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The aim of this study was to investigate the association between major adverse cardiovascular events (MACEs) and inducible ischemia on regadenoson cardiac magnetic resonance (CMR) myocardial perfusion imaging (MPI) performed at 3.0 T. Regadenoson stress CMR MPI is increasingly used to assess patients with suspected ischemia; however, its value in patient prognostication and risk reclassification is only emerging. A total of 346 patients with suspected ischemia who were referred for regadenoson CMR were studied. The prognostic association of presence of inducible ischemia by CMR with MACEs was determined. In addition, we assessed the extent of net reclassification improvement by CMR beyond a clinical risk model. There were 52 MACEs during a median follow-up period of 1.9 years. Patients with inducible ischemia were fourfold more likely to experience MACEs (hazard ratio, 4.14, 95% confidence interval 2.37 to 7.24, p <0.0001). In the best overall model, presence of inducible ischemia conferred a 2.6-fold increased hazard for MACEs adjusted to known clinical risk markers (adjusted hazard ratio 2.59, 95% confidence interval 1.30 to 5.18, p = 0.0069). Patients with no inducible ischemia experienced a low rate of cardiac death and myocardial infarction (0.6% per patient-year), whereas those with inducible ischemia had an annual event rate of 3.2%. Net reclassification improvement across risk categories (low <5%, intermediate 5% to 10%, and high >10%) by CMR was 0.29 (95% confidence interval 0.15 to 0.44), and continuous net reclassification improvement was 0.58. In conclusion, in patients with clinical suspicion of myocardial ischemia, regadenoson stress CMR MPI provides robust risk stratification. CMR MPI negative for ischemia was associated with a very low annual rate of hard cardiac events. In addition, CMR MPI provides effective risk reclassification in a substantial proportion of patients., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Although exercise treadmill testing (ETT) is a useful initial test for patients with suspected cardiovascular (CV) disease, there is concern regarding the use of downstream imaging tests especially in the setting of equivocal or positive ETTs. Patients with no history of coronary artery disease who underwent ETT between 2009 and 2010 were prospectively included. Referring physicians were categorized as cardiologists and noncardiologists. Downstream tests included nuclear perfusion imaging, coronary computed tomography angiography, stress echocardiography, stress magnetic resonance, and invasive coronary angiography performed up to 6 months after the ETT. Patients were followed for CV death, myocardial infarction, and coronary revascularization for a median of 2.7 years. Among 3,656 patients, the ETT were negative in 2,876 (79%), positive in 132 (3.6%), and inconclusive in 643 (18%). Cardiologists ordered less downstream tests than noncardiologists (9.5% vs 12.2%, p=0.02), with less noninvasive tests (5.9% vs 10.4%, p<0.0001) and more invasive angiography (3.6% vs 1.8%, p<0.0001). After adjustment for confounding, patients evaluated by cardiologists were less likely to undergo additional testing after equivocal (odds ratio: 0.65, p=0.02) or positive ETT results (odds ratio: 0.39, p=0.02), whereas after negative ETT, the odds ratio was 1.7 (p=0.06). There was no difference in the rate of adverse CV events between patients referred by cardiologists versus noncardiologists. In conclusion, patients referred for ETT by cardiologists are less likely to undergo additional testing, particularly noninvasive tests, than those referred by noncardiologists. The lower rate of tests is driven by a lower rate of tests after positive or inconclusive ETT., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objectives: The purpose of this study was to estimate the frequency and results of downstream testing after exercise treadmill tests (ETTs)., Background: The utility of additional diagnostic testing after ETT is not well characterized., Methods: We followed consecutive individuals without known coronary artery disease referred for clinical ETT at a large medical center. We measured the frequency and results of downstream imaging tests and invasive angiography within 6 months of ETT and the combined endpoint of survival free from cardiovascular death, myocardial infarction, and coronary revascularization., Results: Among 3,656 consecutive subjects who were followed for a mean of 2.5 ± 1.1 years, 332 (9.0%) underwent noninvasive imaging and 84 (2.3%) were referred directly to invasive angiography after ETT. The combined endpoint occurred in 76 (2.2%) patients. The annual incidence of the combined endpoint after negative, inconclusive, and positive ETT was 0.2%, 1.3%, and 12.4%, respectively (p < 0.001). Rapid recovery of electrocardiography (ECG) changes during ETT was associated with negative downstream test results and excellent prognosis, whereas typical angina despite negative ECG was associated with positive downstream tests and adverse prognosis (p < 0.001). Younger age, female sex, higher metabolic equivalents of task achieved, and rapid recovery of ECG changes were predictors of negative downstream tests., Conclusions: Among patients referred for additional testing after ETT, the lowest yield was observed among individuals with rapid recovery of ECG changes or negative ETT, whereas the highest yield was observed among those with typical angina despite negative ECG or a positive ETT. These findings may be used to identify patients who are most and least likely to benefit from additional testing., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)