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

Abstract Background The pulmonary vein isolation (PVI) for persistent atrial fibrillation (PeAF) ablation proved to be safe and effective. A personalized PVI approach using ablation index (AI) titration according to the local left atrial wall thickness (LAWT) as assessed by pre-procedural multidetector cardiac tomography (MDCT)- data postprocessing reported high efficiency in persistent AF patients, while maintaining good outcomes at long-term follow-up. Up to date, there are no randomized trial comparing the personalized PVI approach based on LAWT-guided titration of the AI for PeAF ablation with the standard of care. Purpose The present study sought to compare the safety, the efficacy, and the efficiency of a LAWT-guided personalized PVI approach with those of a standard CLOSE protocol PVI strategy for PeAF ablation (PeAF-by-LAWT trial, NCT05396534). Methods Consecutive patients referred for PeAF first ablation were prospectively enrolled and randomized on a 1:1 basis to the study arm ("by-LAWT") and the control arm ("CLOSE"). (Figure 1). In the "by-LAWT arm", the AI was titrated according to the local LAWT at each atrial point and the ablation line was personalized to avoid the thickest regions while encircling the PV antrum. In the CLOSE arm, MDCT-derived LAWT information was not available to the operator. Ablation was performed according to the CLOSE study settings: RF was delivered until an AI of > 400 at the posterior wall and floor, while > 550 at the anterior wall and roof. Results One hundred fifty-six patients (69.5% male, mean age of 67.1 years) were included. In comparison to CLOSE group, a significant increase in efficiency was observed in by-LAWT group: procedure time (60.5 [55.0 - 74.0] minutes vs. 80.0 [70.0 - 92.0] minutes; p<0.001) and RF time (14.4 [13.0 - 16.4] minutes vs. 28.9 [26.3 - 31.6] minutes; p<0.001). Complete PVI was achieved in all procedures. No difference was observed between the groups in in-hospital complication rate (2.5% vs. 2.5%, p=0.99). No difference was observed between the groups in first-pass isolation of right PVs (82.1% vs. 78.3%, p=0.42) and of left PVs (83.3% vs. 86.5%, p=0.65). At 12-month mean follow-up, log-rank analysis showed no significant difference in atrial arrhythmia-free survival between groups (by-LAWT 74.7% vs CLOSE 71.9%; p = 0.72) (Figure 2). Conclusions The PeAF-by-LAWT is the first prospective randomized trial comparing the outcomes of a personalized LAWT-guided PVI protocol with the standard of care procedure. LAWT-guided personalized PVI ablation for PeAF ablation proved to be more efficient with respect to the CLOSE protocol approach, demonstrating a significant reduction in procedural and RF time, while maintaining comparable safety and long-term arrhythmia-free survival.