The impact of extensive ablation strategy for persistent atrial fibrillation on left atrial function and cardiovascular events: Insights from EARNEST-PVI randomized controlled trial
Authors: Oka T , Koyama Y , Tanaka N , Masuda M , Watanabe T , Inoue K , Sunaga A , Hikoso S , Sakata Y 
Published: November 2023

Abstract

Background
Left atrial (LA) function is paid attention as the marker for several cardiovascular events. In catheter ablation for persistent atrial fibrillation (AF), extensive ablation strategy, such as linear ablation and/or complex fractionated atrial electrogram ablation in addition to pulmonary vein isolation (PVI-plus), could impair LA function more severely than PVI-alone strategy.

Purpose
The aim of this study is to investigate the impact of PVI-plus strategy on LA function and an incidence of cardiovascular events.

Methods
This study is a post-hoc subanalysis of the EARNEST-PVI randomized controlled trial (NCT03514693), which investigated the efficacy of the PVI-alone strategy in comparison with PVI-plus strategy for persistent AF. From the 497 participants of EARNEST-PVI trial, we enrolled 191 patients with full datasets of pre- and post-ablation cardiac computed tomography (CT). Patients were divided into PVI-alone and PVI-plus groups. Within one month before and 3 months after ablation, LA volume index (LAVI) and LA emptying fraction (LAEF) were calculated. We assessed (i) post-ablation LAEF (LAEFpost), (ii) AF/AT -free rate after final session, and (iii) association between PVI-plus strategy and composite cardiovascular events; all-cause death, embolic stroke, and heart failure (HF) hospitalization.

Results
The baseline LAVI and LAEF were not different between PVI-alone (N=96) and PVI-plus groups (N=95) [LAVI: 71.4(57.8, 82.0) vs. 68.7(61.0, 78.1), P=0.92, LAEF: 13.7(10.0, 17.4) vs. 13.0(10.0, 16.9), PVI-alone vs. PVI-plus, P=0.78]. In overall patients, LAEFpost did not differ [34.4 (26.1, 40.7) vs. 31.6 (26.0, 37.4), P=0.13]. In the analysis of patients showing sinus rhythm during the CT study, however, LAEFpost was significantly higher in PVI-alone (N=87) than in PVI-plus group (N=93) [35.7(29.0, 41.0) vs. 31.7(26.1, 37.5), P=0.011] (Figure 1). AF/AT-free survival rate after final session during median follow-up of 44 months tended to be higher in PVI-plus (72.9% vs. 84.2%, P=0.053) (Figure 2). The composite cardiovascular events-free rate were not different among two groups (94.8% vs. 96.8%, P=0.42) (Figure 3). LAEFpost was significantly lower in patients with composite events (N=8) than those without (N=183) [18.7(11.5, 28.1) vs. 33.1 (27.0-38.1), P=0.0051]. In multivariate Cox regression model adjusted with age≥75, gender and pre-LAVI, PVI-plus did not show association with composite events (HR: 0.90, 95%CI: 0.18-4.47, P=0.89), while LAEFpost showed strong association (HR:0.88, 95%CI: 0.80-0.96, P=0.0039).

Conclusion
Compared with PVI-alone strategy, PVI-plus strategy impaired LA function more severely, but tended to have higher ablation success rate, and did not increase cardiovascular events. LAEFpost was independently associated with cardiovascular events. Regardless of ablation strategy, patients with reduced post-ablation LA function should be observed carefully.Post-ablation LA function and recurrenceCardiovascular events and LA function