Trends in the incidence and survival of patients with hospitalized myocardial infarction, Olmsted County, Minnesota, 1979 to 1994

Abstract

Background: Evidence indicates that deaths from coronary disease are decreasing less in elderly persons and women. Understanding the determinants of these trends is important for prevention.

Objective: To test the hypothesis that trends in incidence and survival of hospitalized myocardial infarction differ according to sex and age.

Design: Longitudinal observational study.

Setting: Community-dwelling persons in Olmsted County, Minnesota.

Patients: 5117 patients who had an estimated 1820 incident myocardial infarctions from 1979 to 1994.

Measurements: Myocardial infarctions were validated by using epidemiologic criteria. Rates were directly adjusted to the age distribution of the 2000 U.S. population.

Results: Of the 1820 incident infarctions, 44% occurred in women and 36% in persons 75 years of age or older. In 1979, the age-adjusted incidence of myocardial infarction was 205 per 100 000 persons (95% CI, 162 to 247 per 100 000 persons). Between 1979 and 1994, the age-adjusted incidence of myocardial infarction decreased by 8% (CI, -23% to 10%) in men but increased by 36% (CI, 9% to 70%) in women. A 31% decrease in the incidence of infarction over time was observed in men 40 years of age compared with a 49% increase in women 80 years of age. Survival improved predominantly in younger persons.

Conclusions: Over time, the incidence of hospitalized infarction decreased in men but increased in women and elderly persons. Survival benefits were clustered among younger persons. These results suggest that both incidence and survival contribute to the contrasting mortality trends by age and sex and that the burden of coronary disease has shifted toward elderly persons, a finding that has public health implications in an aging population.