MP-4 - PREVENTION OF POST-OPERATIVE ATRIAL FIBRILLATION AFTER NON-CARDIAC SURGERY USING AMIODARONE OR BETA BLOCKADE: A META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

Background: Post-operative atrial fibrillation (POAF) after non-cardiac surgery is associated with an increased risk of stroke and mortality. Both amiodarone and beta blockers have been shown to prevent POAF after cardiac surgery. Our objective was to assess the efficacy and safety of beta blocker or amiodarone prophylaxis prior to non-cardiac surgery. To this end, we performed a meta-analysis of randomized controlled trials.

METHODS AND RESULTS: We searched electronic databases for all randomized controlled trials (RCT)s comparing the use of amiodarone and/or beta blocker to placebo or any other comparative agents, including no treatment, for the prevention of POAF after non-cardiac surgery. Two reviewers performed independently the literature search and extraction. We used random-effects models to summarize the studies. The primary efficacy outcome was the incidence of in-hospital POAF. POAF was defined as atrial fibrillation for greater than 30 seconds. Safety outcomes consisted of drug-related post-operative hypotension or bradycardia, which required treatment or temporary drug interruption.
There were 10 RCTs enrolling 9,808 patients in the final analysis. The mean age ranged from 61 to 69 years, and the proportions of females ranged from 15% to 48%. Of the 10 included RCTs, five evaluated beta blockers and five were trials of amiodarone. In the amiodarone RCTs, 20%-30% of patients were also receiving beta blockers in both treatment arms. Compared to controls (placebo, no treatment or magnesium sulphate), patients who received prophylaxis with amiodarone or beta blockers had a lower incidence of POAF (risk ratio [RR]= 0.38, 95% confidence interval [CI] = 0.24- 0.59; p < 0.0001). Similar results were found when restricting the analysis to only one therapy: either amiodarone alone or beta blockers alone. However, prophylaxis with either amiodarone or beta blockers was associated with increased risk of post-operative bradycardia with (RR= 2.04, 95% CI = 1.08- 3.85; p=0.03). There was no difference in post-operative hypotension between the two treatment arms (RR= 1.22, 95% CI = 0.95- 1.56; p=0.12).


Conclusion: Compared to placebo or no treatment, prophylaxis with beta blocker, and/or amiodarone was associated with marked reduction in the incidence of POAF following non-cardiac surgery. In patients at increased risk of POAF following non-cardiac surgeries, prophylaxis of either amiodarone or beta-blockers may be considered.