110 ED patients at intermediate risk for short-term death or infarction, with nondiagnostic Electrocardiograms (ECG) and normal initial cardiac biomarkers, will be randomized to standard care or OU CMR protocols. Subjects in the OU CMR protocol will undergo CMR perfusion and stress testing, followed by serial biomarkers. Standard care subjects will be admitted for usual cardiac testing. ACS (infarction, death, coronary revascularization, unstable angina) will be assessed by evaluation of hospital course and phone follow-up at 30 days. Cost of hospital care will be compared among groups.