Two types amyloid infiltration of the heart: diagnostic challenges and therapeutic strategies

BACKGROUND: Amyloidosis is characterized by extracellular deposition of insoluble fibrils, with light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR) being the most common cardiac subtypes. Early detection and multimodal diagnostic strategies are critical for effective treatment. A 83-year-old woman presented with pseudoinfarction electrocardiogram pattern. Investigations revealed concentric left ventricular hypertrophy and elevated NTproBNP. Multimodality imaging approach confirmed cardiac amyloidosis, both with a monoclonal IgG Lambda component and Perugini grade 3 uptake. Endomyocardial biopsy (EMB) identified dual amyloid infiltration with Lambda light chains and transthyretin. Both hematological and heart failure treatment resulted in clinical improvement. DISCUSSION: Two different types of cardiac amyloidosis can coexist on the same patient. This case underscores the importance of advanced diagnostic techniques, such as 18F-florbetaben PET-CT. Histological amyloid subtype identification is key when tests are inconclusive. TAKE HOME MESSAGES: Multimodality imaging and histological confirmation are key for cardiac amyloidosis diagnosis. Early initiation of disease-modifier therapies can significantly impact on disease progression.