Efficacy of sinus rhythm maintenance after catheter ablation for atrial fibrillation in patients with transthyretin amyloid cardiomyopathy.

Background: Atrial fibrillation (AF) is prevalent and associated with poor prognosis in patients with transthyretin amyloid cardiomyopathy (ATTR-CM).

Objective: This study sought to investigate the efficacy of catheter ablation for AF in ATTR-CM and to examine the impact of ATTR-CM severity and postablation sinus rhythm maintenance on long-term prognosis.

Methods: This retrospective study enrolled 149 ATTR-CM and AF patients from 7 institutions. ATTR-CM severity was classified into 3 stages by serum N-terminal pro-B-type natriuretic peptide and estimated glomerular filtration rate values. Patients were divided into 2 groups according to whether they underwent ablation (ablation and no-ablation groups), and clinical outcomes were compared after matching baseline background. Patients in the ablation group were subsequently evaluated for atrial tachyarrhythmia (ATA) recurrence and composite end points including heart failure hospitalization, ischemic stroke, and all-cause mortality based on disease severity and ATA recurrence after initial ablation.

Results: Of 149 patients (80 ± 6 years; 74% male), 53 patients underwent catheter ablation. Catheter ablation was significantly associated with favorable clinical outcomes (hazard ratio, 0.25; 95% confidence interval, 0.11-0.62; P = .003). In the ablation group, those with stage I had fewer ATA recurrences and better clinical outcomes. Notably, patients without ATA recurrence demonstrated a lower incidence of composite end points (hazard ratio, 0.17; 95% confidence interval, 0.03-0.82; P = .02).

Conclusions: AF ablation appears to be an effective strategy especially for stage I amyloidosis, with maintenance of sinus rhythm associated with better clinical outcomes. However, further study is needed to establish the optimal management for AF in patients with stage II/III amyloidosis.