NT-proBNP
Overview
NT-proBNP measures the inactive N-terminal fragment of pro-brain natriuretic peptide, released from cardiac ventricular myocytes in response to volume expansion and pressure overload. This peptide counterregulates the renin-angiotensin-aldosterone system by promoting natriuresis, diuresis, and vasodilation while inhibiting cardiac fibrosis. Elevated levels indicate heart failure, cardiac strain, or myocardial injury; low levels effectively rule out acute heart failure in symptomatic patients. Clinically, NT-proBNP testing provides rapid diagnosis, risk stratification, and therapy monitoring in heart failure management.
Clinical Use Cases
- Diagnosing acute decompensated heart failure in dyspneic emergency department patients.
- Risk stratification in chronic heart failure and post-myocardial infarction.
- Guiding diuretic and neurohormonal therapy titration.
- Prognostication in cardiovascular disease and critical illness.
Specimen Types
- Plasma (EDTA preferred).
- Serum (less common).
Measurement Methods
- Chemiluminescent microparticle immunoassay.
- Electrochemiluminescent immunoassay.
- Point-of-care fluorescence immunoassay.
Test Preparation and Influencing Factors
- No fasting required; stable at room temperature for 24-48 hours.
- Obesity, atrial fibrillation, and renal impairment elevate NT-proBNP.
- Age >75 years requires higher diagnostic cutoffs.
- SGLT2 inhibitors and sacubitril/valsartan lower NT-proBNP levels.
Synonyms
- N-terminal pro-B-type natriuretic peptide.
- NT-proBNP.