Differences between BNP and NT-proBNP on a biological level really relate to the fact that one is biologically active as a hormone, BNP, whereas NT-proBNP is cleared passively from the body and is not biologically active.
Therefore, BNP has a much shorter half-life, NT-proBNP has a longer half-life. NT-proBNP, as a consequence, circulates in higher concentrations in the bloodstream, which means, therefore, it’s more likely to be more sensitive for detecting earlier forms of heart failure because it circulates at somewhat higher levels.
When looked at with respect to their diagnostic and prognostic abilities, they are largely similar. But I would say that when we look at the value of these markers for managing patients, for therapy monitoring, clearly NT-proBNP has substantially more data behind its use.
Furthermore, with the emergence of newer therapies for heart failure, in particular the ARNi class of heart failure therapeutics, this class of drugs affects BNP concentrations in that it blocks the breakdown of BNP, which means that concentrations of BNP will rise substantially in patients treated with ARNis, whereas, NT-proBNP values are not affected.
