A new area for the management of hyperkalaemia with potassium binders: clinical use in nephrology

DIALIZE China: A Phase IIIb, Randomized, Placebo-Controlled Study to Reduce Predialysis Hyperkalemia With Sodium Zirconium Cyclosilicate in Chinese Patients

PURPOSE

The DIALIZE China study (Reduce Incidence of Pre-Dialysis Hyperkalaemia With Sodium Zirconium Cyclosilicate in Chinese Subjects) (NCT04217590) evaluated sodium zirconium cyclosilicate (SZC) for the management of hyperkalemia in Chinese patients undergoing hemodialysis.

METHODS

In the double-blind, Phase IIIb DIALIZE China study, Chinese adults with kidney failure and predialysis hyperkalemia (predialysis serum potassium [sK+] concentration >5.4 mmol/L after the long interdialytic interval [LIDI] and >5.0 mmol/L after ≥1 short interdialytic interval) who were receiving hemodialysis 3 times weekly were randomized to placebo or SZC 5 g once daily on nondialysis days. Doses were titrated towards maintaining normokalemia for 4 weeks (titration period) in 5-g increments up to 15 g. Primary efficacy was the proportion of responders during the 4-week evaluation period following the titration period (ie, those with a predialysis sK+ of 4.0-5.0 mmol/L for at least 3 of 4 hemodialysis visits following the LIDI) who did not require urgent rescue therapy.

FINDINGS

Overall, 134 adults (mean [SD] age, 55 [11.3] years) were randomized to SZC or placebo (n = 67 each). There were significantly more responders with SZC (37.3%) versus placebo (10.4%; estimated odds ratio [OR] = 5.10; 95% CI, 1.90-15.12; P < 0.001). The probability of all predialysis sK+ concentrations being 3.5 to 5.5 mmol/L was significantly higher with SZC versus placebo (estimated OR = 6.41; 95% CI, 2.71-15.12; P < 0.001). A greater proportion of patients achieved an sK+ of 3.5 to 5.5 mmol/L on at least 3 of 4 LIDI visits during evaluation with SZC (73.1%) versus placebo (29.9%). Serious adverse events occurred in 9.1% and 11.9% of patients in the SZC and placebo groups, respectively.

IMPLICATIONS

SZC treatment for predialysis hyperkalemia is effective and well tolerated in Chinese patients with kidney failure receiving hemodialysis.

CLINICALTRIALS

gov identifier: NCT04217590.

Real-World Management of Hyperkalemia in the Emergency Department: An Electronic Medical Record Analysis

Introduction

Hyperkalemia is often managed in the emergency department (ED) and it is important to understand how ED management and post-discharge outcomes vary by hyperkalemia severity. This study was conducted to characterize ED management and post-discharge outcomes across hyperkalemia severities.

Methods

Adults with an ED visit with hyperkalemia (at least one serum potassium lab measure above 5.0 mEq/L) were selected from US electronic medical record data (2012–2018). Patient characteristics, potassium levels, treatments, and monitoring prior to and during the ED visit were compared by hyperkalemia severity (mild [> 5.0–5.5 mEq/L], moderate [> 5.5–6.0], severe [> 6.0]) using unadjusted analyses. Death, immediate inpatient admission, 30-day hyperkalemia recurrence, and 30-day inpatient admission were also assessed by severity.

Results

Of 6222 patients included, 4432 (71.2%) had mild hyperkalemia, 1085 (17.4%) had moderate, and 705 (11.3%) had severe hyperkalemia. Chronic kidney disease (39.9–50.1%) and heart failure (21.6–24.3%) were common. In the ED, electrocardiograms (mild, 56.5%; moderate, 69.6%; severe, 81.0%) and patients with at least two potassium laboratory values increased with severity (15.0%; 40.4%; 75.5%). Among patients with at least two potassium laboratory values, over half of patients (60.4%) had potassium levels ≤ 5.0 mEq/L prior to discharge. Use of potassium-binding treatments (sodium polystyrene sulfonate: mild = 4.1%; moderate = 17.1%; severe = 27.4%), temporizing agents (5.6%; 15.5%; 31.6%), or dialysis (0.4%; 0.8%; 3.0%) increased with severity; treatment at discharge was not common. Death (1.1%; 3.7%; 10.6%), immediate admission to inpatient care (5.8%; 8.7%; 12.7%), 30-day hyperkalemia recurrence (2.9%; 19.0%; 32.5%), 30-day inpatient admission with hyperkalemia (6.5%; 7.9%; 9.3%) also increased with severity.

