Cardiac Pulsed Field Ablation Lesion Durability Assessed by Polarization-Sensitive Optical Coherence Reflectometry

Area of Science:

• Medical Imaging
• Biophysics
• Electrophysiology

Background:

• Pulsed field ablation (PFA) induces nonthermal cell death via electrical fields over hours.
• Polarization-sensitive optical coherence reflectometry (PS-OCT) is an optical imaging technique detecting real-time ultrastructural changes in damaged muscular tissue.
• PS-OCT can identify tissue damage by detecting changes in birefringence.

Purpose of the Study:

• To evaluate PS-OCT's ability to predict chronic lesion development after PFA.
• To correlate acute birefringence changes with long-term tissue response to PFA.

Main Methods:

• Superior vena cava isolation in 30 swine using a bipolar PFA system with a focal tip catheter.
• Analysis of acute tissue birefringence and voltage abatement for each lesion.
• High-resolution electroanatomical mapping at baseline and 4-12 weeks post-ablation.

Main Results:

• 141 lesions were analyzed; 96% achieved acute isolation, but only 46% showed chronic isolation.
• A ≥20% acute reduction in birefringence predicted chronic lesion formation with 96% sensitivity and 83% specificity.
• Mean birefringence reduction was significantly higher in lesions that developed fibrosis (63.8%) compared to those with electrical gaps (9.1%).

Conclusions:

• Acute changes in tissue birefringence measured by PS-OCT can predict chronic lesion formation after PFA.
• PS-OCT shows promise for guiding PFA procedures by assessing real-time tissue response.
• The predictive capability of PS-OCT may be limited by tissue thickness.