LONG-TERM MORTALITY AND TRAJECTORY OF POTASSIUM MEASUREMENTS FOLLOWING AN EPISODE OF ACUTE SEVERE HYPERKALEMIA

Epidemiology and risk factors for hyperkalaemia in heart failure

Patients with heart failure (HF), particularly those with impaired renal function receiving renin-angiotensin-aldosterone system inhibitors (RAASis), are at risk of hyperkalaemia; when hyperkalaemia is severe, this can have serious clinical consequences. The incidence, prevalence, and risk factors for hyperkalaemia reported in randomized trials of RAASis may not reflect clinical practice due to exclusion of patients with elevated serum potassium (sK+) or severe renal impairment: information on patients managed in routine clinical care is important to understanding the actual burden of hyperkalaemia. This paper reviews the available clinical epidemiology data on hyperkalaemia in HF and considers areas requiring further research. Observational studies published since 2017 that focused on hyperkalaemia, included patients with HF, and had ≥1000 participants were considered. Hyperkalaemia occurrence in HF varied widely from 7% to 39% depending on the setting, HF severity, follow-up length, and concomitant medications. Rates were lowest in patients with newly diagnosed HF and highest in patients with greater disease severity; comorbidities, such as chronic kidney disease and diabetes, and RAASi use, reflected commonly identified risk factors for hyperkalaemia in patients with HF. Hyperkalaemia was most often mild; however, from the limited data available, persistence of mild hyperkalaemia was associated with an increased risk of mortality and major adverse cardiovascular events. There were also limited data available on the progression of hyperkalaemia. Recurrence was common, occurring in one-quarter to two-fifths of hyperkalaemia cases. Despite HF guidelines recommending close monitoring of sK+, 55-93% of patients did not receive appropriate testing before or after initiation of RAASi or in follow-up to moderate/severe hyperkalaemia detection. Many of the observational studies were retrospective and from a single country. There is a need for international, prospective, longitudinal, observational studies, such as the CARE-HK in HF study (NCT04864795), to understand hyperkalaemia's prevalence, incidence, and severity; to identify and characterize cases that persist, progress, and recur; to highlight the importance of sK+ monitoring when using RAASi; and to assess the impact of newer HF therapies and potassium binders in clinical practice. Data from both clinical trials and observational studies with adjustments for confounding variables will be needed to assess the contribution of hyperkalaemia to clinical outcomes.

Rationale and design of CONTINUITY: a Phase 4 randomized controlled trial of continued post-discharge sodium zirconium cyclosilicate treatment versus standard of care for hyperkalemia in chronic kidney disease

Background

Individuals with chronic kidney disease (CKD) hospitalized with hyperkalemia are at risk of hyperkalemia recurrence and re-hospitalization. We present the rationale and design of CONTINUITY, a study to examine the efficacy of continuing sodium zirconium cyclosilicate (SZC)-an oral, highly selective potassium (K⁺) binder-compared with standard of care (SoC) on maintaining normokalemia and reducing re-hospitalization and resource utilization among participants with CKD hospitalized with hyperkalemia.

Methods

This Phase 4, randomized, open-label, multicenter study will enroll adults with Stage 3b-5 CKD and/or estimated glomerular filtration rate <45 mL/min/1.73 m², within 3 months of eligibility screening, hospitalized with a serum potassium (sK⁺) level of >5.0-≤6.5 mmol/L, without ongoing K⁺ binder treatment. The study will include an in-hospital phase, where participants receive SZC for 2-21 days, and an outpatient (post-discharge) phase. At discharge, participants with sK⁺ 3.5-5.0 mmol/L will be randomized (1:1) to SZC or SoC and monitored for 180 days. The primary endpoint is the occurrence of normokalemia at 180 days. Secondary outcomes include incidence and number of hospital admissions or emergency department visits both with hyperkalemia as a contributing factor, and renin-angiotensin-aldosterone system inhibitor down-titration. The safety and tolerability of SZC will be evaluated.Ethics approval has been received from all relevant ethics committees. Enrollment started March 2022 and the estimated study end date is December 2023.

Conclusions

This study will assess the potential of SZC versus SoC in managing people with CKD and hyperkalemia post-discharge.

Trial registration

ClinicalTrials.gov identifier: NCT05347693; EudraCT: 2021-003527-14, registered on 19 October 2021.

Optimization of potassium management in patients with chronic kidney disease and type 2 diabetes on finerenone

INTRODUCTION

Patients with type 2 diabetes (T2DM) and chronic kidney disease (CKD) are at high risk of CKD progression and cardiovascular events. Despite treatment with renin-angiotensin system inhibitors and SGLT-2 inhibitors, the residual risk is substantial. There is preclinical and clinical evidence supporting a key role of mineralocorticoid receptor in cardiorenal injury in T2DM.

