Uncertain clinical relevance of serial bone scintigraphy findings in treated transthyretin amyloid cardiomyopathy
Razvi, Yousuf Porcari, Aldostefano Hutt, David F Lazari, Jonathan Ioannou, Adam Patel, Rishi K Rauf, Muhammad Umaid Rezk, Tamer Hague, Oliver Filisetti, Stefano
Razvi, Yousuf
Porcari, Aldostefano
Hutt, David F
Lazari, Jonathan
Ioannou, Adam
Patel, Rishi K
Rauf, Muhammad Umaid
Rezk, Tamer
Hague, Oliver
Filisetti, Stefano
Affiliation
University College London; Royal Free Hospital; University of Trieste; Eastbourne District General Hospital; University Hospitals Birmingham NHS Foundation Trust; University of Birmingham
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Publication date
2025-07-09
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Abstract
Background: Technetium-99m-labeled 3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy is a critical part of the validated nonbiopsy diagnostic algorithm for transthyretin amyloid cardiomyopathy (ATTR-CM). With the advent of novel disease-modifying therapies for ATTR-CM, there is intense interest in establishing the utility of DPD scans as an indicator of treatment response.
Objectives: The authors conducted a retrospective multimodality imaging study to determine the utility of 99mTc-DPD to track treatment response in ATTR-CM.
Methods: ATTR-CM patients from the United Kingdom National Amyloidosis Centre who were receiving amyloid-specific disease-modifying therapy (DMT) and underwent pre- and post-treatment 99mTc-DPD/single-photon emission computed tomography-computed tomography scans were included. Myocardial percentage injected dose (PID), a proposed scintigraphic indicator of cardiac amyloid burden, was measured at baseline and follow-up. Change from baseline in this variable was compared with that of other validated biomarkers of disease severity.
Results: A total of 66 patients with ATTR-CM who received DMT underwent serial 99mTc-DPD scans. At follow-up, with a median time between 99mTc-DPD scans of 27.5 months (Q1-Q3: 21.9-33.1 months), there was a mean reduction from pre-DMT myocardial PID on 99mTc-DPD scintigraphy of 1.5 ± 1.5%. No statistically significant correlation between the change in PID at follow-up and change in echocardiographic, biochemical, or cardiac magnetic resonance parameters was identified. Discordance in which there was an improvement on follow-up 99mTc-DPD scintigraphy despite disease progression was observed in 28/66 patients (42.4%).
Conclusions: Our study indicates a poor correlation between reduction in 99mTc-DPD uptake at follow-up and numerous established biomarkers of ATTR-CM treatment response. Changes in DPD uptake in ATTR-CM patients receiving DMT should be interpreted with caution.
Citation
Razvi Y, Porcari A, Hutt DF, Lazari J, Ioannou A, Patel RK, Rauf MU, Rezk T, Hague O, Filisetti S, Lachmann HJ, Wechalekar AD, Petrie A, Whelan CJ, Venneri L, Martinez-Naharro A, Gilbertson JA, Rowczenio D, Moody WE, Steeds R, Pinney JH, Hawkins PN, Fontana M, Gillmore JD. Uncertain Clinical Relevance of Serial Bone Scintigraphy Findings in Treated Transthyretin Amyloid Cardiomyopathy. JACC Cardiovasc Imaging. 2025 Aug;18(8):899-908. doi: 10.1016/j.jcmg.2025.03.014. Epub 2025 Jul 9
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Article