Predictors And Mechanisms Of Late Recurrence Of Chronic Atrial Fibrillation After Step-wise Radio-frequency Ablation

Background:Catheter ablation had been used as a relatively safe and effective treatment for persistent atrial fibrillation (PAF), but the ablation had multiple endpoint formats and low success rate. We tried to assess the effect of sinus rhythm conversion of PAF during catheter ablation on recurrence of atrial tachyarrhythmia.Methods:199consecutive PAF patients underwent stepwise approach of catheter ablation were divided into group A (conversion to sinus rhythm, n=80) and group B (not conversion to sinus rhythm, n=119) based on different endpoints of ablation. Sinus rhythm was restored by synchronized external direct-current cardioversion when AF was not terminated after complete ablation.Results:During follow-up, recurrence of atrial tachyarrhythmia (ATa) post initial procedure were10patients (13%) in group A,35patients (29%) in group B within6months (P<0.05) and16patients (20%) in group A,48patients (40%) in group B within12months (P<0.05), respectively. During22±14months follow-up,107patients were free from tachyarrhythmia, thus the success rate of ablation was58.3%. There were23patients (29%) in group A and69patients (58%) in group B (P<0.05) who had ATa recurrence. Ischemic stroke was reduced in patients free from tachyarrhythmia compared with recurrent patients (0vs.4, P<0.05). The risk factors of ATa recurrence increased with longer AF duration (75±86months vs.47±55months, P<0.05), larger left atrial dimension (LAD)(46±9mm vs.42±8mm, P<0.05) and the endpoint of ablation plus electrical cardioversion termination (75%vs.47%, P<0.05), respectively. In COX regression analysis, AF duration and the endpoint of ablation plus electrical cardioversion termination were associated with ATa recurrence, and LAD was not an independent predictor of ATa recurrence.Conclusion:The endpoint of ablation plus electrical cardioversion termination had a profound impact on the efficacy of freedom from atrial tachyarrhythmia after step-wise ablation. Indirect PAF termination and longer AF duration were independent predictors of ATa recurrence post persistent atrial fibrillation ablation.