Which should you choose for post operative atrial fibrillation, carvedilol or metoprolol? A systemic review and meta-analysis.

BACKGROUND: Postoperative atrial fibrillation (POAF) is the most common arrhythmic complication following cardiac surgery. Current guidelines suggest beta-blockers for the prevention of POAF. In comparing metoprolol succinate with carvedilol, the later has sparked interest in its usage as an important medication for POAF prevention. METHODS: We considered randomized controlled studies (RCTs) and retrospective studies that evaluated the efficacy of carvedilol versus metoprolol for the prevention of POAF. After literature search, data extraction, and quality evaluation, pooled data were analyzed using either the fixed-effect or random-effect model using Review Manager 5.3. The Cochrane risk of bias tool was used to assess the bias of included studies. The incidence of POAF was the primary endpoint, while mortality rate and bradycardia were secondary outcomes. RESULTS: In meta-analysis 5 RCTs and 2 retrospective studies with a total of 1000 patients were included. The overall effect did not favor the carvedilol over metoprolol groups in terms of mortality rate [risk ratio 0.45, 95 % CI (0.1-1.97), P=0.29] or incidence of bradycardia [risk ratio 0.63, 95 % CI (0.32-1.23), P=0.17]. However, the incidence of POAF was lower in patients who received carvedilol compared to metoprolol [risk ratio 0.54, 95 % CI (0.42-0.71), P < 0.00001]. CONCLUSION: In patients undergoing cardiac surgery, carvedilol may minimize the occurrence of POAF more effectively than metoprolol. To definitively establish the efficacy of carvedilol compared to metoprolol and other beta-blockers in the prevention of POAF, a large-scale, well-designed randomized controlled trials are required.