Visualization of monopolar biphasic focal pulsed field ablation lesions 3 months after pulmonary vein isolation on high-resolution 3-dimensional dark-blood late gadolinium enhancement cardiac magnetic resonance images.

BACKGROUND

Dark-blood late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging is used to visualize ablation lesions after pulmonary vein isolation (PVI) by cryo- and radiofrequency ablation. The performance of dark-blood LGE CMR in visualizing chronic ablation lesions after PVI by monopolar biphasic focal pulsed field ablation (F-PFA) remains unclear.

OBJECTIVE

This study aimed to determine the visibility and optimal image intensity ratio (IIR) threshold for F-PFA lesion visualization in dark-blood LGE CMR scans 3 months after PVI.

METHODS

In 18 patients, high-resolution 3-dimensional dark-blood LGE CMR was performed 3 months after PVI by F-PFA (Centauri, CardioFocus). Left atrial LGE CMR images were segmented and aligned with the electroanatomic maps obtained during the ablation procedure to identify ablated and nonablated regions. A linear mixed-effects model was used to assess the difference in IIR between ablated and nonablated regions. Receiver operating characteristics (ROC) analyses were conducted to determine the area under the ROC curve and the optimal IIR threshold to detect ablated regions.

RESULTS

Three patients were excluded from the analysis. The median IIR of the nonablated region was 1.048, whereas that of the ablated region was significantly higher with an average increase of 0.099. ROC analysis achieved a median area under the ROC curve of 0.70 to distinguish between ablated and nonablated regions. The median optimal IIR threshold was 1.08.

CONCLUSION

Left atrial regions that were ablated with monopolar F-PFA have a significantly higher IIR than nonablated regions with 1.08 as the optimal IIR threshold to distinguish between ablated and nonablated regions.