Catheter ablation for atrial fibrillation and atypical atrial flutter in transthyretin cardiac amyloidosis: a single center experience
V Morales Oyarvide, S Cuddy, K Bersell, R Falk, S Dorbala, S KapurAbstract
Background
Atrial fibrillation (AF) and atypical atrial flutter (AAFL) are highly prevalent in transthyretin amyloid cardiomyopathy (ATTR-CM). The role of catheter ablation (CAb) in this patient population is not well defined. Previous studies have reported high rates of complications and low efficacy, but there is limited experience with patients receiving amyloid-directed therapies and undergoing pulsed field ablation (PFA).
Purpose
To describe the demographics, clinical and echocardiographic characteristics, procedural parameters, and outcomes of patients with ATTR-CM undergoing first-time CAb for AF/AAFL in a referral center.
Methods
ATTR-CM patients undergoing first-time CAb for AF/AAFL at our institution between 3/2019 and 1/2026 were included. Demographic, clinical, and echocardiographic characteristics were evaluated retrospectively. Arrhythmia recurrence was defined as any supraventricular arrhythmia lasting >30 seconds after a 90-day blanking period. Continuous variables were compared using the Wilcoxon rank sum test. Median and 1-year arrhythmia-free survival (AFS) were estimated with Kaplan-Meier curves.
Results
Twenty-one patients were identified. Baseline characteristics are presented in Table 1. ATTR-CM was diagnosed prior to CAb in 18 (86%) patients, a median of 31 months before CAb. The remaining three patients were diagnosed with ATTR-CM within 35 days after CAb; in two of these cases, abnormal atrial electroanatomical mapping (EAM) findings prompted evaluation for amyloid cardiomyopathy. Overall, abnormal atrial voltage during EAM was noted in 12 (57%) patients (Figure 1). Ablation energy source was radiofrequency (RF) in 8 (38%) cases and PFA in 13 (62%). Additional ablation lesions beyond pulmonary vein isolation (PVI) were performed in 20 (95%) cases, most commonly of the left atrium posterior wall (16) and cavotricuspid isthmus (6). Compared to RF ablation, PFA procedures were shorter (164 vs 275 min, P<0.001) and used less intravenous fluids (750 vs 1,400 mL, P=0.027). Ablation was procedurally successful in all cases. Peri-procedural complications included decompensated heart failure (2), sinus node dysfunction requiring a pacemaker (1), embolic stroke (1), pulmonary embolism (1), and pneumonia (1). The median and 1-year AFS was 15.9 months and 61%, respectively.
Conclusion
In a contemporary series of patients with ATTR-CM undergoing first-time CAb for AF/AAFL, acute procedural success was achieved in all cases, with a 1-year AFS of 61%. Abnormal atrial voltages were observed in more than half of patients and nearly all patients required ablation lesions beyond PVI. Peri-procedural complications remain a significant concern, although the shorter duration and lower fluid volume used with PFA procedures are encouraging.