Assessment of atrial fibrillation catheter ablation outcomes in patients with hypertrophic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial fibrillation (AF) is a frequent manifestation of hypertrophic cardiomyopathy (HCM) and it is associated with increased risk for thromboembolic events and worsening of heart failure. AF is usually refractory to antiarrhythmic drugs in cases with HCM and catheter ablation may be useful in such patients. Purpose We aimed to evaluate outcomes of both cryoballoon and radiofrequency (RF) AF catheter ablation in patients with HCM. Methods All of the patients with HCM who underwent AF catheter ablation between January 2014 and January 2022 were screened and patients with available follow-up datas were included. Results A total of 44 patients were enrolled. Mean age was 54.2±12.6 years and 45.5% of the patients were female. RF ablation was performed in 23 cases and remaining patients underwent cryoablation. Median follow-up was 42.5 (4-94) months. Baseline characteristics were listed in Table-1. Only pulmonary vein isolation was performed in 25 (56.8 %) patients while additional ablation procedures including left atrial appendage isolation and linear ablation were required in other cases. Periprocedural complications occured in 6 cases. Atrial tachycardia recurrence developed in half of patients and mortality occured in 2 (4.5 %) cases during follow-up (Table-2). Six months recurrence free survival (RFS) rate was 90.9% and 1 year RFS was 86.1% however RFS rate reduced to 58.2 after 3 years follow-up. Atrial tachycardia recurrence rates, complication and mortality rates were similar between the patients who underwent cryoablation and RF ablation. Changes in NYHA class and BNP levels were not significant during follow-up, however EHRA class was distinctly improved (II vs. I; p