Prevalence and determinant of iron deficiency in the three main types of cardiac amyloidosis

Cardiac amyloidosis (CA), mainly comprised of light chain (AL), hereditary transthyretin (ATTRv) and wild-type transthyretin (ATTRwt) amyloidosis, is a severe and fatal systemic disease, characterized by accumulation of amyloid fibrils in various tissues/organs, including nerves, kidneys, gastrointestinal tract, and heart. Amyloid deposits in the heart eventually lead to heart failure (HF). Iron deficiency (ID) is common in patient with chronic HF and has been investigated. In contrast, data concerning ID in patients with CA is limited. We performed this study to determine the prevalence and determinants of ID among the three main subtypes of CA. ID status was analysed in 816 CA patients enrolled at the French Referral Center for Cardiac Amyloidosis: 271 (33%) had AL, 164 (20%) ATTRv and 381 (47%) ATTRwt. ID affected 49% of CA patients. We identified ATTR status, diabetes, aspirin treatment, haemoglobin levels, and altered global longitudinal strain as independent ID determinants. ID is quite common in patients with CA whatever the subtype. Patients seem more likely to have ID if diagnosed with ATTR, diabetic, and/or treated with aspirin. Further studies are needed to assess the benefit of ID treatment by intravenous iron therapy in CA.