AREAS COVERED

Finerenone is a selective and nonsteroidal mineralocorticoid receptor antagonist that reduces -on preclinical studies- heart and kidney inflammation and fibrosis. Clinical trials have demonstrated that among patients with T2DM and CKD, finerenone reduces CKD progression and the risk of cardiovascular events. The incidence of adverse events is similar than for placebo. Permanent discontinuation of study drug due to hyperkalemia was low (1.7% of finerenone and 0.6% of placebo participants) as was the risk of hyperkalemia-related severe-adverse events (1.1%). We provide an overview of risk factors for hyperkalemia and management of serum potassium in people with CKD and T2DM on finerenone.

EXPERT OPINION

As finerenone increases potassium levels in a predictable way, patients at risk of hyperkalemia can be identified early in clinical practice and monitored for an easy management. This will allow people with T2DM and CKD to safely benefit from improved cardiorenal outcomes.

Agreement of Potassium, Sodium, Glucose, and Hemoglobin Measured by Blood Gas Analyzer With Dry Chemistry Analyzer and Complete Blood Count Analyzer: A Two-Center Retrospective Analysis

Background

Blood gas analyzers (BGAs) and dry biochemistry analyzers for potassium and sodium are based on direct electrode methods, and both involve glucose oxidase for glucose detection. However, data are lacking regarding whether the results of the two assay systems can be used interchangeably. In addition, there remains controversy over the consistency between BGA-measured hemoglobin and complete blood count analyzer data. Here, we compared the consistency of sodium, potassium, glucose, and hemoglobin levels measured by BGA and dry chemistry and complete blood count analyzers.

Methods

Data from two teaching hospitals, the Zhejiang Provincial People's Hospital (ZRY) and the Qianfoshan Hospital (QY), were retrospectively analyzed based on dry biochemistry and complete blood count analyzer results as the reference system (X) and BGA as the experimental system (Y). Plasma was used for biochemical analysis at the ZRY Hospital, and serum at the QY Hospital. Paired data from the respective hospitals were evaluated for consistency, and biases between methods were assessed by simple correlation, Passing–Bablok regression, and Bland–Altman analyses.

Results

The correlations of potassium, sodium, glucose, and hemoglobin measured by BGA and dry biochemistry and complete blood count analyzers were high, at 0.9573, 0.8898, 0.9849, and 0.9883 for the ZRY Hospital and 0.9198, 0.8591, 0.9764, and 0.8666, respectively, for the QY Hospital. The results of Passing to Bablok regression analysis showed that the predicted biases at each medical decision level were within clinically acceptable levels for potassium, sodium, glucose, and hemoglobin at the ZRY Hospital. Only the predicted bias of glucose was below the clinically acceptable medical decision levels at the QY Hospital, while potassium, sodium, and hemoglobin were not. Compared with the reference system, the mean bias for BGA measurements at the ZRY Hospital was −0.08 mmol/L (95% confidence interval [CI] −0.091 to −0.069) for potassium, 1.2 mmol/L (95% CI 1.06 to 1.42) for sodium, 0.20 mmol/L (95% CI 0.167 to 0.228) for glucose, and −2.8 g/L for hemoglobin (95% CI −3.14 to −2.49). The mean bias for potassium, sodium, glucose, and hemoglobin at the QY Hospital were −0.46 mmol/L (95% CI −0.475 to −0.452), 3.7 mmol/L (95% CI 3.57 to 3.85), −0.36 mmol/L (95% CI −0.433 to −0.291), and −8.7 g/L (95% CI −9.40 to −8.05), respectively.

Conclusion

BGA can be used interchangeably with plasma electrolyte results from dry biochemistry analyzers but does not show sufficient consistency with serum electrolyte results from dry biochemistry analyzers to allow data interchangeability. Good consistency was observed between BGA and plasma or serum glucose results from dry biochemistry analyzers. However, BGA-measured hemoglobin and hematocrit assay results should be treated with caution.

Finerenone: A Potential Treatment for Patients with Chronic Kidney Disease and Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) affects an estimated 463 million people worldwide, equivalent to 1 in 11 adults. Moreover, the rapid growth of this disease has resulted in a high incidence of diabetic kidney disease (DKD), which, together with hypertension, is the main cause of chronic kidney disease (CKD). Hyperglycaemia, low-grade inflammation, altered lipid metabolism and hyperactivation of the renin-angiotensin-aldosterone system (RAAS) seem to be interrelated mechanisms contributing to both T2DM and microvascular complications. The introduction of drugs such as sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists has improved the ability to slow the progression of DKD, and has also demonstrated benefits in cardiovascular disease. Beyond the effects of these novel antidiabetic drugs, a body of evidence suggests that the overactivation of the mineralocorticoid receptor also contributes to CKD progression. Moreover, new and ongoing trials have demonstrated that the selective nonsteroidal mineralocorticoid receptor antagonist (MRA) finerenone improves the risk of CKD progression and cardiovascular events in patients with CKD and T2DM and optimized RAAS blockade. We review the rationale for the development and use of MRA drugs to slow CKD progression in patients with DKD, as well as other pleiotropic effects, and highlight the warnings associated with these agents.