Late outcomes after radial artery versus saphenous vein grafting during reoperative coronary artery bypass surgery

Abstract

We investigated whether use of radial artery versus saphenous vein grafts during coronary artery bypass grafting reoperations is associated with a significant long-term survival benefit. We reviewed a series of 347 consecutive coronary artery bypass grafting reoperations (1996-2007; 270 [78%] male patients; age, 65.3 +/- 9.2 years). Internal thoracic artery grafts were used in 248 (71%) patients at the time of the first coronary artery bypass grafting operation and in 154 (44%) patients at reoperation. Patients were grouped based on whether a functional radial artery graft was present after coronary artery bypass grafting reoperation (radial artery cohort, n = 203 [59%]) or not (saphenous vein cohort, n = 144 [41%]). Median time to reoperation was similar for the radial artery (10.3 years) and saphenous vein (10.1 years) cohorts (P = .55). Angiographic data were used to ascertain the number and type of grafts that remained functional from initial coronary artery bypass grafting. Survival data (< or = 12 years) were time segmented based on multiphase hazard modeling at 90 days, and late survival was then analyzed by using proportional hazard Cox regression, with risk adjustment based on a radial artery-use propensity score computed from 48 covariates, including time to reoperation, month of surgical intervention, and total arterial and vein grafts after reoperation. Propensity-matched and propensity quintile comparisons were also done. Follow-up was similar for the radial artery versus saphenous vein cohorts (5.7 +/- 3.4 vs 5.8 +/- 4.0 years, P = .86), and 112 (50 in the radial artery and 62 in the saphenous vein cohorts) deaths were documented. Early mortality (< or = 90 days) did not differ for the radial artery (7.4%) and saphenous vein (12.5%) cohorts (P = .14). Unadjusted late outcomes were superior for the radial artery versus saphenous vein cohorts, with survival of 97.3% versus 92.9%, 84.9% versus 77.2%, and 74.1% versus 60.3% at 1, 5, and 10 years, respectively. Propensity-adjusted radial artery survival was superior, with a hazard ratio of 0.58 (P = .04), and this result was confirmed in a propensity-matched comparison. We conclude that the use of radial artery as opposed to saphenous vein grafting for reoperative coronary artery bypass grafting, either with or without concomitant internal thoracic artery grafts, is associated with a substantial improvement in late survival. This benefit is likely derived from the increased overall number of arterial grafts.