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

Abstract

Aims: A personalized pulmonary vein isolation (PVI) approach aimed at ablation index (AI) titration according to multidetector computed tomography-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. This non-inferiority randomized controlled trial sought to compare a LAWT-guided PVI with CLOSE protocol-based for PeAF (NCT05396534).

Methods and results: 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 the pulmonary vein antrum. In the CLOSE arm, LAWT information was not available to the operator; the ablation was performed according to the CLOSE study settings: AI is ≥400 at the posterior wall and ≥550 at the anterior wall. Primary endpoint was freedom from atrial arrhythmias recurrence. Secondary endpoints were the major complication rate, procedure time, radiofrequency time, and first-pass PVI rate. One hundred fifty-six 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 (60.5 vs. 80.0 min; P < 0.01) and RF time (14.4 vs. 28.6 min; P < 0.01) was observed. No difference was observed regarding first-pass PVI (P = 0.72) and the 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.

Keywords: Catheter ablation; Left atrial wall thickness; Multidetector computed tomography; Persistent atrial fibrillation; Pulmonary vein isolation.

Graphical Abstract

Figure 1

PeAF-by-LAWT randomized trial flowchart.

Figure 2

PeAF-by-LAWT study workflow. (A) The first step is the multidetector computed tomography (MDCT)-derived image segmentation and the rendering of the 3D colour-coded LAWT map (by-LAWT arm) or 3D LA anatomical map (CLOSE arm). (B) Image integration into the navigation system after performing LA fast electro-anatomical map. (C) Pulmonary vein isolation with AI targets adapted to LAWT information (by-LAWT arm) or with according to the CLOSE protocol (CLOSE arm).

Figure 3

Personalized pulmonary vein isolation with the local LAWT-guided AI target. At the left, an example of a LAWT-guided PVI. The LAWT map is colour-coded in the following manner, as described in the main text: red for LAWT < 1 mm, yellow for LAWT between 1 and 2 mm, green for LAWT between 2 and 3 mm, blue for LAWT between 3 and 4 mm, and purple for LAWT ≥ 4 mm. AI targets were adjusted according to the underlying LAWT in a point-by-point fashion. At the right, an example of a personalized PVI line aiming at avoiding, as far as possible, the closest area (red area) of the oesophagus fingerprint at LA posterior wall; in addition, the AI target in correspondence to the red area of the oesophagus fingerprint was limited to 300.

Figure 4

Procedural outcomes (A) and atrial arrhythmia-free survival Kaplan–Meier curves (B) according to the study arm.

Figure 5

Box plots showing the personalized AI titration according to local left atrial wall thickness in the intervention arm, compared with the fixed AI targets of the CLOSE protocol. AC, anterior carina; AI, antero-inferior; AS, antero-superior; Inf, inferior; LPV, left pulmonary vein; PC, posterior carina; PI, postero-inferior; PS, postero-superior; RPV, right pulmonary vein.