Effect of exercise training on ventricular function, dyssynchrony, resting myocardial perfusion, and clinical outcomes in patients with heart failure: a nuclear ancillary study of Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing (HF-ACTION); design and rationale.

Background: Technetium Tc 99m gated single photon emission computed tomography (SPECT) has become the cornerstone of noninvasive risk stratification in patients with ischemic heart disease, but its role in patients with heart failure is not as well established.

Study Design: This study is a substudy of the Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing (HF-ACTION) trial--a National Institutes of Health/National Heart, Lung, and Blood Institute-funded randomized controlled trial--designed to evaluate the role of exercise training in patients with heart failure due to left ventricular dysfunction. For this substudy, a total of 300 patients distributed on an approximately 1:1 basis between the exercise training and usual care arms of HF-ACTION will undergo resting technetium Tc 99m gated SPECT at baseline and 12 months to compare changes in left ventricular function with exercise training.

Evaluation of left ventricular mechanical dyssynchrony as determined by phase analysis of ECG-gated SPECT myocardial perfusion imaging in patients with left ventricular dysfunction and conduction disturbances.

Background: Cardiac resynchronization therapy (CRT) is approved for the treatment of patients with advanced systolic heart failure and evidence of dyssynchrony on electrocardiograms. However, a significant percentage of patients do not demonstrate improvement with CRT. Echocardiographic techniques have been used for more accurate determination of dyssynchrony.

Myocardial perfusion imaging after transient balloon occlusion during percutaneous coronary interventions.

Background: Myocardial perfusion imaging (MPI) is highly sensitive in detecting rest ischemia when the radiotracer is injected during the episode of ischemia. The frequency of abnormal MPI results after resolution of ischemia is not well defined. The aim of this study was to determine how long MPI results remain abnormal after transient coronary artery occlusion.

Achieving quality in cardiovascular imaging: proceedings from the American College of Cardiology-Duke University Medical Center Think Tank on Quality in Cardiovascular Imaging.

Cardiovascular imaging has enjoyed both rapid technological advances and sustained growth, yet less attention has been focused on quality than in other areas of cardiovascular medicine. To address this deficit, representatives from cardiovascular imaging societies, private payers, government agencies, the medical imaging industry, and experts in quality measurement met, and this report provides an overview of the discussions. A consensus definition of quality in imaging and a convergence of opinion on quality measures across imaging modalities was achieved and are intended to be the start of a process culminating in the development, dissemination, and adoption of quality measures for all cardiovascular imaging modalities.

Outcome of patients with adenosine-induced ST-segment depression but with normal perfusion on tomographic imaging.

Most patients with ST depression during adenosine infusion have reversible perfusion defects by single-photon emission computed tomographic (SPECT) perfusion images. Occasionally ST depression is observed in the setting of normal perfusion images. The outcome of such patients is controversial.

Value of peripheral vascular endothelial function in the detection of relative myocardial ischemia in asymptomatic type 2 diabetic patients who underwent myocardial perfusion imaging.

Background: Endothelial dysfunction precedes overt atherosclerosis and is present in patients with type 2 diabetes mellitus (T2DM). Myocardial perfusion imaging (MPI) is an effective method of detection of coronary artery disease (CAD); however, the relationship between endothelial function and MPI in asymptomatic patients with T2DM has not been examined.

Methods And Results: This study used a subset of the population from the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study.

Effect of caffeine on ischemia detection by adenosine single-photon emission computed tomography perfusion imaging.

Objectives: The purpose of this research was to study the effect of one cup of coffee taken 1 h before adenosine stress on the results of myocardial perfusion imaging.

Background: Caffeine is believed to attenuate the coronary hyperemic response to adenosine by competitive blockade of the A2a receptor. Caffeine is commonly withheld before adenosine single-photon emission computed tomography (SPECT) perfusion imaging so as not to mask ischemia detection.

Gated SPECT perfusion imaging for the simultaneous assessment of myocardial perfusion and ventricular function in the BARI 2D trial: an initial report from the Nuclear Core Laboratory.

Background: The BARI 2D (Bypass Angioplasty Revascularization Investigation 2 Diabetes) trial, a National Heart, Lung, and Blood Institute-sponsored study in type 2 diabetic patients with coronary artery disease, completed patient recruitment in March 2005. This trial had a nuclear substudy in addition to many other substudies.

Methods And Results: After patient enrollment, adenosine gated single photon emission computed tomography perfusion imaging is performed at years 1 and 3.

Onset of left ventricular mechanical contraction as determined by phase analysis of ECG-gated myocardial perfusion SPECT imaging: development of a diagnostic tool for assessment of cardiac mechanical dyssynchrony.

Background: A count-based method using technetium-99m sestamibi electrocardiography-gated myocardial perfusion single photon emission computed tomography imaging has been developed to extract the left ventricular (LV) regional phase of contraction (onset of mechanical contraction [OMC]) throughout the cardiac cycle. This study was performed to develop OMC normal databases and dynamic OMC displays for assessment of cardiac mechanic dyssynchrony.

