Trends in prevalence and clinical outcomes of patients with atrial fibrillation and cardiac amyloidosis- from a nationwide registry - The 72nd Annual Conference of the Israel Heart Society in association with the Israel Society of Cardiothoracic Surgery

Ela Giladi ^1,2 Gal Tsaban ^3,4 Abid Assali ^1,2 Zaza Iakobishvilli ^2,5 Moti Haim ^3,4 Jorge Schliamser ⁶ Alon Eisen ^2,7 Yiska Weisband ⁸ Liaz Zilberman ^1,2 Ziad Arow ^1,2 David Pereg ^1,2 Yoav Arnson ^1,2

¹Department of Cardiology, Meir Medical Center, Israel
²Sackler Faculty of Medicine, Tel Aviv University, Israel
³Department of Cardiology, Soroka University Medical Center, Israel
⁴Faculty of Health Science, Ben Gurion University of the Negev, Israel
⁵Community Cardiology, Clalit Health Services, Israel
⁶Department of Cardiology, Carmel Medical Center, Israel
⁷Department of Cardiology, Rabin Medical Center, Israel
⁸Clalit Research Institute, Clalit Health Services, Israel

Background: Atrial fibrillation (AF) is associated with increased stroke and mortality risk. In cardiac amyloidosis, characterized by extracellular protein deposition leading to restrictive heart failure, arrhythmias such as AF are common and poorly tolerated. Despite the risk of stroke and systemic embolism in these patients, evidence on managing AF in amyloidosis remains limited.

Methods: The study population consisted of patients included in AF nationwide population-based registry of Israel`s largest health maintenance organization, between January 1st, 2010, and January 1st, 2020. Patients with AF and amyloidosis were compared in 3:1 to matched subjects without amyloidosis, for demographic, clinical characteristics and outcomes.

Primary endpoints were survival rated and hospitalization for heart failure.

Results: Among 2,584 patients, 646 had amyloidosis, and 1,938 without amyloidosis. Mean age was 73.1 (11.09) years and 63.5% were male. Among baseline characteristics, CKD (chronic renal failure) and anaemia were significantly higher in amyloidosis patients (30.3% vs. 20.1%, p<0.0001 and 42.1% vs. 35.4%, p=0.0026, respectively). No difference in heart failure (HF) between the groups. Only 2.2% patients in the amyloidosis group treated with Tafamidis. Anticoagulation therapy was significantly more frequent in amyloidosis patients (46.3% vs. 38.2%, p=0.0004). In 15 years follow up, mortality was significantly higher in amyloidosis patients (63.3% vs. 34.7%, p<0.0001). HF events was also more prevalent in amyloidosis patients (71.4% vs. 45.0%, p<0.0001). Similar rates of stroke between the groups (p=0.0759) with overall incidence of 13.9%. Bleeding rates were similar between groups (18.8% vs. 17.0%, p=0.3196), and gastrointestinal bleeding was more frequent in amyloidosis patients (21.6% vs. 16.5%, p=0.0044), required more blood transfusion (16.4% vs. 9.3%, p<0.0001).

Outcomes: In this nationwide, population-based study of patients with AF, amyloidosis was associated with significantly higher rates of mortality and heart failure events over 15 years, with similar rates of overall bleeding and stroke events.