NPPB and heart failure: On the other hand, although a number of heart failure diagnostic guidelines recommend incorporating natriuretic peptides (BNP/NT-proBNP) into the diagnostic pathways [2,4,5,6], prior studies indicated that up to about 30% of patients with HFpEF may have normal BNP values despite the presence of symptoms, echocardiographic abnormalities, and evidence derived from invasive hemodynamic procedures (e.g., elevated filling pressures) [5,29,30].