Conclusion

Patients with moderate and severe hyperkalemia experienced elevated risk of hyperkalemia recurrence and hyperkalemia-related inpatient readmission following discharge from the ED from a descriptive analysis. Future research to assess strategies to reduce hyperkalemia recurrence and inpatient admission in this patient population would be beneficial.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-02017-w.

Safety and Tolerability of the Potassium Binder Patiromer From a Global Pharmacovigilance Database Collected Over 4 Years Compared with Data from the Clinical Trial Program

INTRODUCTION

The availability of the sodium-free potassium binder patiromer opens new opportunities for hyperkalemia management.

OBJECTIVE

Our objective was to compare data from a 4-year global pharmacovigilance database of adverse events (AEs) reported in patients prescribed patiromer in clinical practice compared with data obtained from the clinical trial program.

METHODS

Postmarketing safety data regarding patiromer (Veltassa®; Vifor Pharma, Inc.), collected and recorded in the company's global pharmacovigilance database, were analyzed for the period from January 2016 through September 2019. These data were both solicited (i.e., via an organized data-collection method such as a patient-support program) and unsolicited (i.e., voluntarily reported by healthcare professionals, consumers, and competent authorities worldwide). The cumulative annualized mortality rate (events per 100 patient-years [PYs]) for the pharmacovigilance database analysis period were compared with the rate obtained in the longest patiromer clinical trial to date (up to 52 weeks of treatment). For individual AEs, reporting rates (% of events/100 PYs) for events collected in the global pharmacovigilance database were compared with the frequencies (% of patients with event/patients exposed) of events collected in the clinical trial program (N = 666).

RESULTS

Over 4 years, the global pharmacovigilance database contained an estimated 45,000 PYs of exposure (17,823 individual case reports and 38,109 AEs), with most cases (95%) from the USA; > 85% of cases utilized 8.4 g/day. In total, 1214 deaths were reported, with a cumulative annualized mortality rate of 2.69/100 PYs (vs. 5.70 deaths/100 PYs in the 52-week clinical trial). Global pharmacovigilance reporting rates for the two most common AEs, constipation and diarrhea, were 6.90 and 3.48%, respectively. Respective frequencies were 7.2 and 4.8% in the clinical trial program. The pharmacovigilance reporting rate for AEs of decreased blood potassium was 0.45%; serum potassium < 3.5 mmol/L was reported in 4.7% of patients in the clinical trial program. For hypomagnesemia or decreased blood magnesium, reporting rates in the postmarketing setting were 0.02 and 0.16%, respectively, and they were observed in 5.3 and 0.8% of patients, respectively, in the clinical trial program.

CONCLUSIONS

Global pharmacovigilance data over 4 years confirmed that the tolerability and safety of patiromer in clinical practice is predictable and consistent with clinical trial data, with no evidence of any new safety signals to date.

Consensus-Based Recommendations for the Management of Hyperkalemia in the Hemodialysis Setting

Hyperkalemia (serum K⁺ >5.0 mmol/L) is commonly observed among patients receiving maintenance hemodialysis and associated with increased risk of cardiac arrhythmias. Current international guidelines may not reflect the latest evidence on managing hyperkalemia in patients undergoing hemodialysis, and there is a lack of high-quality published studies in this area. This consensus guideline aims to provide recommendations in relation to clinical practice. Available published evidence was evaluated through a systematic literature review, and the nominal group technique was used to develop consensus recommendations from a panel of experienced nephrologists, covering monitoring, dietary restrictions, prescription of K⁺ binders, and concomitant prescription of renin-angiotensin-aldosterone system inhibitors. Recent studies have shown that K⁺ binders reduce the incidence of hyperkalemia, but further evidence is needed in areas including whether reduced-K⁺ diets or treatment with K⁺ binders improve patient-centered outcomes. Treatment of hyperkalemia in the hemodialysis setting is complex, and decisions need to be tailored for individual patients.

