BNP is a polypeptide, released by ventricular myocytes
directly proportional to wall tension, for lowering reninangiotensin-aldosterone
activation. In the blood, the
cleavage of a precursor protein produces BNP and the
biologically inactive NT-proBNP. For diagnosing CHF,
both BNP and NT-proBNP have similar accuracy [36, 37]
(see Appendix 1 in the supplementary data on the journal’s
website http://www.ageing.oxfordjournals.org). However,
threshold values are higher than in middle-aged population.
A study demonstrated that the use of BNP in patients
>70 years early in the ED reduced the time to discharge,
total treatment cost, and 30-day mortality. Figure 2 shows a
diagnostic strategy based on BNP in elderly patients admitted
for ARF in the ED [38, 39]