NT-proBNP

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is the biologically inactive N-terminal fragment cleaved from proBNP when cardiomyocytes are stretched by elevated ventricular wall stress or volume overload. It has a longer half-life (~60–120 minutes) than BNP itself, making it analytically more stable. NT-proBNP is a central diagnostic and prognostic biomarker for heart failure: in non-acute settings, a value above 125 pg/mL is widely used as a rule-out threshold, while 2023 ESC HFA guidance recommends age-stratified rule-in thresholds for the non-acute / community setting (125 pg/mL for age <50, 250 pg/mL for 50–74 years, and 500 pg/mL for ≥75 years; acute-setting rule-in thresholds — 450/900/1800 pg/mL — are higher). Beyond established heart failure, modestly elevated NT-proBNP in community populations is independently associated with atrial fibrillation, coronary artery disease, chronic kidney disease, and all-cause mortality, so it is increasingly used as a subclinical cardiac stress marker in longevity assessments.