The Impact of Hyperkalemia on Mortality and Healthcare Resource Utilization Among Patients With Chronic Kidney Disease: A Matched Cohort Study in China

Hyperkalaemia among hospital admissions: prevalence, risk factors, treatment and impact on length of stay

BACKGROUND

Hyperkalaemia is one of the common electrolyte disorders among hospital patients, affected by many risk factors including medications and medical conditions. Prompt treatment is important given its impact on patient mortality and morbidity, which can lead to negative patient outcomes and healthcare resource utilisation. This study aims to describe the prevalence, characteristics, and treatment of patients admitted to hospitals with hyperkalaemia and compare findings between patients with kidney failure on maintenance haemodialysis therapy and patients without kidney failure. It also aims to identify associations between hyperkalaemia and hospital length of stay.

METHODS

We undertook a retrospective cohort study on adult patients admitted to Townsville University Hospital between 1st January 2018 and 31st December 2022 (n = 99,047). Patients were included if they had a serum potassium result of 5.1 mmol/L and above during their admission/s. Statistical analysis was conducted using several methods. A Welch's t test and Chi-square test were employed to assess differences between groups of patients with kidney failure on maintenance haemodialysis therapy and those without kidney failure. For comparison among multiple groups with varying severities of hyperkalaemia, the Kruskal-Wallis test with Mann-Whitney U test and logistic regression were used.

RESULTS

8,775 hyperkalaemic patients were included in the study, with a mean age of 64.7 years. The prevalence of hyperkalaemia was 8.9% of patients. Risk factors for hyperkalaemia were highly prevalent among those who had the condition during their admissions. Patients with kidney failure on haemodialysis who had hyperkalaemia were, on average, 6 years younger, more often Indigenous, and experienced more severe hyperkalaemia compared to other patients without kidney failure. There was a notable difference in hyperkalaemia treatment between groups with varying degrees of hyperkalaemia severity. Hyperkalaemia was not found to be associated with prolonged hospital stay.

CONCLUSION

Hyperkalaemia is common among hospital admissions. Patients with kidney failure on haemodialysis are at higher risk of developing severe hyperkalaemia. Treatment for hyperkalaemia was variable and likely insufficient. Timely detection and treatment of hyperkalaemia is recommended.

Economic burden of recurrent hyperkalemia in patients with chronic kidney disease

BACKGROUND

Hyperkalemia is a common complication of chronic kidney disease (CKD) and can become recurrent in half of cases. However, the incremental economic burden associated with recurrent hyperkalemia is unknown.

OBJECTIVE

To evaluate all-cause health care resource utilization (HRU) and medical costs in patients with stage 3/4 CKD with recurrent hyperkalemia vs normokalaemia and vs nonrecurrent hyperkalemia.

METHODS

Data were from Optum's de-identified Market Clarity Data (January 1, 2016, to August 1, 2022). This retrospective observational cohort study compared patients with stage 3/4 CKD with recurrent hyperkalemia (≥2 hyperkalemia events within 1 year [hyperkalemia event: hyperkalemia diagnosis or potassium [K+]>5 mmol/l]; index was the first hyperkalemia event) with an exact- and propensity score-matched cohort of patients with normokalemia (K+ ≥3.5 to ≤5 mmol/l; random K+ as index) and separately with a matched cohort of patients with nonrecurrent hyperkalemia (1 hyperkalemia event within 1 year; index was hyperkalemia event). Patient characteristics, medication use, HRU, and medical costs were compared between cohorts using standardized mean differences during the 12-month baseline period. All-cause HRU and medical costs during the 12-month follow-up were compared using Wilcoxon rank sum tests for continuous variables and McNemar tests for categorical variables. Substudies of recurrent hyperkalemia vs normokalemia were conducted for patients with Medicare coverage and renin-angiotensin-aldosterone system inhibitor (RAASi) use.

