Clinical Implications of Sodium Zirconium Cyclosilicate Therapy in Patients with Systolic Heart Failure and Hyperkalemia

Background: Sodium zirconium cyclosilicate (SZC), a newly introduced specific potassium binder, is introduced to treat hyperkalemia. However, the implications of SZC in up-titrating renin–angiotensin–aldosterone system inhibitors in patients with systolic heart failure remain unknown. Methods and Results: Patients with heart failure with left ventricular ejection fraction <50% and hyperkalemia who had completed 3-month SZC therapy were retrospectively included. Serum potassium levels, the dose of renin–angiotensin–aldosterone system inhibitors, and echocardiographic parameters during the 3-month SZC therapy as compared with the pretreatment 3-month period were investigated. A total of 24 patients (median 77 years old, 71% men, median left ventricular ejection fraction 41%) received a 3-month SZC therapy without any associated adverse events including hypokalemia. Compared with the pretreatment period, serum potassium levels decreased, doses of renin–angiotensin–aldosterone system inhibitors increased, and the left ventricular ejection fraction and plasma B-type natriuretic peptide levels improved following the 3-month SZC therapy (p < 0.05 for all). Conclusions: SZC may be a promising therapeutic option to improve hyperkalemia, indirectly allowing up-titration of renin–angiotensin–aldosterone system inhibitors and facilitating reverse remodeling in patients with heart failure with a left ventricular ejection fraction <50% and hyperkalemia.