Long-term analysis of ventricular function in patients with symptomatic coronary disease undergone on-pump or off-pump coronary artery bypass graft

Background: Systemic non-physiological effects of cardiopulmonary bypass have been observed in the periprocedural period. Long-term assessment, including ventricular function (VF), is unclear. The objective of this study was to compare the evolution of left ventricular ejection fraction (LVEF) in a long-term follow-up among patients with coronary artery disease (CAD) who underwent off-pump (OPCAB) or on-pump coronary artery bypass graft (ONCAB).Methods: This study is a pre-specified analysis of the MASS III trial, a single-center and prospective study that enrolled patients with stable CAD initially preserved VF and randomized to OPCAB or ONCAB. They accomplished a new measure of LVEF by transthoracic echocardiogram in the follow-up, and the primary endpoint was the difference between final and baseline LVEF.Results: Of 308 patients randomized, 225 had a new evaluation of LVEF in a mean of 5.9 years of follow-up: 113 in ONCAB and 112 in the OPCAB group. Baseline characteristics were similar between groups, except for higher subjects with the 3-vessel disease in ONCAB. There was no difference in LVEF at the beginning (P=0.08) but, there was a discrete decrease in both LVEF for ONCAB and OPCAB groups (P <0.001 in both groups) in 5.9 years. Despite this, the decline was not significantly different between groups (delta of -6% for ONCAB and -5% for OPCAB; P=0.78). In a multivariate analysis, myocardial infarction was a predictor of LVEF <40%.Conclusions: Despite non-physiologic effects, there was no difference in the long-term follow-up of LVEF between the ONCAB and OPCAB groups in this studied sample.