NT-proBNP
What it measures, and what changes the number.
NT-proBNP (N-terminal pro B-type natriuretic peptide) is a protein fragment released by heart muscle cells, mainly in the ventricles, when the heart walls are stretched. When the precursor molecule is split, it produces active BNP and this inactive fragment, which stays in the blood longer and is easier to measure.
It is often read alongside kidney function tests such as creatinine and eGFR, because the kidneys help clear it from the blood, and sometimes with high sensitivity troponin, which reflects a different aspect of heart muscle health. Labs take age and sex into account when reporting it.
NT-proBNP is fairly stable in the sample and fasting is not required. Results differ between assay manufacturers, and NT-proBNP and BNP are separate tests whose numbers cannot be compared directly. Labs may print it as NT pro-BNP.
Often read alongside: Troponin I (hs), Creatinine, eGFR (CKD-EPI)