Brain natriuretic peptide

Background

  • Biologically active metabolite of proBNP (released from ventricles in response to increased volume/pressure)
  • Utility is controversial and may not affect patient centered outcomes[1]
  • May be trended to gauge treatment response in acute decompensated CHF
  • May have false negative with isolated diastolic dysfunction
  • N-terminal proBNP is a biologically inert metabolite of proBNP

Indications for Use

  • American College of Cardiology, American Heart Association, Heart Failure Society of America guidelines as of May 2017[2]
    • BNP should be measured in patients presenting with dyspnea to help diagnose or exclude heart failure
    • BNP or nt-pro-BNP should be measured to determine prognosis or disease severity in chronic heart failure
    • Baseline BNP, cardiac troponin, or both should be measured upon hospital admission to determine prognosis in patients with acutely decompensated heart failure

Interpretation

Brain natriuretic peptide (BNP)[3]

  • Measurement
    • <100 pg/mL: Negative for acute CHF (Sn 90%, NPV 89%)
    • 100-500 pg/mL: Indeterminate (Consider differential diagnosis and pre-test probability)
    • >500 pg/mL: Positive for acute CHF (Sp 87%, PPV 90%)
    • Combination of BNP with clinician judgment 94% sensitive 70% specific (compared to 49% sn and 96% spec clinical judgement alone) [4]

NT-proBNP[5][6][7]

  • <300 pg/mL → CHF unlikely
  • CHF likely in:
    • >450 pg/mL in age < 50 years old
    • >900 pg/mL in 50-75 years old
    • >1800 pg/mL in > 75 years old

Special Patient Populations

BNP In Obese Patients

  • Visceral fat expansion leads to increased clearance of active natriuretic peptides[8]
  • Obese patients also frequently treated for hypertension or coronary artery disease which may also contribute to lower BNP levels

Interpretation

  • In one study of 204 patients with acute CHF, an inverse relationship between BMI and BNP was noted. The standard cutoff of 100pg/mL resulted in a 20% false-negative rate[9]
  • Analysis of a subgroup of patients with documented BMI from the Breathing Not Properly study showed that a lower cutoff was more appropriate to maintain 90% sensitivity in obese and morbidly obese patients (54pg/mL)[10]

Differential Diagnosis

Elevated BNP

See Also

External Links

References

  1. Carpenter CR et al. BRAIN NATRIURETIC PEPTIDE IN THE EVALUATION OF EMERGENCY DEPARTMENT DYSPNEA: IS THERE A ROLE? J Emerg Med. 2012 Feb; 42(2): 197–205.
  2. Yancy CW et al. 2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure.
  3. Maisel AS, Krishnaswamy P, Nowak RM, et al. Rapid measurement of B-type natriuretic peptide in the emergency diagnosis of heart failure. N Engl J Med. 2002;347(3):161-167. doi:10.1056/NEJMoa020233.
  4. McCullough et al. B-Type natriuretic peptide and clinical judgment in emergency diagnosis of heart failure: analysis from breathing not properly (BNP) multinational study. Circulation. 2002:DOI: 10.1161/01.CIR.0000025242.79963.4
  5. Januzzi JL, van Kimmenade R, Lainchbury J, et al. NT-proBNP testing for diagnosis and short-term prognosis in acute destabilized heart failure: an international pooled analysis of 1256 patients: the International Collaborative of NT-proBNP Study. Eur Heart J. 2006 Feb. 27(3):330-7.
  6. Kragelund C, Gronning B, Kober L, Hildebrandt P, Steffensen R. N-terminal pro-B-type natriuretic peptide and long-term mortality in stable coronary heart disease. N Engl J Med. 2005 Feb 17. 352(7):666-75.
  7. Moe GW, Howlett J, Januzzi JL, Zowall H,. N-terminal pro-B-type natriuretic peptide testing improves the management of patients with suspected acute heart failure: primary results of the Canadian prospective randomized multicenter IMPROVE-CHF study. Circulation. 2007 Jun 19. 115(24):3103-10.
  8. Clerico A, Giannoni A, Vittorini S, Emdin M. The paradox of low BNP levels in obesity. Heart Fail Rev. 2011;17(1):81-96. doi:10.1007/s10741-011-9249-z.
  9. Krauser DG, Lloyd-Jones DM, Chae CU, et al. Effect of body mass index on natriuretic peptide levels in patients with acute congestive heart failure: A ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) substudy. Am Heart J. 2005;149(4):744-750. doi:10.1016/j.ahj.2004.07.010.
  10. Daniels LB, Clopton P, Bhalla V, et al. How obesity affects the cut-points for B-type natriuretic peptide in the diagnosis of acute heart failure. Results from the Breathing Not Properly Multinational Study. Am Heart J. 2006;151(5):999-1005. doi:10.1016/j.ahj.2005.10.011.
  11. Nikolaos I. Nikolaou, Constantin Goritsas, Maria Dede, Nikolaos P. Paissios, Michalis Papavasileiou, Amalia T. Rombola, Angeliki Ferti, Brain natriuretic peptide increases in septic patients without severe sepsis or shock, European Journal of Internal Medicine, Volume 18, Issue 7, 2007, Pages 535-541, ISSN 0953-6205, https://doi.org/10.1016/j.ejim.2007.01.006.
  12. Radvan M, Svoboda P, Radvanová J, Stumar J, Scheer P. Brain natriuretic peptide in decompensation of liver cirrhosis in non-cardiac patients. Hepatogastroenterology. 2009;56(89):181-185.