Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the Congestive Heart Failure article more useful, or one of our other health articles.
Treatment of almost all medical conditions has been affected by the COVID-19 pandemic. NICE has issued rapid update guidelines in relation to many of these. This guidance is changing frequently. Please visit https://www.nice.org.uk/covid-19 to see if there is temporary guidance issued by NICE in relation to the management of this condition, which may vary from the information given below.
Synonym: B-type natriuretic peptide
Brain natriuretic peptide (BNP) levels increase markedly in left ventricular dysfunction and the level in heart failure correlates with symptom severity. BNP can therefore be an important clinical marker for the diagnosis of heart failure in patients with unexplained dyspnoea. Other clinical applications, such as screening for asymptomatic ventricular dysfunction, establishing the prognosis or guiding the titration of drug therapy and prediction of future cardiovascular events, are under investigation but have not yet been sufficiently validated for widespread clinical use.
BNP is a biologically active peptide of 32 amino acids and has vasodilator and natriuretic properties. BNP is cleaved from the 108-amino acid pro-brain natriuretic peptide released from the cardiac ventricles in response to stretching of the chamber. The second remnant after cleavage, N-terminal pro-brain natriuretic peptide (NT-proBNP), is a 76-amino acid peptide with no known biological function which circulates at higher concentrations than BNP and may represent cardiac status over longer periods.
The release of BNP appears to be in direct proportion to ventricular volume expansion and pressure overload. BNP increases with right or left systolic or diastolic heart failure. It is an independent predictor of high left ventricular end-diastolic pressure. BNP levels decrease after effective treatment of heart failure.
Although testing for BNP provides a useful adjunct to routine assessment for differentiating acute heart failure from other causes of breathlessness, other factors such as comorbid illnesses, age, chronic kidney disease and body mass may affect BNP levels in ways that can obscure the diagnosis of heart failure, particularly when this marker is used in isolation. Therefore, it is essential that BNP be used to aid diagnosis in addition to the patient's history, clinical signs and other investigations. The role of BNP in heart failure and whether it is a target to treat or risk identifier remain contentious.
BNP is mainly used in the assessment of patients with possible heart failure. The National Institute for Health and Care Excellence (NICE) recommends:
- Measure N-terminal pro-B-type natriuretic peptide (NT-proBNP) in people with suspected heart failure.
- Because very high levels of NT-proBNP carry a poor prognosis, refer people with suspected heart failure and an NT-proBNP level above 2000 ng/litre (236 pmol/litre) urgently, to have specialist assessment and transthoracic echocardiography within two weeks.
- Refer people with suspected heart failure and an NT-proBNP level between 400 and 2000 ng/litre (47 to 236 pmol/litre) to have specialist assessment and transthoracic echocardiography within six weeks.
- An NT-proBNP level less than 400 ng/litre (47 pmol/litre) in an untreated person makes a diagnosis of heart failure less likely. The level of serum natriuretic peptide does not differentiate between heart failure with reduced ejection fraction and heart failure with preserved ejection fraction.
- Review alternative causes for symptoms of heart failure in people with NT-proBNP levels below 400 ng/litre. If there is still concern that the symptoms might be related to heart failure, discuss with a heart failure specialist.
Potential causes of abnormal brain natriuretic peptide levels
High levels of serum natriuretic peptides can be associated with:
- Age over 70 years.
- Heart failure
- Left ventricular hypertrophy.
- Right ventricular overload.
- Hypoxaemia (including pulmonary embolism).
- Renal dysfunction (eGFR less than 60 ml/minute/1.73 m2).
- Chronic obstructive pulmonary disease.
- Cirrhosis of the liver.
Reduced levels of serum natriuretic peptides can occur with:
- African or African-Caribbean family origin.
- Treatment with diuretics, angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, angiotensin II receptor blockers (ARBs) or mineralocorticoid receptor antagonists (MRAs).
Further reading and references
Heart failure - chronic; NICE CKS, January 2017 (UK access only)
Ray SG; Natriuretic peptides in heart valve disease. Heart. 2006 Sep92(9):1194-7. Epub 2005 Oct 26.
Jankowski M; B-type natriuretic peptide for diagnosis and therapy. Recent Pat Cardiovasc Drug Discov. 2008 Jun3(2):77-83.
Hobbs FD, Davis RC, Roalfe AK, et al; Reliability of N-terminal pro-brain natriuretic peptide assay in diagnosis of heart failure: cohort study in representative and high risk community populations. BMJ. 2002 Jun 22324(7352):1498.
Desai AS; Are serial BNP measurements useful in heart failure management? Serial natriuretic peptide measurements are not useful in heart failure management: the art of medicine remains long. Circulation. 2013 Jan 29127(4):509-16
Chronic heart failure in adults - diagnosis and management; NICE Guidance (Sept 2018)