British studies of aspirin and myocardial infarction.

The MRC Epidemiology Unit in Cardiff, Wales conducted three randomized, controlled trials of aspirin use in patients who had had myocardial infarction. Follow-up study for one to two years was conducted in 1,239 men after they experienced myocardial infarction and another was based on 1,682 patients followed for one year after infarction. Although the results are not statistically significant in either trial, they are consistent with a reduction of about 26 and 17 percent in the mortality rate of patients during the year after infarction. The third trial, which was concerned with a very early mortality rate, was based on a sample of 2,530 patients. This gave no evidence of benefit from aspirin use during the acute phase of infarction.