Chronic Heart Failure Diagnosing heart failure NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 5.4 Recommendations for diagnosing heart failure 5.4.1 Symptoms, signs and investigations 1. Take a careful and detailed history, and perform a clinical examination and tests to confirm the presence of heart failure. [2010] 2. Measure N-terminal pro-B-type natriuretic peptide [NT-proBNP] in people with suspected heart failure. [2018] 3. Because very high levels of NT-proBNP carry a poor prognosis, refer people with suspected heart failure and an NT-proBNP level above 2,000 ng/litre (236 pmol/litre) urgently, to have specialist assessment and transthoracic echocardiography within 4. Refer people with suspected heart failure and an NT-proBNP level between 400 and 2,000 ng/litre (47 to 236 pmol/litre) to have specialist assessment and transthoracic echocardiography within 6 weeks. [2018] 5. Be aware that: 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. [2018] 6. 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 physician with subspeciality training in heart failure. [2018] 7. Be aware that: obesity, African or African-Caribbean family origin, or treatment with diuretics, angiotensin- converting enzyme(ACE) inhibitors , beta-blockers, angiotensin II receptor blockers (ARBs) or mineralcorticoid receptor antagonist (MRAs) can reduce levels of serum natriuretic peptides. 