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

Question What is the association of sex with the relative outcomes of multiple vs single arterial grafting during coronary artery bypass grafting? Findings In a statewide cohort study of 63 402 patients undergoing coronary artery bypass grafting, at 7 years' follow-up, outcomes with multiple arterial grafting were better among low-risk, but not high-risk, patients. Mortality at 7 years was lower among men, but not women, undergoing multiple arterial grafting. Meaning Multiple arterial grafting was associated with better outcomes among low-risk, but not high-risk, men and women at different thresholds; studies of multiple arterial grafting specifically directed at women are needed. This cohort study compares the outcomes of the use of multiple arterial grafts vs a single arterial graft during coronary artery bypass grafting for women and men. 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 63 402 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 63 402 patients (48 155 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.

Automated summary

This study found that multiple arterial grafting during coronary artery bypass grafting had better outcomes for low-risk patients, especially low-risk men, while showing no significant benefit for high-risk patients or women. This highlights the need for further research on the outcomes of multiple arterial grafting in different patient populations.