RESULTS

The recurrent hyperkalemia vs normokalemia sample comprised 4,549 matched pairs (Medicare substudy: 3,151; RAASi substudy: 3,535) and the recurrent hyperkalemia vs nonrecurrent hyperkalemia sample comprised 1,599 matched pairs. Baseline characteristics, HRU, and medical costs of the cohorts were similar after matching. During follow-up, patients with recurrent hyperkalemia had a mean of 11.2 more health care encounters (0.5 more inpatient admissions, 0.3 more emergency department visits, and 7.2 more outpatient visits) than patients with normokalemia. Patients with recurrent hyperkalemia also had double the total annual medical costs vs normokalemia ($34,163 vs $15,175; P < 0.001), mainly driven by inpatient costs ($21,250 vs $7,392), which accounted for 62.2% and 48.7% of total costs, respectively. Results were similar in the RAASi and Medicare substudies. Recurrent hyperkalemia was associated with a mean 4.3 more all-cause health care encounters and $14,057 higher medical costs (both P < 0.001) than nonrecurrent hyperkalemia.

CONCLUSIONS

Recurrent hyperkalemia in patients with stage 3/4 CKD was associated with higher all-cause HRU and medical costs compared with normokalemia (including in patients with Medicare coverage and RAASi use) and nonrecurrent hyperkalemia. Research is needed to understand if long-term treatment strategies aimed at preventing hyperkalemia recurrence may alleviate this economic burden.

Management of hyperkalemia: Expert consensus from Kuwait - a Modified Delphi Approach

Introduction

Hyperkalemia is common in heart failure (HF) patients on renin angiotensin aldosterone inhibitors (RAASi), in chronic kidney disease (CKD), and in hemodialysis, and it negatively impacts their management. New potassium binders, such as sodium zirconium cyclosilicate (SZC), are effective in management of acute and chronic hyperkalemia. However, guidelines inconsistencies and lack of standardized treatment protocols are hindering proper and wider use of such agents. Therefore, an expert panel from Kuwait developed a consensus statement to address hyperkalemia management in acute settings, in HF, in CKD, and in hemodialysis.

Methods

A three-step modified Delphi method was adopted to develop the present consensus, which consisted of two rounds of voting and in-between a virtual meeting. Twelve experts from Kuwait participated in this consensus. Statements were developed and shared with experts for voting. A meeting was held to discuss statements that did not reach consensus at the first round and then the remaining statements were shared for final voting.

Results

The consensus consists of 44 statements involving an introduction to and the management of hyperkalemia in acute settings, HF, CKD, and hemodialysis. Thirty-six statements approved unanimously in the first vote. In the second vote, four statements were removed and four were approved after editing.

Conclusion

Hyperkalemia management lacks standardized definitions, treatment thresholds and consistent guidelines and laboratory practices. This consensus is in response to lack of standardized treatment in the Arabian Gulf, and it aims to establish guidance on hyperkalemia management for healthcare practitioners in Kuwait and highlight future needs.

Hyperkalemia Management with Intravenous Insulin in Patients with Reduced Kidney Function

Background: Insufficient kidney function increases the risk of hyperkalemia and hypoglycemia, particularly in hemodialysis-dependent patients. Hypoglycemia is a common complication of insulin-based hyperkalemia treatment. This study aims to evaluate the efficacy and safety of hyperkalemia treatment in hemodialysis-dependent and -non-dependent patients and identify risk factors associated with hypoglycemia. Methods: A retrospective observational cohort study was conducted to assess the efficacy and safety of hyperkalemia treatment including patients with reduced kidney function and hyperkalemia treated with intravenous insulin. The decline rate of potassium and glucose levels were compared between hemodialysis-dependent and non-dependent patients. In addition, univariate and multivariable logistic regression analyses were performed to identify risk factors associated with hypoglycemia. Results: A total of 172 patients with hyperkalemia and reduced kidney function were included. The steepest reduction of serum potassium levels happened within the first 6 h after insulin administration, at 1.1 and 0.9 mmol/L for hemodialysis-dependent and non-dependent patients, respectively. The incidence of hypoglycemia was 18%, and no significant difference was found between cohorts. Hemodialysis-dependent patients were more likely to be readmitted within one month with hyperkalemia, while all-cause ICU admission was more likely for non-dependent patients. Older patients, and those who had heart failure or received a second dose of insulin to treat hyperkalemia, were more likely to experience hypoglycemia. Conclusions: Monitoring blood glucose levels following insulin administration is essential given the complexity of patients' factors associated with hypoglycemia resulting from hyperkalemia treatment in patients with insufficient kidney function.

