Sex Differences in Short-term and Long-term All-Cause Mortality Among Patients With ST-Segment Elevation Myocardial Infarction Treated by Primary Percutaneous Intervention

IMPORTANCE: Although outcomes in patients with ST-segment elevation myocardial infarction (STEMI) have improved in the past 2 decades, a sex disparity exists in survival, with women having higher mortality than men. OBJECTIVE: To conduct a meta-analysis of observational studies that examined differences in mortality by sex in patients with STEMI treated with primary percutaneous coronary intervention (PPCI). DATA SOURCES: MEDLINE, EMBASE, Cochrane central, and electronic databases were searched for relevant studies in all languages and without time restriction. STUDY SELECTION: Studies were included if (1) they studied patients who presented with STEMI, (2) primary percutaneous coronary intervention (PPCI) was the treatment for STEMI, (3) PPCI was performed within 12 hours of symptom onset, and (4) sex-specific in-hospital and/or 1-year mortality were reported. DATA EXTRACTION AND SYNTHESIS: Two investigators independently reviewed retrieved citations and assessed eligibility. Discrepancies were resolved by consensus. Quality of included studies was assessed using Newcastle-Ottawa Quality Assessment Scale for cohort studies. Data were pooled using a random-effects model. MAIN OUTCOMES AND MEASURES: Sex-specific in-hospital and 1-year all-cause mortality. Risk ratios (RRs) of mortality were used for these 2 time points, if reported. RESULTS: Of the 149 studies identified, 35 met inclusion criteria, representing 18 555 women and 49 981 men. In the unadjusted analyses, women were at a higher risk for in-hospital (RR, 1.93; 95% CI, 1.75-2.14 P < .001, I2 = 14%) and 1-year all-cause mortality (RR, 1.58; 95% CI, 1.36-1.84 P < .001, I2 = 51%) compared with men. However, when adjusted RRs were used, the association between women and higher risk of all-cause mortality was attenuated but still significantly elevated for in-hospital mortality (RR, 1.48; 95% CI, 1.07-2.05 P = .02, I2 = 56%), but the higher risk for 1-year mortality in women was no longer significant (RR, 0.90; 95% CI, 0.69-1.17 P = .42, I2 = 58%). CONCLUSIONS AND RELEVANCE: An increased mortality in women with STEMI treated with PPCI was detected in this large meta-analysis but is likely confounded by baseline cardiovascular risk factors and the differences in clinical profile of male and female patients with STEMI. Intensive cardiovascular risk modification efforts in women may help to reduce this sex disparity.