Hyperkalemia in Chronic Kidney Disease in the New Era of Kidney Protection Therapies

Despite recent therapeutic advances, chronic kidney disease (CKD) is one of the fastest growing global causes of death. This illustrates limitations of current therapeutic approaches and, potentially, unidentified knowledge gaps. For decades, renin-angiotensin-aldosterone system (RAAS) blockers have been the mainstay of therapy for CKD. However, they favor the development of hyperkalemia, which is already common in CKD patients due to the CKD-associated decrease in urinary potassium (K⁺) excretion and metabolic acidosis. Hyperkalemia may itself be life-threatening as it may trigger potentially lethal arrhythmia, and additionally may limit the prescription of RAAS blockers and lead to low-K⁺ diets associated to low dietary fiber intake. Indeed, hyperkalemia is associated with adverse kidney, cardiovascular, and survival outcomes. Recently, novel kidney protective therapies, ranging from sodium/glucose cotransporter 2 (SGLT2) inhibitors to new mineralocorticoid receptor antagonists have shown efficacy in clinical trials. Herein, we review K⁺ pathophysiology and the clinical impact and management of hyperkalemia considering these developments and the availability of the novel K⁺ binders patiromer and sodium zirconium cyclosilicate, recent results from clinical trials targeting metabolic acidosis (sodium bicarbonate, veverimer), and an increasing understanding of the role of the gut microbiota in health and disease.

[Recurrent hyperkalaemia management and use of renin-angiotensin-aldosterone system inhibitors: Analysis of French data from the PROKALE multinational European study]

INTRODUCTION

Recurrent hyperkalaemia may result in underutilisation of renin-angiotensin-aldosterone system inhibitors. We report an analysis of French data from the PROKALE retrospective study, which assessed the management of recurrent hyperkalaemia in five European countries.

PATIENTS AND METHODS

A retrospective chart review including patients not on dialysis with two or more hyperkalaemia episodes≥5.5 mEq/L documented within a 12-month observation period was performed.

RESULTS

In France, 115 physicians (57 nephrologists et 58 cardiologists) participated in the study and 295 patients were studied in this analysis. Mean age was 68 years; 212 patients (71.9%) had chronic kidney disease, 108 (36.6%) had chronic heart failure and 102 (34.6%) had diabetes mellitus. The mean number of documented hyperkalaemic episodes was 2.3. A total of 90 hospitalizations occurred during the observation period, of which 24 (26.7%) were directly related to a hyperkalaemic episode. At the time of the first documented hyperkalaemic episode, measures used for the management of hyperkalaemia included loop diuretics (144 patients [48.8%]), sodium/calcium polystyrene sulphonate (135 patients [45.8%]), a low-potassium diet (31 patients [10.5%]) and sodium bicarbonate (31 patients [10.5%]). Between the two consecutive hyperkalaemic episodes documented, the proportion of patients on renin-angiotensin-aldosterone system inhibitors treatment decreased from 42.4% to 34.6%.

CONCLUSION

Renin-angiotensin-aldosterone system inhibitors treatment interruptions were observed in the setting of recurrent hyperkalaemic episodes. Recurrent hyperkalaemia is a major cause of hospitalizations. More effective strategies for the prevention of recurrent hyperkalaemia are needed.

Unravelling the interplay between hyperkalaemia, renin-angiotensin-aldosterone inhibitor use and clinical outcomes. Data from 9222 chronic heart failure patients of the ESC-HFA-EORP Heart Failure Long-Term Registry

AIMS

We assessed the interplay between hyperkalaemia (HK) and renin-angiotensin-aldosterone system inhibitor (RAASi) use, dose and discontinuation, and their association with all-cause or cardiovascular death in patients with chronic heart failure (HF). We hypothesized that HK-associated increased death may be related to RAASi withdrawal.

METHODS AND RESULTS

The ESC-HFA-EORP Heart Failure Long-Term Registry was used. Among 9222 outpatients (HF with reduced ejection fraction: 60.6%, HF with mid-range ejection fraction: 22.9%, HF with preserved ejection fraction: 16.5%) from 31 countries, 16.6% had HK (≥5.0 mmol/L) at baseline. Angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) was used in 88.3%, a mineralocorticoid receptor antagonist (MRA) in 58.7%, or a combination in 53.2%; of these, at ≥50% of target dose in ACEi: 61.8%; ARB: 64.7%; and MRA: 90.3%. At a median follow-up of 12.2 months, there were 789 deaths (8.6%). Both hypokalaemia and HK were independently associated with higher mortality, and ACEi/ARB prescription at baseline with lower mortality. MRA prescription was not retained in the model. In multivariable analyses, HK at baseline was independently associated with MRA non-prescription at baseline and subsequent discontinuation. When considering subsequent discontinuation of RAASi (instead of baseline use), HK was no longer found associated with all-cause deaths. Importantly, all RAASi (ACEi, ARB, or MRA) discontinuations were strongly associated with mortality.

CONCLUSIONS

In HF, hyper- and hypokalaemia were associated with mortality. However, when adjusting for RAASi discontinuation, HK was no longer associated with mortality, suggesting that HK may be a risk marker for RAASi discontinuation rather than a risk factor for worse outcomes.

