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

Background: Catheter ablation is a common and effective procedure for addressing atrial fibrillation (AF) refractory to antiarrhythmic drugs. AF can be terminated in 3 modes: (1) directly into sinus rhythm (SR); (2) evolving into regular atrial tachycardia (AT) and subsequently into SR; and (3) after direct current (DC) cardioversion if AF persists. Scarce data are available on the relationship between clinical outcomes and termination mode after 1 catheter ablation.

Objective: The purpose of this study was to evaluate 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.

Methods: This prospective study involved 400 consecutive patients (age 62.7 ± 7.2 years) 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; and through DC cardioversion in 70 patients. After 1-year follow-up with repeated Holter monitoring, the percentages of SR maintenance were 72.6%, 80.0%, and 28.6%, respectively (P < .001). 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 < .001) and higher for those converted through AT (HR = 1.69; P = .027). The latter association was even stronger in the 104 subjects who required a second procedure (HR = 6.25; P = .001).

Conclusion: Termination of AF through AT during catheter ablation was more effective than both DC shock and direct SR in maintaining stable SR 1 year after both the first and the second procedures.