- Cardiac neurohormone released from ventricles in response to increased volume/pressure
- Biologically active metabolite of proBNP
- <100 pg/mL CHF ruled out (Sn 90%, NPV 89%)
- 100-500: Consider differential diagnosis and pre-test probability
- > 500 Positive (CHF Sp 87%, PPV 90%)
- N-terminal proBNP
- Biologically inert metabolite of proBNP
- < 300 ng/mL, CHF unlikely
- CHF likely in:
- > 450 pg/mL in age < 50 years old
- > 900 in 50-75 years old
- > 1800 in > 75 years old
Differential Diagnosis (Elevated BNP)
BNP In Obese Patients
- Visceral fat expansion leads to increased clearance of active natriuretic peptides
- Obese patients frequently co-treated for hypertension or coronary artery disease which may also contribute to lower NP levels
- 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
- 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)
May have false negatives with diastolic dysfunction
↑ 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.
↑ 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.
↑ 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.
↑ 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.
↑ 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.
↑ 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.
↑ 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.
- Obtaining BNP value may not add anything to patient centered outcomes
- May be used to gauge treatment response in acute decompensated CHF