1. GRC Amyloid Research Institute, Hôpitaux Universitaires Henri Mondor
Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology
Early-phase myocardial uptake intensity of 99mTc-HMDP vs. 99mTc-DPD in patients with hereditary transthyretin-related cardiac amyloidosis
Abulizi M, Cottereau AS, Guellich A, Vandeventer S, Galat A, Van Der Gucht A, Plante-Bordeneuve V, Dubois-Randé JL, Bodez D, Rosso J, Damy T, Itti E
GRC Amyloid Research Institute, Hôpitaux Universitaires Henri Mondor
Head shot of author
required
Institution
Picture/Logo
Optional
Copyright American Society of Nuclear Cardiology

2. Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology
BACKGROUND
1- 99mTc-labelled bone tracers are used for noninvasive diagnosis of cardiac amyloidosis (CA) 2- myocardial uptake of 99mTc-labelled bone tracers is high in transthyretin-related CA (TTR-CA) and absent in light-chain CA (AL-CA) 3- early-phase scanning (10 min post-injection) shows same diagnostic performance than late-phase scanning (3 h post-injection) 4- direct comparison of myocardial uptake of DPD and HMDP in the same patients has never been performed although an in vitro study shows higher affinity of DPD for amyloid fibrils compared with HMDP and PYP
Copyright American Society of Nuclear Cardiology

3. METHODS Study type: observational IRB-approved study
Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology
METHODS
Study type: observational IRB-approved study
Study subjects: 6 patients with biopsy-proven hereditary TTR-CA
Study endpoints:
To compare the intensity of early-phase myocardial uptake of two widely used phosphonate-based radiotracers in Europe, 99mTc-HMDP and 99mTc-DPD
To compare the regional distribution within the AHA 17-segment model
Study variables: Heart-to-mediastinum ratio, relative segmental uptake
Copyright American Society of Nuclear Cardiology

4. Average of DPD and HMDP segments (%)
Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology
RESULTS
Comparison of heart-to-mediastinum ratio between both radiotracers in the same patients. Bland-Altman plots of the differences in segmental myocardial radiotracer distribution in the 6 patients: pt 1, blue empty circles; pt 2, blue plain circles; pt 3, red empty squares; pt 4, red plain squares; pt 5, green empty triangles; pt 6, red plain triangles.
HMDP
DPD
Heart / Mediastinum ratio . .
DPD - HMDP segments (%) . .
Average of DPD and HMDP segments (%)
Copyright American Society of Nuclear Cardiology

5. RESULTS 99mTc-HMDP 99mTc-DPD
Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology
RESULTS
Comparison of myocardial uptake (whole-body anterior view with ROIs overlayed and bull’s eye analysis) between 99mTc-HMDP and 99mTc-DPD in the same patient. Heart-to-mediastinum ratio are 1.97 and 2.07, respectively. DPD imaging was performed 4.6 mo after HMDP and patient underwent pacemaker implantation in the mean time (arrow).
99mTc-HMDP
99mTc-DPD
Copyright American Society of Nuclear Cardiology

6. Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology
CONCLUSIONS
1- 99mTc-HMDP and 99mTc-DPD show comparable myocardial uptake intensity on early-phase scintigraphy in TTR-CA
2- Regional distribution of myocardial uptake is also similar on Bull’s eye analysis (17-segment model), showing apical/periapical defects and higher uptake of the septum
3- Both tracers can be used alternatively for the diagnosis of hereditary amyloidosis.
4- Further studies using other, FDA-approved tracers, are warranted
Copyright American Society of Nuclear Cardiology