Impact of Sex on Long-term Mortality From Acute Myocardial Infarction vs Unstable Angina

Background: Patient sex has been shown to differentiallyaffectmortalityfromunstableangina(UA)andacute myocardial infarction (AMI). However, to our knowledge, no prior population-based studies have examined both cohorts simultaneously to explain this intriguing variation. Hence, we undertook to explore and explain sex differences in 5-year mortality after UA and AMI. Methods:Weusedanadministrativedatabaseof22967 patients with AMI and 8441 patients with UA dischargedfromacutecarehospitalsinAlbertabetweenApril 1, 1993, and March 31, 2000. Results:Women were older with more baseline comorbidities, more frequently had a diagnosis of UA, and had 30% lower relative odds of undergoing revascularization than men. Kaplan-Meier estimates of 5-year mortalityweresimilarbetweensexesafterUA(womenvsmen, 21.6% vs 19.5%;P=.09) but markedly higher for women after AMI (38.5% vs 26.6%, P.001). After adjustment forbaselinecharacteristicsandrevascularization,thehazard ratios (95% confidence intervals) for women vs men were 0.81 (0.72-0.92) after UA and 0.99 (0.93-1.05) after AMI. Only women younger than 65 years were at a significantly higher risk after AMI. The reasons for this difference in sex-related outcomes between UA and AMI may relate to greater disparities in the AMI cohort with respecttoage,comorbidities,neighborhoodincomes,and referrals to cardiovascular specialists. Conclusions: Relative to UA, AMI has a more serious impact on women than men, such that women have a survival advantage when afflicted with UA but lose that advantage with AMI. Additional investigation into the causes, treatment, and policy implications of the agesex interaction is warranted. Arch Intern Med. 2003;163:2476-2484