Survival benefit of multiple arterial grafting in a 25-year single-institutional experience: the importance of the third arterial graft

Abstract

The long-term advantages of multiple arterial grafts, particularly a third arterial conduit, for coronary artery bypass (CABG) are not clear. This study was designed to test whether multiple arterial grafts would provide better long-term outcomes when compared with approaches using fewer arterial conduits. Between 1985 and 1995, prospective data were collected for 588 patients undergoing isolated CABG at our institution. We examined long-term survival and freedom from cardiac death. The primary analysis compared patients receiving bilateral internal thoracic artery (BITA) vs. single ITA (SITA). In a subgroup analysis, BITA patients receiving a right gastroepiploic artery (RGEA) were compared with those receiving a saphenous vein graft (SVG) as a third conduit. Cox proportional hazard modelling was used to adjust for relevant confounders. The Kaplan-Meier method was used to create survival curves over the follow-up period. The mean age was 59 ± 9 years and 49% received BITA. Mean follow-up was 16.1 ± 5.4 years. Multivariable analysis revealed that overall survival [hazard ratio (HR): 0.74, P = 0.017] and cardiac survival (HR: 0.61, P = 0.004) was significantly improved in the presence of BITA compared with SITA. The survival at 10 and 20 years was 90.2 ± 3.4 and 56.9 ± 6.4% for the BITA vs. 82 ± 4.4 and 40.9 ± 6% for the SITA, respectively. In the subgroup of BITA patients, those receiving the RGEA as a third conduit had superior overall survival (HR: 0.41, P = 0.0032) and cardiac survival (HR: 0.18, P = 0.004) compared with those receiving an SVG. The survival at 10 and 20 years was 98.9 ± 2 and 68.9 ± 18% for the BITA/RGEA vs. 87.2 ± 4.6 and 50.3 ± 7% for the BITA/SVG, respectively. In a single-institution experience, the use of multiple arterial grafting is independently associated with superior outcomes. Furthermore, the use of a third arterial conduit (RGEA) targeted to the right coronary artery should be considered to improve long-term survival.