Brain natriuretic peptide
In medicine, brain natriuretic peptide (BNP), also called B-Type natriuretic peptide, is a "peptide that is secreted by the brain and the heart atria, stored mainly in cardiac ventricular myocardium. It can cause natriuresis; diuresis; vasodilation; and inhibits secretion of renin and aldosterone. It improves heart function. It contains 32 amino acids."[1]
BNP is one member or a family of closely related peptides called "natriuretic peptides" because of their ability to stimulate sodium excretion (natriuresis). Natriuretic peptides are functional antagonists to the renin-angiotensin-aldosterone system. BNP was given its name because it was first discovered in the porcine brain. [2] However, confusingly, there appears to be relatively little BNP expressed in the brain compared to atrial natriuretic peptide [3] A related peptide is N-terminal pro-B-type natriuretic peptide.
An elevated concentration of BNP in the circulation can detect heart failure:[4]
Test accuracy
| Sensitivity | Specificity | |
|---|---|---|
| BNP > 100 pg per milliliter | 90% | 76% |
| BNP > 50 pg per milliliter | 97% | 62% |
The optimal level to exclude heart failure may depend on the clinical setting.[5]
A value over 500 pg per milliliter is proposed to indicate that heart failure is likely[6]; however, the accuracy of that value is not certain.
Effect on clinical decision making
Providing physicians quick access to BNP results may[7] or may not[6] improve the emergency evaluation of dyspnea.
Clinical practice guidelines
Clinical practice guidelines state regarding the BNP and NT-proBNP:[8]
- "Measurement of natriuretic peptides (BNP and NT-proBNP) can be useful in the evaluation of patients presenting in the urgent care setting in whom the clinical diagnosis of HF is uncertain. Measurement of natriuretic peptides (BNP and NT-proBNP) can be helpful in risk stratification."
References
- ↑ Anonymous (2024), Brain natriuretic peptide (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Baxter GF (2004) The natriuretic peptides. Basic Res Cardiol 99:71-5. PMID 14963664
- ↑ Langub MC et al. (1995) Distribution of natriuretic peptide precursor mRNAs in the rat brain. J Comp Neurol 356:183-99. PMID 7629314
- ↑ 4.0 4.1 Maisel AS, Krishnaswamy P, Nowak RM, et al (July 2002). "Rapid measurement of B-type natriuretic peptide in the emergency diagnosis of heart failure". N Engl J Med 347: 161–7. DOI:10.1056/NEJMoa020233. PMID 12124404. Research Blogging.
- ↑ Rogers RK, Stoddard GJ, Greene T, Michaels AD, Fernandez G, Freeman A et al. (2009). "Usefulness of adjusting for clinical covariates to improve the ability of B-type natriuretic peptide to distinguish cardiac from noncardiac dyspnea.". Am J Cardiol 104 (5): 689-94. DOI:10.1016/j.amjcard.2009.04.043. PMID 19699346. Research Blogging.
- ↑ 6.0 6.1 Schneider HG, Lam L, Lokuge A, et al. (March 2009). "B-type natriuretic peptide testing, clinical outcomes, and health services use in emergency department patients with dyspnea: a randomized trial". Ann. Intern. Med. 150 (6): 365–71. PMID 19293069. [e]
- ↑ Mueller C, Scholer A, Laule-Kilian K, et al. (February 2004). "Use of B-type natriuretic peptide in the evaluation and management of acute dyspnea". N. Engl. J. Med. 350 (7): 647–54. DOI:10.1056/NEJMoa031681. PMID 14960741. Research Blogging.
- ↑ Hunt SA, Abraham WT, Chin MH, Feldman AM, Francis GS, Ganiats TG et al. (2009). "2009 focused update incorporated into the ACC/AHA 2005 Guidelines for the Diagnosis and Management of Heart Failure in Adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the International Society for Heart and Lung Transplantation.". Circulation 119 (14): e391-479. DOI:10.1161/CIRCULATIONAHA.109.192065. PMID 19324966. Research Blogging.