Pulsed field ablation for index pulmonary vein isolation: 3-year learning curve and the influence of adjunctive 3D mapping

The learning curve for pulmonary vein isolation (PVI) using "single-shot" pulsed-field ablation (PFA) is thought to be short. Adjunctive impedance based 3D electro-anatomical mapping (3D-EAM) might provide feedback on device positioning and post-ablation lesion quality for the pentaspline catheter and hence steepen the learning curve.

To analyze performance markers over time for PVI using PFA and 3D-EAM.

Consecutive patients with AF undergoing a first PVI with PFA from May 2021 to April 2024 were included. Impedance based 3D mapping was used based on operator’s experience and the planned lesion set. A learning curve was estimated using an exponential fit to procedure and fluoroscopy times of PVI-only procedures without the use of 3D-EAM. Patients were followed using 7d-Holter ECG at 3, 6, and 12 months. During clinically indicated repeat ablations, 3D mapping was used to assess PVI durability. Using procedure duration, fluoroscopy time, and PV-durability, two cutoffs are proposed to discern between learning curve, intermediate phase, and proficiency.

A total of 1009 AF patients underwent a first PVI using PFA. In 458 (45%) cases, 3D-EAM was used, in 264/702 (37%) for PVI-only cases and 192/298 (64%) for cases involving additional lesions. Procedure and fluoroscopy time were steady after 15 and 8 procedures with a mean of 53 min and 15 min, respectively. Pulmonary vein durability increased from 57% for the first 60 procedures per operator to 68% thereafter, p=<.016. Freedom from any atrial arrhythmia was similar for patients treated during the assumed learning curve (<20 Procedures, 67%), the intermediate phase (>20<60 Procedures, 66%) and proficiency (>60 Procedures, 64%), p=.980. Likewise, 3D-EAM had no discernible effect on freedom from arrhythmia (with 3D-EAM 69%, without 3D EAM 65%, p=.399).

The learning curve for PFA procedures is brief in terms of procedure and fluoroscopy time. Nevertheless, further improvements in PV durability can be expected with increasing experience. 3D-EAM might aid for catheter positioning, although the rates of freedom from arrhythmia and PV durability were comparable regardless of the use of mapping.