Catheter ablation of atrial fibrillation in transthyretin and light-chain cardiac amyloidosis: results from the multicentre AMYL-AF study

Aims: Atrial fibrillation (AF) is highly prevalent among cardiac amyloidosis (CA) patients and contributes significantly to their morbidity and mortality. Evidence regarding AF ablation efficacy and safety in CA patients remains limited. The aim of our study is to evaluate baseline characteristics, clinical course and outcomes of AF ablation in a series of patients with transthyretin (ATTR) or light-chain (AL) CA from a multicentre international registry. Methods and results: Patients with CA who underwent AF ablation were included. Co-primary endpoints were: (i) atrial arrhythmia (AA) recurrence; (ii) a composite endpoint of all-cause mortality and heart failure hospitalization (HFH). 109 patients (mean age 72.4 ± 7.4 years, females 17.4%, persistent AF 64.2%, ATTR 78%, AL 22%) were included. Radiofrequency, cryo-balloon and pulsed-field ablation were performed in 67%, 15% and 18% of patients, respectively; 49.5% received pulmonary vein isolation plus additional ablations. Low voltage zones were documented in 34 out of 44 patients undergoing electro-anatomical mapping (77.3%). During a median follow-up of 22.7 months, 63 patients (58.3%) experienced AA recurrence (32.4% persistent AF recurrence), with no significant differences between CA subtypes (ATTR 59.5% vs. AL 54.2%, log-rank P = 0.55). The composite endpoint of HFH and all-cause death occurred in 27 patients (25%). Recurrence of persistent AF was associated with three-fold higher risk (OR 2.9, P = 0.02) of the composite endpoint. Conclusion: CA patients undergoing AF ablation present high prevalence of persistent AF. Freedom from AA after AF ablation is achieved in 42% of patients after a two-year follow-up. Patients with persistent AF recurrence have a three-fold higher risk of HFH and death.