Aspirin in coronary heart disease. Comparison of six clinical trials.

Data from six randomized, placebo-controlled clinical trials of aspirin, involving a total of 10,703 postmyocardial infarction (MI) patients, are compared and combined. After adjustment for a number of prognostically important baseline factors, the reduction in total mortality by aspirin was 10% (P = 0.044). This beneficial trend was particularly pronounced during the 1st yr of daily aspirin ingestion, but did not differ between patients who entered the trial less than 6 mo and greater than 6 mo after their last MI. Significant beneficial effects of aspirin were noted with respect to 1) diagnosis of definite nonfatal MI and 2) hospitalization for greater than 2 wk for MI. Significant adverse effects of aspirin were noted with respect to the side effects of stomach pain, heartburn and vomiting, elevation of systolic blood pressure to greater than 160 mm Hg, and elevation of serum urea nitrogen and serum uric acid levels to the abnormal range.