Methods And Results: LV regional phases were extracted from 90 enrolled normal subjects (45 men and 45 women) by use of the Emory Cardiac Toolbox and then submitted to statistical analysis to generate the normal databases.

Initial clinical experience with regadenoson, a novel selective A2A agonist for pharmacologic stress single-photon emission computed tomography myocardial perfusion imaging.

Objectives: 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).

Background: 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.

ACCF/ASNC appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI): a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group and the American Society of Nuclear Cardiology endorsed by the American Heart Association.

Under the auspices of the American College of Cardiology Foundation (ACCF) and the American Society of Nuclear Cardiology (ASNC), an appropriateness review was conducted for radionuclide cardiovascular imaging (RNI), specifically gated single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI). The review assessed the risks and benefits of the imaging test for several indications or clinical scenarios and scored them based on a scale of 1 to 9, where the upper range (7 to 9) implies that the test is generally acceptable and is a reasonable approach, and the lower range (1 to 3) implies that the test is generally not acceptable and is not a reasonable approach. The mid range (4 to 6) implies that the test may be generally acceptable and may be a reasonable approach for the indication.

Assessment of left ventricular function during upright treadmill exercise with tantalum 178 and multiwire gamma camera.

Background: Prior studies with first-pass radionuclide angiography (RNA) during treadmill exercise used a single-crystal (Anger) or multicrystal gamma camera and technetium 99m tracers. Motion correction, when done, used point sources, which limited correction to only plane movement.

Methods And Results: We examined the performance of a multiwire gamma camera (MWGC), generator-produced tantalum 178, and a novel method of motion correction during treadmill exercise testing.

Right ventricular pressure-volume loops using simultaneous radionuclide angiography with a multiwire gamma camera and right heart catheterization.

Background: The purpose of this study was to generate right ventricular (RV) pressure-volume loops (PVLs) from time-activity curves obtained by first-pass radionuclide angiography (RNA) and RV pressures obtained by right heart catheterization.

Methods And Results: Short-lived tantalum 178 was used to obtain first-pass RNA at baseline (n = 31), after nitroglycerin (n = 5), or after the conclusion of cardiac catheterization (n = 13). From the radionuclide-derived RV ejection fraction and thermodilution stroke volume, the RV end-diastolic volume and end-systolic volume were measured.

Left ventricular function in patients with type 2 diabetes mellitus.

This study showed that the mean left ventricular ejection fraction, end-diastolic volume, end-systolic volume, and muscle mass are comparable in patients with type 2 diabetes mellitus to gender-matched patients who do not have diabetes mellitus, but abnormal ejection fraction is more common in men, although not in women, with diabetes mellitus than without. The ejection fraction was higher and the volumes and muscle mass were lower in women than men in the presence or absence of diabetes mellitus.

Myocardial viability: nuclear assessment.

There are an estimated 5 million patients with congestive heart failure (CHF) in the United States. The long-term outcome in these patients is poor with a 5-year mortality of 70%. There is evidence suggesting that revascularization in patients with viable myocardium can result in reduced event rate in these patients.

Relation between effects of adenosine on brachial artery reactivity and perfusion pattern in patients with known or suspected coronary artery disease.

This study examined the changes in brachial artery diameter and flow velocity in response to intravenous adenosine and compared the results to cuff occlusion and single-photon emission computed tomographic (SPECT) images. The change in diameter was less with adenosine than with cuff occlusion. There was no correlation between the presence of abnormal SPECT images and the responses to adenosine or cuff occlusion in either diameter or flow velocity.

Artificial neural network modeling of stress single-photon emission computed tomographic imaging for detecting extensive coronary artery disease.

Single-photon emission computed tomographic imaging is a useful, noninvasive method to detect coronary artery disease (CAD). We tested the hypothesis that artificial neural network modeling could predict CAD extent better than visual interpretation; 109 patients who underwent stress single-photon emission computed tomography and coronary angiography were selected. Twenty patients who had a <5% probability of CAD were also selected for calculation of normalcy rate.

Detection of silent myocardial ischemia in asymptomatic diabetic subjects: the DIAD study.

Objective: To assess the prevalence and clinical predictors of silent myocardial ischemia in asymptomatic patients with type 2 diabetes and to test the effectiveness of current American Diabetes Association screening guidelines.

Research Design And Methods: In the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study, 1,123 patients with type 2 diabetes, aged 50-75 years, with no known or suspected coronary artery disease, were randomly assigned to either stress testing and 5-year clinical follow-up or to follow-up only. The prevalence of ischemia in 522 patients randomized to stress testing was assessed by adenosine technetium-99m sestamibi single-photon emission-computed tomography myocardial perfusion imaging.