This prospective observational pilot study was designed to assess the combined diagnostic and prognostic accuracy of sST2 plasma markers, such as highly sensitive C-Reactive Protein (CRP), N-terminal pro–B-type natriuretic peptide (NT-ProBNP), PCT and mid-regional pro-adrenomedullin (MR-proADM), in patients diagnosed with AHF or sepsis/septic shock. This evidence concerns the gene NPPB and Sepsis.