1423 JACC March 21, 2017 Volume 69, Issue 11
Non Invasive Imaging (Echocardiography, Nuclear, PET, MR and CT) HOW USEFUL IS 99MTC-DPD SCINTIGRAPHY IN DIAGNOSIS OF CARDIAC AMYLOIDOSIS IN TRANSTHYRETIN V30M FAMILIAL AMYLOID POLYNEUROPATHY? Moderated Poster Contributions Non Invasive Imaging Moderated Poster Theater, Poster Hall, Hall C Sunday, March 19, 2017, 10:15 a.m.-10:25 a.m. Session Title: Emerging Applications for Imaging Cardiac Amyloidosis: Nuclear Cardiology Abstract Category: 30. Non Invasive Imaging: Nuclear Presentation Number: 1307M-07 Authors: Maria C. Azevedo Coutinho, Nuno Cortez-Dias, Susana Gonçalves, Guilhermina Cantinho, Tatiana Guimarães, Gustavo Lima da Silva, Ana R. Francisco, Laura Santos, Isabel Conceição, Fausto Pinto, Department of Cardiology, Santa Maria University Hospital, Lisbon, Portugal Background: Previous studies suggested that 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy may be useful for early diagnosis of hereditary transthyretin (TTR) related cardiac amyloidosis. However its diagnostic value in V30M TTR familial amyloid polyneuropathy (FAP) remains unknown.
Methods: A total of 108 individuals (51±15 years; 58% male) with V30M TTR mutation underwent DPD scintigraphy, 2DS echocardiography, NTproBNP and evaluation of myocardial sympathetic enervation by late heart-to-mediastinum (H/M) 123I-MIBG ratio. Cardiac DPD uptake was quantified by visual scoring and by the heart-to-contralateral ratio (H/Cl).
Results: Of the 108 patients (pts), 28% were asymptomatic and 72% had neurological involvement (28 submitted to liver transplant and 39 under tafamidis treatment), classified as stage 1, 2 or 3 in 51%, 16% and 5%. Cardiac DPD uptake was present in 20 pts (19%) and the mean H/Cl was 1.3±0.8. Amyloid cardiomyopathy, defined as septal thickness ≥12mm, was present in 26%. H/Cl and septal thickness were positively correlated (Pearson R: 0.22; p=0.027), but the sensitivity and specificity of DPD to detect amyloid cardiomyopathy were only 54% (15/28) and 75% (15/20), respectively. Even among pts with septal thickness ≥14mm, only 65% (11/17) presented abnormal cardiac uptake. Patients with abnormal cardiac uptake were older (69±11 vs. 46±12 years; p<0.001), presented higher prevalence of neurological involvement (100% vs. 66%; p<0.001), lower H/M MIBG (1.4±0.3 vs. 1.8±0.3; p<0.001) and higher NTproBNP [251 (152-1388) vs. 100 (38211) pg/mL; p<0.001]. All pts presented normal left ventricular ejection fraction. Subclinical dysfunction was detected in pts with abnormal cardiac uptake, manifested by reduced global systolic strain (-13.6±4.6% vs. -17.7±3.6%; p=0.001) and strain rate (-0.8±0.2 vs. -1.0±0.2s-1; p=0.001), E/A strain rate ratio [0.8 (0.6-1.3) vs. 1.4(1.1-1.8); p=0.004] and E/e’ ratio (17.5±7.5 vs. 9.1±6.4; p<0.001).
Conclusions: DPD imaging correlates with other parameters of cardiac involvement. However, DPD uptake is not as accurate for detecting amyloid cardiomyopathy in V30M TTR-FAP as it is in other forms of TTR amyloidosis.