AIM-HIGH is a multicenter, randomized, double-blind, parallel-group, controlled clinical trial designed to test whether the drug combination of extended release niacin plus simvastatin is superior to simvastatin alone, at comparable levels of on-treatment LDL-C, for delaying the time to a first major CV disease outcome over a 4-year median follow-up in patients with atherogenic dyslipidemia. Prior clinical trials have found only 25 to 35% CV risk reduction using statin monotherapy (i.e., event rate 2/3 to 3/4 of placebo rate). The study is needed to confirm whether statin-niacin combination therapy, designed to target a wider spectrum of dyslipidemic factors in addition to LDL-C, will provide a more substantial (greater than 50%) reduction of CV events. Epidemiologic studies confirm the high prevalence of atherogenic dyslipidemia and its impact on CV event rates. Preliminary clinical trials suggest that targeting these factors with dyslipidemic therapy will reduce CV events. The study will enroll an estimated 3,300 men and women more than 45 years old at high risk of recurrent CV events by virtue of having established CV disease together with the two dyslipidemic elements of metabolic syndrome: low HDL-cholesterol (HDL-C) (less than or equal to 40 mg/dl) and high triglycerides (TG) (greater than or equal to 150 mg/dl). The study specifically aims to test this hypothesis for the primary composite clinical end point of CHD death, nonfatal MI, ischemic stroke, hospitalization for acute coronary syndrome with objective evidence of ischemia (troponin-positive or ST-segment deviation), or symptom-driven coronary or cerebral revascularization. Secondary end points include the composite of CHD death, nonfatal MI, ischemic stroke, or hospitalization for high-risk acute coronary syndrome; the composite of CHD death, nonfatal MI or ischemic stroke; and cardiovascular mortality.