Radial Artery vs Bilateral Mammary Composite Y Coronary Artery Grafting: 15-Year Outcomes

Abstract

Total arterial coronary revascularization for three coronary territory disease can be achieved with a second arterial conduit joined to the left internal mammary artery as a Y graft, by using either a radial artery (RAY) or a second mammary artery (BIMAY). Patients undergoing total arterial revascularization for three coronary territory disease were identifiedfrom two cardiac surgical databases (in Sydney and Melbourne, Australia) using Society of Thoracic Surgeons-based definitions. BIMAY-treated patients underwentsurgery between 1994 and 2009, mostly usingan age-limited protocol, whereas RAY-treated patientsunderwent surgery between 1996 and 2003 without age limits. All-cause mortality data were acquiredfrom the national death registry, and survivalwas estimated by the Kaplan-Meier method. Propensity score matching was performed using 13 variables. Given the age imbalance between the groups, theprimary comparison was performed for age 66 years or younger. Overall, 1896 patients underwent RAY procedures, and 720 patients underwent BIMAY operations. Older age at surgery was the strongest independent predictor of mortality, with a hazard ratio of 2.06, and a 95% confidence interval of 1.93, 2.22 (P < .001). After propensity score matching, we identified 299 pairs of patients 66 years of age or younger with no preoperative or operative differences and similar ages at surgery: RAY 56.4 ± 7.0 years of age vs BIMAY 56.4 ± 6.8 years of age (P= .96). The RAY group had 4.0 ± 0.9 grafts, and the BIMAY group had 3.9 ± 0.9 grafts (P= .814). All-cause mortality was not different, with the proportion surviving at 15 years at 74.9% for the RAY group vs 76.2% for the BIMAY group (P= .211). Survival was not different between the RAY and BIMAY groups for total arterial revascularization of three coronary territory bypass grafting.