Risk factors for hemorrhage-related reexploration and blood transfusion after conventional versus coronary revascularization without cardiopulmonary bypass

Abstract

The premise of coronary revascularization without cardiopulmonary bypass (off-pump CABG) proposes that patient morbidity and, potentially, mortality can be reduced without compromising the excellent results of conventional revascularization techniques (on-pump CABG). It is unknown, however, whether coronary artery bypass without cardiopulmonary bypass (off-pump CABG) is associated with similar hemorrhage related reexploration rates and blood transfusion requirements compared to the on-pump approach. Between January 1998 and June 2002, 3646 patients underwent off-pump CABG and were compared with a contemporaneous control group of 5197 on-pump CABG patients. A logistic regression model was used to test the difference in the postoperative hemorrhage related reexploration rates and need for postoperative blood transfusions between the groups, controlling for preoperative risk factors. The patients undergoing off-pump CABG were matched to on-pump patients by propensity score. Hemorrhage related reexploration rates were comparable between the 2 groups (odds-ratio [OR]=0.80, 95% confidence intervals [CI]=0.55-1.09, P=0.15). Off-pump CABG was associated with a lower need for single and multiple unit postoperative blood transfusions (OR=0.30, CI=0.24-0.31, P<0.01 and OR=0.4, CI=0.36-0.51, P<0.01, respectively) compared to on-pump CABG patients. Off-pump CABG eliminates the risks of cardiopulmonary bypass and the systemic inflammatory response it elicits. A substantially lower need for postoperative blood transfusions and a comparable hemorrhage-related reexploration rate suggests that off-pump CABG may avoid the morbidity and mortality associated with excessive postoperative blood loss.