Impact of Catheter Ablation on Atrial Fibrillation Burden and Symptoms in Patients With Hypertrophic Cardiomyopathy

BACKGROUND Atrial fibrillation (AF) is more common in patients with hypertrophic cardiomyopathy (HCM) and is often highly symptomatic. The impact of catheter ablation (CA) may be under-reported when evaluated by long-term freedom from any atrial arrhythmia. OBJECTIVES This study aims to evaluate whether CA of AF in patients with HCM would significantly reduce AF burden and improve symptoms. METHODS A multicenter registry was established to enroll HCM patients with pre-existing cardiac implantable electronic devices undergoing CA of AF between 2017 and 2021. The first AF recurrence and burden 12 months before and after CA were determined. RESULTS A total of 81 HCM patients with cardiac implantable electronic devices underwent CA of AF. Patients were followed-up for a minimum of 1-year (35 [Q1-Q3: 23-50] months). AF was paroxysmal in 38 of 81 (46.9%) patients and burden pre-CA was 27.0% (Q1-Q3: 3.0% to 99.0%). A total of 35 (43.2%) patients had AF/atrial tachycardia recurrence within 12 months. AF burden reduced after CA to 0.5% (Q1-Q3 range: 0.0% to 11.1%) (P = 0.001); a 95% CI (13.8% to 100%) relative reduction. European Hearth Rhythm Association class improved by 1.8 f 1.3 classes (P < 0.001). Of those with AF/atrial tachycardia recurrence, the reduction in AF burden was-33.7% (Q1-Q3:-88.9% to-13.8%) (P < 0.001) and 20 (57.1%) patients reported symptomatic improvement by >= 1 European Hearth Rhythm Association class. AF burden reduction was associated with symptomatic improvement. (r =-0.67; P < 0.001) CONCLUSIONS AF recurrence is common after CA in HCM patients, but this may under-represent the impact of CA in this cohort. CA significantly reduced AF burden and improved symptoms. A comprehensive evaluation of AF burden, symptoms, and hard endpoints is needed to determine the utility of CA in this context. (c) 2024 by the American College of Cardiology Foundation.