Our findings are also consistent with those of Hofer et al. [6], who found—in a prospective study including 451 patients undergoing elective coronary artery bypass graft and/or cardiac valve surgery—that preoperative FGF23 serves as an independent predictor of cardiovascular mortality, HF hospitalization and postoperative atrial fibrillation in patients undergoing cardiac surgery. Here, FGF23 is linked to hydrops fetalis.