Clinical Impact of Cryoballoon Ablation for Paroxysmal Atrial Fibrillation in Patients With Enlarged Left Atrium

The impact of cryoballoon ablation (CBA) for atrial fibrillation (AF) in patients with enlarged left atrium (E-LA) has not been sufficiently clarified. A total of 306 patients underwent an initial CBA for paroxysmal AF between February 2017 and March 2022 in our hospital. These patients were categorized into 2 groups according to the preprocedural left atrium (LA) diameter (LAD): E-LA group with LAD ≥40 mm and normal LA (N-LA) group with LAD <40 mm. We compared late recurrence (LR, defined as a recurrence of atrial tachyarrhythmia more than 3 months after the ablation) between the 2 groups. In addition, we made a further classification of the E-LA group into a severely E-LA (SE-LA) group with LAD ≥50 mm and mildly enlarged LA (ME-LA) group with LAD <50 mm and compared LR in the SE-LA, ME-LA, and N-LA groups. In the patients who experienced a second ablation procedure owing to LR, subsequent recurrences were also evaluated. After initial CBA, there was no significant difference in recurrence-free survival between E-LA and N-LA groups (p = 0.447). In contrast, the SE-LA group showed the lowest incidence of recurrence-free survival in the SE-LA, ME-LA, and N-LA groups (p = 0.012). However, when we analyzed recurrences after the ablation including second ablation procedure, there were no significant differences in recurrence-free survival among these 3 groups (p = 0.103). In conclusion, patients with paroxysmal AF with enlarged LA showed favorable outcomes compared with those with N-LA after CBA.