0161: Usefulness of plasma high sensitive troponin t and Nt-proBNP in the diagnosis of cardiopathy in Friedreich ataxia

Friedreich ataxia, due to mitochondrial dysfunction, is the most common genetic sensory ataxia. It’s due to lack of frataxin. Hypertrophic cardiomyopathy is associated with Friedreich ataxia and is the major cause of death, (80%). This study concerned the role of plasma biomarkers, high sensitive troponin and Nt-proBNP, in the diagnostic of cardiopathy in Friedreich ataxia. From December 2012 to January 2015, we included 76 genetically confirmed Friedreich’s ataxia patients in Pitie-Salpetriere Hospital. Clinical examination, ECG, echocardiography and blood samples were obtained. Patients were aged of 38±12 years, (mean±sd), 50% were male. 4 patients had palpitations, 2 dyspnea and no patients had chest pain. 89% had negative T waves on the ECG. 49% had echographic cardiac hypertrophy according to Henry’s nomogram. Patients with hypertrophy were younger: 34±10 years versus 42±14 years, age at onset of the disease was earlier: 15±6 years versus 21±15 years. Interventricular septal wall thickness was 12,9±1,7mm versus 10±1,2mm, and posterior wall thickness was 11,3±1,5mm versus 9,4±1mm. Left ventricle ejection fraction was similar (64%). For patients with hyper-trophy, troponin was higher: 22±21 ng/L versus 10±7 ng/L. Plasma NtproBNP was the same between the 2 groups 104±170 ng/L versus 64±122 ng/ L. 5 patients had plasma Nt-proBNP ≥300 ng/L, they all had had atrial fibrillation or heart failure. Plasma High sensitive troponin is a diagnostic marker of hypertrophic cardiomyopathy in Friedreich ataxia’s patients, whereas plasma Nt-proBNP is associated with cardiac events and could be a prognostic marker in these patients.