Sex Differences in Long-Term Mortality after Myocardial Infarction: A Systematic Review
Background—Studies of sex differences in long-term mortality after acute myocardial infarction (AMI) have reported mixed results. A systematic review is needed to characterize what is known about sex differences in long-term outcomes and to define gaps in knowledge.
Methods and Results—We searched the Medline database from 1966 to December 2012 to identify all studies that provided sex-based comparisons of mortality after AMI. Only studies with at least five years of follow-up were reviewed. Of the 1,877 identified abstracts, 52 studies met inclusion criteria, of which 39 were included in this review. Most studies included less than one-third women. There was significant heterogeneity across studies in patient populations, methodology, and risk adjustment, which produced substantial variability in risk estimates. In general, most studies reported higher unadjusted mortality for women compared with men at both 5 and 10 years after AMI; however, many of the differences in mortality became attenuated after adjustment for age. Multivariable models varied between studies; however, most reported a further reduction in sex differences after adjustment for covariates other than age. Few studies examined sex-by-age interactions; however several studies reported interactions between sex and treatment, whereby women have similar mortality risk as men after revascularization.
Conclusions—Sex differences in long-term mortality after AMI are largely explained by differences in age, comorbidities, and treatment utilization between women and men. Future research should aim to clarify how these differences in risk factors and presentation contribute to the sex gap in mortality.
- Received February 13, 2014.
- Revision received June 7, 2014.
- Accepted June 17, 2014.