Personalized pulmonary vein isolation guided by left atrial wall thickness for persistent atrial fibrillation ablation: the PeAF-by-LAWT randomized trial.

Background: A personalized pulmonary vein isolation(PVI) approach aimed at ablation index(AI)titration according to MDCT-derived left atrial wall thickness(LAWT) maps reported high effectiveness and efficiency outcomes for persistent atrial fibrillation(PeAF) ablation. To date, no randomized trials have compared this approach with the standard CLOSE protocol.

Objectives: This non-inferiority randomized controlled trial sought to compare a LAWT-guided PVI with CLOSE protocol-based for PeAF(NCT05396534). Primary endpoint was freedom from atrial arrhythmias recurrence. Secondary endpoints were major complication rate, procedure time, radiofrequency time, and first-pass PVI rate.

Methods: Consecutive patients referred for first-time PeAF ablation were randomized on a 1:1 basis. In the by-LAWT arm, the AI was titrated according to local LAWT, and the ablation line was personalized to avoid the thickest regions at PV antrum. In the CLOSE arm, LAWT information was not available to the operator; the ablation was performed according to the CLOSE study settings: AI ≥400 at the posterior wall and ≥550 at the anterior wall.

Results: 156 patients were included. At 12-month follow-up, no significant difference occurred in atrial arrhythmia-free survival between groups(p=0.50). In the by-LAWT group a significant reduction in procedure time(60.5vs.80.0 minutes; p<0.01) and RF time(14.4vs.28.6 minutes; p<0.01) was observed. No difference was observed regarding first-pass PVI(p=0.72) and major complication rate(p=0.99).

Conclusions: The PeAF-by-LAWT trial is the first prospective randomized study to demonstrate that a personalized LAWT-guided PVI for PeAF ablation is non-inferior to the standard CLOSE protocol in terms of arrhythmia-free survival, while significantly improving procedural efficiency. The study was not powered to detect differences in safety outcomes.