Several studies had given preliminary evidence that regular administration of aspirin may be of benefit to patients with known coronary artery disease. A National Heart and Lung Institute-sponsored study, the Coronary Drug Project, ran a pilot trial of aspirin and placebo in men with previous myocardial infarctions. Preliminary results from this trial demonstrated its feasibility and led NHLBI to sponsor a more definitive controlled study of the benefit of aspirin in the secondary prevention of coronary heart disease.