Outcomes in patients with cardiometabolic disease who develop hyperkalemia while treated with a renin-angiotensin-aldosterone system inhibitor

Hyperkalaemia-related reduction of RAASi treatment associates with more subsequent inpatient care

BACKGROUND

Hyperkalaemia is a barrier to achieving optimal, guideline-directed treatment with renin-angiotensin-aldosterone system inhibitors (RAASis) in patients with chronic kidney disease (CKD) and/or heart failure (HF). This study describes the association between hyperkalaemia-related RAASi treatment reduction and the number of hospitalized days in patients with CKD and/or HF in Sweden and Japan.

METHODS

Using data from health registers and hospital medical records, patients with CKD and/or HF currently receiving RAASis who experienced an index hyperkalaemia episode were identified and categorized as having maintained or reduced RAASi treatment post-index; propensity score matching (1:1) was applied to balance the groups in terms of baseline characteristics. Changes in the number of all-cause, CKD- and HF-related hospitalized days per patient-year during 6 months pre- versus post-index and the number of days alive and out of hospital (DAOH) during 6 months post-index were described.

RESULTS

Overall, 20 824 and 7789 patients were included from Sweden and Japan, respectively, 42% and 38% of whom reduced their RAASi treatment after the index hyperkalaemia episode. During the 6 months post-index, all-cause hospitalization increased by 18.2 days [95% confidence interval (CI) 17.0-19.2] per person-year in Sweden and 17.9 days (95% CI 17.4-18.5) per person-year in Japan among patients with reduced RAASi treatment compared with increases of 9.4 days (95% CI 8.6-10.4) and 8.5 days (95% CI 8.0-9.0) per person-year, respectively, among patients with maintained RAASi treatment. The mean DAOH was 121.5 [standard deviation (SD) 75.0] in Sweden and 141.7 (SD 54.5) in Japan among patients with reduced RAASi treatment compared with 154.0 (SD 51.3) and 157.5 (SD 31.6), respectively, among patients with maintained RAASi treatment.

CONCLUSION

Patients whose RAASi treatment was reduced after a hyperkalaemia episode had more hospitalized days and fewer DAOH compared with patients whose RAASi treatment was maintained.

Re-Thinking Hyperkalaemia Management in Chronic Kidney Disease-Beyond Food Tables and Nutrition Myths: An Evidence-Based Practice Review

Potassium dysregulation can be life-threatening. Dietary potassium modification is a management strategy for hyperkalaemia. However, a 2017 review for clinical guidelines found no trials evaluating dietary restriction for managing hyperkalaemia in chronic kidney disease (CKD). Evidence regarding dietary hyperkalaemia management was reviewed and practice recommendations disseminated. A literature search using terms for potassium, hyperkalaemia, and CKD was undertaken from 2018 to October 2022. Researchers extracted data, discussed findings, and formulated practice recommendations. A consumer resource, a clinician education webinar, and workplace education sessions were developed. Eighteen studies were included. Observational studies found no association between dietary and serum potassium in CKD populations. In two studies, 40-60 mmol increases in dietary/supplemental potassium increased serum potassium by 0.2-0.4 mmol/L. No studies examined lowering dietary potassium as a therapeutic treatment for hyperkalaemia. Healthy dietary patterns were associated with improved outcomes and may predict lower serum potassium, as dietary co-factors may support potassium shifts intracellularly, and increase excretion through the bowel. The resource recommended limiting potassium additives, large servings of meat and milk, and including high-fibre foods: wholegrains, fruits, and vegetables. In seven months, the resource received > 3300 views and the webinar > 290 views. This review highlights the need for prompt review of consumer resources, hospital diets, and health professionals' knowledge.

Medical Costs in Patients with Hyperkalemia on Long-Term Sodium Zirconium Cyclosilicate Therapy: The RECOGNIZE II Study

Purpose

Hyperkalemia, defined as abnormally high serum potassium levels of ≥5.1 mmol/L, is associated with increased medical costs. This real-world study evaluated the impact of long-term sodium zirconium cyclosilicate (SZC) therapy on medical costs in patients with hyperkalemia.

Patients and Methods

This retrospective, comparative study used claims data from IQVIA PharMetrics® Plus. Patients aged ≥18 years with hyperkalemia who had outpatient SZC fills (>3-month supply over 6 months) between July 2019 and December 2021 and continuous insurance coverage 6 months before and 6 months after the first SZC fill were included. These patients (SZC cohort) were 1:1 exact- and propensity score-matched on baseline variables with patients with hyperkalemia who did not receive SZC (non-SZC cohort). The primary endpoint was hyperkalemia-related medical costs to payers over 6 months.

Results

Each cohort included 661 matched patients. Mean per-patient hyperkalemia-related medical costs were reduced by 49.5% ($3728.47) for the SZC versus non-SZC cohort ($3798.04 vs $7526.51; P<0.001), whereas mean all-cause medical costs were reduced by 21.0% ($5492.20; $20,722.23 vs $26,214.43; P<0.01). A 39.8% ($3621.03) increase in all-cause pharmacy costs ($12,727.20 vs $9106.17; P<0.01) was offset by the medical cost savings.

Conclusion

This study demonstrated that long-term (>3 months) outpatient treatment with SZC was associated with medical cost savings compared with no SZC therapy.

Real-World Modifications of Renin-Angiotensin-Aldosterone System Inhibitors in Patients with Hyperkalemia Initiating Sodium Zirconium Cyclosilicate Therapy: The OPTIMIZE I Study

INTRODUCTION

Hyperkalemia (HK) may result in disruptions of guidelines-concordant renin-angiotensin-aldosterone system inhibitors (RAASi), a standard of care in persons with chronic kidney disease (CKD). Such disruptions-dose reduction or discontinuation-diminish the benefits of RAASi, placing patients at risk of serious events and renal dysfunction. This real-world study evaluated RAASi modifications among patients who initiated sodium zirconium cyclosilicate (SZC) for HK.

METHODS

Adults (≥ 18 years) initiating outpatient SZC (index date) while on RAASi were identified from a large US claims database (January 2018-June 2020). RAASi optimization (maintain same or up-titration of RAASi dosage), non-optimization (down-titration of RAASi dosage or discontinuation), and persistence were descriptively summarized following index. Predictors of RAASi optimization were assessed using multivariable logistic regression models. Analyses were conducted by subgroups, including patients without end-stage kidney disease (ESKD), with CKD, and with CKD + diabetes.

RESULTS

A total of 589 patients initiated SZC during RAASi therapy (mean age 61.0 years, 65.2% male), and 82.7% patients (n = 487) kept RAASi after index (mean follow-up  = 8.1 months). Most patients (77.4%) optimized RAASi therapy after initiating SZC; 69.6% maintained the same dosage while 7.8% had up-titrations. A similar rate of RAASi optimization was observed among subgroups without ESKD (78.4%), with CKD (78.9%), and with CKD + diabetes (78.1%). At 1-year post-index, 73.9% of all patients who optimized RAASi were still on therapy, while only 17.9% of patients who did not optimize therapy were still on a RAASi. Among all patients, predictors of RAASi optimization included fewer prior hospitalizations (odds ratio = 0.79, 95% CI [0.63-1.00]; p < 0.05) and fewer prior emergency department (ED) visits (0.78 [0.63-0.96]; p < 0.05).

CONCLUSION

Consistent with clinical trial findings, nearly 80% of patients who initiated SZC for HK optimized their RAASi therapy. Patients may require long-term SZC therapy to encourage continuation of RAASi therapy especially after inpatient and ED visits.