Sex Differences in Incident and Recurrent Coronary Events and All-Cause Mortality

Abstract

BACKGROUND: Women have lower age-specific rates of incident coronary heart disease (CHD) than men. It is unclear whether women remain at lower risk for CHD events versus men following a myocardial infarction (MI). OBJECTIVES: This study assessed sex differences in recurrent MI, recurrent CHD events, and mortality among patients with MI and compared these associations with sex differences in a control group without a history of CHD. METHODS: This study analyzed data for 171,897 women and 167,993 men age 21 years or older with health insurance in the United States who had a MI hospitalization in 2015 or 2016. Patients with a MI were frequency matched by age and calendar year to 687,588 women and 671,972 men without CHD. Beneficiaries were followed until December 2017 for MI, CHD (i.e., MI or coronary revascularization), and in Medicare for all-cause mortality. RESULTS: Age-standardized rates of MI per 1,000 person-years were 4.5 in women and 5.7 in men without CHD (hazard ratio [HR]: 0.64; 95% confidence interval [CI]: 0.62 to 0.67) and 60.2 in women and 59.8 in men with MI (HR: 0.94; 95% CI: 0.92 to 0.96). CHD rates in women versus men were 6.3 versus 10.7 among those without CHD (HR: 0.53; 95% CI: 0.51 to 0.54) and 84.5 versus 99.3 among those with MI (HR: 0.87; 95% CI: 0.85 to 0.89). All-cause mortality rates in women versus men were 63.7 versus 59.0 among those without CHD (HR: 0.72; 95% CI: 0.71 to 0.73) and 311.6 versus 284.5 among those with MI (HR: 0.90; 95% CI: 0.89 to 0.92). CONCLUSIONS: The lower risk for MI, CHD, and all-cause mortality in women versus men is considerably attenuated following a MI.