NPPB and obesity due to melanocortin 4 receptor deficiency: The performance of MR-proANP in the diagnosis of AHF was slightly lower than that of proBNP, BNP, and NT-proBNP in one study [40] but, in another report, demonstrated non-inferiority to BNP and improved diagnostic accuracy in the BNP “gray zone” (BNP levels 100–500 pg/mL) and in patients with obesity [41].