There was a large body of evidence regarding the fact that apelin influenced direct inotrope, vasodilator and diuretic effects and exerted crucial cardiac and vascular protective effects against angiotensin-II- and aldosterone-induced injuries and thereby counteracted with activated renin-angiotensin-aldosterone system in HF and acute myocardial infarction [22,23,24]. Here, REN is linked to hydrops fetalis.