FGF23 and hydrops fetalis: At the 3-year observation, patients in Tertile 3, who presented the highest percentage increase in FGF-23 and sαKlotho levels between admission and discharge, had a 2-fold higher risk of all-cause mortality and rehospitalization for HF than patients in Tertiles 1 and 2, with a hazard ratio (HR) of 2.75 (95% CI, 1.19–6.35), p = 0.02 (Figure 2A).