Effects of intravenous N-acetylcysteine on periprocedural myocardial injury after on-pump coronary artery by-pass grafting

AIM: Myocardial ischemia/reperfusion injury in patients undergoing coronary artery by-pass grafting (CABG) involves the reperfusion-induced conversion of reversible injured myocardial and endothelial cells. N-acetylcysteine (NAC) has a potential being the minimization of the impact of reperfusion injury. The aim of this study was to evaluate the effects of intravenous NAC on periprocedural myocardial injury after CABG. METHODS: The population of this prospective-randomized, double blind, placebo controlled study consisted of 40 patients undergoing on-pump CABG. All the patients were treated with standard medical therapy and eligible patients were randomized to NAC group (N.=19; intravenous infusion for 1 hour before the procedure at a dose of 50 mg/kg, followed by intravenous infusion for 48 hours after the operation at a dose of 50 mg/kg/day) and placebo (saline) group (N.=21). The study drug and placebo infusions were set to infuse at the same rate. RESULTS: Demographic and procedural variables were similar in the both groups (All P>0.05). Creatine kinase MB isoform (CK-MB) mass levels did not significantly differ between the groups at both preoperative and postoperative periods. Similarly, cTnT levels were similar in the groups at all periods. Eight patients in the NAC group and 7 in the placebo group had increased CK-MB >3 times normal value. However, only 3 patients in the NAC group experienced CK-MB>5 times normal value. CONCLUSION: Results of this study indicated that periprocedural use of NAC as intravenously did not attenuate myocardial damage after on-pump CABG surgery.