Female sex is associated with short-term mortality in coronary artery bypass grafting patients: A propensity-matched analysis.

Background: Females undergoing coronary artery bypass grafting (CABG) surgery have been reported to be at increased risk of postoperative mortality and comorbidity. Our main objective is to evaluate the impact of female sex on 30-day mortality after isolated CABG surgery. Methods: We created a retrospective cohort of adult patients underwent isolated CABG surgery between 2006 and 2020 in a large rural healthcare system. Patients were grouped by sex and a 1:1 nearest neighbor propensity score matching method was performed to reduce the bias due to potential confounding. Association between female sex and 30-day mortality was assessed using conditional regression analysis and appropriate statistical tests for matched analyses. Associations between female sex and eight secondary outcomes were also considered. Results: Out of 5616 adult patients underwent isolated CABG surgery, 1352 were females. The propensity scoring matching method provided 1346 matched pairs with no observed significant imbalance for any of the included confounders. The conditional logistic regression analysis showed independent association between female sex and 30-day mortality (OR = 1.83, CI = 1.10-3.04, p = 0.02). Conclusions: Females undergoing isolated CABG surgery were at significantly greater risk of postoperative 30-day mortality and longer postoperative length of stay. Further research is needed to identify and address the causes of these disparities.