Perioperative supplementation with ascorbic acid does not prevent atrial fibrillation in coronary artery bypass graft patients

Background: Atrial fibrillation occurs after approximately 25% to 45% of coronary artery bypass graft (CABG) surgeries. Oxidative stress and related electrophysiological remodeling has been proposed as a potential cause of this atrial fibrillation. Perioperative supplementation of the antioxidant ascorbic acid has been evaluated as a preventive agent. The current investigation was conducted to evaluate the efficacy of ascorbic acid in reducing atrial fibrillation in CABG patients. Methods: A prospective, randomized, placebo-controlled, triple-blind, single-institution study was conducted in nonemergency CABG patients. Subjects were monitored for episodes of arrhythmia and other complications. Results: Eighty-nine treatment and 96 control subjects completed the study protocol. Demographics, comorbidities, and preoperative drugs were similar between groups. Surgical characteristics and postoperative medication use also were similar. The incidence of atrial fibrillation was 30.3% in the treatment group and 30.2% in the control group (P =.985). No difference was found in postoperative complications or mortality. Conclusions: Our data indicate that supplementation of ascorbic acid in addition to routine postoperative care does not reduce atrial fibrillation after coronary artery bypass grafting.