Ablation therapy for atrial fibrillation in patients with attr-amyloidosis or diastolic dysfunction: evaluation of 12-month success rates

Abstract Background In ATTR cardiac amyloidosis (CA), atrial fibrillation (AF) and diastolic dysfunction (DD) are affecting up to 70% of patients causing severe symptoms like dyspnoea and heart failure. Unlike isolated DD with predominant ventricular stiffness, AF and DD in CA is driven by misfolded protein deposits in both atrium and ventricle. This suggests that AF ablation outcomes may differ between CA and isolated DD patients. Although data on AF ablation efficacy in CA is limited, recent studies indicate positive outcomes in selected DD patients. Purpose This study aimed to compare the success rates and clinical outcomes of catheter ablation in patients with CA versus those with isolated DD. Methods In this retrospective analysis, 22 patients with confirmed Wild-Type ATTR-CA and 30 patients with isolated DD were included (mean age 73 years; CA: 86.4% male, DD: 50.0% male; CA stages: Gilmore I 45.4%, Gilmore II 36.4%, Gilmore III 9.1%). All underwent first-time catheter ablation for AF or left atrial tachycardia (CA: 72.7% persistent AF, 18.2% de novo flutter, 9% paroxysmal AF; DD: 100% persistent AF). The primary endpoint was ablation success, defined as freedom from atrial tachyarrhythmia (AAR) one year post-ablation, with a blanking period of 6 weeks.Secondary endpoints included LVEF, dyspnoea (NYHA class), NT-proBNP levels, hospitalizations, and mortality. Statistical analysis involved chi-square, Mann-Whitney U, t-test, Wilcoxon and two-way repeated measures ANOVA. Results Sinus rhythm (SR) was achieved in all but one patient at the end of the procedure. Recurrence of ARR was observed in 13/22 CA and 15/30 DD patients (59.1% vs. 53.6%; p=0.70). To maintain SR after 12 months, CA and DD patients required an average of 1.45 and 1.3 ablations, respectively. NT-proBNP levels significantly decreased over time in both groups (CA: 2548.5 ng/L to 2194.3 ng/L; DD: 1598.8 ng/L to 532.2 ng/L; p<0.05), with no significant time-group interaction (p=0.09). LVEF improvements were not significant (CA: 44% to 43%; DD: 53.3% to 56.5%; p=0.52). Dyspnoea improvement was significant in DD patients (p<0.05), while CA patients showed a non-significant trend of NYHA improvement. Hospitalizations averaged 1.09 for CA and 0.70 for DD (p=0.502), with one non-procedure-related death in the CA cohort. Conclusion Our study indicates that AF catheter ablation in CA patients yields outcomes comparable to those in isolated DD patients, despite different underlying pathologies. Both groups demonstrated similar recurrence rates and clinical improvements post-ablation, with an overall low complication risk. These findings suggest that the presence of CA does not significantly impact the effectiveness of AF ablation compared to isolated DD.