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

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.

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.

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 perioperative MI (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.

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.