Radionuclide Imaging in Cardiac Amyloidosis: Are Nuclear Bone Tracers a Foreseeable Future?

Amyloidosis is an infiltrative disease caused by the extracellular deposition of misfolded proteins in organs and tissues resulting in progressive functional and structural impairment. Cardiac amyloidosis is a leading cause of morbidity and mortality in primary light-chain amyloid (AL) and transthyretin-related cardiac amyloid (ATTR) and results in a restrictive cardiomyopathy, heart failure, and death. With the emergence of new subtype-specific pharmacological therapies targeting misfolded amyloid fibrils, the need for early recognition of a cardiac amyloid subtype is of major therapeutic and prognostic importance. Recently, nuclear scintigraphy with radioactive bone-seeking tracers has shown promising results in distinguishing ATTR amyloidosis from AL amyloidosis and may potentially be useful in following disease burden. This review begins with an overview of cardiac amyloidosis and then focuses on the current radioactive tracers involved in cardiac amyloid detection and concludes with future outlook.