Comparison between off-pump and on-pump coronary artery bypass grafting in patients with severe lesions at the circumflex artery territory: 5-year follow-up of the MASS III trial.

Abstract

The technical difficulty in the revascularization of the circumflex artery territory with off-pump surgery may compromise the outcome of this method in clinical follow-up. We aimed to evaluate cardiac events in patients with stable coronary artery disease and severe obstruction of the circumflex system, undergoing coronary artery bypass grafting (CABG) with or without cardiopulmonary bypass. MASS III was a single-centre study that evaluated 308 patients with multivessel coronary artery disease randomized to on-pump (153) or off-pump (155) CABG. Of this total, 260 (84.4%) patients had, on coronary angiography, at least one 70% obstruction in the circumflex territory (141 on-pump and 119 off-pump). The combined outcome was death, myocardial infarction, target vessel revascularization (angioplasty or surgery) or hospitalization for cardiac causes. Variables with possible associations (P < 0.1) were included in the multivariate analysis. The two groups were well matched for demographics and clinical and angiographic characteristics. After 5 years of follow-up, off-pump CABG had higher combined events than on-pump had: 25 (21%) vs 17 (12%), hazard ratio 1.88, 95% confidence interval 1.02-3.48, P = 0.041. In the multivariate model with the inclusion of the following variables: age (P = 0.09) and complete revascularization (P = 0.68), off-pump surgery remained as a predictor of combined events in 5 years, P = 0.03. In patients with multivessel coronary artery disease and severe lesions in the circumflex territory, off-pump coronary artery bypass surgery resulted in a higher incidence of cardiac events at 5-year follow-up. ISRCTN59539154 (http://www.controlled-trials.com).