Effects of antiarrhythmic drug responsiveness and diagnosis-to-ablation time on outcomes after catheter ablation for persistent atrial fibrillation

Background: The impact of delaying atrial fibrillation catheter ablation (AFCA) for antiarrhythmic drug (AAD) management on the disease course remains unclear. This study investigated AFCA rhythm outcomes based on the diagnosis-to-ablation time (DAT) and AAD responsiveness in participants with persistent AF (PeAF). Methods: We included data from 1038 AAD-resistant PeAF participants, all of whom had a clear time point for AF diagnosis, especially PeAF at diagnosis time, and had undergone an AFCA for the first time. Participants who experienced recurrences of paroxysmal type on AAD therapy were analyzed as a cohort of AAD-partial responders; those maintaining PeAF on AAD were AAD-non-responders. We determined the DAT cutoff for best discriminating long-term rhythm outcomes using a maximum log-likelihood estimation method based on the Cox proportional hazard regression model. Results: Of the participants (79.8% male; median age 61), 806 (77.6%) were AAD-non-responders. AAD-non-responders had a higher body mass index and a larger left atrial diameter than AAD-partial-responders. They also had a higher incidence of AF recurrence after AFCA (adjusted hazard ratio 1.75, 95% confidence interval 1.33–2.30; log-rank p <.001) compared to AAD-partial-responders. The maximum log-likelihood estimation showed bimodal cutoffs at 22 and 40 months. The optimal DAT cutoff rhythm outcome was 22 months, which discriminated better in the AAD-partial-responders than in the AAD-non-responders. Conclusions: Both DAT and AAD responsiveness influenced AFCA rhythm outcomes. Delaying AFCA to a DAT of longer than 22 months was inadvisable, particularly in the participants in whom PeAF was changed to paroxysmal AF during AAD therapy.