The Ablate-by-LAWT multicentre prospective study: Personalized paroxysmal atrial fibrillation ablation with ablation index adapted to local left atrial wall thickness.

Background: Personalized radiofrequency (RF) ablation for paroxysmal atrial fibrillation (PAF), adapting the ablation index (AI) to local left atrial wall thickness (LAWT), proved to be highly efficient maintaining high arrhythmia-free survival rates. However, multicentre data are lacking. This multicentre, prospective, non-randomized study was conducted at 5 tertiary hospitals and sought to assess the safety, efficacy, and reproducibility of the LAWT-guided ablation for PAF.

Methods: Consecutive patients referred for first-time PAF were prospectively enrolled. The LAWT maps were obtained from preprocedural multidetector computed tomography and integrated into the navigation system. AI was titrated according to the local LAWT, and the ablation line was personalized to avoid the thickest regions while encircling the pulmonary veins (PVs).

Results: A total 109 patients (60.1 ± 9.4 years, 64.2% male) were enrolled. Median procedure time was 61.7 min (48.4-83.8), fluoroscopy time was 1.0 min (0.4-3.3), and RF time was 13.9 min (12.3-16.8). Median AI tailored to the local LAWT was 393 (374-412) for the anterior wall and 340 (315-378) for the posterior wall. Right and left PVs first-pass isolation was achieved in 89% and 91.7% of the patients, respectively. At 12-month follow-up, freedom from any atrial arrhythmia was 93.4% (95% CI 88.7-98.1), without differences across centres (P = 0.169). One patient experienced femoral artery pseudoaneurysm, with no other serious procedural-related complication.

Conclusion: The Ablate-by-LAWT study proved that LAWT-guided PV isolation for PAF is safe, effective, and efficient in a multicentre setting. Twelve-month recurrence-free survival exceeded 90% (NCT04218604).