Abstract 14418: Prevalence, Characteristics, and Factors Associated With Atrial Fibrillation and Flutter in Patients With Transthyretin Cardiac Amyloidosis

Abstract

Introduction: Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized form of restrictive cardiomyopathy in older adults. Adverse chamber remodeling from amyloid infiltration predisposes these patients to tachyarrhythmias such as atrial fibrillation/flutter (AF), which increase the risk of thromboembolic events. The goal of our study was to explore the prevalence, phenotypic characteristics, and factors associated with AF in ATTR-CA patients. Methods: This is a retrospective cohort study of 419 patients diagnosed with ATTR-CA comparing demographics and clinical characteristics between patients with and without AF at baseline. AF was ascertained based on review of prior electrocardiogram, long term monitors when performed, pacemaker interrogations if applicable, and charted history. Binary logistic regression was then performed to determine factors associated with prevalence of AF. Results: AF was prevalent in 58% (n=244) of ATTR-CA patients on initial presentation. Compared to those without AF, individuals with AF were older, of white race, exhibited NYHA class III-IV symptoms, and less frequently had variant disease (ATTRv-CA). They also had more prior stroke/TIA, chronic kidney disease, implanted pacemakers, and need for loop diuretics at baseline (Table 1). AF patients more consistently had Columbia stage II-III disease as per established biomarker cutoffs and greater left atrial volume index on echocardiogram (LAVI). On multivariable logistic regression, per point increase in Columbia score (OR 1.48, 95% CI 1.25-1.75) and per mL/m 2 increase in LAVI (OR 1.05, 95% CI 1.02-1.08) were predictive of prevalent AF, while ATTRv-CA (OR 0.19, 95% CI 0.07-0.55) was protective, all p<0.05. Conclusions: More than half of ATTR-CA patients have preexisting AF. Wild-type ATTR-CA, greater Columbia staging, and a dilated LA are the main clinical factors associated with prevalent AF.