NR3C2 and hydrops fetalis: Mineralocorticoid receptor antagonists (MRAs) have clear “IA” guideline indication for patients with a myocardial infraction (MI) and a left ventricular ejection fraction (EF) inferior to 40% if accompanied by signs and symptoms of heart failure (HF) or diabetes.1, 2 Despite the guideline recommendations, MRAs are prescribed in a small proportion of these patients.3, 4