The coronary primary prevention trial: Design and implementation

Abstract

This report describes the design of the Coronary Primary Prevention Trial (CPPT), a clinical trial sponsored by the National Heart, Lung and Blood Institute (NHLBI). The primary objective of the trial is to test the hypothesis that long-term reduction of serum cholesterol in hypercholesterolemic men initially free of clinical coronary heart disease (CHD) will lead to a lowered incidence of CHD. A total of 3810 men with primary Type II hyperlipoproteinemia were enrolled at 12 North American clinical centers. At the time of entry, these men were 35–59 yr old, in good general health and free of any overt symptoms of CHD. All participants were prescribed a standard diet allowing daily intake of approx 400 mg of cholesterol with a polyunsaturated-to-saturated fat ratio of approx 0.8. In addition, 24 g/day of a bile acid sequestrant, cholestyramine, was prescribed to half the men; the other half received a placebo. The assignment of participants to drug or placebo groups was done randomly within eight welldefined prognostic strata at each clinic and in a double-blind manner. Participants are being followed for a minimum of 7 yr. The primary end points are coronary death and non-fatal myocardial infarction. The CPPT data are reviewed periodically by a Safety and Data Monitoring Board for evidence of adverse and/or beneficial treatment effects.