The Effect of Vitamin C Supplementation on Cardiac Enzymes After Coronary Artery Bypass Graft: A Double-blind Randomized Control Trial

Background: Coronary artery bypass graft (CABG) is associated with oxidative stress and tissue damage. Vitamin C, as an antioxidant agent, has an important role in attenuating the oxidative stress damage and might have cardio-protective effects after CABG. We aimed to evaluate the probable roles of vitamin C supplementation in cardiac biomarkers after CABG. Methods: In this randomized control trial, 122 patients undergoing CABG were randomly assigned to the intervention (n=54) and control group (n=68) and received vitamin C (2 g intravenously) or placebo, respectively. The surgical methods of the patients in the two groups were identical. The primary efficacy endpoint of this trial is the difference in the levels of CK-MB, Troponin and Total Antioxidant Capacity (TAC) were measured at study entry and 24 hrs after surgery between the two groups. Results: The two groups were not significantly different in terms of basic variables. Within-group comparison showed significant rises in the level of troponin (P < 0.001) and CK-MB (P < 0.001) over time. However, between-group comparison showed no significant difference between the two groups in terms of CK-MB (P=0.826) and troponin (P=0.821). As a whole, the correlation between cardiac enzymes and surgical characteristic was not seen. Conclusion: The results showed that pretreatment with vitamin C could not reduce cardiac marker following CABG. After the intervention, TAC did not differ between and within the intervention and the control groups. Pretreatment with vitamin C as an antioxidant agent could not reduce ischemic-reperfusion resulting in CABG.