Relationship between amiodarone response prior to ablation and 1-year outcomes of catheter ablation for atrial fibrillation

Introduction: Catheter ablation for atrial fibrillation (AF) is a common therapeutic strategy for patients with either paroxysmal AF (PAF) or persistent AF (persAF), but long-term ablation success rates are imperfect. Maintenance of sinus rhythm immediately before ablation with antiarrhythmic drug (AAD) therapy has been associated with improved outcomes in patients undergoing ablation. Amiodarone has superior efficacy relative to other AADs. Whether failure of amiodarone to maintain sinus rhythm before ablation for either PAF or persAF is associated with poor outcomes is unknown.

Methods: A total of 307 patients who received amiodarone in a 1-year window before undergoing catheter ablation for AF were included. Patients were divided into amiodarone success (n = 183) and amiodarone failure (n = 124) groups based on the response to pre-ablation amiodarone treatment. Analysis of procedural outcomes as a function of response to amiodarone therapy was performed. Patients were followed for at least 12 months postablation, to assess outcomes (adverse events and arrhythmia recurrence). Procedural success was defined by the absence of documented arrhythmia (>30 s) without any antiarrhythmic agents beyond a 90-day blanking period.

Results: Following ablation for either PAF or persAF, freedom from any recurrent atrial arrhythmia at 1 year was 57.7% for the entire cohort. One-year freedom from recurrent arrhythmia in the amiodarone success group was comparable to that in the amiodarone failure group (55.7% vs. 60.5%; p = .54). Success rates following ablation did not vary by the response to amiodarone when analyzed for PAF or persAF subgroups.

Conclusion: Failure to restore and maintain sinus rhythm with amiodarone before ablation for either PAF or persAF is not a predictor of ablation procedural failure. Amiodarone failure alone should not deter practitioners from considering ablation therapy for patients with AF.