Machine learning models for early prediction of potassium lowering effectiveness and adverse events in patients with hyperkalemia

The aim of this study was to develop a model for early prediction of adverse events and treatment effectiveness in patients with hyperkalemia. We collected clinical data from patients with hyperkalemia in the First Hospital of Zhejiang University School of Medicine between 2015 and 2021. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to analyze the predictors on the full dataset. We randomly divided the data into a training group and a validation group, and used LASSO to filter variables in the training set. Six machine learning methods were used to develop the models. The best model was selected based on the area under the curve (AUC). Shapley additive exPlanations (SHAP) values were used to explain the best model. A total of 1074 patients with hyperkalemia were finally enrolled. Diastolic blood pressure (DBP), breathing, oxygen saturation (SPO2), Glasgow coma score (GCS), liver disease, oliguria, blood sodium, international standardized ratio (ISR), and initial blood potassium were the predictors of the occurrence of adverse events; peripheral edema, estimated glomerular filtration rate (eGFR), blood sodium, actual base residual, and initial blood potassium were the predictors of therapeutic effect. Extreme gradient boosting (XGBoost) model achieved the best performance (adverse events: AUC = 0.87; therapeutic effect: AUC = 0.75). A model based on clinical characteristics was developed and validated with good performance.

Cost-effectiveness analysis of sodium zirconium cyclosilicate for treating hyperkalemia among Chinese patients

Objectives

Hyperkalemia most commonly develops in chronic kidney disease (CKD) or heart failure (HF) patients. Sodium zirconium cyclosilicate (SZC) is a new selective potassium (K+) binder for treating hyperkalemia. The aim of this study was to evaluate the cost-effectiveness of SZC vs. usual care for the treatment of hyperkalemia among CKD patients or HF patients in China.

Methods

Individual patient microsimulation models were constructed to simulate a CKD cohort until the initiation of renal replacement therapy (RRT) and a HF cohort across the lifetime horizon. K+ levels were based on two phase 3 clinical trials. Health state utility and event incidence rates were retrieved from literature. Drug costs and healthcare utilization costs were obtained from negotiated price, literature, and expert interviews. Costs and quality-adjusted life-years (QALYs) were both discounted at 5%. The main outcomes were overall costs, QALYs, and incremental cost-effectiveness ratio (ICER). The willingness-to-pay (WTP) threshold in China is CNY 80,976-242,928/QALY, which is one to three times the gross domestic product per capita. Sensitivity analyses were performed to characterize the models' uncertainty.

Results

In the HF cohort, the base case results revealed that SZC was associated with 2.86 QALYs and the total cost was CNY 92671.58; usual care was associated with 1.81 QALYs and CNY 54101.26. In the CKD cohort, SZC was associated with 3.23 QALYs and CNY 121416.82 total cost; usual care was associated with 2.91 QALYs and CNY 111464.57. SZC resulted in an ICER of CNY 36735.87/QALY for the HF cohort and CNY 31181.55/QALY for the CKD cohort, respectively. The one-way and probability sensitivity analyses found that the results were robust.

Conclusion

SZC is a cost-effective treatment compared to usual care in HF and CKD patients. SZC is an important novel treatment option for managing patients with hyperkalemia in China.

Impact of hyperkalemia on hospitalization days in advanced chronic kidney disease patients with Type-2 diabetes mellitus: A prospective study

Objective

This study aimed to explore the impact of hyperkalemia at admission on hospitalization days (HDs) among advanced chronic kidney disease patients (CKD) with type two diabetes mellitus (T2DM) in China.

Methods

A total of 270 CKD patients with T2DM were prospectively selected from January 1, 2020 to December 31, 2021. These patients were divided into Group-A (n = 150, serum potassium ≤ 5.5 mmol/L) and B (n = 120, serum potassium > 5.5 mmol/L). The comparison method between the two groups was taken. Linear correlation analysis was performed using the Spearman correlation method, and multivariate analysis was tested using linear regression.

