BNP stands for Brain-type Natriuretic Peptide (BNP). It’s made in the heart and has nothing to do with the brain, just that the molecule resembles one in the brain (hence “brain-type“). The test was invented around 2005 and is a quick, easy way to decide if a patient might have Heart Failure. Normal is <100 pg/ml, >200 is probably abnormal, >400 definitely so. Before its availability, we had to order echocardiograms, which are much more useful, but take time to schedule. Also, changes in the value can reflect response to treatment, or worsening disease.
There’s a very similar test called the N-terminal prohormone-B-type Natriuretic Peptide, abbreviated “NT-pro-BNP” or something close. The only difference is that the latter has different normal values, which are higher than those for the BNP. The Cleveland Clinic interprets NT-pro-BNP as normal if <125 for patients <75 years-old; and if <450 for those over 75. However, many laboratories may have higher ranges.
- BNP and NT-pro-BNP both mean exactly the same thing: high values suggest Heart Failure, although results may be elevated in kidney disease and some other conditions.
- These tests are very convenient for rapid assessment of Heart Failure, and determining if treatment is working.
- For any lab test at all, “normal” almost always depends on the ranges given by each individual lab.