Catheter Ablation for Atrial Arrhythmias in Patients With Cardiac Amyloidosis

Background: Cardiac amyloidosis (CA) is associated with increased atrial arrhythmias risk. The efficacy/safety of catheter-based ablation therapy in patients with CA has not been adequately assessed. Methods and Results: All diagnosed CA patients who underwent atrial arrhythmia ablation therapy from 1995 to 2015 were reviewed. Arrhythmia recurrence, NYHA symptoms, and mortality were recorded. A total of 26 patients with CA and atrial arrhythmias were included; there were 7 light-chain (AL), 17 wild-type transthyretin (ATTRwt), and 2 mutated transthyretin (ATTRm) amyloidosis patients in total. Of which 13 underwent atrial arrhythmia ablation (CA-A) and 13 underwent AV nodal ablation (CA-AVN). In the CA-A group, there were: 3 with atrial fibrillation (AF); 6 with atrial flutter (AFL); 2 with AF/AFL; and 2 with atrial tachycardia (AT). One-year and 3-year recurrence-free survival were 75% and 60%, respectively. NYHA symptom improvement 6 months postablation was observed in both CA-A and CA-AVN groups: 7/10 (70%) and 4/8 (50%), respectively. Eleven patients with CA died (8 in CA-AVN group vs. 3 in CA-A group). Conclusions: Catheter-based ablation for patients with CA appears to provide important symptomatic relief. However, mortality from the underlying disease remains a significant issue for the amyloid light-chain subtype.