Is a third arterial conduit necessary? Comparison of the radial artery and saphenous vein in patients receiving bilateral internal thoracic arteries for triple vessel coronary disease.

Objectives: The use of bilateral internal thoracic arteries (BITAs) is associated with improved long-term survival after coronary artery bypass grafting (CABG). However, it is unclear whether the addition of a radial artery (RA) in patients already receiving BITA confers any additional survival benefit over that of a saphenous vein (SV). As such, we reviewed our multicentre experience and compared both strategies.

Methods: From 1995 to 2010, 1497 patients underwent primary isolated CABG for three-vessel coronary disease using BITAs. An SV was used as a third conduit in 460 (31%) patients and an RA in 1037 (69%). A total of 1258 distal anastomoses were performed using RAs and these were to the diagonal territory in 169, the circumflex in 454 and the right coronary in 635. Survival data were obtained using the National Death Index and propensity-score matching was used for risk-adjustment.

Results: The overall cohort was young (mean age 61 ± 9 years). Patients receiving RAs were more likely to be younger, and were less likely to have experienced a prior myocardial infarction. At 30 days, mortality was similar (BITA + SV: 5, 1.1% vs BITA + RA: 9, 0.9%, P = 0.77). At 15 years, BITA + RA patients experienced improved unadjusted survival (BITA + SV: 67 ± 4.6% vs BITA + RA: 82 ± 3.2%, P < 0.0001). Multivariable Cox regression in the entire cohort also showed the BITA + RA group to be associated with better survival (HR 0.58, 95% CI 0.44-0.75, P < 0.001). After propensity-score matching of 262 patient-pairs, BITA + RA experienced similar 30-day mortality (BITA + SV: 3, 1.1% vs BITA + RA: 3, 1.1%, P > 0.99). However, at 15 years, BITA + RA patients experienced improved risk-adjusted survival (BITA + SV: 72 ± 6.0% vs BITA + RA: 82 ± 5.2%, P = 0.021). The RA was associated with better risk-adjusted survival for grafting of the right coronary and its branches (148 matched pairs; SV-RCA: 74 ± 7.8% vs RA-RCA: 86 ± 6.5%, P = 0.0046 at 15 years).

Conclusions: The addition of an RA graft even in patients already receiving BITAs is associated with a survival benefit. In younger patients with a reasonable long-term life expectancy, surgeons should strive to achieve total arterial revascularization with BITAs and radial arteries.