technetium-tc-99m-tetrofosmin and Coronary-Restenosis

Usefulness of diastolic dysfunction after adenosine stress for detecting coronary stenosis has not been defined. The diagnostic accuracy of a combination of myocardial perfusion and diastolic function, as defined by prolongation of time to peak-filling rate (TTPF)/R-R and myocardial perfusion alone for the detection of coronary restenosis, was evaluated..  We used rest (201)Tl/ adenosine stress (99m)Tc-tetrofosmin myocardial perfusion singlephoton emission computed tomography (SPECT) in 70 patients. Patients were divided into the following 4 groups: 20 patients with normal SPECT without stent (Control group), 20 patients showing normal SPECT without coronary restenosis (Group 1), 16 patients showing significant coronary restenosis and myocardial ischemia (Group 2a) and 14 patients showing significant coronary restenosis without myocardial ischemia (Group 2b). The TTPF, which was calculated by quantitative gated SPECT (QGS)/R-R, was not different between after stress and at rest in Control group (0.18±0.02 vs 0.19±0.04, P=NS). The TTPF/R-R after stress was significantly lower than that at rest in Group 1 (0.17±0.02 vs 0.18±0.03, P<0.05), but TTPF/R-R after stress was significantly higher than that at rest in Groups 2a and 2b (0.22±0.03 vs 0.16±0.03, P<0.001 in Group 2a and 0.19±0.02 vs 0.16±0.02, P<0.001 in Group 2b, respectively). Diagnostic accuracy improved from 72% to 92% when prolongation of TTPF/R-R was taken into account (P<0.001).. Diastolic dysfunction after stress was an accurate marker for detecting significant restenosis following stent implantation.

Topics: Adenosine; Aged; Anti-Arrhythmia Agents; Coronary Restenosis; Electrocardiography; Exercise Test; Female; Humans; Male; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Radiography; Radiopharmaceuticals; Stents; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

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

If coronary artery was treated with optimal stent implantation, myocardial perfusion in the territory supplied by a dilated coronary artery should be not reversible. However, several studies have demonstrated reversible perfusion in the territory supplied by a coronary artery with an optimally implanted stent. The main objective of this study was to evaluate the incidence of reversible defects detected by M-SPECT early after optimal PTCA with stent implantation. Its second objective was to determine the predictive value of detecting reversible defects after stent implantation for late restenosis.. About 66 patients that underwent M-SPECT within 24 h of successful PTCA with stent implantation were included. All patients were followed up clinically and angiographically. The incidence of reversible perfusion defects on M-SPECT and the rate of late restenosis in target coronary arteries were evaluated retrospectively.. Reversible perfusion defects on M-SPECT were observed in 26% of the patients and in 36% of lesions following successful PTCA with stent implantation. The incidence of late restenosis was significantly higher in patients and lesions with reversible perfusion defects (47% vs. 18%). According to binary logistic regression analysis, the presence of a reversible perfusion defects was the only independent predictor of late restenosis.

Topics: Adult; Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Circulation; Coronary Restenosis; Coronary Stenosis; Female; Humans; Logistic Models; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Retrospective Studies; Risk Assessment; Stents; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

The aim of this study was to assess the accuracy of stress 99m technetium tetrofosmin myocardial perfusion imaging for the diagnosis of in stent stenosis (ISS).. We studied 72 patients who underwent exercise or dobutamine stress 99m technetium tetrofosmin imaging, 0.9+/-0.5 years after percutaneous coronary interventions in which stents were deployed. Coronary angiography was performed within 3 months of the stress test. ISS was defined as > or =50% stenosis in a coronary segment with previous stenting. Significant coronary artery disease (CAD) was defined as > or =50% stenosis within or outside the stented coronary segment.. The stent was deployed in 1 coronary artery in 52 patients, and in 2 coronary arteries in 20 patients (a total of 92 detected in 42 (58%) patients (51 stents). Reversible perfusion abnormalities were present in 34 of patients with ISS (sensitivity=81%, CI 70-94). Regional sensitivity for diagnosis of stenosis per stent was 76% (CI 65-88), specificity was 83% (CI 71-94) and accuracy was 79% (CI 69-85). Reversible perfusion abnormalities were detected in > or =2 vascular distributions in 15 of 22 patients with multi-vessel CAD and in 5 of 50 patients without (sensitivity for identifying multivessel CAD=68%, CI 50-89; specificity=90%, CI 82-98; and accuracy=83%, CI 75-90).. Stress 99m technetium tetrofosmin myocardial perfusion imaging is a useful non-invasive technique for the diagnosis of in stent stenosis and extent of CAD in patients with previous percutaneous coronary artery interventions.

Topics: Adrenergic beta-Agonists; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Artery Disease; Coronary Circulation; Coronary Restenosis; Dobutamine; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Research Design; Sensitivity and Specificity; Stents; Time Factors; Tomography, Emission-Computed, Single-Photon

A high number (30%-50%) of reversible defects have been detected early after coronary balloon angioplasty. Inadequate luminal enlargement despite a good angiographic appearance has been suggested as a possible mechanism of these perfusion abnormalities, and some reports have shown better coronary flow reserve after coronary stent implantation than after balloon dilatation. The primary objective of this study was to evaluate the frequency of early ischemic defects detected by maximal exercise (plus dipyridamole) with (99m)Tc-tetrofosmin SPECT after successful coronary angioplasty with stent implantation. A secondary objective was to determine the prognostic value of these early ischemic defects.. Thirty patients without previous myocardial infarction who successfully underwent 1-vessel coronary angioplasty with stent implantation were studied. Maximal-exercise (99m)Tc-tetrofosmin myocardial SPECT, with simultaneous dipyridamole if exercise was suboptimal, was performed at 6 +/- 1 d (mean +/- SD) after percutaneous transluminal coronary angioplasty. At 8 +/- 3 mo, all patients were followed up clinically, and 77% of them underwent follow-up angiography.. The percentage of stenosis decreased from 68.5% +/- 12.6% of luminal diameter to 9.3% +/- 8.8% after stent implantation, and minimal luminal diameter increased from 0.89 +/- 0.36 mm to 2.85 +/- 0.45 mm. Mild-to-moderate reversible myocardial defects in the territory of the dilated artery were detected in 5 patients (17%), with no angiographic or procedural differences occurring between them and patients without ischemic defects. At follow-up, the target lesion revascularization rates depending on the presence or absence of early ischemic defects were 40% and 8%, respectively (P = 0.18). Angiographic restenosis occurred in 3 of 4 patients who had early ischemic defects and underwent follow-up angiography and in 3 of 19 patients who had no early ischemic defects and underwent follow-up angiography (restenosis rate, 75% and 16%, respectively; P < 0.05).. Coronary angioplasty with stent implantation is associated with a 17% rate of ischemic defects early after the procedure. Patients with early myocardial perfusion defects after coronary stent implantation had a high rate of restenosis.

Topics: Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Dipyridamole; Exercise Test; Female; Follow-Up Studies; Humans; Incidence; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Stents; Time Factors; Tomography, Emission-Computed, Single-Photon