technetium-tc-99m-tetrofosmin and regadenoson

In patients undergoing regadenoson SPECT myocardial perfusion imaging (MPI), it is unknown how soon and at which dose intravenous aminophylline can be administered to reverse regadenoson-related adverse effects without blunting stress-induced myocardial ischemia.. In patients undergoing regadenoson-stress SPECT-MPI, the intravenous administration of 75 mg of aminophylline as early as 90 seconds after radioisotope injection does not seem to attenuate the burden of myocardial ischemia.

Topics: Administration, Intravenous; Aged; Aminophylline; Double-Blind Method; Drug Administration Schedule; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Purines; Pyrazoles; Tomography, Emission-Computed, Single-Photon

Regadenoson, a selective A2A adenosine receptor agonist, was evaluated for tolerability and effectiveness as a pharmacological stress agent for detecting reversible myocardial hypoperfusion when combined with single-photon emission computed tomography (SPECT).. Adenosine and dipyridamole are nonselective adenosine agonists currently used as pharmacologic stressors. Despite proven safety, these agents often cause undesirable side effects and require a continuous infusion.. This Phase II, multicenter, open-label trial was conducted in 36 patients who had demonstrated ischemia on a 6-min adenosine SPECT imaging study within the previous 2 to 46 days. Patients received regadenoson as a rapid intravenous bolus dose of 400 microg (n = 18) or 500 microg (n = 18). The radiopharmaceutical was then delivered within one minute. The SPECT images were acquired in a standard manner and uniformly processed at a central laboratory. Regadenoson and adenosine studies were presented in random order and interpreted blindly with a 17-segment model by three observers. Additionally, quantitative analysis was performed with 4D-MSPECT software (University of Michigan, Ann Arbor, Michigan).. Overall agreement for the presence of reversible hypoperfusion was 86%. The 400-mug dose was better tolerated. Overall, regadenoson was well-tolerated; side effects (e.g., chest discomfort, flushing, dyspnea) were generally mild in severity and self-limiting. High-grade atrioventricular block and bronchospasm were not observed.. Regadenoson is well-tolerated and seems as effective as adenosine for detecting and quantifying the extent of hypoperfusion observed with SPECT perfusion imaging. Phase III clinical trials are now underway, given the promise of regadenoson's reduced side effects and simplicity of bolus administration.

Topics: Adenosine; Adenosine A2 Receptor Agonists; Electrocardiography; Heart; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Pilot Projects; Purines; Pyrazoles; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

Topics: Humans; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Takotsubo Cardiomyopathy; Tomography, Emission-Computed, Single-Photon

Regadenoson Stress Echocardiography (RSE) can detect myocardial ischemia, and its diagnostic accuracy should be evaluated. We sought to investigate the agreement between RSE and gated-SPECT myocardial perfusion imaging (MPI) and appraise its diagnostic accuracy. Consecutive patients (n = 202) referred for non-invasive evaluation of myocardial ischemia, with (38.6%) or without a previous coronary artery disease (CAD) diagnosis, were enrolled. Both tests were performed simultaneously. Invasive coronary angiography (CA) is considered the gold standard. The mean age was 70.9 (9.8) years, and 59.9% were male. The prevalence of cardiovascular risk factors (arterial hypertension [81.7%], diabetes mellitus [37.6%], hypercholesterolemia [71.8%], and smoking [18.8%]) was high. Forty-four patients (21.8%) had a non-interpretable electrocardiogram, 15 (34.1%) of them were a result of ventricular paced-rhythm, while 29 (65.9%) were a result of advanced left ventricular branch block. The overall agreement between both diagnostic techniques was good: Gwet's AC1 0.66 (CI95% 0.55 to 0.76), and it was higher in patients without a previous CAD diagnosis: 0.76 (CI95% 0.65 to 0.87). In the biased sample (those who underwent CA), RSE and nuclear study sensitivity was 0.50 and 0.78 and specificity was 0.75 and 0.75, respectively. We noted a dramatic reduction in sensitivity for RSE after debiasing (debiased sensitivity of 0.16), and the negative predictive value was similar to the biased and debiased samples. RSE is in strong agreement with gated-SPECT MPI. However, its low sensitivity and negative predictive value preclude its use as a bedside test to detect myocardial ischemia.

