Sex differences in outcomes following coronary artery bypass grafting: a meta-analysis

OBJECTIVES: Previous reports have found females are a higher risk of morbidity and mortality following isolated coronary artery bypass grafting (CABG). Here, we describe the differences in outcomes following isolated CABG between males and females. METHODS: Following a systematic literature search, studies reporting sex-related outcomes following isolated CABG were pooled in a meta-analysis performed using the generic inverse variance method. The primary outcome was operative mortality. Secondary outcomes included rates of stroke, repeat revascularization, myocardial infarction, major adverse cardiac events, and late mortality. Subgroup analyses were performed for studies published before and after the year 2000 and for the type of risk adjustment. RESULTS: Eighty-four studies were included with a total of 903 346 patients. Females were at higher risk for operative mortality (odds ratio: 1.77, 95% confidence interval [CI]: 1.64-1.92, P < 0.001). At subgroup analysis, there was no difference in operative or late mortality between studies published prior and after 2000 or between studies using risk adjustment. Females were at a higher risk of late mortality (incidence rate ratio [IRR]: 1.16, 95% CI: 1.06-1.26, P < 0.001), major adverse cardiac events (IRR: 1.40, 95% CI: 1.19-1.66, P < 0.001), myocardial infarction (IRR: 1.28, 95% CI: 1.13-1.45, P < 0.001) and stroke (IRR: 1.31, 95% CI: 1.15-1.51, P > 0.001) but not repeat revascularization (IRR: 0.99, 95% CI: 0.76-1.29, P = 0.95). The use of the off-pump technique or multiple arterial grafts was not associated with the primary outcome. CONCLUSIONS: Females undergoing CABG are at higher risk for operative and late mortality as well as postoperative events including major adverse cardiac events, myocardial infarction and stroke. PROSPERO REGISTRATION: CRD42020187556.