Atrial Fibrillation in Transthyretin Cardiac Amyloidosis Predictors, Prevalence, and Efficacy of Rhythm Control Strategies

OBJECTIVES This study sought to determine the incidence and prevalence of atrial fibrillation (AF) in transthyretin cardiac amyloidosis (ATTR-CA); to study the factors associated with the development of AF in this population; to study the prognostic implications of AF and maintenance of normal sinus rhythm (NSR) in patients with ATTR-CA; and to determine the impact of ATTR-CA stage on AF prevalence, outcomes, and efficacy of rhythm control strategies. BACKGROUND AF is common in patients with ATTR-CA. The aim of this study was to determine the predictors, prevalence, and outcomes of AF in patients with ATTR-CA in addition to the efficacy of rhythm control strategies. METHODS This was a retrospective cohort study of 382 patients with ATTR-CA diagnosed at our institution between January 2004 and January 2018. Means testing, and univariable and multivariable models were used. RESULTS AF occurred in 265 (69%) patients. Factors associated with the development of AF included older age, advanced ATTR-CA stage, and higher left atrial volume index. Antiarrhythmic therapy (AAT) was used in 35% of patients with AF; cardioversion was performed in 45%, and 5% underwent AF ablation. Rhythm control strategies were substantially more effective when performed earlier in the disease course. During a mean follow-up of 35 months, no difference in mortality between patients with AF and those without AF was observed (65% vs. 49%; p = 0.76). On Cox proportional hazards analyses, maintenance of normal sinus rhythm and tafamidis use were associated with improved survival, whereas advanced ATTR-CA stage and higher New York Heart Association functional dass were associated with increased mortality. CONCLUSIONS With advancing ATTR-CA stage, AF became more prevalent, occurring in 69% of our entire study cohort. Rhythm control strategies including AAT, direct-current cardioversion, and AF ablation were substantially more effective when performed earlier during the disease course. (C) 2020 by the American College of Cardiology Foundation.