved segments 1.79 +/- 0.68, unimproved segments -0.15 +/- 0.16, p < 0.01 for improved segments compared with other groups), suggesting the efficacy of this tracer for the assessment of the acute therapy. These data suggest that 99mTc tetrofosmin imaging is a useful method for the assessment of the myocardial area at risk and the efficacy of acute therapy in acute myocardial infarction and unstable angina.

Topics: Aged; Aged, 80 and over; Angina, Unstable; Angioplasty, Balloon, Coronary; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging

First-pass radionuclide angiography (FPRNA) was performed with the new myocardial perfusion agent 99mTc-1,2,bis[bis(2-ethoxyethyl)phosphino] ethane (99mTc-PPN 1011) on stress and at rest. One hour after that, myocardial perfusion was counted by 99mTc-PPN 1011 SPECT. Left ventricular ejection fraction (LVEF) obtained by FPRNA correlated with that by multigated image with 99mTc-HSAD (r = 0.94, n = 11). The reduction of left ventricular function under the exercise (delta LVEF) and the increase of severity score (delta Severity score) have a good relation (r = 0.88) in 7 patients with prior myocardial infarction. Thus 99mTc-PPN 1011 appears to be an ideal radiopharmaceutical for evaluation of ventricular function and myocardial perfusion.

Topics: Aged; Cardiomyopathy, Dilated; Coronary Circulation; Exercise Test; Heart; Humans; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left; Ventriculography, First-Pass

The determination of the myocardium at risk before intervention and the change in that region after intervention constitute a promising measurement tool for the assessment of acute therapy. We used 99mTc PPN-1011 in 4 patients with acute myocardial ischemia (2 patients with acute myocardial infarction, 2 unstable angina) and subsequent successful reperfusion. All 4 patients had perfusion defect on the pre-reperfusion image. Perfusion abnormality on post-reperfusion image was all improved significantly compared with pre-reperfusion image, suggesting the efficacy of acute treatment in acute myocardial ischemia. We conclude that 99mTc PPN-1011 scintigraphy is useful method for the assessment of myocardial area at risk and the efficacy of PTCA/PTCR in myocardial infarction and unstable angina.

Topics: Aged; Angina, Unstable; Angioplasty, Balloon, Coronary; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Risk; Thrombolytic Therapy