Divergent Findings in the Diagnosis of ATTR-CM Using Common Cardiac Diagnostics and 99mTc-DPD Scintigraphy

Abstract

A 77-year-old man presented with progressive deterioration of physical capacity after successful percutaneous coronary intervention of known chronic coronary syndrome. Transthoracic echocardiography revealed hypertrophy of the left ventricle, and electrocardiogram showed low QRS voltage in all leads. 99mTc-DPD scintigraphy was conducted to differentiate etiology such as amyloidosis and revealed increased cardiac tracer uptake in the left (grade 3) and right ventricle. Immunofixation showed no signs of paraproteinemia or Bence-Jones proteinuria. Thus, biventricular involvement of ATTR-cardiomyopathy was identified by 99mTc-DPD scintigraphy. This approach should be considered if hypertrophic phenotype is present in patients with persistent deterioration of physical capacity not attributable to coronary artery disease.

“Loss of Bone Signal” on 99mTc-Labeled Pyrophosphate Scintigraphy in a Patient With Wild-Type Transthyretin Amyloidosis

“… 99m Tc-3,3-diphosphono-1,2-propanedicarboxylic acid (DPD) scintigraphy and 99m Tc-pyrophosphate (PYP) Scintigraphy have high sensitivity for imaging both myocardial and extracardiac amyloid transthyretin in patients with wild-type transthyretin (ATTRwt) amyloidosis 1–12 . “Loss of bone signal” on planar imaging of 99m Tc-DPD scintigraphy, in which the tracer uptake in bone is obscured by marked tracer uptake in the overlying skeletal muscles, is reported 1,13 ; however, this phenomenon has not yet been documented on 99m Tc-PYP scintigraphy. An 89-year-old woman was admitted to our hospital because of new-onset atrial flutter ( upper ).…”