Pre- and post-treatment with amiodarone for elective electrical cardioversion of atrial fibrillation: a systematic review and meta-analysis

Aims Clinicians frequently pre-treat patients with amiodarone to increase the efficacy of electrical cardioversion for atrial fibrillation (AF). Our objective was to determine the precise effects of amiodarone pre- and post-treatment on conversion efficacy and sinus rhythm maintenance. Methods and results We conducted a systematic review and meta-analysis of trials comparing pre- and post-treatment for electrical cardioversion with amiodarone vs. no therapy on (i) acute restoration and (ii) maintenance of sinus rhythm after 1 year. We searched MEDLINE and EMBASE from inception to July 2018 for randomized controlled trials. We evaluated the risk of bias for individual studies with the Cochrane tool and overall quality of evidence with the GRADE framework. We identified eight eligible studies (n=1012). Five studies were deemed to have unclear or high risk of selection bias. We found the evidence to be of high quality based on GRADE. Treatment with amiodarone (200-800mg daily for 1-6 weeks pre-cardioversion; 0-200mg daily post-cardioversion) was associated with higher rates of acute restoration [relative risk (RR) 1.22, 95% confidence interval (CI) 1.07-1.39, P=0.004, n=1012, I-2=65%] and maintenance of sinus rhythm over 13 months (RR 4.39, 95% CI 2.99-6.45, P<0.001, n=695, I-2=0%). The effects of amiodarone for acute restoration were maintained when considering only studies at low risk of bias (RR 1.22, 95% CI 1.10-1.36, P<0.001, n=572, I-2=0%). Adverse effects were typically non-serious, occurring in 3.4% (6/174) of subjects receiving amiodarone. Conclusion High-quality evidence demonstrated that treatment with amiodarone improved the restoration and maintenance of sinus rhythm after electrical cardioversion of AF. Short-term amiodarone was well-tolerated.