Usefulness of^99mTc-HMDP scintigraphy for the etiologic diagnosis and prognosis of cardiac amyloidosis

Abstract

This preliminary study suggests that (99m)Tc-HMDP-scintigraphy may aid differentiation between transthyretin and AL-CA as well as CA from other LVHs. (99m)Tc-HMDP-scintigraphy appears to provide prognostic information in CA.

Nuclear imaging of cardiac amyloidosis

“…20 Similar findings have been reported with 18 F-florbetabir from other laboratories 22 and with another amyloid specific PET tracer, 18 F-florbetaben. 23 The current study by Capelli et al 21 confirms earlier findings of smaller studies and case reports 13,14 as well as the large-scale study by Gillmore et al 17 showing the potential of 99m Tc-HMDP nuclear imaging in patients with suspected TTR-CA, to reliably differentiate those from AL-CA and other causes of LVH. The biggest limitations, as the authors point out, are small sample size and lack of biopsy confirmation in several patients.…”

“…Planar imaging alone or with single-photon emission computed tomography (SPECT) using nonamyloid-specific, bone-avid radiotracers ( 99m Tc-DPD [3,3- [8][9][10][11][12][13][14][15][16][17] Recent data indicate that the increased level of microcalcifications may explain the enhanced affinity of bone-seeking tracers for TTR over AL amyloidosis. 18 Amyloidspecific, positron emitting 18 F-and 11 C-tagged tracers have been used successfully with positron emission tomography (PET) imaging for the identification of both AL and TTR subtypes of CA.…”

Transthyretin Cardiac Amyloidosis in Black Americans

“…Considering that prior autopsy data in Val122Ile carriers showed 100% prevalence of TTR amyloid at the time of death, imaging modalities such as 99m Tc-PYP or 99m Tc-DPD based nuclear imaging, which have been shown to detect cardiac amyloid prior to echocardiographic manifestations, may be more effective to detect early disease. 23,24 …”

Technetium 99m pyrophosphate radioisotope for diagnosis and prognosis of transthyretin cardiac amyloidosis: A call for collaboration

“…2 In a study among 121 patients with suspected cardiac amyloidosis in France (55 ATTR and 14 AL), increased myocardial retention of another Tc99m PYP-like isotope, (99m)Tc-hydroxymethylene diphosphonate (Tc99m HMDP), using a heart-to-skull retention ratio, was associated with lower LVEF and increased acute heart failure and/or death. 7 In our own experience among 121 patients with biopsy confirmed ATTR pooled from three centers in the United States, despite a referral population with high pre-test probability of disease and employment of two scan protocols, a Tc99m PYP H/CL ratio of 1.6 or greater was associated with lower LVEF, increased interventricular septal wall thickness, lower stroke volume index, lower myocardial contraction fraction, and worse survival. 3 Potential reasons for the discrepant results in the current study may include its (1) relatively smaller sample size with limited power, (2) inclusion of the different endpoint of heart failure hospitalization compared to previously studied all-cause mortality or MACE endpoints, and (3) differences in the Tc99m PYP scan protocol, which the authors highlight.…”

“…These findings contradict prior reports. 2,3,7 Among 63 patients with hereditary ATTR in Italy, increased myocardial uptake of the Tc99m PYP-like isotope, (99m)Tc-3,3-diphosphono-1,2-propanodicarboxylic acid (Tc99m DPD), using a heart-to-whole body ratio, was associated with increased left ventricular wall thickness and lower left ventricular ejection fraction (LVEF), in addition to worse MACEfree survival. 2 In a study among 121 patients with suspected cardiac amyloidosis in France (55 ATTR and 14 AL), increased myocardial retention of another Tc99m PYP-like isotope, (99m)Tc-hydroxymethylene diphosphonate (Tc99m HMDP), using a heart-to-skull retention ratio, was associated with lower LVEF and increased acute heart failure and/or death.…”