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). The levels of natriuretic peptides correlate with prognosis in patients with heart failure (HF).
In the recent NICE guideline for Chronic Heart Failure in adults (NG106 2018), NT-proBNP replaced BNP as the biomarker of choice in people with suspected heart failure for two main reasons. Firstly, NT-proBNP has a greater sensitivity compared to BNP for the diagnosis of heart failure. As the test is used as a ‘rule out’ for heart failure, the sensitivity is of more clinical importance than specificity. Secondly on a practical level, NT-proBNP has a longer stability in blood samples than BNP (days versus 4-6 hours), therefore NT-proBNP is more appropriate for testing in primary care where samples need to be transported to laboratories.
Additionally, NT-proBNP may be requested by the Cardiology team for the monitoring of patients on Entresto.
As per the Pan London Heart Failure Diagnostic Pathway:
NT-proBNP <400 ng/L: HF unlikely, consider alternative. Please refer to: https://www.nice.org.uk/guidance/ng106/resources/chronic-heart-failure-diagnosis-visual-summary-pdf-6663137726
NT-proBNP 400-2000 ng/L: Requires assessment by a specialist heart failure team (including an echocardiogram), should be seen within 6 weeks.
NT-proBNP >2000 ng/L: Requires assessment by a specialist heart failure team (including an echocardiogram), should be seen within 2 weeks.
For further guidance, please see the North West London pathway: https://www.healthiernorthwestlondon.nhs.uk/sites/nhsnwlondon/files/documents/heart_failure.pdf
Sample Required Serum (yellow top) so no separate sample is required
Sample Collection No special requirements. Collect in serum (yellow top)
Sample Volume 0.5ml
Turnaround Time 5 days
Notes Newly launched test - UKAS accreditation pending