Vein Graft Use and Long-Term Survival Following Coronary Bypass Grafting

Abstract

Background: Although placement of at least 1 arterial graft during coronary artery bypass grafting (CABG) has a proven survival benefit, it is unknown what degree of revascularization with saphenous vein grafting (SVG) is associated with improved survival.

Objectives: The authors sought to determine whether undergoing surgery performed by a surgeon who is liberal with vein graft utilization is associated with improved survival in patients undergoing single arterial graft CABG (SAG-CABG).

Methods: This was a retrospective, observational study of SAG-CABG performed in Medicare beneficiaries from 2001 to 2015. Surgeons were stratified by number of SVG utilized per SAG-CABG into conservative (≥1 SD below mean), average (within 1 SD of mean), and liberal (≥1 SD above mean). Long-term survival was estimated using Kaplan-Meier analysis and compared among surgeon groups before and after augmented inverse-probability weighting.

Results: There were 1,028,264 Medicare beneficiaries undergoing SAG-CABG from 2001 to 2015 (mean age 72.0 ± 7.9 years, 68.3% male). Over time, 1-vein and 2-vein SAG-CABG utilization increased, whereas 3-vein and ≥4-vein SAG-CABG utilization decreased (P < 0.001). Surgeons who were conservative vein graft users performed a mean 1.7 ± 0.2 vein grafts per SAG-CABG, whereas those who were liberal vein graft users performed a mean 2.9 ± 0.2 vein grafts per SAG-CABG. Weighted analysis demonstrated no difference in median survival among patients undergoing SAG-CABG by liberal vs conservative vein graft users (adjusted median survival difference 27 days).

Conclusions: Among Medicare beneficiaries undergoing SAG-CABG, there is no association between surgeon proclivity for vein graft utilization and long-term survival, suggesting that a conservative approach to vein graft utilization is reasonable.

Keywords: Medicare; coronary artery bypass grafting; single artery graft; vein grafts.