Restoration, but not maintenance of sinus rhythm during amiodarone pretreatment predicts the success of pulmonary vein isolation in persistent atrial fibrillation

Abstract Introduction Restoration and maintenance of sinus rhythm (SR) in the months before pulmonary vein isolation (PVI) by antiarrhythmic drug (AAD) therapy may lead to a better outcome in persistent atrial fibrillation (AF). Amiodarone is the only AAD that has been shown to be effective not only in achieving rhythm control, but also in reversing atrial remodeling. It is unknown, however if persistent AF patients who convert upon amiodarone loading exhibit better outcomes after ablation, compared to those that also need electrical cardioversion (ECV) to achieve SR. It is also controversial whether subsequent AF episodes before the PVI, while on amiodarone, portend a worse outcome after ablation. Purpose Our aim was to evaluate whether amiodarone response before the procedure has predictive value in patients with persistent AF undergoing PVI. Methods We retrospectively collected data from patients with persistent AF who underwent PVI between 2013 and 2023, and who received temporary amiodarone therapy, with or without ECV to restore and maintain sinus rhythm prior to the intervention. Results A total of 371 patients (51% female, mean age: 63.76 ± 9.32 years) were included. Conversion to sinus rhythm was achieved solely by amiodarone therapy (AmioConv) in 104 patients (28%), while 267 patients (72%) required additional ECV as well. There were no differences between the two groups in terms of comorbidities and CHADS-VASc score (2.19±1.41 vs. 2.05±1.41; p=0,484), but the AmioConv group had smaller left atrial diameter (47 ± 6.6 mm vs. 49 ± 6.9 mm, p=0.034), higher left ventricular ejection fraction (57 ± 12.0% vs. 54 ± 13.3%, p=0.054) and a shorter history of AF (2.49 ± 3.0 years vs. 3.8 ± 4.67 years, p=0.01). During a mean follow-up of 2.47 ± 2.07 years after PVI, patients in the AmioConv group less frequently experienced AF recurrences (17% vs. 33%, p<0.01) and had longer mean recurrence-free survival (4.73±0.45 years vs. 3.9±0.29 years, p=0.02), compared to the ECV group. Conversion by amiodarone therapy was found to be an independent predictor of success of PVI (OR 2.03, 95% CI 1.20-3.43, p<0.01). On the contrary, AF episodes during amiodarone therapy, before ablation were not predictive of recurrences post PVI (p=0.32). Conclusion In patients with persistent atrial fibrillation, the success of PVI is predicted by the spontaneous restoration, but not the maintenance of sinus rhythm during amiodarone pretreatment.