Noninvasive Etiologic Diagnosis of Cardiac Amyloidosis Using 99m Tc-3,3-Diphosphono-1,2-Propanodicarboxylic Acid Scintigraphy

Abstract

Etiology is a third major cause--in addition to type of organ-involved (soft-tissue/heart) and tracer type--of scintigraphic variability in cardiac amyloidosis. This is a highly relevant consideration for future studies. We conclude that 99mTc-DPD scintigraphy is a useful step in the workup of the differential diagnosis of TTR versus AL etiology in patients with documented cardiac amyloidosis.

Nuclear imaging in cardiac amyloidosis

“…Different phosphate derivatives (PYP, MDP, DPD) labelled with 99m Tc seem valuable for detecting cardiac involvement of amyloidosis, but a certain amount of amyloid is necessary. There seems to be no role for this approach in the early detection of cardiac amyloidosis, but it may play a role in the differential diagnosis of ATTR versus AL aetiology in patients with documented cardiac amyloidosis [58]. There is only a limited role for 67 Ga for detection amyloid depositions in the heart with no advantages compared to other tracers.…”

“…These patients showed no MDP myocardial uptake. The authors concluded that 99m Tc-DPD scanning is a useful step in the work-up for the differential diagnosis of ATTR versus AL aetiology in patients with documented cardiac amyloidosis [58].…”

“…The only exception may be, as suggested by Perugini at al. [58], helping in the differential diagnosis of ATTR versus AL aetiology [58]. Positive phosphate scanning seems to correlate with high amounts of amyloid fibrils in the heart, but this occurs at an advanced stage when clinical symptoms of cardiomyopathy are already apparent.…”

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

“…3 The authors of the current study performed a retrospective analysis in 75 patients with suspected ATTR cardiac amyloidosis who underwent planar Tc99 m PYP cardiac imaging, 48 of whom were reported to have ATTR, 12 with endomyocardial biopsy-proven disease. Myocardial Tc99 m PYP uptake was evaluated on planar images using the established semiquantitative score 5 and the quantitative H/CL chest ratio, 6 although the authors used a semiquantitative score threshold of C1, not C2, for detecting ATTR, in part because they used a 3 hour, not 1 hour, imaging time (see below). They found that both the Tc99m PYP semiquantitative score and H/CL ratio were associated with mortality with HRs of 1.49 (95% CI 1.08-2.08, P = 0.016) and 5.19 (95% CI 1.46-18.4, P = 0.0111), respectively, and with death or heart failure hospitalization with HRs of 1.49 (95% CI 1.17-1.90) and 3.15 (95% CI 1.21-8.23), respectively.…”

Pursuing an underdiagnosed disease: a simple imaging test for increasing suspicion of cardiac amyloidosis

“…In 2005, the Bologna group published data from 25 patients with amyloidosis (17 of whom had TTR-related amyloidosis) suggesting the bone-scanning agent 99m Tc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) was preferentially taken up by the heart in patients with TTR amyloidosis, whereas it showed no uptake in AL amyloidosis or in controls without the disease [9]. This appeared to be isotope specific, as 99m Tc-methylene diphosphonate (MDP) showed no uptake in 11 patients who showed distinct myocardial uptake with 99m Tc-DPD.…”