ACE and hydrops fetalis: Accordingly, most of the agents that block the activation of these systems are part of the current HF therapeutic armamentarium [i.e. β-blockers, Angiotensin II receptor (AT1R) blockers, ACE inhibitors, and MR antagonists] (Cannavo et al., 2013; D’Addio et al., 2017; Komici et al., 2017).