Cardiac Scintigraphy with Bone Markers in Clinical Practice: When to Solicit the Exam? How to Interpret the Results?

In one of the first studies to demonstrate this application, Wizenberg et al. evaluated 10 consecutive patients with biopsy-confirmed CA, having observed that all patients exhibited intense and diffuse anomalous myocardial uptake on cardiac scintigraphy with 99mTc-pyrophosphate.2 However, later studies showed variable yield of these images in patients with different forms of CA, underscoring CA associated with immunoglobulin light chains (AL-CA), in addition to transthyretin-associated CA (ATTR-CA). The mechanisms by which bone radiotracers are accumulated in tissue deposits of amyloid protein probably involve the presence of microcalcifications in these protein aggregates, as these radiotracers are highly avid for calcium deposits. It is this aspect that also makes it possible for us to detect accumulation of these radiotracers in the hearts of patients with ischemic heart disease with recent acute myocardial infarction, and this was, historically, the first clinical application of this type of image.