Head-to-head comparison of pulsed-field ablation, high-power short-duration ablation, cryoballoon and conventional radiofrequency ablation by MRI-based ablation lesion assessment.

Background: Novel concepts for pulmonary vein isolation (PVI) like pulsed-field ablation (PFA) or high-power short-duration ablation (HPSD) promise favorable profiles of safety and efficacy. However, clinical comparisons of those novel concepts with conventional ablation approaches regarding ablation lesions are lacking. To systematically investigate lesion characteristics of novel ablation concepts, we performed a prospective head-to-head comparison using late gadolinium enhancement (LGE)-CMR.

Methods: This study included patients undergoing first-time PVI-only atrial fibrillation ablation-either by ablation index-guided radiofrequency ablation (RF), cryoballoon ablation (CRYO), HPSD (90W, 4 s), or PFA (Farapulse). All patients received an LGE-CMR 3 months post-ablation to assess ablation lesions.

Results: Post-ablation LGE-CMRs from 138 patients were analyzed (43 RF, 40 CRYO, 25 PFA, 30 HPSD). PFA resulted in the least continuous LGE lesion with the lowest proportion of complete PV-encircling LGE lesions (PFA 12%, HPSD 40%, RF 26%, CRYO 24%; p = 0.0069). Ablation with the CRYO and PFA single-shot devices resulted in the widest lesions. Of note, HPSD lesions were significantly wider than conventional RF lesions (PFA 12.7 mm, HPSD 10.9 mm, RF 8.7 mm; CRYO 13.3 mm; p < 0.0001).

Conclusions: Lesion characteristics differed significantly among the four ablation techniques. HPSD ablation resulted in the most continuous LGE lesions. Of note, HPSD lesions were also wider than conventional RF lesions, thus corroborating the concept of a shallower HPSD lesion geometry from experimental studies. PFA lesions cover relatively large areas but are more inhomogeneous. Wether this indicates ineffective ablation or lower detectability of PFA lesions by LGE-CMR remains unknown.