AUTHOR=Harapoz Mehmet , Evans Scott , Geenty Paul , Kwok Fiona , Stewart Graeme , Taylor Mark S. , Farlow David , Thomas Liza 

TITLE=Correlation Between Quantitative Uptake of 99mTC-DPD and Echocardiographic Parameters in Cardiac ATTR: A Novel Follow-Up Strategy

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2021.663929

DOI=10.3389/fcvm.2021.663929

ISSN=2297-055X

ABSTRACT=<p><bold>Aims:</bold> There has been a paradigm shift in diagnosis of cardiac transthyretin amyloidosis (ATTR) with non-invasive techniques including technetium-99m 3,3-diphosphono-1,2-propanodicarboxylic acid (<sup>99m</sup>Tc-DPD) bone scintigraphy. We evaluated structural and functional biventricular alterations by transthoracic echocardiography (TTE) and determined the correlation with <sup>99m</sup>Tc-DPD tracer uptake in ATTR.</p><p><bold>Materials and Methods:</bold> ATTR patients (wild-type, hereditary or asymptomatic transthyretin [<italic>TTR</italic>] variant carriers) with <sup>99m</sup>Tc-DPD and TTE were selected; <sup>99m</sup>Tc-DPD uptake was analyzed quantitatively. TTE assessment of left ventricle (LV) and right ventricle (RV) parameters was performed.</p><p><bold>Results:</bold> Forty ATTR patients (wild-type <italic>n</italic> = 17; hereditary ATTR and <italic>TTR</italic> variant carriers <italic>n</italic> = 23; median age 68.8 ± 22 years) were included. TTE parameters displaying good correlation with <sup>99m</sup>Tc-DPD tracer uptake included LV average wall thickness (<italic>r</italic> = 0.837), LV indexed mass (LVMI; <italic>r</italic> = 0.802), RV wall thickness (<italic>r</italic> = 0.610), average e' (<italic>r</italic> = −0.830), E/e' ratio (<italic>r</italic> = 0.786), LV global longitudinal strain (GLS; <italic>r</italic> = 0.714) and RV GLS (<italic>r</italic> = 0.632; <italic>p</italic> &lt; 0.001 for all). Hereditary ATTR and <italic>TTR</italic> variant carriers without cardiac tracer uptake had normal echocardiographic parameters. Receiver operating characteristic curves demonstrated strong diagnostic accuracies for structural (LV wall thickness, LVMI and RV wall thickness; area under the curve (AUC) of 0.96 for all) and functional (LV and RV GLS; AUC of 0.86 and 0.88, respectively) parameters.</p><p><bold>Conclusion:</bold> Good correlations between TTE biventricular structural and functional parameters were demonstrated with quantitative <sup>99m</sup>Tc-DPD uptake. Echocardiography may potentially assume a significant role in longitudinal follow-up for monitoring disease progression and for evaluating treatment response.</p>