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

Background: 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). Methods: Patients undergoing total arterial revascularization for three coronary territory disease were identified from two cardiac surgical databases (in Sydney and Melbourne, Australia) using Society of Thoracic Surgeons–based definitions. BIMAY-treated patients underwent surgery between 1994 and 2009, mostly using an age-limited protocol, whereas RAY-treated patients underwent surgery between 1996 and 2003 without age limits. All-cause mortality data were acquired from the national death registry, and survival was estimated by the Kaplan-Meier method. Propensity score matching was performed using 13 variables. Given the age imbalance between the groups, the primary comparison was performed for age 66 years or younger. Results: 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). Conclusions: Survival was not different between the RAY and BIMAY groups for total arterial revascularization of three coronary territory bypass grafting.