Initial experience with left atrial posterior wall debulking technique

Background

Catheter ablation is currently the most effective rhythm control strategy for atrial fibrillation (AF). Although pulmonary vein isolation (PVI) remains the cornerstone of ablation therapy, the role of additional left atrial substrate modification in patients with persistent AF remains controversial.

Objective

To assess the efficacy and safety of three radiofrequency (RF) ablation strategies—PVI alone, PVI with posterior box lesion (PostBOX), and PVI with posterior wall debulking (PWD)—in patients with persistent AF.

Methods

A retrospective analysis was conducted on 133 patients with persistent AF (66.9% male; mean age 62.4 ± 13.4 years; AF duration 6.0 ± 5.7 years) who underwent first-time RF catheter ablation. PVI group (n = 44): PVI alone using a high-power short-duration (HPSD, 50 W) technique. PostBOX group (n = 41): PVI combined with a posterior box lesion (HPSD, 50 W).PWD group (n = 48): PVI combined with posterior wall "debulking" (anterior wall ablation using HPSD, 50 W; posteriorwall ablation using very high-power short-duration [vHPSD], 90 W).The primary endpoint was AF recurrence after a 3-month blanking period, defined as any atrial tachyarrhythmia lasting >30 seconds or requiring cardioversion after a single procedure. Secondary endpoints included arrhythmia recurrence patterns, need for cardioversion, and procedural characteristics.

Results

All patients completed 12 months of follow-up (mean follow-up 12 ± 9 months). Sinus rhythm without antiarrhythmic drugs was maintained in:

50% of patients in the PVI group,

56% in the PostBOX group, and

73% in the PWD group (Chi-square test P < 0.04 as compared to PVI, and PWD). Major complication rates were low and comparable among groups (2.4% vs. 2.2% vs. 0%, respectively; P = 0.10). Procedure duration was significantly shorter in the PVI group [71 (58–78) min] compared with the PostBOX [88 (71–91) min, P = 0.01] and PWD [90 (77–97) min, P = 0.02] groups.

Conclusion

In patients with persistent AF, posterior wall debulking using very high-power short-duration ablation demonstrated superior arrhythmia-free survival compared with PVI or PWD plus , without an increase in procedural complications. These findings support further evaluation of atrial "debulking" as a substrate modification strategy in persistent AF.