RLN2 and hydrops fetalis: Regarding acute-HF, the Pre-RELAX-AHF (phase 2b study of recombinant human relaxin-2, serelaxin), RELAX-AHF (phase 3 study of serelaxin), and BLAST-AHF (phase 2b study of the biased ligand of the angiotensin 2 type 1 receptor, TRV027) studies showed that NLR was an independent predictor of 30-day all-cause mortality, 60-day HF/renal failure rehospitalizations or CV death, 180-day CV death and 180-day all-cause mortality, surpassing traditional markers, like natriuretic peptides [29].