178-03: Radiofrequency vs. Cryoablation for atrial fibrillation: a comparison of induced atrial scaring using cardiac magnetic resonance imaging with late-gadolinium enhancement

Abstract

Introduction: Cryo-ablation is emerging as a consistent modality to perform single-shot pulmonary veins (PV's) electrical isolation in paroxystic AF. Short term electrical isolation is evaluated just after energy delivery, but the healing process can hamper durable effects. Using cardiac magnetic resonance imaging (MRI), definite fibrosis can be detected and the long term effects of energy be assessed. The aim of this analysis is to compare the number, extension and localization of gaps and the incidence of recurrences when cryo-energy and point-by-point RF are used to isolate PV's. Methods: Case-control study with prospective follow-up. The population of patients submitted to PV's isolation with the 2nd generation Cryo-balloon at our left was included (CA group, n = 30). Controls were selected among population undergoing PV isolation using RF, matching for age, sex, and the presence of hypertension, diabetes and obstructive sleep apnea, in a 1:1 ratio (RF group, n = 30). Cardiac 3T MRI was obtained 3 months after the procedure for all patients, and a dedicated software (ADAS AF®) was used to process late gadolinium enhancement images. The number of gaps around PV's ostia, its localization, and the proportion between gap length and total PV antrum perimeter (gap normalized length - GNL) were analysed. The population was followed for 12 months. Results: A total of 239 veins were analysed (120 in CA group and 119 in RF group). Mean gap number per patient was not significantly different (4.32 vs 5.2, p = 0.12), as well as GNL (0.21 vs 0.25, p = 0.31). For both techniques, mean gap number was higher in right PV than in left ones (1.23 vs 0.58, p < 0.001 for RF; 1.31 vs 0.32, p < 0.001 for CA). The incidence of recurrences was similar - p = 0.277 (see image).