PIP: 1529 men with a history of myocardial infarction (MI) and previously treated with either dextrothyroxine or estrogen therapy in the Coronary Drug Project were selected for a study on the administration of aspirin on a daily basis. Patients received 324 mg aspirin daily or a placebo on a double-blind basis. Follow-up ranged from 10-28 months and was carried out at 4-month intervals. 60% of the patients were over 55 years and approximately 1/3 had had 2 MIs. There were 32 dropouts from the program. Patients taking aspirin experienced 30% fewer deaths (5.8% compared to 8.3%). For combined fatal and nonfatal events the aspirin group was 21% lower than the placebo group. The differences seen are suggestive of a beneficial effect of aspirin but the data are from too small a sample to be conclusive.