The Effect of High-Dose Vitamin C on Biochemical Markers of Myocardial Injury in Coronary Artery Bypass Surgery

Abstract Objective: To evaluate the effect of high-dose vitamin C on cardiac reperfusion injury and plasma levels of creatine kinase-muscle/brain (CK-MB), troponin I, and lactate dehydrogenase (LDH) in patients undergoing coronary artery bypass grafting (CABG). Methods: This is a double-blind randomized clinical trial study. Fifty patients (50-80 years old) who had CABG surgery were selected. The intervention group received 5 g of intravenous vitamin C before anesthesia induction and 5 g of vitamin C in cardioplegic solution. The control group received the same amount of placebo (normal saline). Arterial blood samples were taken to determine the serum levels of CK-MB, troponin I, and LDH enzymes. Left ventricular ejection fraction was measured and hemodynamic parameters were recorded at intervals. Results: High doses of vitamin C in the treatment group led to improvement of ventricular function (ejection fraction [EF]) and low Intensive Care Unit (ICU) stay. The cardiac enzymes level in the vitamin C group was lower than in the control group. These changes were not significant between the groups in different time intervals (anesthesia induction, end of bypass, 6 h after surgery, and 24 h after surgery) for CK-MB, LDH, and troponin I. Hemodynamic parameters, hematocrit, potassium, urinary output, blood transfusion, arrhythmia, and inotropic support showed no significant difference between the groups. Conclusion: Vitamin C has significantly improved the patients’ ventricular function (EF) 72 h after surgery and reduced the length of ICU stay. No significant changes in cardiac biomarkers, including CK-MB, troponin I, and LDH, were seen over time in each group. IRCT code: IRCT2016053019470N33

摘要 目的：评估大剂量维生素C对接受冠状动脉旁路移植术（coronary artery bypass grafting, CABG）患者的心肌再灌注损伤，以及血浆肌酸激酶同工酶（CK-MB）、肌钙蛋白I和乳酸脱氢酶（LDH）水平的影响。方法：本研究为双盲随机临床试验。纳入50名年龄50~80岁、拟行CABG手术的患者。干预组于麻醉诱导前静脉给予5 g维生素C，并在心脏停搏液中加入5 g维生素C；对照组给予等量安慰剂（生理盐水）。采集动脉血样以检测血清CK-MB、肌钙蛋白I及LDH水平，定期检测左心室射血分数并记录血流动力学参数。结果：干预组应用大剂量维生素C可改善心室功能（射血分数[EF]），并缩短重症监护病房（ICU）停留时间；维生素C组心肌酶水平低于对照组，但在各时间节点（麻醉诱导时、旁路手术结束时、术后6 h及术后24 h），两组间CK-MB、LDH及肌钙蛋白I水平的差异均无统计学意义。两组间血流动力学参数、血细胞比容、血钾水平、尿量、输血情况、心律失常发生率及正性肌力药物支持情况均无显著差异。结论：术后72 h，维生素C可显著改善患者心室功能（EF），并缩短ICU停留时间；各组内随时间推移，心脏生物标志物CK-MB、肌钙蛋白I及LDH水平均无显著变化。IRCT注册号：IRCT2016053019470N33