Abstract 13845: Atrial Fibrillation in Patients With Biopsy-Proven Cardiac Al Amyloidosis; A Cancer Center Experience

Introduction: Atrial fibrillation (AF) is common in cardiac amyloidosis and often symptomatic. Commonly used therapeutics may be poorly tolerated. Patients with cardiac AL amyloidosis carry a high risk of stroke and bleeding, making anticoagulation challenging. This study examined the incidence of AF, treatment patterns, and incidence of thrombotic or bleeding complications. Methods: Patients with endomyocardial biopsy-proven cardiac AL amyloidosis treated at a tertiary cancer center between 6/2011 and 6/2020 were identified. Demographic and clinical data were abstracted. Outcomes included the development of AF, stroke and bleeding. Severe bleeding was defined as intracranial bleeding, hemorrhagic pericardial tamponade, or bleeding requiring endoscopic investigation. Results: Out of 43 patients with cardiac AL amyloidosis, 51% were diagnosed with AF during the follow up period (median 4.2 years (95% CI, 2.8-8.6)). Of those, 41% were women and 73% were white. Median age was 65.5 years (61-70). No significant demographic differences were identified between patients with and without AF. Beta-blockers were initiated in 86% and continued for more than 3 months in 59% of patients. Amiodarone was initiated in 50% and continued for more than 3 months in 18%. Treatment with digoxin and diltiazem were less common (27% and 14%, respectively). Pulmonary vein isolation was performed in 14% of patients. Anticoagulation (AC) was used in 59% of patients with AF and 19% of patients without AF for a different indication. Bleeding was common; 23% of AF patients reported an episode of severe bleeding, 60% of whom were on AC, in comparison to 19% in patients without AF, 50% of whom were on AC. Stroke was diagnosed in 14% of patients with AF, 67% of whom received AC, compared to 14% of patients without AF, 33% of whom received AC. Conclusions: Although AF is common (51%) in patients with cardiac AL amyloidosis, treatment with rate or rhythm control strategies is challenging. Many patients do not tolerate treatment for more than 3 months. While a significant number did not receive AC, there was a substantial risk of severe bleeding (1/4) and stroke (1/7). Given improved survival with newer therapies for AL amyloidosis, a greater focus on improving management of AF and outcomes is needed.