Comparison of late coronary artery bypass graft survival effects of radial artery versus saphenous vein grafting in male and female patients.

Background: This study aimed to compare the survival benefit derived from using radial artery (RA) as a second arterial conduit in combination with internal thoracic artery (ITA), as opposed to ITA plus saphenous vein (SV) in men and women.

Methods: We reviewed the 1996 to 2007 primary, nonsalvage coronary artery bypass graft surgery (CABG) experience at Mercy Saint Vincent Medical Center (n = 6,384; 69% men, 31% women). Study subjects had two or more completed grafts including one ITA graft. Patients with bilateral ITA, ITA-only grafts, or concomitant valve/aortic surgery were excluded. Separate sex nonparsimonious propensity models for RA grafting based on 47 preoperative and intraoperative factors were used to identify matched ITA/RA and ITA/SV cohorts. Kaplan-Meier and Cox regression analyses were then applied to assess sex-specific 12-year survival risk ratios of RA versus SV grafting.

Results: Patient variables for the RA and SV cohorts were well-matched in both men (n = 1,416 each; median age 62 years) and women (n = 567 each; median age 66 years). Thirty-day mortality was similar for ITA/RA versus ITA/SV in men (1.3% versus 1.2%; p = 1.0) and women (1.4% versus 1.9%; p = 0.664). Late mortality (1 to 144 months) was significantly better for ITA/RA in men (risk ratio 0.65, 95% confidence interval: 0.54 to 0.79; p < 0.001) and women (risk ratio 0.75, 95% confidence interval: 0.57 to 0.99; p = 0.045).

Conclusions: Late survival results suggest that male and female CABG patients benefit appreciably from use of RA as a second arterial conduit in combination with ITA. Yet, the late survival advantage derived from RA use was relatively less for women. This sex variance in benefit likely reflects differences in risk profiles of male and female CABG patients.