Background: The systemic inflammatory response syndrome induced by cardiopulmonary bypass (CPB) is responsible for organ dysfunction observed in patients undergoing coronary arterial bypass grafting (CABG). This study was conducted to determine whether patients who underwent off-pump CABG operations and thereby eliminated CPB would have improved cardiac function postoperatively.
Methods: Twenty-four patients were randomized to one of two groups: CABG with CPB (Group 1) or off-pump (Group 2). Cardiac index (CI) and left ventricular stroke work index (LVSWI) measurement were performed after anesthetic induction, after protamin, at the 0, 12, 24, and 48 hours after operation. In addition, serum myocardial bundle of creatine phosphokinase (CPK-MB), myoglobin and troponin T (TnT) were measured during the same periods.
Results: Serial CPK-MB, myoglobin, and TnT values increased significantly in both group compared with the baseline controls. But, the increase in CPK-MB and myoglobin levels in Group 1 were significantly higher than in Group 2 (p < 0.05). In Group 2, TnT levels were significantly less than those of the Group 1 (p < 0.01). Off-pump group had better CI and LVSWI than CPB group (p < 0.05). The patients in Group 1 required more inotropic drugs (p < 0.01) had increased postoperative bleeding (p < 0.05), and a longer intubation time (p < 0.01).
Conclusions: Off-pump CABG operation by using cardiac stabilization technique is safe and avoids the risk of myocardial injury.

Keywords : Cardiopulmonary bypass, beating heart, coronary bypass, cardiac index, troponin T