Posterior Wall Isolation Improves Outcomes for Persistent AF With Rapid Posterior Wall Activity: CAPLA Substudy

Area of Science:

• Electrophysiology
• Cardiology
• Medical Devices

Background:

• Pulmonary vein isolation (PVI) efficacy is lower in persistent atrial fibrillation (PerAF) than paroxysmal AF.
• Previous studies, like the CAPLA trial, did not support routine posterior wall isolation (PWI) in PerAF.
• Investigating electrical characteristics of pulmonary veins (PV) and posterior wall (PW) may identify PerAF patients benefiting from PWI.

Purpose of the Study:

• To determine if PV and PW electrical characteristics predict AF ablation outcomes in the CAPLA randomized study.
• To identify specific patient subgroups within PerAF who may benefit from additional PWI.
• To analyze the impact of PV and PW electrical properties on AF recurrence after catheter ablation.

Main Methods:

• Analysis of 151 patients from the CAPLA study randomized to PVI or PVI+PWI.
• Measurement of PV, PW, and left atrial appendage cycle lengths preablation.
• Utilized Cox proportional hazards regression to identify predictors of AF recurrence.
• 12-month follow-up using ECG monitoring.

Main Results:

• Overall freedom from AF at 12 months was similar between PVI (51.7%) and PVI+PWI (49.7%).
• Rapid PW activity (shortest PW cycle length < 140 ms) was associated with higher AF recurrence risk with PVI alone (55.3% vs 46.5%).
• Addition of PWI in patients with rapid PW activity significantly improved arrhythmia-free survival (56.4% vs 38.6%).
• Rapid PV activity did not correlate with ablation outcomes.

Conclusions:

• Rapid PW activity predicts increased AF recurrence risk post-catheter ablation.
• PWI addition in patients with rapid PW activity significantly improves freedom from AF.
• Identifying rapid PW activity may guide patient selection for PVI+PWI in PerAF.