Oral ascorbic acid in combination with beta-blockers is more effective than beta-blockers alone in the prevention of atrial fibrillation after coronary artery bypass grafting

Because adrenergic beta antagonists are not sufficient to prevent atrial fibrillation after coronary artery bypass grafting, this prospective, randomized trial was designed to evaluate the effects of ascorbic acid as an adjunct to beta-blockers. Fifty patients formed our ascorbic acid group, and another 50 patients formed our control group. All patients were older than 50 years, were scheduled to undergo coronary artery bypass grafting, and had been treated with beta-blockers for at least 1 week before surgery. The mean age of the population was 60.19+/-7.14 years; 67% of the patients were men. Patients in the ascorbic acid group received 2 g of ascorbic acid on the night before the surgery and 1 g twice daily for 5 days after surgery. Patients in the control group received no ascorbic acid. Patients in both groups continued to receive beta-blockers after surgery. Telemetry monitoring was performed in the intensive care unit, and Holter monitoring was performed for 4 days thereafter. The incidence of postoperative atrial fibrillation was 4% in the ascorbic acid group and 26% in the control group (odds ratio, 0.119; 95% confidence interval, 0.025-0.558, P = 0.002). We conclude that ascorbic acid is effective, in addition to being well-tolerated and relatively safe. Therefore, it can be prescribed as an adjunct to beta-blockers for the prophylaxis of post-bypass atrial fibrillation.