Drug treatment that increases survival and decreases HF decompensations and hospital admissions is suboptimally prescribed in HF patients with severe kidney function impairment, despite current strong evidence showing the benefits of many of these drugs (renin–angiotensin–aldosterone inhibitors, β-blockers, neprilysin inhibitors and mineralocorticoid receptor antagonists) [11,12,13,14], mainly due to concerns about renal function worsening and hyperkalemia [11,12]. This evidence concerns the gene MME and hydrops fetalis.