A tailored substrate-based approach using focal pulsed field catheter ablation in patients with atrial fibrillation and advanced atrial substrate: Procedural data and 6-months success rates

Background: Focal pulsed-field ablation (F-PFA) integrated in electroanatomical mapping (EAM) systems allows tailored lesion sets in patients with atrial fibrillation (AF).

Objective: To determine feasibility, safety and 6-months outcome of F-PFA for a tailored substrate-based catheter ablation (CA) approach in patients with AF and advanced atrial substrate.

Methods: Consecutive patients with AF and advanced atrial substrate treated by a F-PFA system (Cardiofocus) through contact-force sensing catheters integrated in EAM systems were prospectively enrolled. The tailored substrate-based CA approach included isolation of all pulmonary veins (PVI) with wide area circumferential ablation, posterior wall isolation (PWI), mitral anterior line and cavo-tricuspid isthmus (CTI) ablation, according to substrate. At 6 months, feasibility, arrhythmia recurrence and safety were evaluated.

Results: In 83 patients (33% female, indexed left atrial volume: 44±15ml/m², 80% persistent AF or atrial flutter (AFl), 57% re-do procedures), successful de-novo PVI was performed in 36 patients and PV reisolation in 30 patients. Mitral anterior line was performed in 19 patients with atypical AFl or anterior low voltage areas; PWI was performed in 38 patients with low voltage areas or evoked delayed electrograms during premature atrial extrastimuli; CTI was performed in 24 patients with typical AFl. Median procedural and fluoroscopy times were 115 and 7 minutes, respectively. No complications occurred. At 6 months, arrhythmia recurrence occurred in 30/83 patients (21 AF; 9 atypical AFl).

Conclusion: Tailored substrate-based F-PFA in patients with AF and advanced atrial substrate is safe and effective. Acute procedural success was 100% with 64% freedom from arrhythmias after 6 months.