Marked improvement in survival after acute myocardial infarction in middle-aged men but not in women. The Northern Sweden MONICA study 1985-94

Abstract

Objectives: The aim of this study was to analyse time trends in survival after acute myocardial infarction with special emphasis on sex differences.

Design: Within the framework of the population-based WHO MONICA Project, all acute myocardial infarction events were recorded in the age group 25-64 years in northern Sweden during the period 1985-94. All first-ever myocardial infarction patients were followed for information on vital status.

Subjects: A total of 3397 men and 860 women with acute myocardial infarction, during the period between 1985 and 1994.

Main outcome measures: Case fatality rates after first-ever acute myocardial infarction.

Results: When compared with the 1985-86 cohort, the age-adjusted odds ratio for death within 1 year after acute myocardial infarction was 0.59 (95% CI 0.46-0.76) in the 1993-94 male cohort but 0.99 (95% CI 0.61-1.60) in the female 1993-94 cohort. Corresponding age-adjusted proportions of death within 1 year were 33.3% and 22.9% in men and 27.5% and 27.3% in women in 1985-86 and 1993-94, respectively. The odds ratio for 3-year case fatality amongst those who survived the first 28 days was 0.34 (95% CI 0.21-0.55) in 1991-92 compared with 1985-86 in men and 0.91 (0.43-1.94) in women.

Conclusion: Both short- and long-term survival after AMI have improved markedly in men over the last decade. There is a disturbing sex difference in that, during the same period, survival in women with AMI has not improved at all. This sex difference was not explained by differences in conventional prognostic factors.