The Comparative Study Of Myocardial Injury And Clinical Efficacy In Patients Undergoing Coronary Artery Bypass Grafting With Versus Without Cardiopulmonary Bypass

In order to provide theoretical proof to select the method of operation in clinic, we study the change of plasma malondialdehyde, glutathione peroxidase, cardiac Troponin I and the clinical efficacy in patients undergoing coronary artery bypass grafting with versus without cardiopulmonary bypass to identify the degree of lipid peroxidation and myocardial injury, the ability of antioxygen and the efficacy in both operative methods. Methods 20 patients with coronary artery disease were selected continuously to undergo the coronary artery bypass grafting during the period from May in 2005 to November in 2005, and they were randomly separated into the on-pump group (CCABG group) and off-pump group (OPCAB group), each group has 10 patients. All patients were given the isosorbide dinitrate to treat the disease before the operation. After positive preoperative preparation, all patients underwent coronary artery bypass grafting with general intravenous anesthesia. We took 4 ml venous blood from the patients in different time points, then centrifugated the blood samples to obtain the blood serum and put them into the -70℃ refrigerator. At some special time points, we took 3 ml venous blood to detect the contents of cardiac Troponin 1 with fluorescence immunoassay method. When all samples were collected, we detected the contents of MDA and the enzyme activity of GPx with the chromatometry method, meanwhile we collected the clinical data, and then compared the results. Results (1) The contents of MDA obviously arised in OPCAB group at 1h after heparinization, and reached the peak at 6h after heparinization;in CCABG group, the contents of MDA began to arise at lh after the clamp of the ascending aortic, and reached the peak at 6h after the clamp of the ascending aortic;then began to decrease at 24h after operation in both of the groups, but still remained above the preoperative content at 48h after operation. The contents of MDA in CCABG group at 3h and 6h after the clamp of the ascending aortic were much higher than those in OPCAB group at 3h and 6h after heparinization, and the difference has statistical significance(t=2.3630~2.3870, P<0.05). (2) The enzyme activity of GPx in OPCAB group began to decrease after heparinization, reached to the minimum at lh and began to arise at 3h after heparinization;in the CCABG group the enzyme activity of GPx began to decrease before the clamp of the ascending aortic, reached to the minimum at lh and then began to arise at 3h after the clamp of ascending aortic;in both groups the enzyme activity of GPx were higher than that of the preoperation at 24h and 48h after the operation. The enzyme activity of GPx in CCABG group at 1h, 3h 6h after heparinization and 24h after operation were much lower than those who received OPCAB at 1h, 3h, 6h after the clamp of the ascending aortic and 24h after operation, the difference has significant statistical significance(t=2.4416~5.5357,P<0.05). (3) The contents of cTNI in both groups began to arise after the beginning of the operation;in OPCAB group the contents of cTNI were lower at 6h after heparinization and 24h after operation than that in CCABG group at 6h after the clamp of the ascending aortic and 24h after operation, and the difference has the statistical significance(t=2.4336~2.5156,P<0.05). (4) Comprising with those who received the CCABG, the patients who received the OPCAB had so many advantages, such as the amount of blood drainage in 24h after operation and the total drainage were fewer, the time of tracheal intubation was shorter, the implications of atrial fibrillaton were fewer, the length of stay is shorter, and the cost ofhospitalization is lower. And all the difference had significant statistical significance. Conclusion In the procedure of the OPCAB operation, the contents of the plasma malondialdehyde and cTNI are lower, the enzyme activity of GPx is higher, and it can reduce less degree of lipid peroxidation caused by the production of oxygen free radicals, nevertheless it can provide better myocardial protection than CCABG Furthermore, the OPCAB operation have many advantages, such as the amount of blood drainage in 24h after operation and the total drainage are fewer, the cost of hospitalization is lower, so they can recover quickly after operation and discharge earlier. In a word, the OPCAB operation is a good method.Postgraduate student: Wu Yu-hui(Cardiovascular Surgery) Directed by Prof.: Xu Ping...