Optimizing the Diagnosis of ATTR-CM: Updates in Imaging and Best Practices-99mTechnetium-Pyrophosphate Imaging for ATTR-CM Practice Points

99mTechnetium-Pyrophosphate Imaging for ATTR-CM Practice Points

Pdf Summary

The document from the American Society of Nuclear Cardiology (ASNC) outlines critical components for using 99mTechnetium-pyrophosphate (99mTc-PYP) imaging to evaluate transthyretin cardiac amyloidosis (ATTR), a misdiagnosed cause of heart failure primarily affecting older men and African Americans with a certain genetic mutation. This imaging technique holds high sensitivity and specificity for identifying cardiac ATTR amyloidosis and distinguishing it from light chain amyloidosis, which has significant implications for patient management.<br /><br />99mTc-PYP imaging offers a non-invasive method to specifically identify ATTR cardiac amyloidosis, aiding in patient diagnosis and treatment planning. The procedure involves injecting a radiotracer and performing standard planar or SPECT imaging, commonly done an hour post-injection, though sometimes delayed imaging is employed based on clinical considerations. Imaging patterns are categorized to determine ATTR presence or absence through H/CL ratios or semi-quantitative visual grading.<br /><br />Patient selection is crucial and typically involves individuals over 60 with unexplained heart failure or increased ventricular wall thickness, especially within certain at-risk populations. It also serves patients with familial amyloidosis or those unsuitable for MRI due to other health conditions.<br /><br />The process of obtaining the radiotracer is streamlined through kits available from commercial distributors, assuring ease of availability. The document offers comprehensive guidelines on imaging procedures, image interpretation, reporting, and billing, providing a robust framework for professionals in nuclear cardiology.<br /><br />Finally, the document acknowledges contributions from various experts in the field and notes the support of Pfizer in its publication, while clarifying their non-involvement in creating the guidelines. Updated as of February 2019, these practice points are intended to enhance the consistency and accuracy of diagnosing and managing cardiac ATTR using 99mTc-PYP imaging.

Keywords

99mTechnetium-pyrophosphate

transthyretin cardiac amyloidosis

heart failure

nuclear cardiology

radiotracer

99mTc-PYP imaging

SPECT imaging

H/CL ratios

patient selection

image interpretation