Effects of perioperative administration of L-carnitine on myocardial protection in patients undergoing coronary artery bypass grafting / 中国医师杂志

ABSTRACT

Objective:To investigate the effect of L-carnitine on myocardial ischemia-reperfusion injury in patients undergoing coronary artery bypass grafting (CABG) operation.Methods:The clinical data of 60 patients who had underwent CABG under extracorporeal circulation in Department of Cardiovascular Surgery, the First Affiliated Hospital of Medical College of Xi′an Jiaotong University from January 2015 to December 2017 was retrospectively analyzed. L-carnitine was infused into the patients in the observation group while the equal amount of normal saline was given to the patients in the control group during perioperative period. Venous blood was collected from each patient 1 hour before the surgery and at 2, 6, 24 and 72 hours after unclamping the aorta, then serum levels of aspartate aminotransferase (AST), lactic acid dehydrogenase (LDH), creatine kinase (CK), and creatine kinase-MB isozyme (CK-MB) were detected. Additionally, cardiac function indices including stroke volume (SV), left ventricular diastolic diameter (LVDD), cardiac output (CO), Left ventricular ejection fraction (lVEF) were compared between the two group patients before the surgery and 6 days after operation.Results:Compared with before the operation, the levels of serum enzymes were all significantly increased after unclamping the aorta. The levels of serum AST, LDH and CK reached their peak at 24 hours after unclamping the aorta. Notably, the levels of serum AST, LDH and CK in the experimental group were lower than that in the control group at each time point after unclamping the aorta ( P<0.05). For serum CK-MB, the level in the experimental group reached its peak at 6 hours after unclamping the aorta, while the peak value was observed at 24 hours after unclamping the aorta in the control group. The level of CK-MB in the experimental group was significantly decreased compared with the control group at each time point after unclamping the aorta ( P<0.05). Moreover, there were no significant differences in cardiac function indices between the 2 groups before the operation ( P>0.05). The levels of SV, CO and LVEF in the experimental group were significantly increased while the level of LVDD was obviously decreased compared to that in the control group after the operation ( P<0.05). Conclusions:L-carnitine has protective effects on myocardial ischemia-reperfusion injury in patients undergoing CABG operation under cardiopulmonary bypass, with reducing serum levels of myocardial enzyme in these patients.