OBJECTIVE: We examined relations between characteristics of the metabolic syndrome, early cardiovascular risk, and effect of early, intensive statin therapy after acute coronary syndrome. RESEARCH DESIGN AND METHODS: A total of 3,038 patients in the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) trial were characterized by the presence or absence of a history of diabetes, a history of hypertension and/or blood pressure > or = 130/> or = 85, BMI >30 kg/m2, HDL cholesterol <40 mg/dl (men) or <50 mg/dl (women), and triglycerides > or = 150 mg/dl. Patients with three or more of these characteristics were categorized as having metabolic syndrome. RESULTS: A total of 38% of patients (n = 1,161) met criteria for metabolic syndrome as defined in this study and had a 19% incidence of a primary end point event (death, nonfatal myocardial infarction, cardiac arrest, or recurrent unstable myocardial ischemia) during the 16-week trial. Patients with two or fewer characteristics (n = 1,877) were classified as not having metabolic syndrome and had a 14% incidence of a primary end point event. In univariate analysis, the individual characteristics that bore a significant relation to risk were diabetes and low HDL cholesterol. In a multivariable model including age, sex, and randomized treatment assignment, presence of metabolic syndrome was associated with a hazard ratio of 1.49 (95% CI 1.24-1.79, P < 0.0001). Relative risk reduction with 80 mg atorvastatin daily compared with placebo was similar in patients with and without metabolic syndrome. CONCLUSIONS: Metabolic syndrome, as defined in the context of this clinical trial, is a strong predictor of early recurrent ischemic events after acute coronary syndrome.