Risk factors associated with the incidence and recurrence of hyperkalaemia in patients with cardiorenal conditions

Impact of Sodium Zirconium Cyclosilicate Therapy Cessation in Patients with Systolic Heart Failure

Background: Sodium zirconium cyclosilicate (SZC), a newly introduced potassium binder, is indicated for treating hyperkalemia. SZC-incorporated up-titration of renin-angiotensin system inhibitors and mineralocorticoid receptor antagonists has been recommended for those with systolic heart failure, whereas SZC is often terminated following the improvement of hyperkalemia in real-world practice. We aimed to investigate the impact of SZC cessation on the recurrence of hyperkalemia. Methods: Patients with systolic heart failure, in whom SZC was discontinued following improvement in hyperkalemia, were studied and compared to those who had continued SZC. All patients were followed for one year or until August 2022. The recurrent rates of hyperkalemia were compared between the two groups. Results: A total of 30 patients (median age 83 years, 53% men, median left ventricular ejection fraction 42%) were included. The one-year cumulative incidence of recurrent hyperkalemia was 93% in the group who discontinued SZC versus 22% in those who continued SZC (p = 0.032). In the group where SZC was withdrawn, doses of renin-angiotensin system inhibitors and mineralocorticoid receptor antagonists were less up-titrated, echocardiographic evidence of reverse remodeling occurred less, and readmission due to worsening heart failure tended to be higher compared to those who remained on SZC therapy. Conclusions: SZC cessation was associated with recurrent hyperkalemia and suboptimal medical therapy optimization compared to continuation of SZC therapy.

Cost effectiveness of sodium zirconium cyclosilicate for the treatment of hyperkalaemia in patients with CKD in Norway and Sweden

Background

Hyperkalaemia is common in patients with chronic kidney disease (CKD) and is associated with a range of adverse outcomes. Historically, options for management of chronic hyperkalaemia in the outpatient setting have been limited. Novel oral potassium binders provide a safe, effective therapy for maintenance of normokalaemia in patients with CKD, but despite being approved for reimbursement in many countries, prescription data indicate uptake has been slower than anticipated. This analysis aimed to demonstrate the value to patients and the healthcare system of the potassium binder sodium zirconium cyclosilicate (SZC) for treatment of hyperkalaemia in patients with CKD in Norway and Sweden.

Methods

A published simulation model reflecting the natural history of CKD was adapted to the Norwegian and Swedish settings and used to predict long-term health economic outcomes of treating hyperkalaemia with SZC versus usual care.

Results

SZC was highly cost effective compared to usual care in Norway and Sweden, with incremental cost-effectiveness ratios of €14,838/QALY in Norway and €14,352/QALY in Sweden, over a lifetime horizon. The acquisition cost of SZC was largely offset by cost savings associated with reductions in hyperkalaemia events and hospitalisations; a modest overall increase in costs was predominantly attributable to costs associated with gains in life years compared with usual care. SZC remained cost effective in all scenarios examined.

Conclusions

SZC was estimated to be cost effective for treating hyperkalaemia. Consequently, improving access to a clinically effective, safe and cost-effective therapy, such as SZC, may result in considerable benefits for CKD patients with hyperkalaemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02903-7.

Serum potassium variability as a predictor of clinical outcomes in patients with cardiorenal disease or diabetes: a retrospective UK database study

Background

Hyperkalaemia is an electrolyte abnormality associated with adverse clinical outcomes; however, few studies have investigated the relationship with patterns of hyperkalaemia over time. This study explored the impact of time spent in a hyperkalaemic state and variability of serum potassium (sK⁺) on major adverse cardiovascular events (MACE) and all-cause mortality in patients with chronic kidney disease (CKD), resistant hypertension, heart failure and diabetes.

Methods

Cohorts comprised adult patients diagnosed with CKD stage 3+, resistant hypertension, heart failure or diabetes, and/or renin–angiotensin–aldosterone system inhibitor prescription, between 1 January 2003 and 30 June 2018, from the UK Clinical Practice Research Datalink. Associations between percentage of follow-up spent in a hyperkalaemic state (sK⁺ ≥5.0 mmol/L, ≥5.5 mmol/L, ≥6.0 mmol/L) or sK⁺ variability (standard deviation above or below median standard deviation) and all-cause mortality or MACE were investigated.

Results

For sK⁺ ≥5.0 mmol/L, time spent in a hyperkalaemic state was associated with reduced risk of all-cause mortality across all cohorts. For higher sK⁺ thresholds, this trend was attenuated or reversed; for time spent in a hyperkalaemic state at sK⁺ ≥6.0 mmol/L, an increased risk of mortality was seen in the overall cohort and for patients with diabetes, resistant hypertension or prescribed renin–angiotensin–aldosterone system inhibitors, with no consistent association seen for patients with CKD or heart failure. Risk of MACE in the overall cohort and in patients with CKD, diabetes or resistant hypertension increased with time spent in a hyperkalaemic state at all sK⁺ thresholds; however, no correlation was seen in patients with heart failure or those receiving dialysis. High sK⁺ variability was associated with a higher risk of MACE compared with low sK⁺ variability across most sK⁺ categories in the overall population and in all disease cohorts, except patients on dialysis; however, no association between sK⁺ variability and all-cause mortality was observed.

Conclusions

Patterns of hyperkalaemia, including time spent in hyperkalaemia and sK⁺ variability, are associated with adverse clinical outcomes. Regular monitoring of sK⁺ in high-risk populations in broader community, primary care and outpatient settings may enable guideline-recommended management of hyperkalaemia and help avoid adverse events.