Extended Period Outcomes of Posterior Box Isolation in 4 Randomized Atrial Fibrillation Catheter Ablation Trials.

Background: Catheter-based electrical posterior box isolation (POBI) and circumferential pulmonary vein isolation (CPVI) do not improve the rhythmic outcomes of atrial fibrillation catheter ablation in previous studies with 12 to 24 months of follow-up.

Objectives: The authors analyzed the long-term rhythm outcomes of our 4 previously conducted randomized controlled trials comparing CPVI alone vs CPVI plus additional POBI using the intention-to-treat principle.

Methods: The authors analyzed 575 AF patients included in our 4 previous randomized controlled trials. We compared clinical recurrence defined as recurrent atrial arrhythmia after the index procedure. In patients who underwent a repeat procedure because of recurrence after the index procedure, the mechanism of recurrence was analyzed.

Results: After a median follow-up of 48 months, there were no significant differences in the clinical recurrence or major adverse cardiac events between the CPVI alone and CPVI plus POBI groups. The procedure time was significantly longer, and the atrial tachycardia recurrence rate was higher in the CPVI plus POBI group. In the patients who experienced clinical recurrence, there were no significant differences in the rates of cardioversion or need for repeat procedures between the groups. In patients who underwent a repeat procedure because of recurrence after the index procedure (n = 64), the pulmonary vein reconnection rate did not differ, but re-entrant atrial tachycardia was more common in the CPVI plus POBI group, while extrapulmonary vein triggers were more common in the CPVI alone group.

Conclusions: The addition of POBI to CPVI did not improve the long-term rhythm outcomes in patients undergoing atrial fibrillation catheter ablation. (The Evaluation for Prognostic Factors After Catheter Ablation of Atrial Fibrillation, NCT02138695; Evaluation of Proper Radiofrequency Catheter Ablation Strategy for the Patients Who Were Changed to Paroxysmal Atrial Fibrillation From Persistent Atrial Fibrillation, NCT02176616; Comparison of Circumferential Pulmonary Vein Isolation Alone Versus Linear Ablation in Addition to Circumferential Pulmonary Vein Isolation for Catheter Ablation in Persistent Atrial Fibrillation: Prospective Randomized Controlled Trial, NCT02721121; Comparison of Circumferential Pulmonary Vein Isolation and Complex Pulmonary Vein Isolation Additional Linear Ablation for Recurred Atrial Fibrillation After Previous Catheter Ablation: Prospective Randomized Trial [RILI Trial]; NCT02747498.