Heart failure: BNP blood test
The BNP or NTproBNP blood test may be arranged to help diagnose heart failure.
The sample of blood is tested in a laboratory for natriuretic peptide.
When heart failure develops or worsens, the ventricles or lower chambers of the heart produce a substance that breaks down to form two proteins: B-type natriuretic peptide (BNP) and N-terminal-pro-BNP (NT-pro-BNP). Both substances are secreted in response to changes in pressure that occur with heart failure. BNP and NT-pro-BNP levels in the blood increase when heart failure symptoms worsen, and decrease when the heart failure condition is stable.
BNP and NT-pro-BNP levels in a person with heart failure -- even someone whose condition is stable -- are higher than in a person with normal heart function.
Why is this test needed?
BNP levels help to determine if you have heart failure, rather than another condition that may cause similar symptoms. In addition, BNP testing helps your doctor determine if your heart failure has worsened, evaluate what other treatments are needed, if you need to be admitted to hospital, and determine your prognosis (how well you will do in the future). Depending on what tests are available in your area, the BNP and/or NT-pro-BNP test may be performed. Both tests have been shown to be beneficial.
What happens during the test?
A small amount of blood is taken and placed in a machine that detects the level of BNP and NT-pro-BNP in your blood. The test takes about 15 minutes.
What do the results mean?
The level of BNP tends to increase with the level of disease severity.
In studies, patients who had an elevated level of either BNP or NT-pro-BNP had a higher risk of death and illness from heart failure.
Ask your doctor to explain the results of your BNP tests.