Witt BJ et al. (2005) A community-based study of stroke incidence after myocardial infarction. Ann Intern Med 143: 785–792

The risk factors and treatments for myocardial infarction (MI) and stroke are similar. Investigations have shown that the incidence of MI is decreasing and survival after such an event is increasing; however, it is not known whether these changes also affect the incidence of stroke after index MI. Witt and colleagues examined the occurrence of ischemic and hemorrhagic stroke in a community-based cohort study of 2,160 patients who were hospitalized with incident MI within the period 1979–1998.

The median follow-up was 5.6 years (range 0–22 years) and 273 strokes were recorded. The rate of stroke occurring within 30 days of the index MI was 22.6 per 1,000 person-months—a 44-fold increase relative to the expected rate for the general population, calculated from the Rochester Stroke Registry of the same community. In the first 3 years following MI, the incidence of stroke was 2–3 times higher than in the general community, and the risk of stroke was increased with diabetes, increasing age and previous stroke. The risk of stroke after MI did not decline over the 19-year study period and the occurrence of stroke was associated with increased risk of death (adjusted hazard ratio 2.89; 95% CI 2.44–3.43).

The results show that treatments that have reduced the incidence of MI do not decrease the risk of subsequent stroke. The use of antithrombotic interventions to prevent stroke should be considered, particularly in the 3 years immediately after MI. The study cohort was mostly white and, therefore, these findings might not be generalizable to other ethnic populations.