Introduction
Atrial fibrillation (AF) is the most common arrhythmia worldwide and contributes to a variety of pathophysiological consequences including reduced functional capacity, increased risk of thromboembolism, heart failure, depression, and dementia (1,2,3). Catheter ablation for patients with either paroxysmal or persistent AF (PAF or persAF) has become a common therapeutic option, particularly for patients intolerant of anti-arrhythmic drug (AAD) therapy (4). The cornerstone of catheter ablative therapy for both PAF and persAF patients remains pulmonary vein isolation (PVI). While superior to AAD therapy in preventing recurrent AF, ablation remains imperfect in preventing AF recurrence in a substantial minority of patients (5,6).
Assessing the likelihood of AF ablation success is clearly important when considering the risk/benefit profile associated with ablation therapy. Several studies have demonstrated improved ablation outcomes in patients restored to normal sinus rhythm (NSR) with AAD therapy in the run-up phase to ablation for persAF (7,8,9). However, these investigations excluded PAF patients, used a variety of AADs, and employed ablation strategies beyond standard PVI. More importantly, patients who did not maintain sinus rhythm despite amiodarone therapy were explicitly excluded from investigation (9).
No studies, to our knowledge, have focused exclusively on therapeutic response to amiodarone as a screening tool for the prediction of AF ablation outcomes. The current investigation hypothesized that failure of amiodarone to maintain sinus rhythm in the pre-ablation window would correlate with increased post-ablation recurrence of AF. Use of amiodarone is often confined to a particular subset of AF patients (those with coronary artery disease, heart failure, advanced age); accordingly, in an effort to minimize confounding patient characteristics, we compared AF ablation outcomes in patients treated successfully with amiodarone (but who nevertheless opted for ablation) versus those in whom amiodarone was unsuccessful in maintaining NSR.