Unlike ST-segment elevation myocardial infarction, the degree of stenosis and physiology of ischemia varies in patients with non-ST-segment elevation myocardial infarction (NSTEMI). The prevalence, predictors, and outcomes of patients with NSTEMI who lack significant epicardial coronary artery disease (CAD) in routine clinical practice remain poorly characterized. We sought to determine the prevalence, predictors, and outcomes of patients with NSTEMI and insignificant CAD.