Impact of the Radial Artery as an Additional Arterial Conduit During In-Situ Bilateral Internal Mammary Artery Grafting: A Propensity Score-Matched Study

Abstract

Background: Bilateral internal mammary artery (BIMA) grafting has been associated with improved long-term outcomes after CABG. We sought to evaluate the early results and long-term survival among coronary artery bypass graft patients who underwent in-situ BIMA grafting with the radial artery (RA) as an additional arterial conduit compared with those who underwent BIMA with additional saphenous vein graft (SVG).

Methods: Between 1991 and 2013, 1,750 consecutive patients with triple-vessel disease or left main plus right coronary system disease underwent primary isolated in-situ BIMA grafting with at least one internal mammary artery to the left anterior descending artery. Patients were divided into a BIMA-RA group (n = 255) and BIMA-SVG group (n = 1,495). Propensity score matching was used to create two comparable cohorts: 249 BIMA-RA patients were one-to-one-matched to 249 BIMA-SVG patients. The date of death was obtained from provincial vital statistics. The median follow-up was 8 years.

Results: There was no difference in operative mortality between matched BIMA-RA and BIMA-SVG (0.8% versus 0.4%, respectively; p = 0.6). Five-year, 10-year, and 15-year survival rates were 98.3%, 92.0%, and 92.0%, respectively, among BIMA-RA patients, versus 96.5%, 93.0%, and 87.0% in the matched BIMA-SVG group (log rank p = 0.44). When we stratified the BIMA-RA patients into subgroups according to the severity of target artery stenosis, late survival was also similar among the BIMA-RA subgroups matched to BIMA-SVG patients (log rank p = 0.12).

Conclusions: The use of the RA as an additional arterial graft in patients undergoing coronary artery bypass graft surgery with in-situ BIMA does not prolong late survival when compared with BIMA patients who received additional SVG.