Evaluation of an Individualized Dose Titration Regimen of Patiromer to Prevent Hyperkalaemia in Patients with Heart Failure and Chronic Kidney Disease

Aims Hyperkalaemia risk precludes optimal renin–angiotensin–aldosterone system inhibitor use in patients with heart failure (HF), particularly those with chronic kidney disease (CKD). Patiromer is a sodium-free, non-absorbed potassium (K+)-binding polymer approved for the treatment of hyperkalaemia. In PEARL-HF, patiromer 25.2 g (fixed dose) prevented hyperkalaemia in HF patients with or without CKD initiating spironolactone. The current study evaluated the effectiveness of a lower starting dose of patiromer (16.4 g/day) followed by individualized titration in preventing hyperkalaemia and hypokalaemia when initiating spironolactone. Methods and results This open-label 8-week study enrolled 63 patients with CKD, serum K+ 4.3–5.1 mEq/L, and chronic HF, who, based on investigator opinion, should receive spironolactone. Eligible patients started spironolactone 25 mg/day and patiromer 16.8 g/day (divided into two doses), with patiromer titrated to maintain serum K+ 4.0–5.1 mEq/L. Mean (standard deviation) serum K+ was 4.78 (0.51) mEq/L at baseline; weekly values were 4.48–4.70 mEq/L during treatment. Serum K+ of 3.5–5.5 mEq/L at the end of study treatment (primary endpoint) was achieved by 57 (90.5%) patients; 53 (84.1%) had serum K+ 4.0–5.1 mEq/L. One patient (1.6%) developed hypokalaemia, and two patients (3.2%) developed hypomagnesaemia. Spironolactone was increased to 50 mg/day in all patients; 43 (68%) patients required one or more patiromer dose titration. Adverse events (AEs) occurred in 36 (57.1%) patients, with a low rate of discontinuations [four (6.3%) patients]. The most common AE was mild to moderate abdominal discomfort [four (6.3%) patients]. Conclusions In this open-label study, patiromer 16.8 g/day followed by individualized titration maintained serum K+ within the target range in the majority of patients with HF and CKD, all of whom were uptitrated to spironolactone 50 mg/day, patiromer was well tolerated, with a low incidence of hyperkalaemia, hypokalaemia, and hypomagnesaemia.