397a Quantitative 99mTc-DPD Scintigraphy Correlation with Structural and Functional Changes on Echocardiography in Transthyretin Amyloidosis

Abstract

Cardiac involvement portends poor prognosis in transthyretin amyloidosis (ATTR); increase in LV wall thickness and altered LV function are common manifestations. Our aim was to determine the correlation of LV structural (LVH and wall thickness) and functional changes (LVEF and global longitudinal strain (GLS)) on TTE with Technetium-3-3 Diphosono-1-2 propanodicarboxylic acid (99mTc-DPD) scintigraphy uptake. Hereditary and wild-type ATTR patients with TTE and 99mTc-DPD were selected. Offline measurements performed included LV average wall thickness (AWT = IVS+ PW/2), LV mass indexed (LVMI), LVEF and LV GLS. 99mTc-DPD LV uptake intensity was quantified with reference to aortic arch blood pool with custom software in Interactive Data Language (using a cut-off value of >1.1 for positive findings). Spearman rank correlation, Fisher’s Exact test and ROC curves were performed. The study cohort included 40 patients (male 75%, median age 69±22 years) with a median time difference between imaging of 7 days (IQR=100 days). 99mTc-DPD LV uptake >1.1 was evident in 75% of ATTR patients. Increased AWT (r=0.84), LVMI (r=0.80), reduction in GLS (r=0.71) (p<0.001 for all) were great predictors for increased 99mTc-DPD uptake, while reduction in LVEF (r=-0.55, p<0.001) had moderate prediction of increased uptake (Figure 1). Alterations in LV structure (increased LV AWT and LVMI) with reduced LV function in cardiac ATTR were associated with increased 99mTc-DPD uptake. Therefore, TTE could assess for LVH progression or reduction in LV function for longitudinal follow up of ATTR patients.