Aspirin and Recurrent Myocardial Infarction

To the Editor.— The COMMENTARY by Richard J. Jones, MD (1980;244:667), summarizes the clinical trials of aspirin in patients with myocardial infarction. Jones indicates the possibility that in the Aspirin Myocardial Infarction Study (AMIS) the excess number of patients in the aspirin group with congestive heart failure, history of angina pectoris, and history of cardiac arrhythmias at baseline may have masked a significant effect in favor of aspirin. The data suggest that this is not the case. As was noted by Jones, statistical corrections for the imbalances did not alter the conclusions. In addition, among patients with none of these three baseline characteristics, total mortality was 8% in the aspirin group (n=1,050) and 6.4% in the placebo group (n=1,160). Thus, it appears that the indicated baseline imbalance between groups is not responsible for the observed lack of benefit from aspirin.