Conduit choice and volume-outcome relationships in multi-arterial coronary artery bypass grafting among Medicare beneficiaries in the US.
Academic Article
Overview
abstract
BACKGROUND: Multi-arterial grafting (MAG) is under-utilized. We evaluated the association between surgeon experience and conduit utilization outcomes following MAG. METHODS: Using US Centers for Medicare and Medicaid data, we identified 29,268 patients ≥ 65 years undergoing isolated, primary, non-emergency MAG, of which 15,682 met the inclusion criteria. Propensity score matching was performed on 26 baseline patient characteristics. Individual surgeons were grouped into tertiles based on conduit use. Low volume:<3 radial arteries or 2 bilateral internal thoracic artery (BITA) grafts annually; high-volume:>10 radial arteries or 4 BITAs annually. The primary outcome was major adverse cardiac events (MACE): death, myocardial infarction or repeat revascularization at 4-years. Outcomes were compared in a multivariable Cox-proportional hazard model adjusting for the individual surgeon's case volume of each conduit. RESULTS: Among MAG recipients, 5,784 (20%) received radial artery grafts and 9,989 (34%) received BITA grafts. Radial artery recipients were younger (70.6 vs. 71.2years) and more likely diabetic (46.9% vs 43.2%) than BITA recipients. Among 5,778 matched pairs, at 4-years, the incidence of MACE was numerically lower in the radial group (14.7% vs 15.7%, p=0.05), but there was no difference in all-cause mortality (10.8%radial vs 11.5%BITA, p=0.06). Among BITA recipients, surgeon experience was associated with MACE only among the lowest vs the highest volume tertile (Adjusted HR:1.15, 95%CI: 1.01=1.33, p=0.046). There was no association between MACE and surgeon volume for radial artery graft recipients. CONCLUSIONS: Radial artery and BITA grafting demonstrated similar mid-term outcomes, while there was a surgeon volume effect for BITA use.
