Considering the central role of the renin-angiotensin-aldosterone system and the sympathetic nervous system in HF with reduced HFrEF, angiotensin-converting enzyme inhibitors (ACEIs) [6,7] or angiotensin II receptor blockers (ARBs) [8,9], β-blockers [10,11], and mineralocorticoid receptor antagonists (MRAs) [12,13] are administered for such patients; these are Class I, evidence level A recommended drugs that improve the life prognosis of HFrEF patients [1]. Here, REN is linked to hydrops fetalis.