Secondary prevention of myocardial infarction.

Aspirin, sulfinpyrazone and the combination of aspirin/dipyridamole, which inhibit some aspects of platelet function, have been evaluated in large-scale clinical trials in secondary prevention of myocardial infarction. The Persantine-Aspirin Reinfarction Study using dipyridamole, and Anturane Reinfarction Trial and Anturan Reinfarction Italian Study with sulphinpyrazone did not yield conclusive results. There have been five trials in which aspirin has been compared with a placebo. When the results were pooled, the outcome was consistent with a reduction during aspirin treatment of 5-10% in mortality and 20% in coronary event-rate. Whether this small benefit to an individual patient is worthwhile, and whether the effect of aspirin is influenced by coexistent beta-blocker treatment, is not clear.