What is NT-proBNP?
NT-proBNP (N-terminal pro-brain B-type natriuretic peptide) is a signalling molecule produced by heart cells.1
Strained heart cells in patients with heart failure typically produce higher levels of NT-proBNP in the blood than heart cells in healthy individuals, making it an excellent biomarker for the disease.1–3
The data supporting the test are such that it is recommended by the ESC and NICE.3,4
How to interpret test results
If NT-proBNP levels are ≥400 ng/L, the patient should be referred to a cardiologist for assessment and diagnosis.4,5
Referral recommendations in the UK4,5
Special populations
For some special patient groups, it might not be appropriate to use the standard thresholds because other factors may be influencing their NT-proBNP level.2,6
Two of the most powerful confounders of NT-proBNP levels are renal function and obesity.2,6,7
Renal function2,6,7
- Chronic or acute kidney disease can lead to elevated NT-proBNP levels
- NT-proBNP thresholds may need to be raised when eGFR is <60 mL/min
Obesity2,6
- People with a BMI ≥30 kg/m2 may have disproportionally lower NT-proBNP levels than those with a lower BMI
- NT-proBNP thresholds should be lowered by about 50% in obese patients
Helpful information for the referral
If NT-proBNP levels are above the threshold for referral, ≥400 ng/L, the patient should be referred to a cardiologist for assessment and diagnosis.2–5
Consider including the following information in the referral8
Patient details
Patient history
Current medication(s)
Blood pressure
Pulse
BMI
Breathlessness
Fatigue
Swollen ankles
NT-proBNP
ECG
Chest x-ray
Other blood test results (e.g. full blood count, albumin, urea and electrolytes, thyroid function)
Who should be referred?
Robert
Age : 68
Gender : Male
Height : 180 cm
Weight : 90 kg
Pre-existing conditions:
High cholesterol
NT-proBNP levels:
520 ng/L
Should Robert be referred to a cardiologist based on his NT-proBNP
levels and the information provided?
Explanation:4,5
An NT-proBNP level of 520 ng/L is above the UK threshold for referral, ≥400 ng/L. Robert should be seen within 6 weeks.
For further information, see the Test and refer page
Patricia
Age : 87
Gender : Female
Height : 157 cm
Weight : 68 kg
Pre-existing conditions:
Cancer
Osteoporosis
Mobility issues
NT-proBNP levels:
2030 ng/L
Should Patricia be referred to a cardiologist based on her NT-proBNP levels and the information provided?
Explanation:4,5
An NT-proBNP level of 2030 ng/L is above the the UK threshold for urgent referral, 2000 ng/L.
Patricia should be seen urgently, within 2 weeks.
For further information, see the Test and refer page
Mary
Age : 79
Gender : Female
Height : 155 cm
Weight : 71 kg
Pre-existing conditions:
Hypertension
Diabetes
High cholesterol
NT-proBNP levels:
456 ng/L
Should Mary be referred to a cardiologist based on her NT-proBNP levels and the information provided?
Explanation:4,5
An NT-proBNP level of 456 ng/L is above the UK threshold for referral, ≥400 ng/L.
Mary should be seen within 6 weeks.
For further information, see the Test and refer page
The patient profiles displayed in this material are hypothetical.
BMI, body mass index; ECG, electrocardiogram; eGFR, estimated glomerular filtration rate; ESC, European Society of Cardiology; NICE, National Institute for Health and Care Excellence; NT-proBNP, N-terminal pro-B-type natriuretic peptide; SIGN, Scottish Intercollegiate Guidelines Network.
References
1. Doust J, et al. Am Fam Physician. 2006;74:1893–1898. 2. Heindenreich PA et al. JACC. 2022;79:e263–e421. 3. McDonagh TA, et al. Eur Heart J. 2021;42:3599–3726. 4. National Institute for Health and Care Excellence (NICE). Chronic heart failure in adults: diagnosis and management. 2018. Available at: www.nice.org.uk/guidance/ng106 (accessed September 2023). 5. Scottish Intercollegiate Guidelines Network (SIGN). Management of chronic heart failure. 2016. Available at: https://www.sign.ac.uk/assets/sign147.pdf (accessed September 2023). 6. Mueller C, et al. Eur J Heart Fail. 2019;21:715–731. 7. Charmetant X, et al. Clin Nephrol. 2019;92:65–72. 8. Data on file. REF-200932