Chronic Heart Failure Diagnosing heart failure NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 5 Diagnosing heart failure The update to the heart failure guideline includes topics where new evidence has emerged since the publication in 2010. A review of new evidence published after 2010 was carried out in order to determine whether any changes to current recommendations where likely to be required. The decision on which topics to include in the update of the guideline was made following consultation of the scope. The following topics were not within the scope of the update. For more information refer to the 2010 Guideline: Symptoms, signs and investigation. Natriuretic peptides versus echocardiography See section 5.1 and 5.5 of 2010 guideline (Appendix R). 5.1 BNP and NT-proBNP in diagnosing heart failure The diagnosis of heart failure can be challenging because of the frequent overlap of the symptoms of breathlessness and fluid retention with other conditions, because the patient may already have a condition that produces similar symptoms, for example chronic obstructive pulmonary disease, and because the presence of co-morbidities may delay the diagnosis of heart failure. Furthermore, the demonstration of a structural or functional cardiac abnormality on imaging may not necessarily be the cause of the presenting symptoms. There is no single diagnostic test for heart failure, and the diagnosis relies on clinical judgement based on a combination of history, physical examination and appropriate investigations. Biomarkers are substances measurable in the blood stream which can be used to diagnose and monitor disease. Natriuretic peptides are released from the myocardium in response to fluid overload. The two main natriuretic peptides used in clinical practice are amino-terminal pro-B-type natriuretic peptide (NT-proBNP) and B-type natriuretic peptide (BNP). 