Effects of N-acetylcysteine on myocardial ischemia–reperfusion injury in bypass surgery
Myocardial ischemia–reperfusion injury may complicate coronary artery bypass grafting (CABG) operations. N-Acertylcysteine (NAC) had antioxidant and microcirculatory effects, and inhibits neutrophil aggregation. The aim of this study was to determine the effects of NAC in limiting myocardial ischemia–reperfusion injury in CABG operations. Twenty patients undergoing elective coronary bypass operation with cardiopulmonary bypass were enrolled and randomly assigned to two groups: a control group operated with a routine CABG protocol, and one where NAC was administered intravenously during the operation (NAC group). Blood samples from coronary sinus for tumor necrosis factor-α assay, myocardial biopsy specimens for chemiluminescent luminol, and lucigenin measurements of reactive oxygen species were taken. The luminol (specific for •OH, H2O2, and HOCl− radicals) and lucigenin (specific for O2•−) levels and the difference ratios after reperfusion were significantly lower in the NAC group. Tumor necrosis factor-α levels increased in the control group but, in contrast, a significant decrease was detected in the NAC group (P < 0.01). Creatine kinase-MB levels at 6 and 12 hours were singnificantly lower in the NAC group (P = 0.02). N-Acetylcysteine has potential effects to limit ischemia reperfusion injury during CABG operations. We believe that its effects on clinical outcome may be more apparent in patients prone to ischemia–reperfusion injury.