Abstract
OBJECTIVE: To evaluate sex differences in perioperative characteristics, in-hospital outcomes and long-term survival following coronary artery bypass grafting (CABG). METHODS: Prospective data were collected for all patients undergoing isolated CABG at a single centre during 2001-2021. Baseline characteristics were adjusted between females and males using 1:1 propensity score matching (nearest-neighbour, without replacement). Kaplan-Meier analysis assessed long-term survival. A predefined sub-analysis assessed risk mitigation associated with using off-pump CABG (OPCABG) in females in the matched cohort. RESULTS: Prematching, 11 563 males and 2573 females were included. Females were older with higher prevalences of class III-IV angina, hypertension and diabetes. After matching, 2573 patients per group were analysed, with standardised mean differences <0.1 for all covariates. Females had fewer left internal mammary artery (LIMA) grafts (84% vs 88%, p<0.001), fewer total grafts (median 2 vs 3, p<0.001), higher in-hospital mortality (2.2% vs 1.3%, OR 1.74, 95% CI 1.14 to 2.71, p=0.011) and longer hospital stays (median 7 days vs 6 days, beta 0.51, 95% CI 0.12 to 0.90, p=0.01). Long-term survival was similar (stratified log-rank p=0.79). OPCABG mitigated the risk of in-hospital mortality in females (1.1% males vs 1.6% females, OR 0.69, 95% CI 0.33 to 1.43, p=0.32; 1.6% OPCABG females vs 3.0% on-pump females, OR 0.53, 95% CI 0.31 to 0.91, p=0.021). CONCLUSIONS: Females suffer higher in-hospital mortality and receive fewer LIMA and total number of grafts than males; however, 20-year survival is similar. OPCABG protects females from in-hospital mortality. A new female-tailored peri-operative care approach is warranted for females undergoing CABG.