Sex difference in outcomes after coronary artery bypass grafting: follow-up data of the Netherlands Heart Registration

Objectives: Controversies exist regarding sex differences in outcomes after coronary artery bypass grafting (CABG). This study assessed sex differences in early and mid-term outcomes after CABG and factors associated with these differences. Outcomes were based on data from the Netherlands Heart Registration (NHR).

Methods: Data of patients undergoing CABG in the Netherlands between 2013 and 2019 were retrieved from the NHR database. Primary outcomes were early mortality, morbidity and mid-term survival. The population was divided into subgroups based on age (≥ 70 years and < 70 years). Regression analyses investigated the correlation between sex and both early and mid-term mortality.

Results: This study included 41,705 male and 10,048 female patients. Median follow-up was 3.6 (1.8-4.8) years. Female patients were less likely to receive ≥ 2 arterial grafts (15.9% vs 23.2%, p < 0.001), had fewer anastomoses (3.2 ± 1.1 vs 3.5 ± 1.1, p < 0.001), higher 30-day mortality (1.9% vs 1.0%; p < 0.001) and a lower mid-term survival rate (91.3% vs 93.1%, p < 0.001). Perioperative complications, including myocardial infarction and stroke, were more common in female patients (all p < 0.001). Women aged < 70 years had a lower mid-term survival rate than men < 70 years (94.5% vs 96.0%, p < 0.001). Cox regression analysis showed that female sex was not significantly associated with mid-term mortality in the total cohort [hazard ratio (HR) 1.03; p = 0.45] but was associated with mid-term mortality in patients aged < 70 years (HR 1.19; p < 0.001).

Conclusions: Women undergoing CABG in our cohort presented with more complex risk profiles, received different surgical strategies and had worse early and mid-term outcomes compared to men. Female sex was associated with mid-term mortality only in patients < 70 years of age.