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

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.