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Myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) is useful in the evaluation of cardiac allograft vasculopathy (CAV) in heart transplant (HTx) recipients. The current study evaluated the long-term prognostic value of stress SPECT MPI for predicting all-cause mortality and cardiac events in HTx recipients. The study population consisted of 166 HTx recipients (mean age 54 ± 10 years, 84% male) who underwent exercise or dobutamine stress 99mTc-tetrofosmin SPECT MPI for the assessment of CAV. An abnormal SPECT MPI was defined as the presence of a fixed or a reversible perfusion defect. Endpoints were all-cause mortality, cardiac mortality, and non-fatal myocardial infarction (MI). MPI abnormalities were detected in 55 patients (33%), including fixed defects in 28 patients (17%), partially reversible in 17 patients (10%), and completely reversible defects in 10 patients (6%). During a median follow-up of 12.8 years (range 0-15, mean follow-up 9.5 years), 109 (66%) patients died (all-cause mortality), of which 67 (40%) were due to cardiac causes. A total of 5 (3%) patients experienced a non-fatal MI. HTx recipients with a normal stress 99mTc-tetrofosmin SPECT MPI had a significantly better prognosis as compared with those with an abnormal study, up to 5 years after the initial test. The presence of a reversible perfusion defect was a significant predictor of all-cause mortality, cardiac mortality, and major cardiac events, during the entire follow-up period. Stress 99mTc-tetrofosmin SPECT MPI provides valuable prognostic information for the prediction of long-term outcome in HTx recipients. Patients with a normal stress 99mTc-tetrofosmin SPECT MPI have a significantly better prognosis as compared with those with an abnormal study, up to 5 years after initial testing.

Previous studies have reported a favorable outcome of patients with normal single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). The aim of this study was to assess the very long-term prognosis of patients with known coronary artery disease (CAD) and normal SPECT MPI results. The population consisted of 266 patients with known CAD (defined as a healed myocardial infarction and/or a previous coronary revascularization), who underwent exercise bicycle or dobutamine-atropine stress SPECT MPI and had normal perfusion during stress and at rest. End points during follow-up were all-cause mortality, cardiac mortality, and nonfatal myocardial infarction. Univariate and multivariate analyses were performed to identify predictors of long-term outcome. Follow-up was completed in 261 (98%) patients. During a median follow-up of 12 years, 94 (36%) patients died, of which 26 (10%) died due to cardiac causes, and 15 (6%) had a nonfatal myocardial infarction. The annualized mortality rate was 3.1%, annualized cardiac mortality rate was 0.9%, and the annualized event rate for cardiac death and/or nonfatal infarction was 1.2%. Independent predictors of total mortality were age, diabetes mellitus, and rate-pressure product at peak stress. Independent predictors of cardiac mortality were age, male gender, and rate-pressure product at peak stress. Patients with known CAD and a normal SPECT MPI study have a favorable long-term prognosis. Clinical and stress test variables can be used to identify patients with a higher risk status.

The goal of this study was to evaluate the very long-term outcome after normal exercise 99mTc-sestamibi myocardial perfusion single-photon emission computed tomography (SPECT). Exercise 99mTc-sestamibi SPECT is widely used for risk stratification, but data on very long-term outcome after a normal test are scarce. A consecutive group of 233 patients (122 men, mean age 54 ± 12 years) with known or suspected coronary artery disease (CAD) underwent exercise 99mTc-sestamibi SPECT and had normal myocardial perfusion at exercise and at rest. Follow-up endpoints were all-cause mortality, cardiac mortality, nonfatal myocardial infarction, and coronary revascularization. Predictors of outcome were identified by Cox proportional hazard regression models using clinical and exercise testing variables. During a mean follow-up of 15.5 ± 4.9 years, 41 (18%) patients died, of which 13 were cardiac deaths. A total of 18 (8%) patients had a nonfatal myocardial infarction, and 47 (20%) had coronary revascularization. The annualized event rates for all-cause mortality, cardiac mortality, cardiac mortality/nonfatal infarction, and major adverse cardiac events were, respectively, 1.1%, 0.3%, 0.7%, and 1.8%. Multivariate analysis demonstrated that the variables age, male gender, diabetes, diastolic blood pressure at rest, rate pressure product at rest, peak exercise heart rate, and ST segment changes were independent predictors of major adverse cardiac events. Patients with suspected or known CAD and normal exercise 99mTc-sestamibi myocardial perfusion SPECT have a favorable 15-year prognosis. Follow-up should be closer in patients with known CAD, and/or having clinical and exercise parameters indicating higher risk status.

Current developments in cardiovascular biology and imaging enable the noninvasive molecular evaluation of atherosclerotic vascular disease. Intraplaque neovascularization sprouting from the adventitial vasa vasorum has been identified as an independent predictor of intraplaque hemorrhage and plaque rupture. These intraplaque vasa vasorum result from angiogenesis, most likely under influence of hypoxic and inflammatory stimuli. Several molecular imaging techniques are currently available. Most experience has been obtained with molecular imaging using positron emission tomography and single photon emission computed tomography. Recently, the development of targeted contrast agents has allowed molecular imaging with magnetic resonance imaging, ultrasound and computed tomography. The present review discusses the use of these molecular imaging techniques to identify inflammation and intraplaque vasa vasorum to identify vulnerable atherosclerotic plaques at risk of rupture and thrombosis. The available literature on molecular imaging techniques and molecular targets associated with inflammation and angiogenesis is discussed, and the clinical applications of molecular cardiovascular imaging and the use of molecular techniques for local drug delivery are addressed.