Natriuretic Peptide Assay(BNP levels) in Heart Failure

These proteins are released by ventricular pressure or volume stimulus.
Age < 50    BNP level cut point = 450 pg/ml
Age 50-75  BNP level cut point = 900 pg/ml
Age >75     BNP level cut point = 1900 pg/ml


There are confounders to BNP as an HF test. BNP is increased in the elderly, women, those with cirrhosis or renal failure, possibly those on hormone replacement therapy, and probably those with pulmonary embolus and primary pulmonary hypertension.