The following are key points to remember from this state-of-the-art paper on how to image cardiac amyloidosis:

1. Cardiac amyloidosis is a rapidly progressive form of heart disease, with a median survival from diagnosis, if untreated, ranging from <6 months for light chain (AL) amyloidosis to 3-5 years for transthyretin (ATTR) amyloidosis.
2. Emerging novel disease-modifying therapies increase the urgency to diagnose cardiac amyloidosis at an early stage and identify patients who may benefit from life-saving therapies.
3. Cardiac amyloidosis remains substantially underdiagnosed and AL amyloidosis, if untreated, is rapidly fatal.
4. Until recently, cardiac amyloidosis was only diagnosed by a positive endomyocardial biopsy or a positive extracardiac biopsy in combination with left ventricular (LV) wall thickness >12 mm on echocardiography unexplained by other causes.
5. Classic imaging features on echocardiography and cardiac magnetic resonance, although typical for cardiac amyloidosis, are not specific enough to distinguish AL amyloidosis from ATTR amyloidosis. Quantification of amyloid burden is currently based on evaluation of LV mass, wall thickness, extracellular volume, or semi-quantitative metrics on amyloid positron emission tomography (PET) tracer imaging.
6. Due to the unique insights provided by each of the imaging tests into the pathogenesis and functional effects of amyloid deposits, patients often need to undergo >1 test for a complete evaluation.
7. Global subendocardial enhancement, transmural late gadolinium enhancement (LGE), and to a lesser degree, a focal, patchy LGE, are all features of cardiac amyloidosis, with a sensitivity of 86% and specificity of 92%. LGE is highly prevalent (100% LGE in LV and 96% LGE in right ventricle) and more common in ATTR than AL cardiac amyloidosis, but cannot distinguish between subtypes of cardiac amyloidosis.
8. Myocardial bone-avid radiotracer uptake is highly specific for ATTR amyloidosis when plasma cell dyscrasia has been excluded; it is now replacing the need for biopsy in many patients.
9. Accumulating literature now supports the new notion that typical imaging features on technetium-99m (Tc-99m)−pyrophosphate (PYP)/3,3-diphosphono-1,2-propanodicarboxylicacid (DPD)/hydroxymethylene diphosphonate (HMDP) imaging can almost definitively diagnose ATTR cardiac amyloidosis.
10. Detection of early cardiac amyloidosis, quantitation of its burden, and assessment of response to therapy are important next steps for imaging to advance the evaluation and management of cardiac amyloidosis.

Clinical Topics: Heart Failure and Cardiomyopathies, Noninvasive Imaging, Prevention, Valvular Heart Disease, Acute Heart Failure, Computed Tomography, Echocardiography/Ultrasound, Magnetic Resonance Imaging, Nuclear Imaging

Keywords: Amyloidosis, Amyloidosis, Familial, Contrast Media, Diagnostic Imaging, Echocardiography, Gadolinium, Heart Failure, Heart Valve Diseases, Magnetic Resonance Imaging, Plaque, Amyloid, Positron-Emission Tomography, Prealbumin, Radionuclide Imaging, Secondary Prevention, Technetium, Technetium Tc 99m Pyrophosphate

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