Radial artery versus saphenous vein as the second conduit for coronary artery bypass surgery: A meta-analysis

Objective: Individual studies may be limited by sample size to detect differences in late survival between radial artery (RA) or saphenous vein graft (SVG) as a second conduit for coronary artery bypass surgery. Here we undertook a meta-analysis of the best evidence available on the comparison of early and late clinical outcomes of the RA and the SVG. Methods: MEDLINE and EMBASE were searched for studies comparing use of the RA versus SVG for isolated coronary artery bypass surgery. Time-to-event outcomes for long-term mortality, repeat revascularization, and myocardial infarction (MI) were extracted as incidence rate ratios (IRR) with 95% confidence intervals (95% CI). Odds ratios (OR) were extracted for perioperative mortality, stroke, and MI. A random effects meta-analysis was performed. Sensitivity analyses included leave-one-out-analyses and meta-regression. Results: Among 1201 articles, 14 studies (20,931 patients) were included (mean follow-up: 6.6 years). Operative mortality was 1.25% in the RA versus 1.33% in the SVG group (OR, 0.93; 95% CI, 0.68-1.28). No difference in perioperativeMI (OR, 0.96; 95% CI, 0.59-1.56) or stroke (OR, 0.70; 95% CI, 0.43-1.13) was found between RA and SVG. Long-term mortality (mean follow-up 6.6 years) was 24.5% in RA versus 34.2% in SVG group (IRR, 0.74; 95% CI, 0.63-0.87, P<. 001). No difference in follow-up MI or repeat revascularization was found (IRR, 0.76; 95% CI, 0.42-1.36 and IRR, 0.68; 95% CI, 0.42-1.09 respectively). At meta-regression, RA survival advantage was independent of age, sex, diabetes, and ventricular function. Conclusions: Compared with the SVG, using the RA as the second conduit is associated with a 26% relative risk reduction in mortality at 6.6-year follow-up.