All-Venous Grafting and Very Long-Term Survival After Coronary Artery Bypass Grafting.

Abstract

Observational studies of coronary artery bypass grafting (CABG) have associated single-arterial grafting with superior outcomes compared with all-venous grafting. Current guidelines assign single-arterial grafting a class I recommendation. However, no adequately powered randomized controlled trials were undertaken to confirm this benefit, and very long-term data on outcomes of various conduit strategies from more contemporary eras remain lacking. This study retrospectively analyzed Medicare beneficiaries who underwent CABG from 1999 to 2004, the period immediately preceding the first publication of guidelines affording single-arterial grafting a class I indication. The study compared survival between beneficiaries undergoing all-venous grafting and those undergoing single-arterial grafting by using restricted mean survival times (RMSTs). Risk adjustment was performed for all available covariates by using overlap propensity score weighting. Among 640,116 Medicare beneficiaries, 101,120 (15.8%) underwent all-venous grafting and 538,996 (84.2%) underwent single-arterial grafting. Beneficiaries undergoing all-venous grafting, vs single-arterial grafting, were noted to have worse risk-adjusted operative survival (30-day RMST, 28.6 [95% CI: 28.6-28.7] days vs 29.3 [95% CI: 29.2-29.3] days; difference, 0.73 [95% CI: 0.73-0.73] days; P < .001), short-term survival (1-year RMST, 324 [95% CI: 324-325] days vs 339 [95% CI: 338-339] days; difference, 14 [95% CI: 13-15] days; P < .001), and very long-term survival (20-year RMST, 8.34 [95% CI: 8.30-8.38] vs 9.55 [95% CI: 9.51-9.59] years; difference, 1.21 years; P < .001). Medicare beneficiaries undergoing CABG with all-venous grafting had inferior risk-adjusted survival compared with patients receiving single-arterial grafting. These findings support current multidisciplinary guideline recommendations offering a class I indication for use of at least 1 arterial graft during CABG.