Rare Hereditary Cardiac Amyloidosis Treated With SGLT2 Inhibitor: Beyond ATTR/AL.

BACKGROUND: Rare hereditary cardiac amyloidosis (CA) may mimic transthyretin or light-chain cardiomyopathy, and reports for effective therapy in these entities are limited. CASE SUMMARY: A 61-year-old man presented with progressive heart failure (NYHA functional class III). Medical history included bilateral carpal tunnel syndrome, chronic kidney disease, and family history notable for amyloidosis in his brother and suspected CA-related death in their mother. Cardiac magnetic resonance imaging showed late gadolinium enhancement consistent with CA, echocardiography increased left ventricular thickness and diastolic dysfunction. Light-chain CA was excluded. Genetic testing identified an Apolipoprotein A-I (ApoA1) mutation (p.L202P). ApoA1 amyloid was confirmed in a gastric biopsy. Therapy with dapagliflozin led to clinical improvement. DISCUSSION: Recognition of ApoA1-associated CA relies on clinical history and genetic confirmation. Screening of first-degree relatives is advised. SGLT2-inhibitor therapy may improve symptoms, extrapolated from observational transthyretin-cardiomyopathy studies. TAKE-HOME MESSAGE: Rare hereditary CA represents an important differential diagnosis in CA cases. Sodium-glucose cotransporter 2 inhibitors may represent a treatment option.