Cardiac amyloidosis (CA) frequently coexists with atrial fibrillation (AF), but the extent and impact of this relationship remain unclear. This study investigates the prevalence of AF in CA, compares clinical characteristics between amyloid light-chain (AL)-CA and amyloid transthyretin (ATTR)-CA, and assesses the implications for treatment strategies. We conducted a retrospective analysis of 108 patients with confirmed CA, categorizing them into 2 groups: 51 with AF and 57 with sinus rhythm (SR). We compared demographic, clinical, and echocardiographic data, as well as treatment modalities and outcomes between AL-CA and ATTR-CA subgroups. AF was present in 47% of the cohort, with a notably higher prevalence in wild-type ATTR-CA (80%) compared to AL-CA (33%). Patients with AF were older (73.8 ± 8.5 years) than those with SR (67.7 ± 10.6 years, P < .001) and had more severe heart failure symptoms, comorbidities, and echocardiographic abnormalities, including reduced left ventricular ejection fraction (LVEF; 47% vs 53%, P = .003) and higher pulmonary artery pressures (41 ± 11 mm Hg vs 35 ± 17 mm Hg, P = .02). Logistic regression identified BMI (OR 1.2, 95% CI: 1.05-1.57, P = .02) and eGFR (OR 0.91, 95% CI: 0.92-0.99, P = .04) as independent predictors of AF. CHA2DS2-VASc scores were higher in ATTR-CA patients (4.5 ± 1.2) compared to AL-CA (2.4 ± 1.1, P < .001). Despite a high rate of anticoagulation (78%), ischemic stroke or TIA incidence was low at 6% over 12 months.
