Expanding indications for non-biopsy diagnosis of transthyretin amyloid cardiomyopathy
Sharmila Dorbala
Abstract
Patients with suspected transthyretin amyloid cardiomyopathy (ATTR-CM) based on clinical features + abnormal echocardiogram, or cardiac MRI Evaluate for monoclonal gammopathy using serum-free light chain (FLC) assay + serum and urine immuno xation electrophoresis Any abnormal Isolated FLC abnormality Refer to haematologist Abnormal Normal Apply estimated glomerular ltration rate (eGFR) adjusted re ned / FLC ratio All normal Grade 0/1 Bone-avid tracer cardiac SPECT/CT Endomyocardial/involved organ biopsy and typing Cardiac amyloidosis and type con rmed ATTR-CM con rmed Wild type ATTR-CM Hereditary ATTR-CM TTR gene testing Cardiac amyloidosis excluded High clinical suspicion or typical echocardiogram or typical cardiac MRI Yes Yes No No Grade 2/3 *Re ned / FLC ratio limits eGFR / ratio >90ml/min 60-90ml/min 30-60ml/min <30ml/min 0.26-1.65 0.26-2.65 0.26-2.50 0.26-3.10