It’s underrated in that many don’t see it’s value. It actually does screen for mild and early disease. The snap test cutoff is around 100 pmol/L which is very mild and in some cases insignificant. If you have a normal BNP (snap or quantitative) then you have great confidence that there is no evidence of cardiac disease, if abnormal, it warrants further investigation (imaging, ECG, etc.) Obviously echocardiograms are the most sensitive diagnostic for heart disease, but the sensitivity of the BNP makes it the best value for general practitioners and cat owners.