A randomized comparison of right ventricular function after on-pump versus off-pump coronary artery bypass graft surgery

Objectives: Right ventricular dysfunction occurs very soon after conventional coronary bypass surgery with cardiopulmonary bypass and might not recover within 1 year after the operation. It has been postulated that performing coronary surgery without cardiopulmonary bypass might preserve right ventricular function. We hypothesized that right ventricular global and overall systolic functions are better preserved 3 months after off-pump surgery than after conventional coronary bypass surgery. Methods: Fifty patients scheduled for elective coronary bypass surgery were randomly assigned to conventional or off-pump surgery. Right ventricular function was assessed by means of transthoracic echocardiographic analysis the day before the operation and 3 months later. Right ventricular myocardial performance index was used as a marker of global right ventricular function, and right ventricular fractional area change was used as a marker of overall right ventricular systolic function. Peak systolic velocities of the lateral tricuspid annulus were studied to assess regional systolic function of the right ventricular free wall. Results: Surgical intervention was completed according to randomization in 48 of 50 patients. Demographic and perioperative characteristics were similar in the 2 groups. Over the study period, right ventricular myocardial performance index and right ventricular fractional area change did not change in comparison with the baseline values in both groups. Peak systolic velocity of the lateral tricuspid annulus was decreased significantly in both groups 3 months after the operation. There were no significant intergroup differences in any echocardiographic marker of right ventricular function. Conclusions: Global right ventricular function was not better preserved 3 months after off-pump surgery than after conventional coronary bypass surgery. (J Thorac Cardiovasc Surg 2011;141:361-7)