Le type B natriuretic peptide, or BNP (for Brain natriuretic peptide, in English), is a neuro-hormone synthesized by heart cells called cardiomyocytes in response to an increase in blood pressure, especially during the development of a Heart Failure.

The BNP plays the following roles:

• diuretic (increases urinary secretion)

• natriuretic (promotes urinary sodium excretion)

• vasodilatation (dilation of vessels)

• antagonistic effect of the renin-angiotensin system (hormonal system of the kidney which regulates in particular the sodium balance)

The amount of BNP in the blood is an indicator of the progress of heart failure. It increases when it gets worse, and decreases when the disease stabilizes.

The doctor can therefore prescribe a measurement of the BNP level for:

• confirm a diagnosis of heart failure

• measure its severity

• predict the risk of future cardiac events (including sudden death)

• evaluate the effectiveness of the treatment

Because the level of BNP is correlated with the degree of heart failure, cardiologists use the measurement to best adjust the medical treatment of their patients.

The examination consists of a venous blood test. It does not require any special preparation.

The blood test is very reliable for diagnosing a Heart Failure.

Beyond a quantity of BNP of 100 pg / mL (picograms per milliliters), the diagnosis is in favor of heart failure. It is certain above 300 pg / mL.

Below 100 pg / mL, heart failure can be excluded.

Between 100 and 400 pg / mL, additional examinations such as chest x-ray and transthoracic Doppler ultrasound are necessary.

It should be noted that the blood BNP concentration may be found to be elevated in circumstances other than that of heart failure, in particular depending on:

• age: moderate increase

• gender: values ​​are slightly higher in women

• some cases of high blood pressure

• kidney failure

• cirrhosis of the liver

• Cushing’s syndrome

• hyperthyroidism, etc.

Only the doctor will be able to interpret the results of the analysis.