Pulsed field ablation (PFA) has demonstrated favorable safety and efficacy in atrial fibrillation ablation, particularly for pulmonary vein isolation (PVI). However, the optimal PFA-based ablation strategy for non-paroxysmal atrial fibrillation remains uncertain. In addition to anatomical lesion sets such as PVI and posterior wall isolation (PWI), Electrogram Mapping of Key Substrates may allow identification of residual arrhythmogenic areas that contribute to the maintenance of atrial fibrillation. In the investigators' previously completed single-center cohort study, adjunctive ablation targeting key substrates identified by electrogram mapping on top of PVI+PWI was feasible and associated with improved rhythm outcomes. This prospective multicenter randomized controlled study is designed to compare PFA-based PVI+PWI alone versus PVI+PWI plus adjunctive ablation guided by Electrogram Mapping of Key Substrates in patients with non-paroxysmal atrial fibrillation, in order to evaluate the efficacy and safety of this strategy in a broader and more rigorous clinical setting.
Pulsed field ablation (PFA) has emerged as a promising energy source for atrial fibrillation ablation because of its myocardial selectivity and favorable safety profile. Previous studies have demonstrated high procedural success and encouraging clinical outcomes for PFA-based pulmonary vein isolation (PVI), particularly in patients with paroxysmal atrial fibrillation. However, in patients with non-paroxysmal atrial fibrillation, the underlying arrhythmogenic substrate is often more complex and extends beyond the pulmonary veins, and the optimal lesion set for PFA-based ablation in this population remains to be established. Posterior wall isolation (PWI) is commonly added to PVI in an effort to improve substrate modification in non-paroxysmal atrial fibrillation. Nevertheless, recurrence after PVI+PWI remains common, suggesting that additional mechanisms outside conventional anatomical targets may play an important role in arrhythmia maintenance. Electrogram Mapping of Key Substrates provides a strategy to identify localized abnormal electrophysiological regions that may represent critical drivers or perpetuators of atrial fibrillation and may therefore serve as adjunctive ablation targets beyond standard anatomical lesion sets. In the investigators' previous studies of catheter ablation for persistent atrial fibrillation, substrate modification guided by electrogram characteristics showed promising efficacy. More specifically, in the investigators' completed single-center cohort study of PFA for non-paroxysmal atrial fibrillation, adjunctive ablation based on Electrogram Mapping of Key Substrates in addition to PVI+PWI was shown to be feasible and was associated with favorable rhythm control outcomes. These findings support the hypothesis that a strategy incorporating electrogram-defined key substrate identification may provide incremental benefit over PVI+PWI alone. However, whether adjunctive ablation guided by Electrogram Mapping of Key Substrates improves clinical outcomes in a reproducible manner has not yet been validated in a prospective multicenter randomized controlled trial. Given the potential influence of operator experience and center-level variability on substrate-based ablation, a multicenter randomized design is necessary to provide more robust evidence regarding the efficacy, safety, and generalizability of this strategy. Therefore, the present study is designed as a prospective multicenter randomized controlled trial to compare two PFA-based ablation strategies in patients with non-paroxysmal atrial fibrillation: 1. PVI+PWI alone; and 2. PVI+PWI plus adjunctive ablation guided by Electrogram Mapping of Key Substrates. The primary objective of this study is to determine whether the addition of ablation targeting key substrates identified by electrogram mapping improves rhythm outcomes compared with PVI+PWI alone. The study will also assess procedural characteristics and safety outcomes to further define the role of Electrogram Mapping of Key Substrates in optimizing PFA-based ablation strategies for non-paroxysmal atrial fibrillation.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
300
In the experimental arm, electrogram mapping will be performed before pulmonary vein isolation (PVI) and posterior wall isolation (PWI) to identify key atrial substrates for adjunctive ablation. Mapping may be conducted using machine learning-assisted electrogram mapping, operator-guided electrogram mapping, or a combination of both, based on the same predefined criteria for target identification. Electrogram analysis will then be performed to identify target regions with the following characteristics: 1)Spatial-temporal dispersion activation; 2)Short cycle length activity; 3)Focal activity. After completion of electrogram mapping and target identification, all participants in the experimental arm will undergo standard PFA-based PVI and PWI. Adjunctive pulsed-field ablation will subsequently be delivered to the electrogram-defined key substrates identified during the pre-ablation mapping phase.
Ablation will be performed using a pulsed-field ablation system. Participants in this arm will undergo standard pulmonary vein isolation and posterior wall isolation only, without additional substrate ablation guided by electrogram mapping.
Montefiore Medical Center
The Bronx, New York, United States
The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology
Wuhan, Hubei, China
Changshu Hospital of Traditional Chinese Medicine
Changshu, Jiangsu, China
Xuzhou Central Hospital
Xuzhou, Jiangsu, China
Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine
Jinan, Shandong, China
Jinan City People's Hospital
Jinan, Shandong, China
Wenling Hospital of Traditional Chinese Medicine
Wenling, Zhejiang, China
Yuhuan Second People's Hospital
Yuhuan, Zhejiang, China
Shanghai Jiao Tong University School of Medicine, Shanghai Chest Hospital
Shanghai, China
Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine Shanghai
Shanghai, China
freedom from any AF/AT
The feasibility primary endpoint was defined as freedom from any AF/AT episodes lasting more than 30 seconds after the blanking period without anti-arrhythmic drugs at 3 months, 6 months, 12 months and 36 months respectively after the procedure.
Time frame: freedom from any AF/AT at 3 months, 6 months, 12 months and 36 months respectively after the procedure; adverse events occurring within 30 days of the index or reassessment procedures.
composite of major safety events
The safety endpoint is a composite of major safety events including cardiac tamponade or perforation, peripheral or organ thromboembolism, stroke or transient ischemic attack (TIA), diaphragmatic paralysis, block, pericarditis, hemolysis, myocardial infarction, PV stenosis, atrioesophageal fistula, and death. The endpoint includes events occurring within 30 days of the index or reassessment procedures.
Time frame: adverse events occurring within 30 days of the index or reassessment procedures.
AF recurrence
freedom from any documented AF episode lasting more than 30 seconds after the blanking period without anti-arrhythmic drug treatment at 3 months, 6 months, 12 months and 36 months respectively
Time frame: freedom from any AF at 3 months, 6 months, 12 months and 36 months respectively after the procedure
AT recurrence
any documented AT episode lasting more than 30 seconds after the blanking period without anti-arrhythmic drug treatment at 3 months, 6 months, 12 months and 36 months respectively.
Time frame: freedom from any AT at 3 months, 6 months, 12 months and 36 months respectively after the procedure
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