The N-terminal prohormone of brain natriuretic peptide (NT-proBNP or BNPT) is a
prohormone with a 76 amino acid
N-terminal inactive protein that is cleaved from the molecule to release
brain natriuretic peptide 32 (BNP, also known as B-type natriuretic peptide).
Both BNP and NT-proBNP levels in the blood are used for screening, diagnosis of acute
congestive heart failure (CHF) and may be useful to establish prognosis in heart failure, as both markers are typically higher in patients with worse outcome.[1] The plasma concentrations of both BNP and NT-proBNP are also typically increased in patients with asymptomatic or symptomatic left ventricular dysfunction and is associated with
coronary artery disease,
myocardial ischemia, and severity of
aortic valve stenosis.[2][3][4][5][6][7]
There is no level of BNP that perfectly separates patients with and without heart failure.[10]
In screening for
congenital heart disease in pediatric patients, an NT-proBNP cut-off value of 91 pg/mL could differentiate an
acyanotic heart disease (ACNHD) patient from a healthy patient with a
sensitivity of 84% and
specificity of 42%.[11] On the other hand, an NT-proBNP cut-off value of 318 pg/mL is more appropriate in differing patients with
congenital nonspherocytic hemolytic disease (CNHD) from healthy patients, with 94% sensitivity and 97% specificity.[11] An NT-proBNP value of 408 pg/mL has been estimated to be 83% sensitive and 57% specific in differentiating patients with ACNHD from patients with CNHD.[11] In patients with non-severe asymptomatic aortic valve stenosis, increased age- and sex adjusted NT-proBNP levels alone and combined with a 50% or greater increase from baseline had been found associated with increased event rates of
aortic valve stenosis related events (
cardiovascular death, hospitalization with
heart failure due to progression of aortic valve stenosis, or
aortic valve replacement surgery).[12] In severe
aortic valve stenosis, NT-proBNP provide important prognostic information beyond clinical and
echocardiographic evaluation.[13]
Test usage in a clinical setting
Canada
While discussed in Canadian medical journals in the mid to late 2000s,[14] the test is not widely used. It was only approved for use in
Alberta in February 2012.[15]
Test usage in the life insurance industry
The test has been widely used in the
life insurance industry to screen applicants as part of the routine requirements when applying for a life insurance policy. It is also inexpensive and can be measured from blood samples routinely drawn as part of the application process. The test can be used to evaluate for a number of health conditions.[7][16][17]
^Atisha D, Bhalla MA, Morrison LK, Felicio L, Clopton P, Gardetto N, et al. (September 2004). "A prospective study in search of an optimal B-natriuretic peptide level to screen patients for cardiac dysfunction". American Heart Journal. 148 (3): 518–523.
doi:
10.1016/j.ahj.2004.03.014.
PMID15389242.
^"N-terminal-pro-BNP". LABORATORY SERVICES HANDBOOK. The University of Iowa (UIHC), Department of Pathology. 28 May 2020.
Archived from the original on 2008-10-11. Showing 95th percentiles. Epic Lab Code: LAB649.
^Clark M, Kaufman V, Fulks M, Dolan VF, Stout RL (2014). "NT-proBNP as a predictor of all-cause mortality in a population of insurance applicants". Journal of Insurance Medicine. 44 (1): 7–16.
PMID25004594.