The radial artery versus the saphenous vein graft in contemporary CABG: a case-matched study

Abstract

Background. Although use of the internal thoracic artery has been shown to improve outcomes after coronary artery bypass grafting, the same cannot be said of alternative arterial conduits. To determine the benefit of radial artery (RA) grafting, a case-matched review was undertaken. Methods. Between March 1994 and March 1999, 2,847 patients underwent isolated coronary artery bypass grafting with a left internal thoracic artery graft, plus saphenous vein grafts (SVGs). Of these patients, 478 also received an RA graft (RA group). The RA patients were matched at a ratio of 1:2 with patients receiving only SVGs and a left internal thoracic artery graft (SVG group; n = 956) using six prognostic risk factors: age, sex, Canadian Cardiovascular Society class, left ventricular grade, number of diseased vessels, and timing of operation. Target vessels were graded according to quality and graftability and were similar between groups. Outcomes were evaluated by univariate and multivariate analyses. Results. There was a significantly higher prevalence of diabetes, hypertension, and peripheral vascular disease in the RA group ( p < 0.05). Although stay in the intensive care unit was shorter in the RA group (RA, 30 ± 2 hours, and SVG, 37 ± 2 hours; p = 0.0002), total hospital stay was similar between groups. The incidence of perioperative myocardial infarction was higher in the SVG group (SVG, 31 of 956 or 3.2%, and RA, 6 of 478 or 1.3%; p = 0.02). Multivariate analysis revealed RA grafting to be protective against early mortality and morbidity (odds ratio = 0.58; 95% confidence interval, 0.37 to 0.90; p = 0.015) and late mortality and morbidity including late reintervention (risk ratio = 0.60; 95% confidence interval, 0.37 to 0.93; p = 0.02). Actuarial freedom from events at 36 months postoperatively was greater in the RA group (RA, 95% ± 2%, and SVG, 86% ± 4%; p = 0.01). Conclusions. Despite a higher prevalence of preoperative comorbidity, patients in the RA group demonstrated improved outcomes after coronary artery bypass grafting. The RA is a viable and beneficial conduit for this operation.