Randomized, Phase III. Each patient was randomly assigned to a lipid-altering strategy or its placebo and to an antioxidant vitamin strategy or its placebo, in a 2 x 2 factorial design. The four groups were simvastatin-niacin plus an antioxidant vitamin cocktail; simvastatin-niacin plus vitamin placebo; antioxidant vitamins alone plus simvastatin-niacin placebo; or placebos for both strategies. All groups were counseled with respect to diet, exercise, and smoking cessation. The primary endpoint was the average change in proximal obstructive disease during the 2.5 year interval between baseline and the followup study. Secondary endpoints included the frequency of cardiac events, including cardiac death, confirmed non-fatal myocardial infarction, cerebrovascular accident, or revascularization by bypass or angioplasty for medically refractory unstable ischemia. The trial ended in August, 1999.