A coronary artery bypass graft (CABG) procedure where blockages in the coronaries are bypassed using a blood vessel harvested from elsewhere in the body and connected to the vessel past the blockage to supply blood to the heart. A new study shows better outcomes seen in multiple vs. single coronary artery bypass grafts (CABG) in men and sex appears to play a role in mortality. Getty Images
January 6, 2020 — A new Weill Cornell Medicine found the risk of dying seven years after coronary artery bypass graft (CABG) surgery was significantly lower in men receiving multiple bypass grafts rather than single grafts. The study also looked at CABG in women and there was no apparent difference between single or multiple vessel bypass procedures, but overall women had a higher mortality rate. The study published online Dec. 23 in the Journal of the American Medical Association (JAMA) Cardiology.
Led by WCM cardiology expert Mario F.L. Gaudino, M.D., analyzed data from more than 63,402 patients in New York’s Cardiac Surgery Reporting System and New York’s Vital Statistics file who underwent CABG between Jan. 1, 2005, to Dec. 31, 2014. The findings raises important questions about why cardiovascular outcomes differ by sex and underscores the need for prospective clinical trials in women.
In this statewide cohort study, 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.
“Previous evidence for women has been unclear as women typically represent only about 20 percent of patients who undergo coronary artery bypass procedures overall and less than 15 percent of clinical trial participants,” Gaudino explained.
The study suggests that women have a worse pre-operative 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.
Results of the study show patients (48,155 men [76%]; 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 9,512 male pairs and 1,860 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.
1. Mario Gaudino, MD, MSCE; Zaza Samadashvili, MD; Irbaz Hameed, MD; et al. Differences in Long-term Outcomes After Coronary Artery Bypass Grafting Using Single vs Multiple Arterial Grafts and the Association With Sex. JAMA Cardiol. Published online Dec. 23, 2020. doi:10.1001/jamacardio.2020.6585.