PURPOSE: Reversible ischaemia at radionuclide myocardial perfusion imaging (MPI) accurately predicts risk of cardiac death and nonfatal myocardial infarction (major adverse cardiac events, MACE). This prognostic penetrance might be empowered by accounting for exercise tolerance as an indirect index of ischaemia severity. The present study aimed to verify this hypothesis integrating imaging assessment of ischaemia severity with exercise maximal rate pressure product (RPP) in a large cohort of patients with suspected or known coronary artery disease (CAD). METHODS AND RESULTS: We analysed 1,502 consecutive patients (1,014 men aged 59 ± 10 years) submitted to exercise stress/rest MPI. To account for exercise tolerance, the summed difference score (SDS) was divided by RPP at tracer injection providing a clinical prognostic index (CPI). Reversible ischaemia was documented in 357 patients (24 %) and was classified by SDS as mild (SDS 2-4) in 180, moderate (SDS 5-7) in 118 and severe (SDS >7) in 59. CPI values of ischaemic patients were clustered into tertiles with lowest and highest values indicating low and high risk, respectively. CPI modified SDS risk prediction in 119/357 (33 %) patients. During a 60-month follow-up, MACE occurred in 68 patients. Kaplan-Meier analysis revealed that CPI significantly improved predictive power for MACE incidence with respect to SDS alone. Multivariate Cox analysis confirmed the additive independent value of CPI-derived information. CONCLUSION: Integration of ischaemic threshold and ischaemia extension and severity can improve accuracy of exercise MPI in predicting long-term outcome in a large cohort of patients with suspected or known CAD.

BACKGROUND AND AIMS: Despite an extensive use of stress myocardial perfusion single-photon emission computed tomography (MPS), no study addressed the role of perfusion imaging in diabetic patients with abnormal resting electrocardiogram (ECG). We compared analytical approaches to assess the added value of stress MPS variables in estimating coronary heart disease outcomes in diabetic patients with abnormal resting ECG. METHODS AND RESULTS: A total of 416 patients with diabetes and abnormal resting ECG who underwent stress MPS were prospectively followed up after the index study. The end point was the occurrence of a major cardiac event, including cardiac death and nonfatal myocardial infarction. At the end of follow-up (median 58 months), 42 patients experienced events. MPS data increased the predictive value of a model including traditional cardiovascular risk factors and left ventricular (LV) ejection fraction (likelihood ratio ?² from 17.54 to 24.15, p < 0.05, with a C statistic of 0.72, 95% confidence interval: 0.65-0.79). The addition of MPS data resulted in reclassification of 25% of the sample with a net reclassification improvement of 0.20 (95% confidence interval: 0.05-0.36). Overall, 63 patients were reclassified to a lower risk category, with a 5-year event rate of 3.5%, and 40 patients were reclassified to a higher risk category, with a 5-year event rate of 20%. CONCLUSION: The addition of MPS findings to a model based on traditional cardiovascular risk factors and LV ejection fraction improves risk classification for incident cardiac events in diabetic patients with abnormal resting ECG.

Background: We evaluated the relationship between diabetes and temporal characteristics of cardiac risk at long-term follow-up in a propensity score-matched cohort of diabetic and non-diabetic patients with normal stress myocardial perfusion single-photon emission computed tomography (MPS). Methods and Results: We studied 828 consecutive patients with suspected or known coronary artery disease and normal perfusion at stress MPS. To account for differences in baseline characteristics between diabetics and non-diabetics, we created a propensity score-matched cohort considering clinical variables and stress type. After matching, clinical characteristics were comparable in 260 diabetic and 260 non-diabetic patients. All patients were followed for at least 1 year (median 53 months). End-point events were cardiac death or nonfatal myocardial infarction. At Cox analysis, diabetes (hazard ratio 3.9, P <.01) and post-stress left ventricular ejection fraction (LVEF) <=45% (hazard ratio 4.1, P <.01) were independent predictors of events. At parametric analysis, non-diabetic patients with post-stress LVEF >45% remained at low risk for the entire length of follow-up, while the highest probability of events and the major risk acceleration was observed in patients with diabetes and post-stress LVEF <=45%. Conclusions: After a normal stress MPS, diabetic patients are at higher risk for cardiac events than non-diabetic subjects also after balancing clinical characteristics and stress type by propensity score analysis. The warranty period of a normal stress MPS varies according to diabetic status and post-stress LVEF. © 2013 American Society of Nuclear Cardiology.

The rapid technological evolution accomplished in noninvasive cardiac imaging techniques over the past few decades has provided physicians with a large armamentarium for the evaluation of patients with known or suspected coronary heart disease. Noninvasive assessment of coronary artery calcium or noninvasive coronary angiography may be performed using computed tomography or magnetic resonance imaging. These techniques evaluate the presence of atherosclerosis rather than ischemia. Conversely, nuclear cardiology is the most widely used noninvasive approach for the assessment of myocardial perfusion and function. These techniques coupled with the development of dedicated image fusion software packages to merge data sets from different modalities have paved the way for hybrid imaging. This article provides a description of the available noninvasive imaging techniques in the assessment of coronary anatomy, myocardial perfusion, and cardiac function in patients with known or suspected coronary heart disease. © 2014 SIMI.

The prognostic value of normal stress myocardial perfusion single-photon emission computed tomography (MPS) in patients with diabetes has only been evaluated in single-center studies of relatively limited sample size. We performed a meta-analysis of published studies, including diabetic patients with known or suspected coronary artery disease (CAD), to assess the predictive value for adverse cardiac ischemic events of normal stress MPS.

