Sudden death and recurrent ischemic events after myocardial infarction in the community

Abstract

As myocardial infarction (MI) hospital fatalities decline, survivors are candidates for recurrent events. However, little is known about morbidity after MI and how it may have changed over time. The authors examined the incidence of sudden cardiac death and recurrent ischemic events post-MI to test the hypothesis that it has declined over time. MIs were validated by using standardized criteria. Sudden cardiac death and recurrent ischemic events (recurrent MI or unstable angina) were identified through Olmsted County, Minnesota, community medical records and their association with time examined after adjustment for age, sex, and comorbidity. Between 1979 and 1998, 2,277 MIs occurred (57% in men; mean age, 67 (standard deviation, 14) years). After 3 years, the event-free survival rate was 94% (95% confidence interval: 93, 95) for sudden cardiac death and 56% (95% confidence interval: 54, 58) for recurrent ischemic events. Both outcomes were more frequent with older age and greater comorbidity. The temporal decline in both events was of similar magnitude; for an MI occurring in 1998 versus 1979, risk of subsequent recurrent ischemic events or sudden cardiac death declined by 24% (relative risk = 0.76, 95% confidence interval: 0.63, 0.93). Thus, in the community, recurrent ischemic events are frequent post-MI, while sudden cardiac death is less common. Their incidence declined over time, supporting the notion that contemporary treatments effectively improve outcomes after MI.