In patients with hyperkalemia, education regarding a low potassium diet should be provided. In addition, newer potassium binders (patiromer and sodium zirconium cyclosilicate) are now approved by the Food and Drug Administration and may be considered; however, more data are needed regarding use of such agents in patients with HFrEF, as their use has not been shown to increase GDMT use or have an impact on outcomes in patients. Additionally, these agents raise concerns in terms of cost/ access and their contribution to polypharmacy. A trial examining whether a strategy of potassium binding will potentiate GDMT prescription and improve HFrEF Maddox et al. J outcomes is ongoing, and more data may be available in the future. For patients with established renal disease, caution may be necessary when starting GDMT. In patients with ), no adjustment is needed when deciding the starting dose of the ARNI sacubitril/valsar- tan. In those with severe renal impairment (eGFR <30 mL/ ), the starting dose of sacubitril/valsartan should be reduced to 24/26 mg twice daily (Table 4). ACEIs/ARBs are generally considered safe in patients with severe renal impairment, although de nitive data are lacking. Aldosterone antagonists are contraindicated in patients with severe renal impairment (eGFR <30 mL/ , or creatinine >2.5 mg/dL in men or creati- nine >2 mg/dL in women) or with potassium >5.0 mEq/L (Figure 2). Renal function and potassium should be assessed within 1 to 2 weeks after initiation or dose increase of an ARNI/ACEI/ARB. In patients with preserved renal func- tion or mild to moderate renal impairment, renal function and potassium after initiation and titration of aldosterone antagonists should be assessed within 2 to 3 days and again at 7 days. 