Impact of atrial fibrillation termination mode during catheter ablation procedure on maintenance of sinus rhythm

Objectives: We evaluated for the first time the association between 1-year ablation efficacy and termination mode after repeated catheter ablations in patients presenting with persistent or long-standing persistent AF. Background: Catheter ablation is a common and effective procedure to address atrial fibrillation (AF) refractory to antiarrhythmic drugs. AF can be terminated directly into sinus rhythm (SR); evolving into regular atrial tachycardia (AT) and subsequently into SR; after direct current (DC) cardioversion if AF persists. Scarce data are available on the relationship between clinical outcomes and termination mode after one catheter ablation. Methods: This prospective study involved 400 consecutive patients (62.7±7.2y) who underwent catheter ablation for drug-refractory persistent AF (4.6±2.4 months) using a stepwise ablation approach. Results: AF was terminated by radiofrequency application directly into SR in 135 patients; passing through AT into SR in 195 patients; through DC cardioversion in 70 patients. After 1 year of follow-up with repeated Holter monitoring, the percentages of SR maintenance were, respectively, 72.6%, 80.0% and 28.6% (p<0.001). As compared with the subjects who were converted directly into SR, the adjusted hazard ratios (HRs) of SR maintenance were significantly lower for those who required DC cardioversion (HR=0.54; p<0.001); higher for those converted through AT (HR=1.69; p=0.027). The latter association was even stronger in the 104 subjects who required a second procedure (HR=6.25; p=0.001). Conclusions: Termination of AF through AT during catheter ablation was more effective than both DC shock and direct SR in maintaining stable SR at 1 year after both the first and the second procedures.