Sex differences after coronary artery bypass grafting with a second arterial conduit.

Abstract Objectives Double arterial conduit (DAC) use during coronary artery bypass grafting (CABG) is associated with improved clinical outcomes as compared to single arterial conduits (SAC) in the general population. However, the sex-specific outcomes of this strategy remain unknown and are needed to inform sex-specific revascularization guidelines. Methods We conducted a population-based, retrospective cohort study of all Ontarians who underwent primary isolated CABG with SAC or DAC between October 2008 and September 2017. The primary outcome was all-cause mortality. Secondary outcomes included major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of myocardial infarction, heart failure hospitalization, repeat revascularization, and stroke. We used inverse probability of treatment weighting to account for group imbalances. Results A total of 9,135 women and 36,748 men underwent CABG. At 30 days, there was no between group difference in mortality or MACCE in men. However, among women DAC was associated with an increased rate of 30-day death (HR 1.48; 95% CI(1.23, 1.79)) and MACCE (HR 1.32; 95%CI(1.14, 1.51)). The risk of medium-term mortality with DAC was less in both men (HR 0.88; 95%CI(0.84-0.92)) and women (HR 0.87; 95%CI(0.81-0.94)), as was the medium-term risk of MACCE (HR 0.91; 95%CI(0.87-0.94) [men], HR 0.91; 95%CI(0.86-0.97) [women]). The incremental improvement in 9-year survival in women with DAC was 4.0% whereas it was 0.9% in men. Conclusion DAC is associated with better medium-term survival and cardiovascular outcomes in both sexes. DAC is associated with increased perioperative risk in women, but the medium-term benefit is greater than in men.