Catheter ablation of atrial fibrillation in cardiac amyloidosis

Background Cardiac amyloidosis is a progressive infiltrative disease involving deposition of amyloid fibrils in the myocardium and cardiac conduction system that frequently manifests with heart failure (HF) and arrhythmias, most frequently atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia (AT). Methods We performed an observational retrospective study of patients with a diagnosis of cardiac amyloid who underwent catheter ablation at our institution between January 1, 2011 and December 1, 2018. Patient demographics, procedural characteristics, and outcomes were determined by manual chart review. Results A total of 13 catheter ablations were performed over the study period in patients with cardiac amyloidosis, including 10 AT/AF/AFL ablations and three atrioventricular nodal ablations. Left ventricular ejection fraction was lower at the time of AV node ablation than catheter ablation of AT/AF/AFL (23% vs 40%,P = .003). Cardiac amyloid was diagnosed based on the results of preablation cardiac MRI results in the majority of patients (n = 7, 70%). The HV interval was prolonged at 60 +/- 15 ms and did not differ significantly between AV nodal ablation patients and AT/AF/AFL ablation patients (69 +/- 18 ms vs 57 +/- 14 ms,P = .36). The majority of patients undergoing AT/AF/AFL ablation had persistent AF (n = 7, 70%) and NYHA class II (n = 5, 50%) or III (n = 5, 50%) HF symptoms, whereas patients undergoing AV node ablation were more likely to have class IV HF (n = 2, 66%,P = .014). Arrhythmia-free survival in CA patients after catheter ablation of AT/AF/AFL was 40% at 1 year and 20% at 2 years. Conclusions Catheter ablation of AT/AF/AFL may be a feasible strategy for appropriately selected patients with early to mid-stage CA, whereas AV node ablation may be more appropriate in patients with advanced-stage CA.