Results

The study found statistically significant result between the two groups (Group-A vs Group-B): HDs (7.4 (5.3-11.2) vs 12.1 (8.2-16.5), p < 0.001), renin-angiotensin-aldosterone system inhibitors (RAASIs) (36.2% vs 55.8%, p = 0.014), systolic blood pressure (148.35 ± 19.51 vs 162.26 ± 21.31, p < 0.05), estimated glomerular filtration (eGFR) (20.35) (18.31-25.26) vs13.4 (12.50-18.50), p < 0.001, N-terminal pro-B type natriuretic peptide (NT-proBNP) (2245.42 ± 61.09 vs 3163.39 ± 85.15,p < 0.001), and Hb (88.45 ± 12.35 vs 72.26 ± 14.2, p = 0.023). Correlation analysis showed that HDs were positively correlated with age, serum potassium, systolic blood pressure, and NT-proBNP, while negatively with eGFR and Hb. After adjusting for relevant confounding variables, the multivariable linear regression analysis showed that hyperkalemia was an independent risk factor for HDs.

Conclusions

Hyperkalemia could be an independent risk factor increasing HDs of advanced CKD patients with T2DM.

Evaluation of safety, effectiveness and treatment patterns of sodium zirconium cyclosilicate in management of hyperkalaemia in China: a real-world study protocol

INTRODUCTION

Hyperkalaemia (HK) is a potentially life-threatening electrolyte imbalance associated with several adverse clinical outcomes. The efficacy and negative effects of currently existing treatment options have made HK management questionable. Sodium zirconium cyclosilicate (SZC), a novel highly selective potassium binder, is approved for the treatment of HK. The present study will be aimed to assess the safety, effectiveness and treatment patterns of SZC in Chinese patients with HK in a real-world clinical setting as it is required by China's drug review and approval process.

METHODS AND ANALYSIS

This is a multicentre, prospective cohort study which plans to enrol 1000 patients taking SZC or willing to take SZC from approximately 40 sites in China. Patients ≥18 years of age at the time of signing the written informed consent and with documented serum potassium levels ≥5.0 mmol/L within 1 year before study enrolment day will be included. Eligible patients will receive SZC treatment and will be followed up for 6 months from enrolment day. The primary objective will be to evaluate the safety of SZC for the management of HK in Chinese patients in terms of adverse events (AEs), serious AEs as well as discontinuation of SZC. The secondary objectives will include understanding the SZC dosage information in terms of its effectiveness and treatment patterns under real-world clinical practice and assessing effectiveness of SZC during the observational period.

ETHICS AND DISSEMINATION

This study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Dalian Medical University (approval number: YJ-JG-YW-2020). All the participating sites have received the ethics approval. Results will be disseminated through national and international presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05271266.

An evaluation of sodium zirconium cyclosilicate: a new treatment option for hyperkalaemia in China

INTRODUCTION

Hyperkalemia is a common complication of chronic kidney disease (CKD), diabetes mellitus (DM), and heart failure (HF) that can lead to severe arrhythmias and sudden death and is associated with a higher risk of mortality. Therefore, the prevention and treatment of hyperkalemia is important. Sodium zirconium cyclosilicate (SZC), a new oral potassium-lowering drug, has offered an additional treatment option for Chinese patients with hyperkalemia since its launch in China in late 2019, and some experience has been accumulated regarding its efficacy and safety.

AREAS COVERED

In this review, the authors summarize the epidemiological features of hyperkalemia in China and review the clinical data regarding the use of sodium zirconium cyclosilicate in Chinese patients.

EXPERT OPINION

The prevalence of hyperkalemia is particularly high in Chinese patients with chronic kidney disease and heart failure. In China, recent clinical studies have shown that SZC rapidly reduces serum potassium, maintains normal potassium concentration, and is well tolerated and safe. Two Chinese expert consensus statements have recommended the use of SZC for the acute correction and chronic maintenance of potassium concentration.