Differences in Long-term Outcomes after Coronary Artery Bypass Grafting Using Single vs Multiple Arterial Grafts and the Association with Sex

Importance: Sex-related differences in the outcome of using multiple arterial grafts during coronary artery bypass grafting (CABG) remain uncertain. Objective: To compare the outcomes of the use of multiple arterial grafts vs a single arterial graft during CABG for women and men. Design, Setting, and Participants: This statewide cohort study used data from New York's Cardiac Surgery Reporting System and New York's Vital Statistics file on 63402 patients undergoing CABG from January 1, 2005, to December 31, 2014. Statistical analysis was performed from January 10 to August 20, 2020. Exposures: Multiple arterial grafting or single arterial grafting. Main Outcomes and Measures: Mortality, acute myocardial infarction (AMI), stroke, repeated revascularization, major adverse cardiac and cerebrovascular event (composite of mortality, AMI, and stroke), and major adverse cardiac event (composite of mortality, AMI, or repeated revascularization) were compared among propensity-matched patients and stratified by the risk of long-term mortality. Results: Of the 63402 patients (48155 men [76.0%]; mean [SD] age, 69.9 [10.5] years) in the study, women had worse baseline characteristics than men for most of the explored variables. Propensity matching yielded a total of 9512 male pairs and 1860 female pairs. At 7 years of follow-up, mortality was lower among men who underwent multiple arterial grafting (adjusted hazard ratio, 0.80; 95% CI, 0.73-0.87) but not women who underwent multiple arterial grafting (adjusted hazard ratio, 0.99; 95% CI, 0.84-1.15). When stratified by the estimated risk of death, the use of multiple arterial grafts was associated with better survival and a lower rate of a major adverse cardiac event among low-risk, but not high-risk, patients of both sexes, and the risk cutoff was different for men and women. Conclusions and Relevance: This study suggests that women have a worse preoperative risk profile than men. Multiple arterial grafting is associated with better outcomes among low-risk, but not high-risk, patients, and the risk cutoffs differ between sexes. These data highlight the need for new studies on the outcome of multiple arterial grafts in women.