Prevalence of Transthyretin Amyloid Cardiomyopathy Among Acute Heart Failure Patients with Hypertrophy Across the Left Ventricular Ejection Fraction Spectrum

<b>Background/Objectives:</b> Transthyretin amyloid (ATTR) cardiomyopathy mimics left ventricular hypertrophy (LVH) and has been identified as a specific cause of heart failure (HF). The aim of this study was to assess the prevalence of ATTR among patients presenting to the Emergency Department (ED) with acute HF (AHF) and LVH and explore their clinical characteristics and outcomes. <b>Methods:</b> Of 127 AHF patients with LVH, 95 completed the diagnostic protocol, which included monoclonal paraprotein testing and technetium-99 m pyrophosphate scintigraphy. Patients were followed for 6 months, and adverse events, including mortality and HF-related hospitalizations, were recorded. <b>Results:</b> ATTR was diagnosed in 8.4% of patients. The mean left ventricular ejection fraction (EF) was 46 ± 7% in ATTR subjects, with 25% classified as HF with reduced EF, 37.5% HF with mildly reduced EF, and 37.5% HF with preserved EF. N-terminal pro b-type natriuretic peptide (NT-proBNP) and high sensitivity troponin T (hs-TnT) were higher in ATTR compared to the non-ATTR group [NT-proBNP: 5863 (6519-12382) pg/mL versus 3586 (1393.5-6322) pg/mL, <i>p</i> = 0.007; hs-TnT: 35.9 (47.9-83.8) pg/mL versus 30.0 (19.4-49.5) pg/mL, <i>p</i> = 0.0006]. During follow-up, twenty-three patients from the cohort died: six in the ATTR and seventeen in the non-ATTR group. The estimated survival rate was significantly lower in ATTR versus non-ATTR patients (log-rank <i>p</i> < 0.0001). <b>Conclusions:</b> In this cohort of AHF patients with LVH presenting to the ED, ATTR cardiomyopathy was detected in 8.4%. Using routinely used cardiac biomarkers and basic echocardiography allows for the raising of suspicion of the disease from the ED setting, potentially facilitating earlier diagnosis in this population.