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.