Experience of a Bespoke Hyperkalaemia Clinic to Facilitate Prescribing of Renin-Angiotensin-Aldosterone System Inhibitors in Patients with Heart Failure with Reduced Ejection Fraction

Background: Renin-angiotensin-aldosterone system inhibitors (RAASi) improve prognosis in patients with heart failure with reduced ejection fraction (HFrEF), but suboptimal dosing or discontinuation of these medications often occurs due to RAASi-associated hyperkalaemia. We established a nephrology-led hyperkalaemia clinic to oversee prescribing of patiromer, an oral potassium binder, to facilitate RAASi optimization. Methods: The clinic was established in July 2019 at a nephrology tertiary centre in the UK. Patients with HFrEF who were unable to increase RAASi dosage due to hyperkalaemia were referred to the clinic, where all patients commenced patiromer 8.4 g daily. RAASi adjustments were deferred to the referring teams. Study outcomes included the percentage of patients who achieved a RAASi dose increase and the proportion of patients with normokalaemia at follow-up. Outcomes were evaluated until 1 May 2021. Results: A total of 34 patients were reviewed in the clinic between July 2019 and December 2020. Mean age was 71.6 years (±10.6 years), 56% had diabetes, and 71% had chronic kidney disease stages 3a-5; mean estimated glomerular filtration rate was 56 mL/min/1.73 m² (±21 mL/min/1.73 m²). During follow-up, 13 patients discontinued patiromer (6 of whom did so due to gastrointestinal side effects) and were discharged; 2 patients died from non-hyperkalaemia-related illness; one switched to an alternative potassium binder. Over a mean follow-up of 13.4 months (±5.8 months), 17 of the 20 patients (85%) who continued with a potassium binder achieved a RAASi dose increase, with 4 patients (20%) receiving maximal dosages. This was attained by achieving normokalaemia during follow-up. No patients required magnesium supplementation. Of the 19 patients on patiromer, 12 continued this therapy for more than 12 months and 4 received it safely for 20 months. Discussion/Conclusion: Patiromer prescribing in a nephrology-led hyperkalaemia clinic facilitated RAASi up-titration in patients with HFrEF by controlling potassium levels.