074: Potential role of peptide natriuretic and troponin-T to predict cardiac echocardiographic findings in hereditary transthyretin amyloidosis patients

Background Transthyretin (TTR) familial amyloid polyneuropathy (FAP) is a fatal autosomal dominant neurodegenerative disease characterized by deposition of transthyretin targeting mainly the peripheral nervous system and the heart. Early noninvasive detection of cardiac impairment is of importance for the therapeutic management. Aim Assess if natriuretic peptide (NT-proBNP) or troponin T (cTnT) are reliable biomarkers to predict echocardiographic left ventricle (LV) impairment in a wide variety of TTR patients. Methods 36 asymptomatic carriers and patients with proven FAP genetic mutation had clinical, biological and echocardiography assessment of left ventricle (LV) systolic function (SD), filling pressure (FP) and hypertrophy (LVH) as marker of amyloid deposition Results In the all cohort, the median (IQR) age, NT-proBNP, LV ejection fraction were respectively 59 (41-74), 323pg/ml (58-1960) and 60% (51-66). 64% were men and 12 had an increased in cTnT. TTR gene mutations prevalence was 50% for Val30Met. 4 patients were asymptomatic, 6 had only neurologic clinical signs and 26 had echo-LV abnormalities with or without neurologic disorders. Their median NT-proBNP value were respectively: 33 (19-50), 54 (37-154) and 747 (253;2840). Using received-operator curve, NTproBNP identified significantly patients with echo-LV abnormalities (Area: 0.92;(0.83-0.99), p=0.001) with a threshold above 82pg/ml and a sensitivity of 92% and specificity of 90%. Elevated cTnT (superior to 0.01ng/ml) was only observed in patients combining impairment of LVH and SD or LVH, SD and FP. Conclusion In TTR amyloidosis, NTproBNP and troponin T are associated with LV impairment measured by echocardiography suggesting that NTproBNP could be useful in FAP carriers to start echocardiographic follow-up whereas troponin would identify patients with severe cardiac disease.