- Elevated BNP/NT-proBNP (NT-proBNP ≥1000 pg/mL or BNP ≥300 pg/mL in sinus rhythm, or NT-proBNP ≥1600 pg/mL or BNP ≥500 pg/mL in atrial fibrillation). Here, NPPB is linked to atrial fibrillation.