Correlation Between Quantitative Uptake of TC-DPD and Echocardiographic Parameters in Cardiac ATTR: A Novel Follow-Up Strategy.

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 (Tc-DPD) bone scintigraphy. We evaluated structural and functional biventricular alterations by transthoracic echocardiography (TTE) and determined the correlation with Tc-DPD tracer uptake in ATTR. ATTR patients (wild-type, hereditary or asymptomatic transthyretin [] variant carriers) with Tc-DPD and TTE were selected; Tc-DPD uptake was analyzed quantitatively. TTE assessment of left ventricle (LV) and right ventricle (RV) parameters was performed. Forty ATTR patients (wild-type = 17; hereditary ATTR and variant carriers = 23; median age 68.8 ± 22 years) were included. TTE parameters displaying good correlation with Tc-DPD tracer uptake included LV average wall thickness ( = 0.837), LV indexed mass (LVMI; = 0.802), RV wall thickness ( = 0.610), average e' ( = -0.830), E/e' ratio ( = 0.786), LV global longitudinal strain (GLS; = 0.714) and RV GLS ( = 0.632; < 0.001 for all). Hereditary ATTR and 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. Good correlations between TTE biventricular structural and functional parameters were demonstrated with quantitative Tc-DPD uptake. Echocardiography may potentially assume a significant role in longitudinal follow-up for monitoring disease progression and for evaluating treatment response.