LA strain analysis in patients undergoing atrial fibrillation ablation using cryoballoon or pulsed-field-ablation
Authors: Jungen C , Eitel C , Mavrakis E , Vlachopoulo D , Rudolph I , Bohnen J , Rattka M , Rassaf T , Mathew S 
Published: October 2024

Abstract

Background
Catheter ablation for atrial fibrillation (AF) is increasing as rhythm control therapy. Besides thermal ablation approaches, such as cryoballoon ablation (CBA), a novel non-thermal and tissue-specific ablation modality – pulsed field ablation (PFA) – has been introduced. Left atrial reservoir strain (LArS) has been suggested to predict arrhythmia recurrences after AF ablation. Up to now, data describing LArS in patients undergoing their first AF ablation using PFA or CBA are sparse.

Purpose
To compare LArS in patients undergoing first catheter ablation for AF using either PFA or CBA.

Methods
Patients with transthoracic echocardiography prior to their first catheter ablation for AF were included. Patients in AF during transthoracic echocardiography, with poor 2D image quality and those that did not have a transthoracic echocardiography after AF ablation were excluded. Clinical characteristics and echocardiography parameters were analyzed. LArS was measured before and after AF ablation and was correlated with the recurrence of atrial arrhythmias in the follow-up period.

Results
Of 267 patients undergoing their first AF ablation, 67 patients (69% male, 65 ± 11 years) fulfilled the inclusion criteria and were further analyzed. AF ablation was performed using PFA in 55% and CBA in 45% of patients. Baseline characteristics were similar in both groups. Before ablation LArS was similar for PFA (17.69 ± 6.92%) and CBA patients (19.38 ± 9.42%, P=0.45). After AF ablation, LArS did not change significantly compared to the values before (before ablation: 20.96 ± 15.9 vs. after ablation: 19.87 ± 9.38, P=0.18), irrespective of the ablation mode (PFA before: 17.69 ± 6.92%vs. PFA after: 18.06 ± 8.9%, P=0.53; CBA before: 19.38 ± 9.42% vs. CBA after: 21.08 ± 9.48%, P=0.36). After a median of 190 days [95% confidence interval: 89 - 454 days], 25 patients (37%) experienced an arrhythmia recurrence (PFA: 38%, CBA: 37%). Comparing patients with and without arrhythmia recurrences, LArS before catheter ablation was lower in those experiencing an arrhythmia recurrence (16.02 ± 6.8%) compared to those without arrhythmia recurrence (25.58 ± 20.32%, P=0.02). However, this was independent from the ablation mode (PFA: AF-recurrence: 16.51 ± 4.27 vs. no recurrence: 21.31 ± 15.9, P=0.19; CBA: AF-recurrence: 15.48 ± 9.03 vs. no recurrence: 27.34 ± 22.14, P=0.07). Univariable regression analysis - including sex, age and comorbidities - revealed a trend for baseline LArS being associated with arrhythmia recurrence (HR 0.92, 95% CI: 0.86 – 1.01; P=0.065).

Conclusions
This hypothesis generating study indicates that LArS is not affected by AF ablation irrespective of the ablation mode. Patients with lower LArS before ablation had more arrhythmia recurrences independent of the ablation mode. A larger patient population is needed to assess the association of LArS and arrhythmia recurrences after AF ablation using different ablation modalities.