P825 Multi-modality imaging for noninvasive diagnosis of transthyretin amyloid cardiomyopathy-single centre experience

Background Thransthyretin amyloidosis (ATTR) is a rare progressive disease that may present as heart failure with preserved ejection fraction, severe aortic stenosis, hypertrophic cardiomyopathy (HCM) or resctrictive cardiomyopathy. There are two types of ATTR: hereditary ATTR (hATTR) caused by mutations in the TTR gene and wild-type ATTR (wtATTR) resulting from deposition of wild-type TTR protein. Purpose We describe the clinical heterogeneity of ATTR patients from our centre diagnosed noninvasively in 2018-2019. Methods All patients presented intensive cardiac uptake at 99mTc-DPD scintigraphy. Light chain amyloidosis was excluded. Results 8 patients were diagnosed with ATTR (Table 1). Three unrelated male patients were diagnosed with hATTR due to rare mutations: 2 of them had Phe33Leu, 1 patient had Glu89Lys mutation. Five patients (males) were diagnosed with wtATTR. Age of onset differed among the patients. Characteristic clinical features included cardiomyopathy with increased left and right ventricular wall thickness. Only 2 patients had restrictive filling pattern, 3 patients had atrial fibrillation. Laboratory examination showed increased level of troponin T and NT-proBNP. Three patients had bilateral carpal tunnel syndrome. Thanks to DPD-scintygraphy we excluded ATTR in two patients with false-positive results of histological exam for TTR-related amyloid deposits. Conclusions Although ATTR is known for its broad clinical spectrum, patients from our center presented mostly as HCM phenocopies but in different stages of heart failure. Appropriate diagnosis of ATTR is crucial and have direct therapeutic impact. Echocardiography raise the suspicion of amyloid cardiomyopathy, while other imaging technique (DPD-scintigraphy) confirm it or exclude it in noninvasive way. Patient 1 2 3 4 5 6 7 8 Mutation Glu89Lys Phe33Leu Phe33Leu wild type wild type wild type wild type wild type Sex male male male male male male male male Age of onset 57 56 55 77 78 80 77 76 Electrocardiogram AF low QRS voltage low QRS voltage AF, RBBB LVH LVH pseudoinfarct pattern, low QRS voltage AF, LVH Maximal wall thickness [mm] 23 20 18 28 22 23 18 20 LVEF% 45 40 40 60 65 60 45 55 Asymmetric hypertrophy pattern + - - - + + - + NYHA III II II II III II II II NT-proBNP pg/ml 2122 1200 1500 2755 222 2630 2426 hs-Troponin T ng/l 50 98 42 65 35 63 64 Abstract P825 Figure 1