Wild-Type Transthyretin Cardiac Amyloidosis, Atypical Presentation. Case Report

Cardiac amyloidosis is characterized by the extracellular deposition of misfolded proteins. Currently, there are more than 30 proteins that can form amyloid fibrils in vivo, 9 of which accumulate in the myocardium. A 70-year-old male with a history of supraventricular tachycardia, type 2 diabetes, systemic arterial hypertension, and prostatic adenocarcinoma. As part of the treatment for bone metastases due to a history of cancer, a Tc99m methylenediphosphonate bone scan was performed, revealing an abnormal increase in myocardial bone turnover. A technetium-99 (Tc99) and pyrophosphate cardiac scan was performed, yielding a positive result for infiltrative process (AC-ATTR), Perugini 3, and H/CL ratio of 1.52. Based on cardiac scan findings of infiltrative process, absence of a polyclonal light chain spike, and a negative ATTR gene, the diagnosis of ATTRwt cardiac amyloidosis was reached.