Role of natriuretic peptide to predict cardiac abnormalities in patients with hereditary transthyretin amyloidosis

Background: Familial amyloid polyneuropathy (FAP) mainly targets the peripheral nervous system and heart. Early noninvasive detection of cardiac impairment is critical for therapeutic management. Aim: To assess if amino-terminal pro-brain natriuretic peptide (NT-proBNP) or troponin T (cTnT) can predict echocardiographic left-ventricle (LV) impairment in FAP. Methods: Thirty-six asymptomatic carriers and patients with FAP had echocardiographic measurement of left-ventricular (LV) systolic function, hypertrophy (LVH) and estimation of filling pressure (FP). Results: Overall, median age, NT-proBNP, and LV ejection fraction were, respectively, 59 years (41-74), 323 pg/ml (58-1960), and 60% (51-66). Twelve patients had increased cTnT. Prevalence of ATTR gene mutations was 53% for Val30Met. Four individuals were asymptomatic, 6 patients had isolated neurological clinical signs, and 26 had echo-LV abnormalities. The ROC curve identified NT-proBNP patients with echo-LV abnormalities (area: 0.92; (0.83-0.99), p = 0.001) at a threshold > 82 pg/ml with a sensitivity of 92%, and a specificity of 90%. Increased in NT-proBNP occurred in patients with SD and/or LVH with or without increase in FP. Elevated cTnT (> 0.01 ng/ml) was only observed in patients with LVH and systolic dysfunction, with or without FP. Conclusion: In FAP, NT-proBNP was associated with cardiac impairment suggesting that NT-proBNP could be used in carriers or in FAP patients with only neurologic symptoms for identifying the appropriate time to start cardiac echocardiographic assessment and follow-up. cTnT identified patients with severe cardiac disease.