One-year Outcomes of a Conformable Single-shot Pulsed Field Ablation Catheter for the Treatment of Paroxysmal Atrial Fibrillation.

Background: Most single-shot pulsed field ablation (PFA) catheters require extensive repositioning for pulmonary vein isolation (PVI), posing a challenge for obtaining contiguous, durable lesions.

Objective: To determine one-year outcomes of a single-shot, all-in-one mapping and ablation PFA catheter for treating paroxysmal atrial fibrillation (PAF).

Methods: After PVI with the large-lattice catheter with expandable tip (Sphere-360), follow-up included Holters at 180 and 365 days and scheduled/symptomatic trans-telephonic monitoring (TTM) or modeled insertable loop recorder (ILR) data. Efficacy outcomes were acute PVI and 12-month freedom from atrial arrhythmias (AA), after 90-day blanking. Optional invasive remapping at 75 days facilitated waveform refinement from PULSE1, PULSE2, to the optimized PULSE3.

Results: At three centers, 100 PAF patients underwent PFA with PULSE1 (n =30), PULSE2 (n=20), or PULSE3 (n=50). Procedure, left atrial dwell, and fluoroscopy times were 57.9±20.6, 22.2±11.8 and 6.8±5.7 minutes, respectively. All 395 targeted PVs were acutely isolated, with a transpired PVI time of 11.5±6.0 minutes, using 4.0±1.3 lesions/PV. There were no primary safety events (serious device-related events within 7 days post-PFA). PVI durability with PULSE3 (n=40) was 98% (per vein) and 93% (per-patient). One-year freedom from AA recurrence was 82.0% (95%CI:73.0-88.3%) overall, and 88.0% (95%CI:75.2-94.4%) for PULSE3 patients. Of the ILR sub-cohort (n=15 PULSE3 patients), 3 patients (20%) had recurrences, with an AA burden reduction from 26% (baseline) to 1.6% (post-ablation).

Conclusions: The large lattice PFA catheter was efficient, safe, and effective in treating PAF. The observed high PVI durability translated to clinical effectiveness, even in continuously monitored patients.