Long-term analysis of ventricular function in patients with symptomatic coronary disease who underwent on-pump or off-pump coronary artery bypass grafting

Abstract

Abstract Background Systemic deleterious effects of cardiopulmonary bypass have been observed in the postprocedural period. Long-term assessment, including ventricular function (VF), is unclear. The objective of this study was to compare the change of left ventricular ejection fractions (LVEFs) during a long-term follow-up of coronary artery disease (CAD) patients who underwent off-pump (OPCAB) or on-pump coronary artery bypass grafting (ONCAB). Methods This study is a prespecified analysis of the MASS III trial, which was a single-center and prospective study that enrolled stable CAD patients with preserved VF. The CAD patients in our study were randomized to OPCAB or ONCAB. A transthoracic echocardiogram was performed during follow-up and a LVEF value was obtained. The primary endpoint was the difference between the final LVEF and the baseline LVEF. Results Of the 308 randomized patients, ventricular function were observed in 225 over a mean of 5.9 years of follow-up: 113 in the ONCAB group and 112 in the OPCAB group. Baseline characteristics were similar between the two groups, but there was a larger proportion of subjects with 3-vessel disease in the ONCAB group. There was no difference in the LVEF at the beginning (P = 0.08), but there was a slight decrease in the LVEF in the ONCAB and OPCAB groups (P < 0.001 in both groups) at 5.9 years. The decline was not significantly different between the two groups (delta of -6% for ONCAB and -5% for OPCAB; P = 0.78). In a multivariate analysis, myocardial infarction in the follow-up was a predictor of an LVEF < 40%. Conclusions There was no difference in the long-term development of ventricular function between the surgical techniques, despite a decline in the LVEF in both groups. Trial registration Clinical Trial Registration Information—URL: http://www.controlled-trials.com. Registration number: ISRCTN59539154. Date of first registration: 10/03/2008.