Transient ischemic dilation (TID) of the left ventricle during stress myocardial perfusion SPECT (MPS) has been shown to be a useful marker of severe coronary artery disease (CAD). However, investigations in diabetic patients with available coronary angiographic data are still limited. We evaluated the incremental diagnostic value of TID in identifying the presence of angiographically severe CAD in diabetic patients.

Exercise training might exert its beneficial effects on myocardial perfusion by inducing coronary vascular adaptations or enhancing collateralization. We evaluated whether long-term exercise-based cardiac rehabilitation started early after ST-elevation acute myocardial infarction (STEMI) improves myocardial perfusion and left ventricular (LV) function.

Objective: Stress myocardial perfusion single-photon emission computed tomography (MPS) variables are robust estimators of prognosis. No data are available on the comparative ability of stress MPS risk markers using varied iterative and risk classification approaches in asymptomatic diabetic patients. We compared analytical approaches to estimate the added value of MPS variables in estimating coronary artery disease (CAD) outcomes in asymptomatic diabetic patients. We also evaluated the temporal characteristics of cardiac risk according to MPS findings.

Revascularization procedures, including percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), are performed in many patients with coronary artery disease. Despite the effectiveness of these procedures, different follow-up strategies need to be considered for the management of patients after revascularization. Stress myocardial perfusion single-photon emission computed tomography (MPS) is a suitable imaging method for the evaluation of patients who have undergone PCI or CABG, and it has been used in the follow-up of such patients. Radionuclide imaging is included in the follow-up strategies after PCI and CABG in patients with symptoms, but guidelines warn against routine testing of all asymptomatic patients after revascularization. After PCI, in the absence of symptoms, radionuclide imaging is recommended and indicated as appropriate after incomplete or suboptimal revascularization and in specific asymptomatic patient subsets. On the other hand, the value of MPS late after CABG in risk stratification has been demonstrated even in the absence of symptoms. Thus, given the adverse outcome associated with silent ischaemia, it can be speculated that all patients regardless of clinical status should undergo stress testing late after revascularization. Larger prospective studies are needed to assess whether stress MPS will have an impact on the outcome in asymptomatic patients after revascularization.

Background We prospectively evaluated the incremental prognostic value of transient ischemic dilation (TID) in patients with type 2 diabetes mellitus during long-term follow-up and estimated cardiac death and nonfatal myocardial infarction (MI) using traditional approaches of prognostication to more recent methods.

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We assessed the impact of type 2 diabetes, in the presence of other major cardiovascular risk factors, on coronary microvascular function and myocardial perfusion in patients without obstructive coronary artery disease (CAD).In this prospective study, 23 patients with type 2 diabetes and 26 nondiabetic patients matched for age, sex and other cardiovascular risk factors underwent a cold pressure test (CPT) and dipyridamole transthoracic echocardiography to determine their coronary flow (CF) ratio. Within 2 weeks, all diabetic patients also underwent dipyridamole-rest myocardial perfusion single-photon emission (MPS) CT. None of the patients with or without diabetes had significant CAD on invasive coronary angiography.

The aim of this study was to compare the prognostic value of coronary calcium scoring and coronary computed tomography (CT) angiography in assessing the cardiac risk and its temporal characteristics in patients at intermediate pre-test likelihood of coronary artery disease (CAD). Cardiac CT was performed in 326 patients at intermediate (15-85%) pre-test likelihood of CAD to evaluate calcium score and presence and severity of the disease. Patients were followed-up for the occurrence of major cardiac events (cardiac death, myocardial infarction, and unstable angina requiring revascularization). During follow-up (26 +/- A 12 months) 34 events occurred. Calcium score, extent of CAD, and plaque extent and distribution were higher (all P < 0.001) in patients with events than in those without. No patients with calcium score of 0 had events at follow-up. Calcium score (P < 0.001), number of segments with non-calcified or mixed plaque (P < 0.05), and segments-at-risk-score (P < 0.005) were independent predictors of events. Cardiac risk was greater for all time intervals and accelerated more over time with worsening of calcium score. In presence of coronary calcium, significant CAD further increased the probability of failure for all time intervals. Therefore, patients at intermediate CAD risk without coronary calcium do not need further evaluation with longer and higher-radiation-dose protocols, while in the presence of coronary calcium CT angiography is useful to further stratify patients.

The assessment of coronary flow reserve (CFR) may be useful for the functional evaluation of coronary artery disease (CAD). Invasive techniques, such as intracoronary Doppler ultrasound and pressure-derived method, directly assess CFR velocity and fractional flow reserve. Positron emission tomography (PET) has emerged as an accurate noninvasive technique to quantify CFR. Nevertheless, this approach has not been applied to routine studies because of its high cost and complexity. Recently, attempts to estimate CFR with single-photon emission computed tomography (SPECT) tracers have been made in order to obtain, with noninvasive methods, data for quantitative functional assessment of CAD. This review analyzes the relative merit and limitations of CFR measurements by cardiac imaging techniques and describes the potential clinical applications.

After acute myocardial infarction (AMI), left ventricular (LV) remodelling may occur despite successful reperfusion. This study aimed to investigate by gated single photon emission computed tomography (SPECT) the long-term evolution of myocardial perfusion and LV function after AMI and to identify the predictors of LV remodelling.