October 27, 2023

NT proBNP – Warde Medical Laboratory (wardelab.com)

NT-ProBNP is the pro-hormone form of BNP (brain natriuretic peptide); BNP is secreted from cardiac atria and ventricles as a response to increased wall tension, and has therefore served as a marker for heart failure or left ventricular dysfunction (symptomatic or asymptomatic). Initial studies showed that measuring the N-terminal pro-hormone form (NT-ProBNP) offered a more accurate separation of patients with normal versus impaired left ventricular ejection fraction than BNP (Bay et al., Heart 2003 89(2): 1504). Evidence-based risk scoring systems for heart failure show improved performance with addition of either BNP or NT-ProBNP in calculations (Khanam et al., PLOS One 2018 13(11): e0206380). 

Indications for use of the Roche electrochemiluminescence immunoassay for NT-ProBNP include the following:

-Aid in the diagnosis of acute decompensated heart failure in patients presenting to the emergency department with signs and symptoms characteristic of the disease.

-Risk stratification of patients with acute coronary syndrome and congestive heart failure.

-Aid in assessment of increased risk of cardiovascular events and mortality in stable coronary artery disease patients at risk for heart failure.

NT-ProBNP has a longer half-life than BNP, and is thus more reflective of mean left ventricular filling pressure over the preceding several hours; in contrast, BNP may be more influenced by acute hemodynamic variation. A major difference between the two assays, favoring NT-ProBNP, is in the first 8 to 10 weeks after initiation of sacubitril/valsartan therapy. Neprilysin inhibition affects BNP as a substrate, but not NT-ProBNP (which is not itself a neprilysin substrate). Measurable BNP increases may be seen early in sacubitril/valsartan therapy, with the potential for clinical confusion if the rightward shift in BNP distribution is not accounted for by ordering providers. As such, NT-ProBNP offers an advantage over BNP in the setting of early sacubirtil/valsartan use, though either biomarker is predictive of adverse outcomes in patients with long-term use of angiotensin receptor-neprilysin inhibitor drugs (Mhyre et al., J Am Coll Cardiol 2019 73(11): 1264-72).