Lesion characteristics after pulsed-field ablation in patients with paroxysmal atrial fibrillation and a left common ostium (PFALCO RE-MAP STUDY).

BACKGROUND

Approximately one-fifth of patients undergoing pulmonary vein isolation have a left common ostium (LCO). These patients tend to have worse arrhythmia-free survival when treated with a single-shot device, which may be related to lesion location and ablation thermodynamics.

PURPOSE: This study evaluates lesion characteristics around the LCO in paroxysmal atrial fibrillation (AF) patients treated with a pentaspline pulsed-field ablation (PFA) modality.

METHODS

Twenty-two patients underwent PFA. Directly after the PFA applications, an electro-anatomical map (EAM) was created using the PFA catheter. After the procedure, three experienced operators were asked to draw a fictional ideal ablation line in the EAM encompassing the LCO. Outcome measurements were operators' satisfaction with the lesion characteristics and the distance from the lesion to the fictional ablation line.

RESULTS

The median age was 61 years [56-73] and the median CHA2DS2-VA was 1.0 [0.0-2.0]. Based on the EAM, the majority of the operators (≥ 2/3) considered unintended ablation at the mitral isthmus or posterior wall in 9 patients (40.9%), would perform additional ablation at the LCO in 11 patients (50.0%), and had no remarks in 6 patients (27.3%). The distance (lesion - fictional ablation line) at the left atrium roof was 3.6 mm [-4.8-11.2], mid posterior wall 3.3 mm [-2.6-8.9] and inferior --1.7 mm [-7.9-2.7].

CONCLUSIONS

The LCO lesion location after PFA in paroxysmal AF patients varies widely compared to the ideal ablation line. According to three experienced operators, unintended ablation and/or electrical activity were present in a substantial group of patients.