Recurrent myocardial infarction. 1. Natural history of fatal and non-fatal events.

1306 men below 68 years of age who survived a first myocardial infarction (MI) during 1968-1977 were followed up between 2 and 12 years after discharge from hospital. The mean follow-up time was 6.5 years. The patients were unselected and paid regular visits to a Post-MI Clinic where treatment was standardized. The diagnosis of a non-fatal reinfarction was based on conventional clinical criteria, and the diagnosis of a fatal reinfarction on autopsy findings of a recent myocardial injury and/or a fresh coronary thrombus. The autopsy rate was high and the follow-up of endpoints was complete. The total cumulative rate of endpoint free patients was 64% at 5 years and 50% at 10 years follow-up. The total mortality rate was 19% at 5 years and 33% at 10 years follow-up. The total cumulative rate of a first reinfarction was 28% at 5 years and 37% at 10 years follow-up (80% non-fatal and 20% fatal). 63 patients suffered more than one reinfarction. The mortality rate was strongly associated with age. In contrast the rate of non-fatal reinfarctions was independent of age.