Abstract: Objective： To examine the circulating levels of creatine kinase-MB and cardiac troponin I (cTnI) following coronary artery bypass graft(CABG) surgery by either standard cardiopulmonary bypass (CPB) or the ′octopus technique′ on a beating heart. Methods： Sixty patients with coronary heart disease (CHD) undergoing CABG surgery were randomly divided into two groups (n=30): the OPCABG group, which received off-pump CABG and the CPB-CABG group, which received CPB. Blood samples were obtained prior of the operation and at the 2nd, 6th, 24th h after the end of the operation. The serum creatine kinase-MB(CK-MB) and the cardiac troponin I (cTnI) were determined. Results： In both groups, the CK-MB and cTnI levels were significantly increased at the post-operative 2nd, 6th, 24th h compared with those before the operation(P＜0.01 or P＜0.05). Compared with those of the CPB-CABG group, the CK-MB and cTnI of the OPCABG group were markedly decreased at the 2nd,6th,24th h after the operation(P＜0.05). Conclusion： These data demonstrate that off-pump CABG has a greater protective effect on myocardial injury than CPB-CABG.

Key words: Creatine kinase-MB, Cardiac troponin I, Cardiopulmanory bypass, Beating heart, Coronary artery bypass