PO-02-001 MODIFIED BOX ABLATION WITH OR WITHOUT DRIVERS ABLATION FOR CHINESE PATIENTS WITH NON-PAROXYSMAL ATRIAL FIBRILLATION: A RETROSPECTIVE REAL-WORLD STUDY

Abstract

The use of circumferential pulmonary vein electrical isolation (CPVI) combined with modified posterior wall box isolation (m-BOX) has been proved an improvement in the long-term success of chronic atrial fibrillation (AF) patients’ treatment. More evidence shows that electrical drivers are associated with the maintenance of persistent AF (PsAF). To explore the long-term effectiveness of m-BOX or m-BOX with driver-guided ablation for non-paroxysmal AF using high-density mapping (HOT). Data were obtained from electronic medical records between January 1,2018 and May 31, 2022 from Xiangya Hospital Central South University, Changsha, China. Patients aged ≥18 years, diagnosed as PsAF or long-standing PsAF and underwent either m-BOX or HOT index ablation after CPVI, were included. Patients were expected to follow up ≥12 months post index procedure. Recurrence was defined as AF, or atrial tachycardia, or flutter lasting ≥30 seconds after 3-month blanking period, which came first. The Cox proportional model adjusting for propensity score (including age, gender, AF type, baseline left ventricular ejection fraction, left atrial diameter, and medical history) was used for 2-group comparison. The proportion of patients with event, adjusted hazard ratio (HR) [95% CI], and stratified log-rank P were presented. A total of 148 and 113 patients were identified in the HOT and m-BOX groups, with mean (SD) ages 61.7 (10.1) and 60.8 (8.9) years, male sex 64.2% and 67.3%, and long-standing PsAF diagnosis in 54.1% and 41.6% of population, respectively. The 12-month recurrence rate was lower in the HOT group than in m-BOX group (21.8% vs. 34.8%, adjusted HR [95% CI]:0.49 [0.30,0.80]; P=0.005). In the HOT group, the recurrence rate of patients who restored sinus rhythm (SR) by ablation was numerically lower than those who did not (16.7% vs. 26.7%, adjusted HR [95% CI]:0.60 [0.28,1.28]; P=0.37). Regardless of the ablation strategy, the recurrence rate was lower when SR was restored by ablation (16.2% vs. 34.4%, adjusted HR [95% CI]:0.43 [0.24,0.76]; P=0.01). Restoration of SR in non-paroxysmal AF patients is associated with lower recurrence rates at 12 months. In patients who do not achieve SR after CPVI and m-BOX, HOT ablation may lead to improved long term clinical outcomes. Future’s prospective study is needed for a more comprehensive view of the comparison results.