At a Glance
Why Get Tested?
To help detect, diagnose, and evaluate the severity of congestive heart failure (CHF)
When to Get Tested?
When you have symptoms of heart failure, such as shortness of breath and fatigue, or when you are being treated for CHF
A blood sample drawn from a vein in your arm
Test Preparation Needed?
The Test Sample
What is being tested?
These tests measure the concentration of B-type natriuretic peptide (BNP) or N-terminal pro b-type natriuretic peptide (NT-proBNP) in the blood in order to detect and evaluate heart failure. BNP was initially called brain natriuretic peptide because it was first found in brain tissue (and to distinguish it from a similar protein made in the atria, or upper chambers, of the heart, termed ANP). BNP is actually produced primarily by the left ventricle of the heart (the heart's main pumping chamber). It is associated with blood volume and pressure and with the work that the heart must do in pumping blood throughout the body. Small amounts of a precursor protein, pro-BNP, are continuously produced by the heart. Pro-BNP is then cleaved to release the active hormone BNP and an inactive fragment, NT-proBNP, into the blood.
When the left ventricle of the heart is stretched, the concentrations of BNP and NT-proBNP produced can increase markedly. This situation indicates that the heart is working harder and having more trouble meeting the body's demands. This may occur with heart failure as well as with other diseases that affect the heart and circulatory system. Heart failure is a somewhat misleading term. It does not mean that the heart has stopped working; it just means that it is not pumping blood as effectively as it should be. BNP or NT-proBNP concentrations will reflect this diminished capacity.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
Sources Used in Current Review
(Updated 2010 January 1). What is Heart Failure? National Heart Lung and Blood Institute [On-line information]. Available online at http://www.nhlbi.nih.gov/health/health-topics/topics/hf/ through http://www.nhlbi.nih.gov. Accessed November 2011.
Lehman, C. et. al. (Revised 2011 March). Heart Failure. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/HeartFailure.html?client_ID=LTD through http://www.arupconsult.com. Accessed November 2011.
(© 1995-2011). Test ID: BNP83873 B-Type Natriuretic Peptide (BNP), Plasma. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/83873 through http://www.mayomedicallaboratories.com. Accessed November 2011.
(© 1995-2011). Test ID: PBNP84291 NT-Pro B-Type Natriuretic Peptide (BNP), Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/84291 through http://www.mayomedicallaboratories.com. Accessed November 2011.
Malcolm, J. and Arnold, O. (Revised 2010 January) Heart Failure (HF) (Congestive Heart Failure). Merck Manual for Healthcare Professionals. [On-line information]. Available online at http://www.merckmanuals.com/professional/cardiovascular_disorders/heart_failure/heart_failure_hf.html?qt=BNP&alt=sh through http://www.merckmanuals.com. Accessed November 2011.
Pagana, K. D. & Pagana, T. J. (© 2011). Mosby's Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 690-692.
Sources Used in Previous Reviews
Interview with Alan H.B. Wu, PhD. Director, Clinical Chemistry, Hartford Hospital, Hartford, CT.
"First Blood Test for Congestive Heart Failure Wins FDA Clearance." Clinical Laboratory Strategies, December 2000, Vol. 5, No. 12, Pg.1.
Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].
Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.
Tang, W. (2004 February 27). NACB: Recommendations for the use of Cardiac Biomarkers in Heart Failure. NACB: Recommendations for the use of Cardiac Biomarkers in Heart Failure – Chapter 2 [Draft Guidelines]. Available online at http://www.nacb.org/lmpg/biomark/card_biomarkers_chp2.doc through http://www.nacb.org.
Bay, M. et. al. (2003). NT-proBNP: a new diagnostic screening tool to differentiate between patients with normal and reduced left ventricular systolic function. Heart ONLINE Heart 2003;89:150-154 [On-line journal]. Available online at http://heart.bmjjournals.com/cgi/content/full/89/2/150 through http://heart.bmjjournals.com.
Diagnostic Products Corporation Acquires Nonexclusive Rights to a Key Cardiac Marker, NT-proBNP, from Roche Diagnostics—Agreement widens access to unique marker for heart failure and allows for better/earlier/improved therapy. (2004 February 11) DPC [On-line press release]. Available online at http://www.dpcweb.com/newsreleases/2004/february/ntprobnp.htm through http://www.dpcweb.com.
Roche Receives FDA Clearance for Elecsys proBNP Assay – First Automated Blood Test to Aid in the Diagnosis of Congestive Heart Failure (2002). Roche Diagnostics [On-line press release]. Available online at http://www.roche-diagnostics.com/press_lounge/press_releases/archive/2002_11_20.html through http://www.roche-diagnostics.com.
Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Burtis CA, Ashwood ER, Bruns DE, eds. St. Louis: Elsevier Saunders; 2006 Pp. 1630-1631.
Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry. AACC Press, Washington, DC; Pg. 264.
deFilippi C. Natriuretic Peptides for Diagnosing Heart Failure and Beyond: What We Know in 2007. (May 24, 2007) Medscape Today. Available online at http://www.medscape.com/viewarticle/557030 through http://www.medscape.com. Accessed September 2008.
Maher KO et al. B-type natriuretic peptide in the emergency diagnosis of critical heart disease in children. Pediatrics 2008 Jun; 121:e1484. Available online at http://pediatrics.aappublications.org/cgi/content/full/121/6/e1484?linkType=FULL&journalCode=pediatrics&resid=121/6/e1484 through http://pediatrics.aappublications.org. Accessed September 2008.