RLN2 and hydrops fetalis: Conversely, negative transcardiac gradient and relaxin-2 extraction were reported during moderate CHF in patients undergoing coronary artery bypass grafting surgery but with no HF and preserved left ventricle ejection fraction (LVEF), and in non-failing hearts, which suggests that the participation of the heart in circulating relaxin-2 differs according to the presence or absence of heart disease [70,96].