Coronary risk equivalence of diabetes assessed by SPECT-MPI.

Background: Several publications and guidelines designate diabetes mellitus (DM) as a coronary artery disease (CAD) risk equivalent. The aim of this investigation was to examine DM cardiac risk equivalence from the perspective of stress SPECT myocardial perfusion imaging (MPI).

Methods And Results: We examined cardiovascular outcomes (cardiac death or nonfatal MI) of 17,499 patients referred for stress SPECT-MPI.

Cardiovascular risk stratification in diabetic patients following stress single-photon emission-computed tomography myocardial perfusion imaging: the impact of achieved exercise level.

Background: Previous studies have demonstrated that diabetic patients undergoing exercise stress single-photon emission-computed tomography (SPECT) myocardial perfusion imaging (MPI) have significantly lower cardiac events when compared to the diabetic patients undergoing pharmacologic stress SPECT MPI across all perfusion categories. However, there are limited data on the level of exercise achieved during exercise SPECT MPI among diabetic patients and its impact on cardiovascular outcomes.

Methods: We retrospectively analyzed 14,849 consecutive patients (3,654 diabetics and 11,195 non-diabetics) undergoing exercise stress, combined exercise and pharmacologic stress, and pharmacologic stress SPECT MPI from 1996 to 2005 at a single tertiary care center.

Does risk for major adverse cardiac events in patients undergoing vasodilator stress with adjunctive exercise differ from patients undergoing either standard exercise or vasodilator stress with myocardial perfusion imaging?

Background: In patients with functional limitations, the use of adjunctive exercise with vasodilator stress has advantages over vasodilator stress alone in single photon emission computed tomography myocardial perfusion imaging (MPI) for technical reasons and with regards to more effective cardiac risk stratification. Whether patients who undergo vasodilator with adjunctive exercise stress MPI possess clinical characteristics and cardiac risk that differs from those who undergo standard exercise or vasodilator stress MPI is unknown.

Methods: Prospectively collected data on 19,367 consecutive patients referred for stress MPI to a tertiary care center (9,331 [48%] underwent exercise-only, 3,793 [20%] underwent vasodilator plus exercise, and 6,243 [32%] underwent vasodilator-only) were analyzed.

Risk stratification using line source attenuation correction with rest/stress Tc-99m sestamibi SPECT myocardial perfusion imaging.

Background: Although line source attenuation correction (AC) in SPECT MPI studies improves diagnostic accuracy, its prognostic value is less understood.

Methods: Consecutive patients (n = 6,513) who underwent rest/stress AC ECG-gated SPECT MPI were followed for cardiac death or non-fatal myocardial infarction (MI). A 17-segment model and AC summed stress score (SSS) were used to classify images.

Risk stratification among diabetic patients undergoing stress myocardial perfusion imaging.

Background: Previous studies have suggested that diabetic patients undergoing single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) are at greater risk for cardiac events than non-diabetic patients with both normal and abnormal imaging results. However, the impact of stress modality on outcomes in this patient group has not been examined.

Methods: The data on all patients undergoing exercise stress or vasodilator stress SPECT MPI from 1996 to 2005 were reviewed.

A strategy of symptom-limited exercise with regadenoson-as-needed for stress myocardial perfusion imaging: a randomized controlled trial.

Background: Ambulatory patients with uncertain functional capacity may benefit from combined exercise and vasodilator stress protocols for myocardial perfusion imaging (MPI). The safety and MPI image quality with regadenoson administered during symptom-limited exercise have not been prospectively evaluated.

Methods And Results: A total of 140 patients (mean age 61 years, 48% female) referred for exercise with vasodilator stress MPI were randomized 2:1 to a strategy of exercise with regadenoson-as-necessary (Ex-Reg, n = 96) or dipyridamole with exercise (Dip-Ex, n = 44) after Duke Activity Status Index (DASI) scoring (median score 28 vs 24, P = .

Clinical value of stress-only Tc-99m SPECT imaging: importance of attenuation correction.

Background: In selected patients, stress-only SPECT imaging has been proposed as an alternative to rest-stress SPECT imaging to improve laboratory efficiency and reduce radiation exposure. The impact of attenuation correction (AC) upon interpretation, post-test patient management and cardiac risk stratification in relation to stress-only imaging is not well understood.

Objectives: The purpose of this study was to determine the clinical value for laboratory throughput and predicting outcomes of normal and abnormal stress-only SPECT imaging with AC in a consecutive series of clinically referred patients.

Risk stratification of CAD with SPECT-MPI in women with known estrogen status.

Objective: To compare exercise tolerance testing (ETT) with gated single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) risk stratification in women with an intermediate to high CAD pretest risk and known estrogen status (ES).

