Aim Quantitative single-photon emission computed tomography (SPECT) with 99mTc-3,3-diphosphono-1,2 propanodicarboxylicacid (99mTcTc-DPD) is a cornerstone in the noninvasive diagnostic workup of amyloid transthyretin-related cardiomyopathy (ATTR-CM). As diagnosis is often suspected after transthoracic echocardiography (TTE), this study aims to explore the correlations between global and regional quantitative 99mTcTc-DPD SPECT results and TTE findings in patients with suspected ATTR-CM.Methods Patients with suspected ATTR-CM from a single-center registry (B-CARE) were retrospectively included. All underwent quantitative 99mTcTc-DPD SPECT/CT at the baseline examination with calculation of standardized values maximum standardized uptake value (SUVmax) and peak SUV (SUVpeak), also normalized to bone activity (nSUVmax and nSUVpeak). Data on TTE, performed within 2 weeks from the DPD scintigraphy, were also collected.Results One hundred forty four patients were included. Of these, 99 patients were eventually diagnosed with ATTR-CM. There was a significant correlation between septal (P ≤ 0.001) and lateral wall thickness (P = 0.004) and their respective, regional SUVs (P < 0.001 and P = 0.004, respectively), as well as global SUVs and maximum wall thickness (P = 0.024). Also, the presence of severe diastolic dysfunction correlated with nSUVs (P = 0.011).Conclusion The robust correlation found between TTE-derived parameters and the corresponding 99mTcTc-DPD SPECT SUVs supports the link between morphologic alterations and 99mTcTc-DPD activity within the myocardium, also potentially highlighting a pathophysiological mechanism involved in the progression of ATTR-CM.
Caobelli et al. (Tue,) studied this question.