[Use of brain natriuretic peptide (BNP) in the diagnosis and treatment of heart failure].

Utility of the dosage of brain natriuretic factor (BNP) in the diagnosis and treatment of heart failure. Congestive heart failure (HF) is the main reason for hospitalisation of elderly patients. HF affects nearly 15% of patients aged 75 years or older. Prognosis after the diagnosis of HF is comparable to that of cancers with 50% survival after 4 years for mild HF and 50% after one year in more severe cases. Systolic HF defined by a left ventricular ejection fraction (LVEF) < 40% is asymptomatic in half the patients. In patients with symptomatic HF, LVEF is normal in almost 50% of the cases suggesting a diastolic HF. BNP is secreted after distension of left ventricule mainly in patients with systolic or diastolic HF, in proportion to the severity of the disease. A serum level of BNP > 100 pg/ml has a sensitivity of 90 percent and a specificity of 76 percent for the diagnosis of HF. Serum BNP is also increased in kidney insufficiency and in cirrhosis. BNP increase has a prognostic value to predict mortality after cardiac failure or myocardial infarction. Except for digoxin, all the drugs used to treat HF decrease serum levels of BNP. In dyspneic patients, serum levels of BNP < 50 pg/ml can exclude HF with a good probability. However BNP determination is not useful to diagnose HF in a general population.