[BNP or NT-proBNP: "that is the question"]. / BNP ou NT-proBNP : "mon coeur balance"

Blood measurements of BNP and NT-proBNP, its catabolite, improve diagnosis for patients admitted to emergency departments with dyspnoea. In this paper, we have compared the BNP to the NT-proBNP for 119 dyspnoeic patients using at random clear clinical status. Among the test group of 119 patients, 57 showed coherent biological results for the 2 markers. These results confirm the final clinical diagnosis. Nine patients with congestive heart failure had abnormally low BNP and NT-proBNP rates. Six of these patients experienced long delays (longer than 48 hours and less than 72 hours) between their admission in emergency and the biological measurement of the natriuretic biomarkers. Three of the other patients could be not only flash OAP cases with a fast growth and a fast normalisation of BNP but also could have existing genetical factors. These genetical factors leading to high variability in BNP synthesis are not related to physiological or cardiac factors. 43 patients showed a mismatch between BNP and NT-proBNP. BNP appeared to be unstable in vitro. The lack of stability in whole blood or plasma samples is increased by sampling in a glass EDTA collection tube and too long delays in transferring the samples from the emergency area and the laboratory in a big hospital. Ten patients showed a mismatch with abnormally high NT-proBNP or false positive results. Among these 10 patients, 5 had renal dysfunction with a high level of creatinine concentration. It is clear that all Diagnostics Manufacturers should now propose different cut-off for natriuretic peptides tests according to the degree of patients' renal impairment.

[Biomarkers as prognostic factors in pulmonary arterial hypertension. Rationale and study design]. / Evaluation pronostique de biomarqueurs dans l'hypertension artérielle pulmonaire. Justification et plan expérimental.

CURRENT SITUATION: Pulmonary arterial hypertension (PAH) is a serious disease. Its prognostic is based on the functional status quantified by the NYHA class and the 6-min walking test, and the hemodynamic data. The algorithms of treatment are solely based on the hemodynamic data and the functional status. The main objective is to test whether basal concentrations of isoprostanes, Big endotheline 1, ADMA, high sensitivity CRP, NT-Pro-BNP and cardiac troponin T are a 3-year prognostic factor in PAH using a combined criterion: death from any cause and pulmonary or cardiopulmonary transplantation. MATERIALS AND METHODS: This is a multicenter, prospective, prognostic, single blinded study (plasma and urinary samples being blinded). The study started in november 2003, running for 2 years, with a 3 year follow-up for each patient. The main inclusion criterion is PAH. The data analysis will use a multivariable Cox model, taking into account the functional and hemodynamic parameters. EXPECTED RESULTS: This study will determine whether any of the biomarkers tested provides additional prognostic information in PAH in addition to the functional and hemodynamic parameters.