Metoprolol for prophylaxis of postoperative atrial fibrillation in cardiac surgery patients: systematic review and meta-analysis

PURPOSE

Postoperative atrial fibrillation (POAF) is a potentially lethal and morbid complication after open heart surgery. This systematic review and meta-analysis aimed to investigate metoprolol compared with other treatments for prophylaxis against POAF.

METHODS

We searched CENTRAL, MEDLINE, EMBASE and trial registries for randomised controlled trials that evaluated metoprolol for preventing the occurrence of POAF after surgery against other treatments or placebo. Random-effects model was used for estimating the risk ratios (RRs) and mean differences with 95% CIs.

RESULTS

Nine trials involving 1570 patients showed metoprolol reduced POAF compared with placebo (416 patients; RR 0.46, 95% CI 0.33 to 0.66; I²=21%; risk difference (RD) -0.19, 95% CI -0.28 to -0.10). However, metoprolol increased the risk of POAF compared with carvedilol (159 patients; RR 1.59, 95% CI 1.20 to 2.12; I²=4%; RD 0.13, 95% CI 0.06 to 0.20). There was no difference when compared with sotalol or amiodarone. The occurrence of cardiovascular conditions after drugs administration or death between the groups was not different. The overall quality of evidence was moderate to high. Subgroup analysis and funnel plot were not performed.

CONCLUSIONS

Metoprolol is effective in preventing POAF compared with placebo and showed no difference with class III antiarrhythmic drugs. Death and thromboembolism are associated with open heart surgery, but not significant in relation to the use of metoprolol.

PROSPERO REGISTRATION NUMBER

CRD42019131585.

Perioperative Beta-Blocker for Atrial Fibrillation after Cardiac Surgery: A Meta-Analysis

Background This meta-analysis was conducted to evaluate the impact of perioperative use of beta-blocker (BB) on postoperative atrial fibrillation (POAF) after cardiac surgery other than isolated coronary artery bypass grafting (CABG).

Methods Five online databases were searched. Studies were included if they (1) enrolled patients who underwent cardiac surgery other than isolated CABG and (2) demonstrated the impact of perioperative use of BB on POAF based on the randomized controlled trial or adjusted analysis. The primary outcome was the occurrence rates of POAF after cardiac surgery. A meta-regression and subgroup analysis were performed according to the proportion of patients with cardiac surgery other than isolated CABG and the timing of BB use, respectively.

Results Thirteen articles (5 randomized and 8 nonrandomized studies: n = 25,496) were selected. Proportion of enrolled patients undergoing cardiac surgery other than isolated CABG ranged from 7 to 100%. The BBs were used in preoperative, postoperative, and both periods in 5, 5, and 3 studies, respectively. The pooled analyses showed that the risk of POAF was significantly lower in patients with perioperative BB than those without (odds ratio, 95% confidence interval = 0.56, 0.35–0.91 and 0.70, 0.55–0.91 in randomized and nonrandomized studies, respectively). The risk of POAF was lower in the BB group irrespective of the proportion of nonisolated CABG. Benefit regarding in-hospital mortality was inconclusive. Perioperative stroke and length of stay were not significantly different between BB and non-BB groups.

Conclusions Perioperative use of BB is effective in preventing POAF even in patients undergoing cardiac surgery other than isolated CABG, although it did not translate into improved clinical outcomes.

Role of Metoprolol Succinate in the Treatment of Heart Failure and Atrial Fibrillation: A Systematic Review

BACKGROUND

Beta-blockers are one of the most important classes of cardiovascular agents and have been considered a cornerstone therapy in heart diseases, such as heart failure (HF) and atrial fibrillation (AF). Among different beta-blockers, metoprolol is a selective beta1-adrenergic antagonist, which has been extensively used since the 1970s.

AREAS OF UNCERTAINTY

Although current guidelines include recommendations for the use of controlled-release metoprolol succinate in specific HF and AF indications, and despite extensive clinical experience with metoprolol, comparative evidence on the use of metoprolol succinate compared with other beta-blockers in these indications is limited.

DATA SOURCES

We systematically reviewed the data from head-to-head studies directly comparing this compound with other beta-blockers in the treatment of HF or AF. Only clinical trials and observational studies were considered; no other limits were applied. The quality and relevance of retrieved articles were reviewed.

RESULTS

A total of 18 articles of the 353 articles identified were selected for inclusion; 12 HF articles and 6 for AF. Additional references were identified from the bibliographies of retrieved articles. The studies show that oral prophylaxis with an appropriate dose of metoprolol may reduce new incidents of AF in high-risk patients. Furthermore, metoprolol succinate is associated with significant mortality and morbidity benefits in the treatment of HF.

CONCLUSIONS

Despite the introduction of newer beta-blockers with differing clinical characteristics since its introduction, metoprolol succinate remains a useful drug in both HF and AF.