One study mentions the relationship between FGF23 and B-type atrial natriuretic peptide (BNP), which are associated with an increase depending on the degree of right ventricular dysfunction, only being relevant in patients who are in a severe state of HF with reduced ejection fraction, regardless of whether there is congestion in the systemic circulation or a subjective perception of congestion. Here, FGF23 is linked to hydrops fetalis.