The effect of amiodarone given periprocedurally on the effectiveness of catheter ablation in patients with persistent atrial fibrillation refractory to cardioversion

Abstract Background Rhythm control strategy in patients with persistent atrial fibrillation refractory to electrical cardioversion (AF-REC) poses an important clinical problem. Little is known about the effect of amiodarone therapy given periprocedurally with catheter ablation on maintaining sinus rhythm in this group of patients. Purpose This study aimed to determine whether initial amiodarone therapy introduced prior to AF ablation and continued for one month after the procedure affects the long-term effectiveness of the rhythm control strategy in patients with AF-REC. Methods We conducted a retrospective case-control study of medical records of AF-REC patients treated periprocedurally with amiodarone in addition to pulmonary vein isolation. Data on comorbidities, transthoracic echocardiogram results, and short- and long-term effectiveness of ablation was extracted. Patients were followed up in the out patient clinic with the use of a 72-hour Holter monitoring and telephone interviews. AF recurrence was defined as ≥ 30s episode of atrial tachyarrhythmia. Results The analysis comprised 56 patients: 37 in the amiodarone and 19 in the control group; 12 women, mean age 57 years, mean follow-up of 39.5 months. Amiodarone was discontinued after 1 month at the most after the ablation in all of the patients. The primary endpoint (AF-free survival) was achieved in 17 (45,9%) pts in the amiodarone group and 3 (15,8%) pts in the control group (p=0.026). On multivariable analysis, amiodarone therapy was the only variable correlating with the primary endpoint: OR 6.8 (95% CI: 1.4 - 33.9), p=0.019. Conversion of AF from persistent to paroxysmal or no AF in the follow-up was achieved in 32 pts (86,5%) in the amiodarone group and 9 pts (47,4%) in the control group: OR 8.0 (95% CI: 2.1 - 30.0), p=0.002. Patients in the amiodarone group experienced a borderline better increase of left ventricular ejection fraction: ∆ 5.2% (95% CI: -0.1 - 10.5), p= 0.054. Conclusion Periprocedural use of amiodarone in patients ablated due to persistent atrial fibrillation refractory to electrical cardioversion may lead to significantly better long-term efficacy of catheter ablation in this group of patients.