- N-terminal brain natriuretic peptide
- Pro-BNP
- NTpBNP
- proBNP
- Plastic lavender top tube
- 4 mL of venous blood
Additional information on specimen collection:
- Reject:
- Non-EDTA plasma specimen
- EDTA plasma collected in glass tubes
- Specimen that has undergone hemolysis
- 8 hrs of fasting before the test (if possible)
- Specimen should be handled gently, sent to the lab immediately, and frozen immediately until tested
- This test is a measure of the concentration of NT-proBNP in the blood
- Pre-proBNP, a precursor, is cleaved by protease resulting in two peptides – signal peptide and proBNP. Further processing of the prohormone proBNP by the enzyme furin results in BNP and NT-proBNP, and release into the blood circulation in equimolar concentration
- NT-proBNP is a cardiac neurohormonal peptide co-secreted with B-type natriuretic peptide, primarily by the cardiac myocytes of the left ventricle, and to a lesser extent, of the left atrium
- NT-proBNP is released into thecirculation in response to increased myocardial stretch andwall tension. It produces vasodilatation, natriuresis, and inhibitionof the renin–angiotensin and sympathetic nervous systems, similar to the effects of BNP
- NT-proBNP has a longer half life than BNP
Clinically, the NT-proBNP test is useful in:
- Confirming the diagnosis of heart failure
- Monitoring prognosis of therapy in patients with heart failure
- Aids in the disease diagnosis and therapy monitoring of the patients with heart failure
- Detection of acute right ventricularstrain caused by pulmonary embolism (PE)
- As a short-term estimation of risk for mortality in acute congestive heart failure
- Useful as a biomarker of cardiovascular risk, even in the absence of clinical evidence indicating cardiovascular disease
- Predicts the risk of
- Congestive heart failure
- Atrial fibrillation
- Stroke
- Transient ischemic attack
Additional information:
- NT-proBNP levels in the blood increase in proportion to severity of heart failure
- NT-proBNP is detectable even with minimal clinical symptoms
- NT-proBNP regulates blood pressure and fluid balance by counter-balancing the renin-angiotensin system
- Women have slightly higher NT-proBNP levels than men
- NT-proBNP level increases with the age of the person
- A rising NT-proBNP level suggests a higher risk for adverse outcomes and suggests need for more aggressive therapy
- Renal failure patients often have chronically elevated levels of BNP and NT-proBNP (especially NT-proBNP as this is primarily renally excreted); Comparison of baseline level to current level is useful in determining fluid overload states
- Drugs interfering with the test results, include:
- Cardiac glycosides
- Diuretics
Consult your laboratory for their normal ranges as these may vary somewhat from the ones listed below.
Assays significantly vary in their normal ranges; and a high or normal result based upon the assay being utilized is required.
One common assay, which reports results in pmol/L another reports in pg/mL.
pmol/L results:
<357 pmol/L (negatively predictive of LV dysfunction/CHF in 98%)
pg/mL results:
- Males
- 45-59 yrs: <82 pg/mL
- >60 yrs: <143 pg/mL
- Females
- 45-59 yrs: <145 pg/mL
- >60 yrs: <195 pg/mL
Conditions associated with elevated NT-proBNP levels include:
- Ascites (Hepatic cirrhosis)
- Heart failure
- Cardiac inflammation
- Cardiac allograft rejection
- Myocarditis
- Endocrine disorders
- Cushing's syndrome
- Primary hyperaldosteronism
- Hypertrophic or dilated cardiomyopathy
- Kawasaki's disease
- Myocardial infarction
- Pregnancy
- Pulmonary embolus
- Pulmonary hypertension
- Renal failure (NT-proBNP renally excreted)
- Tachycaarrhythmias
- Valvular disease (Mitral or aortic stenosis)
- Ventricular dysfunction or hypertrophy
- Alibay Y et al. Plasma N-terminal pro-brain natriuretic peptide and brain natriuretic peptide in assessment of acute dyspnea. Biomed Pharmacother. 2005 Jan-Feb;59(1-2):20-4. Epub 2005 Jan 20.
- Cameron SJ et al. Cardiac Biomarkers in Renal Disease: The Fog Is Slowly Lifting. Clinical Chemistry. 2004; 50:2233-2235.
- Galasko GIW et al. What is the normal range for N-terminal pro-brain natriuretic peptide? How well does this normal range screen for cardiovascular disease? Eur Heart J. 2005 Nov;26(21):2269-76. Epub 2005 Jul 21.
- Hess G et al N-terminal pro-brain natriuretic peptide (NT-proBNP) in healthy blood donors and in patients from general practitioners with and without a diagnosis of cardiac disease. Clin Lab. 2005;51(3-4):167-72.
- Lab Tests Online®. BNP and NT-proBNO. [Homepage on the Internet] ©2001-2006.Last reviewed onSeptember 2, 2005. Last accessed on November 3, 2006. Available at URL: http://www.labtestsonline.org/understanding/analytes/bnp/sample.html
- Schwachtgen L et al. Reference values of NT-proBNP serum concentrations in the umbilical cord blood and in healthy neonates and children. Z Kardiol. 2005 Jun;94(6):399-404.
- Vanderheyden M et al. Head to head comparison of N-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide in patients with/without left ventricular systolic dysfunction. Clin Biochem. 2006 Jun;39(6):640-5. Epub 2006 Mar 3.