REN and hydrops fetalis: To reduce mortality/morbidity in HF, the 2021 European Society of Cardiology (ESC) guidelines on HF provide a class I recommendation for the use of renin–angiotensin–aldosterone system inhibitors (RAASi) and angiotensin receptor–neprilysin inhibitors (ARNi), beta‐blockers, and sodium–glucose cotransporter 2 inhibitors (SGLT2i) in HF with reduced ejection fraction (HFrEF), and a IIb recommendation for RAASi/ARNi and beta‐blockers in HF with mildly reduced ejection fraction (HFmrEF).6