Background: SPECT-MPI is an effective test for risk stratifying patients with stable angina. However in women, the current guidelines recommend the exercise tolerance testing (ETT) as first line test.

The clinical value of single photon emission computed tomography myocardial perfusion imaging in cardiac risk stratification of very elderly patients (≥80 years) with suspected coronary artery disease.

Background: The role of single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) in cardiac evaluation of the very elderly patients is unclear. We investigated the clinical value of SPECT MPI in very elderly patients (≥80 years) with suspected coronary artery disease (CAD) as well as in comparison to younger patients.

Methods And Results: A retrospective analysis of prospectively collected data from 8,864 patients [1,093 patients ≥80 years (very elderly), 3,369 patients 65-79 years (elderly), and 4,402 patients 50-64 years (middle-aged)] with suspected CAD who underwent exercise and/or pharmacologic stress testing with SPECT MPI between 1996 and 2005 was performed.

Electrocardiographic changes during vasodilator SPECT myocardial perfusion imaging: does it affect diagnosis or prognosis?

Background: Significance of electrocardiographic (ECG) changes during vasodilator stress myocardial perfusion imaging (MPI) is controversial. We examined the diagnostic and prognostic significance of ECG changes during vasodilator single photon emission computerized tomography (SPECT) MPI.

Methods: We studied consecutive patients who underwent vasodilator SPECT MPI from 1995 to 2009.

Usefulness of stress gated technetium-99m single photon emission computed tomographic myocardial perfusion imaging for the prediction of cardiac death in patients with moderate to severe left ventricular systolic dysfunction and suspected coronary artery disease.

Although stress gated technetium-99m single-photon emission computed tomographic (SPECT) myocardial perfusion imaging (MPI) is useful in differentiating ischemic from nonischemic cardiomyopathy, its prognostic usefulness in this patient population is not well understood. Consecutive unique patients with suspected coronary artery disease who, for clinical indications, underwent technetium-99m rest and stress MPI demonstrating ejection fractions ≤40% by gated SPECT imaging were retrospectively identified. In addition to prescan variables, previously defined cutoffs for gated SPECT parameters using visual and standard 17-segment semiquantitative scoring were applied and related to the occurrence of cardiac death up to 5 years after MPI.

Signs and symptoms of suspected myocardial ischemia in women: results from the What is the Optimal Method for Ischemia Evaluation in WomeN? Trial.

Background: Much of our understanding of gender differences in chest pain was derived from noncontemporary reports. The aim of the current report was to compare the frequency of chest pain by measures of ischemia in 824 women with suspected myocardial ischemia prospectively enrolled in a clinical trial of exercise testing with electrocardiography (ETT-ECG) alone compared to myocardial perfusion single photon emission computed tomography (SPECT) (ETT-MPS).

Methods: Women seeking evaluation of chest pain or anginal equivalent symptoms were randomized to ETT-ECG or ETT-MPS with Tc-99m tetrofosmin.

Duration and type of therapy for diabetes: impact on cardiac risk stratification with stress electrocardiographic-gated SPECT myocardial perfusion imaging.

Background: Stress electrocardiogram(ECG)-gated single photon emission computed tomography (SPECT) imaging is highly effective in risk stratification of diabetic patients for adverse cardiac events. While patients with diabetes are predisposed to a more aggressive progression of vascular disease, the impact of its duration and type of therapy on risk stratification are unknown.

Methods: From the Hartford Hospital Nuclear Cardiology clinical database, 886 diabetic patients who underwent exercise or pharmacologic stress ECG-gated SPECT were identified, with complete follow-up regarding the occurrence of adverse cardiac events and information regarding the duration of diabetes and the type of therapy (insulin vs oral medication only) at the time of testing.

Blunted heart rate response as a predictor of cardiac death in patients undergoing vasodilator stress technetium-99m sestamibi gated SPECT myocardial perfusion imaging.

Introduction: The prognostic value of a blunted heart rate response (BHR) during ECG-gated vasodilator stress SPECT MPI in relation to ventricular function on long-term cardiovascular events is not well established. We performed this study to evaluate the incremental prognostic value of BHR during pharmacological stress SPECT MPI.

Methods: Consecutive patients who underwent dipyridamole stress Tc-99m sestamibi ECG-gated SPECT MPI (without exercise) were identified.

A multicenter evaluation of a new post-processing method with depth-dependent collimator resolution applied to full-time and half-time acquisitions without and with simultaneously acquired attenuation correction.

Background: The field of nuclear cardiology is limited by image quality and length of procedure. The use of depth-dependent resolution recovery algorithms in conjunction with iterative reconstruction holds promise to improve image quality and reduce acquisition time. This study compared the Astonish algorithm employing depth-dependent resolution recovery and iterative reconstruction to filtered backprojection (FBP) using both full-time (FTA) and half-time (HTA) data.

