Does antiarrhythmic drugs premedication improve electrical cardioversion success in persistent atrial fibrillation?

AIMS: Aim of this study is to evaluate the impact of antiarrhythmic drugs (AADs) administration for at least one month before ECV on the acute and long term success rate of the procedure. METHODS: 1313 consecutive persistent AF patients were enrolled in 3 different centers (Turin, Asti and Avellino): 692 patients received AADs before and after ECV (group A), 621 patients were treated only after the procedure, at discharge (group B). Primary end point was the restoration and maintenance of sinus rhythm acutely and at a long-term follow up. RESULTS: Acute ECV success was higher in group A compared with group B (99% vs. 88%, p=0.0001) and a fewer number of shock attempts were administered (1.15±0.42 vs. 1.27±0.53 p<0.0001). Moreover group A maintained SR more often than group B at one month (99% vs. 89%, log-rank p<0.0001), at one year (55% vs. 48% log-rank p=0.01) and at the end of follow up (mean 2.7±2.1years, 45% vs. 29%, log-rank p<0.0001). At multivariate analysis AADs premedication was the strongest independent predictor of acute and long-term ECV success (respectively p<0.0001 OR 10.71 CI 5.10-22.50 and p=0.004, OR 1.50 CI 1.14-1.97). At sensitivity analysis no differences were found between ADDs in terms of acute success improvement (p=0.605), number of shock attempts (p=0.853) and long term SR maintenance (log-rank p=0.480). CONCLUSIONS: AADs administration for at least 4weeks before the ECV in persistent AF increases significantly the acute success rate and this result was maintained over a long-term follow-up.