Topics: Aged; Cardiac-Gated Imaging Techniques; Comorbidity; Echocardiography, Stress; Female; Heart Disease Risk Factors; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prevalence; Purines; Pyrazoles; Radiopharmaceuticals; Reproducibility of Results; Smoking; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Topics: Aged, 80 and over; Bile Ducts; Dilatation; Disease Progression; Echocardiography; Humans; Incidental Findings; Liver; Male; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Pancreatic Neoplasms; Perfusion; Purines; Pyrazoles; Syncope; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Patients with chronic kidney disease (CKD) have worse cardiovascular outcomes. The prognostic value of the new pharmacological stressor regadenoson (REG) in patients with varying levels of kidney function is not known (REG-SPECT). Furthermore, the impact of varying levels of kidney dysfunction on cardiac outcomes in patients undergoing REG-SPECT has not been defined. Our objective was to evaluate the prognostic value of regadenoson stress imaging in patients with different levels of kidney dysfunction.. We followed 1107 consecutive patients who underwent REG-SPECT for a mean duration of 1.8 ± 0.8 years. CKD was defined as estimated glomerular filtration rate (GFR) 60 mL/min/1.73 m(2). Kaplan-Meier survival analysis was performed to evaluate survival, free of major adverse cardiac events (MACE). CKD patients with GFR <60 (47% male, mean age 70 years) had a higher prevalence of cardiac risk factors and a history of coronary artery disease and were on significantly more cardiac medications (P < 0.001) than those with GFR >60. Patients with GFR <60 were significantly more likely to develop adverse cardiac outcomes including congestive heart failure (CHF) (P = 0.02), cardiac death (P < 0.001), all-cause death (P < 0.001), and MACE (P < 0.001) over the period of follow-up. Cardiac death increased with worsening levels of perfusion defects (SSS) across the entire spectrum of renal function (P < 0.001). GFR <60 was an independent predictor of MACE with a hazard ratio (HR) of 1.49 (95% CI: 1.06-2.08). The presence of transient ischaemic dilation (TID) was associated with an HR of 5.06 (95% CI: 1.43-17.90).. Renal function is a powerful risk predictor in patients undergoing REG-SPECT. REG-SPECT provides robust prognostication across the entire spectrum of renal function.

Topics: Adenosine A2 Receptor Agonists; Aged; Biomarkers; Cardiovascular Diseases; Electrocardiography; Endpoint Determination; Female; Humans; Kidney Failure, Chronic; Kidney Function Tests; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Purines; Pyrazoles; Radiopharmaceuticals; Risk Factors; Survival Rate; Tomography, Emission-Computed, Single-Photon

Topics: Adenosine A2 Receptor Agonists; Cardiovascular Diseases; Female; Humans; Kidney Failure, Chronic; Male; Organophosphorus Compounds; Organotechnetium Compounds; Purines; Pyrazoles; Tomography, Emission-Computed, Single-Photon

Regadenoson (REG) is a A2a receptor selective pharmacologic SPECT imaging agent. Its safety in unselected chronic obstructive pulmonary disease (COPD) or asthma (AM) undergoing SPECT imaging has not been well evaluated. We retrospectively identified 228 patients (COPD n = 126 and AM n = 102, Grp 1) undergoing REG SPECT from Jan to Nov 2009 and compared to 1,142 patients without COPD and AM (control, Grp 2). A standard 400 μg REG bolus was used and gated Tc-99 m tetrofosmin SPECT done. Patient demographics, REG SPECT data, side effects, arrhythmia occurrences, and any exacerbation of COPD or AM leading to treatment, hospitalization or death were evaluated. The side effect profile of Grp 1 was also compared to a historical cohort who underwent intravenous dipyridamole thallium-201 imaging and adenosine SPECT. Both groups were comparable with regards to baseline characteristics. There was 0% incidence of clinical exacerbation of COPD or AM after REG. COPD patients had more non-significant arrhythmias (58.3% vs. Grp 2, 43%, P = 0.004). There was 0% incidence of any atrio-ventricular block and only 2 instances of brief supraventricular tachycardia. When compared to the historical cohort of COPD who underwent IV dipyridamole thallium imaging, COPD in Grp 1, had more dyspnea and flushing and when compared to COPD/AM patients who underwent adenosine SPECT, Grp 1 pts had more of flushing and headache (24.9% vs. 2.8%, P = <0.001) but less of bronchospasm (1.3% vs. 6.9%, P = 0.022) and AV block (0% vs. 4.2%, P = 0.014). REG SPECT can be safely performed in COPD and AM population.

Topics: Adenosine A2 Receptor Antagonists; Aged; Asthma; Atrioventricular Block; Bronchoconstriction; Chi-Square Distribution; Female; Heart Diseases; Hemodynamics; Humans; Male; Middle Aged; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Pulmonary Disease, Chronic Obstructive; Purines; Pyrazoles; Radiopharmaceuticals; Retrospective Studies; Risk Assessment; Risk Factors; Tachycardia, Supraventricular; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents