The effect of intravenous N-acetylcysteine on prevention of atrial fibrillation after coronary artery bypass graft surgery: a double-blind, randomised, placebo-controlled trial

Atrial fibrillation (AF) is one of the most frequently occurring dysrhythmias after coronary artery bypass graft (CABG) surgery. The aim of this study was to evaluate the effect of intravenous N-acetylcysteine (NAC) on the prevention of AF after CABG surgery. In a double-blind, randomised controlled trial, a total of 150 patients who were scheduled for on-pump CABG surgery were randomly assigned into two groups. In group A, patients received an intravenous NAC infusion (50 mg/kg) after induction of anaesthesia. These patients additionally received two intravenous doses of NAC on postoperative days 1 and 2. Patients in group B received normal saline (as a placebo) with the same volume, during the same time interval. During the first three days after surgery, postoperative AF (POAF) was assessed by continuous electrocardiogram monitoring; serum high-sensitivity C-reactive protein (hsCRP) level was also assessed before and three days after surgery. During follow-up, 17 patients (17/141, 12.1%) developed POAF. POAF occurred in four (5.6%) patients in the NAC group and 13 (18.8%) patients in the placebo group (OR 0.23; 95% CI 0.08-0.82; p = 0.02). In the multivariable logistic regression analysis, the only predictor of AF after CABG surgery was the use of NAC (OR 0.21; 95% CI 0.06-0.73; p = 0.01). Also, the hsCRP level trend in the NAC group was different from the trend in the control group (group time interaction or interaction effect) (p < 0.001). It seems that perioperative intravenous NAC therapy can be effectively used to reduce inflammation and the incidence of POAF after CABG surgery. The clinical trial registration number: IRCT2015040921669N1.