Background
In patients with symptomatic atrial fibrillation (AF), rhythm control via catheter ablation (CA) has become part of the standard care. There are thermal approaches as well as a novel non-thermal approach, pulsed-field-ablation, utilizing electroporation. LArS is thought to be a non-invasive surrogate marker for left atrial (LA) function and pre-interventional left atrial reservoir strain (LArS) is described to be a predictor of rhythm outcome after AF ablation. However, structural and functional influences of different ablation modalities on the LA are not fully understood yet.
Aim
The aim of this study was to analyze the influence of different energy modalities on LA function, quantified by the surrogate marker LArS, as well as to evaluate post-procedural outcome after CA.
Methods
Patients with symptomatic AF undergoing first CA from 2018 - 2024 from the Essen Registry of Cardiac Arrhythmias (ERCAS) were included. Inclusion criteria were as following: Pre- & post-procedural transthoracic echocardiography (TTE) in continuous sinus rhythm (SR) of adequate image quality (unadulterated apical 2-/4-chamber view), 12 month follow-up information after blanking period. Clinical as well as procedural parameters were collected & retrospectively analyzed. LA strain analysis was performed for pre- & post-procedural TTE.
Results
Of 903 patients undergoing first CA from ERCAS, 220 patients fulfilled inclusion criteria. Among the study population, 106 patients underwent CA utilizing non-thermal pulsed-field-ablation (PFA) technology, 114 patients underwent thermal CA - using cryoballoon ablation (CBA) in 44 and radiofrequency ablation (RFA) in 70 patients.
A total of 92 patients (42%) experienced recurrence of AF after CA. For those patients, baseline LArS was significantly reduced in comparison to those without recurrence (LArS_pre_no recurrence: 24.82%, LArS_pre_recurrence: 20.19%; p<0.001). ROC analysis revealed a baseline LArS of ≤ 23,24% to be associated with a significantly higher risk of AF recurrence after CA (AUC: 0.711, 95%CI: 0.64-0.78, p<0.001).
Looking at the overall cohort, LArS_post was significantly reduced in comparison to LArS_pre (LArS_pre: 22.88%, LArS_post 22.39%; p=0.001). Specifying by ablation modality, this significancy was only applicable for thermal ablation modalities CBA (LArS_pre: 22.12%, LArS_post: 21.21%; p=0.007) and RFA (LArS_pre: 23.63%, LArS_post: 23.03%; p=0.025). Postinterventional LArS in the PFA subgroup appeared to be unaffected by CA (LArS_pre: 22.71%, LArS_post: 22.46%; p=0.27).
Conclusion
Baseline LArS was significantly associated with AF recurrence after CA, underlining its value as a marker of atrial substrate and rhythm outcome. Thermal ablation modalities but not PFA was associated with a postprocedural reduced LArS. However, changes in LArS were not related to recurrence, suggesting that baseline atrial remodeling may be more relevant for postprocedural outcome than acute changes in LA function.