Use of potassium-binder patiromer for up-titration of renin-angiotensin-aldosterone system inhibition therapy in a patient with chronic heart failure and reduced ejection fraction followed in a multidisciplinary integrated chronic care management programme: a case report

BACKGROUND

Chronic heart failure (CHF) is a growing epidemic. The cornerstone of pharmacological therapy in CHF patients with reduced ejection fraction (HFrEF) is the inhibition of the renin-angiotensin-aldosterone system (RAAS). One of the adverse effects of RAAS blockade is the development of hyperkalaemia, which often limits the optimization of recommended, Class I treatments. In this context, potassium binders patiromer or sodium zirconium cyclosilicate (ZS-9) provide an opportunity to optimize the pharmacological management of these patients.

CASE SUMMARY

We present a case report illustrating our real-life experience using the potassium-binder patiromer in a patient with HFrEF, in whom recurrent hyperkalaemia (up to 6.3 mmol/L with low doses of enalapril) was preventing titration of RAAS inhibition therapies. Use of patiromer allowed re-introducing ramipril (subsequently switched to sacubitril/valsartan) and eplerenone. Serum potassium levels remained normal with patiromer 16.8 g/24 h, and the patient's tolerance to patiromer was excellent.

DISCUSSION

In patients with HFrEF and recurrent hyperkalaemia, optimal RAAS inhibition is often discontinued. In this context, novel potassium binders such as patiromer or ZS-9 have been shown to be effective in lowering potassium and maintaining normokalaemia, with a good safety profile and patient tolerance, all of which make them promising alternative options. Our preliminary experience suggests that patiromer may be a helpful and well-tolerated treatment option, which may aid in achieving optimal RAAS inhibition in HFrEF patients with recurrent hyperkalaemia. Registries of HFrEF patients will help better understand whether therapies such as patiromer have prognostic benefits through facilitating optimal RAAS blockade.

Hyperkalaemia and hypokalaemia outpatient management: a survey of 500 French general practitioners

AIMS

How general practitioners (GPs) manage dyskalaemia is currently unknown. This study aimed at describing GP practices regarding hypokalaemia or hyperkalaemia diagnosis and management in their outpatients.

METHODS AND RESULTS

A telephone survey was conducted among French GPs with a 20-item questionnaire (16 closed-ended questions and 12 open-ended questions) regarding their usual management of hypokalaemia or hyperkalaemia patients, both broadly and more specifically in patients with heart failure and/or chronic kidney disease and/or in patients treated with angiotensin-converting enzyme/angiotensin receptor blockers or mineralocorticoid receptor antagonists. We aimed to interview 500 GPs spread geographically throughout France. This descriptive survey results are presented as mean ± standard deviation (if normally distributed or as median and inter-quartile range if the distribution was skewed). Categorical variables are expressed as frequencies and proportions (%). A total of 500 GPs participated in the study. Dyskalaemia thresholds (for diagnosis and intervention) and management patterns were highly heterogeneous. The mean ± SD (range) potassium level leading to 'intervene' was 5.32 ± 0.34 mmol/L (4.5-6.5) for hyperkalaemia and 3.23 ± 0.34 mmol/L (2.0-6.5) for hypokalaemia. Potassium levels leading to refer the patient to the emergency department (ED) were 6.14 ± 0.55 (4.5-10) and 2.69 ± 0.42 mmol/L (1-4), respectively. Potassium binders (51-65%) or potassium supplements (67-74%) were frequently used to manage hyperkalaemia or hypokalaemia. GPs uncommonly referred their dyskalaemic patients to cardiologists or nephrologists (or to the emergency department, if the latter was deemed necessary owing to the severity of the dyskalaemia). We identified an association between the close vicinity of GP office from an ED and 'referring a heart failure patient' (19.2% with ED vs. 8.6% without ED) and referring a heart failure and chronic kidney disease patient on mineralocorticoid receptor antagonist (16.7% with ED vs. 9.3% without ED). Although the majority (67%) of GPs had an electrocardiogram on hand, it was rarely used (14%) in dyskalaemic patients. Subgroup analyses considering gender, age of the participating GPs, and high-income/low-income regions did not identify specific patterns regarding the multidimensional aspect of dyskalaemia management.

CONCLUSIONS

Owing to the considerable heterogeneity of French GP practices toward dyskalaemia diagnosis and management approaches, there is a likely need to standardize (potentially enabled by therapeutic algorithms) practices.