Posterior wall isolation in persistent atrial fibrillation feasibility, safety, durability, and efficacy

Abstract

Introduction: Posterior wall isolation (PWI) added to pulmonary vein isolation (PVI) is increasingly used despite limited evidence of clinical benefit. We investigated the feasibility, durability, and efficacy of index-procedure PVI + PWI radio frequency ablation (RFA) in patients with persistent atrial fibrillation (PeAF).

Methods and results: Twenty-four patients with PeAF participated in the prospective PeAF-Box study and underwent RFA with wide area circumferential ablation, roof- and inferior lines to achieve PVI + PWI at index procedure. Follow-up included monitoring by an implantable cardiac monitor, esophagoscopy and mandated invasive lesion-reassessment at 6 months. PWI was achieved at minor procedural cost in all patients following PVI. In 33% of patients a median of three ablations in the narrow zone between the center of the posterior wall (PW) and the posterior right carina was pivotal for swift achievement of PWI. At the 6-month reassessment procedure 85% (95% confidence interval [CI]: 77%-92%) of pulmonary veins (PVs) and 46% (95% CI: 26%-67%) of PWs remained durably isolated. AF recurred in 25% and was associated with PV-reconnection (p = .02) but not PW-reconnection (p = .27). AF-burden was 0% (interquartile range [IQR]: 0%-0%) overall and after recurrence 1% (IQR: 0%-7%).

Conclusion: Index procedure PVI + PWI for PeAF was feasible when recognizing that limited ablation in a PW center-to-right-carina zone was required in a subset of patients. Despite limited chronic PWI durability this strategy was followed by low AF-burden. A PVI + PWI strategy appears promising in ablation for PeAF.

Trial registration: ClinicalTrials.gov NCT05045131.

Keywords: AF burden; center-right zone (of left atrial posterior wall); implanted continuous rhythm monitor; mandated invasive reassessment; persistent atrial fibrillation; posterior wall.

Figure 1

PVI + PWI. (A) Planned lesion set with WACA segments 1–12 and Roof/Inferior segments PW1‐PW6. (B) Posterior view of actual lesion set to obtain PVI + PWI in a patient where center‐right zone ablation was required. PVI, pulmonary vein isolation; PWI, posterior wall isolation

Figure 2

Chronic durability of PVI + PWI after 6 months: (A) Bipolar voltage map showing durable PVI but reconnected PW with lesions (red and pink tags) to reestablish PWI. (B) Durable PVI + PWI. (C) Location and frequency of conduction gaps at 6 months mandated reassessment. PVI, pulmonary vein isolation; PWI, posterior wall isolation

Figure 3

Time to first recurrence of AF detected on ICM. Bar depicts 90‐day blanking period postablation. ICM, implantable cardiac monitor