Risk stratification with attenuation corrected stress Tc-99m sestamibi SPECT myocardial perfusion imaging in the absence of ECG-gating due to arrhythmias.

Background: Despite growing recognition of attenuation correction (AC) utilizing an external radiation source, prognostic studies using AC are lacking.

Methods: Consecutive patients (n = 419) who underwent stress Tc-99m sestamibi SPECT imaging with AC but without ECG-gating, due to arrhythmia, were followed for cardiac death or non-fatal myocardial infarction (MI). A 17-segment model and the summed stress score (SSS) were used to classify both the non-AC and AC images.

Validation of attenuation correction using transmission truncation compensation with a small field of view dedicated cardiac SPECT camera system.

Background: Although attenuation correction (AC) has been successfully applied to large field of view (LFOV) cameras, applicability to small field of view (SFOV) cameras is a concern due to truncation. This study compared perfusion images between a LFOV and SFOV camera with truncation compensation, using the same AC solution.

Methods And Results: Seventy-eight clinically referred patients underwent rest-stress single-photon emission computed tomography (SPECT) using both a SFOV and LFOV camera in a randomized sequence.

Independent and incremental prognostic value of left ventricular ejection fraction determined by stress gated rubidium 82 PET imaging in patients with known or suspected coronary artery disease.

Background: Whether left ventricular ejection fraction (EF) obtained by gated rubidium 82 positron emission tomography (PET) myocardial imaging can identify patients at risk for future cardiac events is unclear.

Methods And Results: Consecutive patients with known or suspected coronary artery disease who underwent dipyridamole stress gated Rb-82 PET imaging were evaluated. Scoring of perfusion was accomplished by use of a 17-segment model.

Symptom-limited exercise combined with dipyridamole stress: prognostic value in assessment of known or suspected coronary artery disease by use of gated SPECT imaging.

Background: Combining vasodilator and exercise stress reduces noncardiac side effects, improves image quality, and enhances the detection of ischemia, compared with suboptimal exercise or vasodilator stress alone. However, prognostic data with combined protocols are limited.

Methods And Results: Consecutive patients (n = 2064) who underwent symptom-limited exercise and dipyridamole stress with gated single-photon emission computed tomography (SPECT) imaging, without early revascularization, were studied.

Regional wall-motion abnormalities on post-stress electrocardiographic-gated technetium-99m sestamibi single-photon emission computed tomography imaging predict cardiac events.

Background: The global left-ventricular (LV) ejection fraction (EF) is a powerful predictor of cardiac death (CD). There are limited data on the prognostic value of regional LV function. We examined the role of visually assessed regional wall motion in risk stratification for future cardiac events.

Glucose and cardiac risk factor control in individuals with type 2 diabetes: implications for patients and providers.

Purpose: The purpose of this descriptive study was to describe attainment of glucose and coronary heart disease (CHD) risk factor goals and to identify factors that were associated with successful goal achievement.

Methods: A cross-sectional survey enrolled 110 subjects with type 2 diabetes undergoing screening for asymptomatic myocardial ischemia.

Results: Many participants had HbA1c levels > or =7% (45%), and 46% to 79% were not meeting goals for CHD risk reduction.

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.

The impact of screening for asymptomatic myocardial ischemia in individuals with type 2 diabetes.

Little is known about factors that contribute to either emotional or behavior outcomes following screening for coronary artery disease (CAD). The purpose of this prospective study was to explore these outcomes, along with potentially contributing factors in individuals enrolled in a screening trial for asymptomatic CAD. Included were 47 subjects with type 2 diabetes.

The association of psychological factors, physical activity, neuropathy, and quality of life in type 2 diabetes.

The objective of this study was to determine the relationship of sociodemographics; diabetes-related factors, including diabetes-related microvascular complications; cardiac risk factors; and psychological factors with quality of life (QOL). Participants enrolled at three sites in the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study were invited to participate in this ancillary study. Questionnaires assessing psychological factors were completed by participants, and the remainder of the data was obtained as part of the DIAD study.

Risk stratification with electrocardiographic-gated dobutamine stress technetium-99m sestamibi single-photon emission tomographic imaging: value of heart rate response and assessment of left ventricular function.

Objectives: The purpose of this research was to evaluate the significance of heart rate response to dobutamine and the assessment of left ventricular (LV) function during risk stratification of patients undergoing dobutamine stress myocardial perfusion imaging (DSMPI).

Background: Dobutamine stress myocardial perfusion imaging has been shown to effectively risk stratify highly selected patients. However, based on perfusion alone, patients with normal and abnormal tests have twice the risk as comparable patients with exercise testing.