Patiromer in patients with kidney disease and hyperkalemia receiving RAAS inhibitors

Can patiromer allow for intensified renin-angiotensin-aldosterone system blockade with losartan and spironolactone leading to decreased albuminuria in patients with chronic kidney disease, albuminuria and hyperkalaemia? An open-label randomised controlled trial: MorphCKD

INTRODUCTION

Chronic kidney disease (CKD) is associated with significantly increased morbidity and mortality. No specific treatment of the underlying condition is available for the majority of patients, but ACE-inhibitors (ACE-I) and angiotensin II-receptor blockers (ARB) slows progression in albuminuric CKD. Adding a mineralocorticoid receptor-antagonist (MRA) like spironolactone has an additive effect. However, renin-angiotensin-aldosterone system (RAAS)-blockade increases the risk of hyperkalaemia which is exacerbated by the presence of CKD. Thus, hyperkalaemia may prevent optimal use of RAAS-blockade in some patients.This project hypothesises that adding a potassium binder (patiromer) allows for improved RAAS-blockade including the use of MRA, thereby reducing albuminuria in patients with albuminuric CKD where full treatment is limited by hyperkalaemia.If successful, the study may lead to improved treatment of this subgroup of patients with CKD. Furthermore, the study will examine the feasibility of potassium binders in patients with CKD.

METHODS AND ANALYSIS

An open-label, randomised controlled trial including 140 patients with estimated glomerular filtration rate (eGFR) 25-60 mL/min/1.73 m², a urinary albumin/creatinine ratio (UACR) >500 mg/g (or 200 mg/g if diabetes mellitus) and a current or two previous plasma-potassium >4.5 mmol/L. Patients who develop hyperkaliaemia >5.5 mmol/L during a run-in phase, in which RAAS-blockade is intesified with the possible addition of spironolactone, are randomised to 12-month treatment with maximal tolerated ACE-I/ARB and spironolactone with or without patiromer.The primary endpoint is the difference in UACR measured at randomisation and 12 months compared between the two groups. Secondary endpoints include CKD progression, episodes of hyperkalaemia, blood pressure, eGFR, markers of cardiovascular disease, diet and quality of life.

ETHICS AND DISSEMINATION

This study is approved by The Central Denmark Region Committees on Health Research Ethics (REFNO 1-10-72-110-20) and is registered in the EudraCT database (REFNO 2020-001595-15). Results will be presented in peer-reviewed journals, at meetings and at international conferences.

RAAS Inhibitor Prescription and Hyperkalemia Event in Patients With Chronic Kidney Disease: A Single-Center Retrospective Study

Hyperkalemia is common in patients treated with renin-angiotensin-aldosterone system inhibitors (RAASis), and it represents the main cause of the large gap reported between guideline recommendations and real-world practice in chronic kidney disease (CKD). We conducted a CKD-population-based restrospective study to determine the prevalence of patients with CKD treated with RAASis, incidence of hyperkalemia in patients with CKD treated with RAASis, and proportion of patients with RAASi medication change after experiencing incident hyperkalemia. Among 809 patients with CKD analyzed, 556 (68.7%) were treated with RAASis, and RAASi prescription was greater in stages 2-4 of CKD. Hyperkalemia occurred in 9.2% of RAASi-treated patients, and the adjusted rate of hyperkalemia among patients with stage 4-5 CKD was 3-fold higher compared with patients with eGFR > 60 ml/min/1.73 m2. RAASi treatment was discontinued in 55.3% of the patients after hyperkalemia event (74.2% discontinued therapy, 3.2% received a reduced dose, and 22.6% reduced the number of RAASi drugs). This study shows that the incidence of hyperkalemia is frequently observed in patients with CKD patients with RAASis, and that rates increase with deteriorating levels of kidney function from stages 1 to 3. RAASi medication change following an episode of hyperkalemia occurred in almost half of the patients after experiencing hyperkalemia.

Cost Consequence Analysis of the Management of Hyperkalemia by Patiromer and Optimization of Renin-Angiotensin-Aldosterone System Inhibitors Therapy in Chronic Kidney Disease Patients in Saudi Arabia

Renin-angiotensin-aldosterone system inhibitors (RAASi) have been shown to improve outcomes in chronic kidney disease (CKD) patients but are associated with an increased risk of hyperkalemia in this vulnerable population. Hyperkalemia often leads to patients' downtitrating or discontinuing RAASi which can result in sub-optimal health outcomes. The objective is to evaluate the cost and health benefits of maintaining normokalemia using patiromer, an oral potassium binder while optimizing RAASi therapy in CKD patients in the Kingdom of Saudi Arabia. The medium-to long-term costs and health outcomes of patients with CKD stage 3-4 and raised serum potassium levels (≥5.5 mmol/L) at baseline were estimated, from a Saudi Arabia payer perspective, using a Markov state-transition model simulating the natural progression of CKD depending on patients' serum potassium level and usage of RAASi at different dosages. The analysis demonstrated that appropriate management of hyperkalemia, enabling optimization of RAASi, leads to cost and health benefits. The cost of patiromer is offset by 68% due to a reduction in management costs associated with CKD progression, hyperkalemia-related hospitalization, and cardiovascular (CV) events. Over a 10-year time horizon, a pool of 300 patients treated with patiromer experience increased life-expectancy [+3.78 life-years (LYs)] and slower disease progression, with decreased time spent in end-stage renal disease (-9.59 LYs). Patiromer may deliver value to both CKD patients and payers in Saudi Arabia, leading to better health outcomes for the former and reduced cost of management of CKD progression and CV events at low additional costs for the latter.

Phase I Study of the Pharmacodynamics and Safety of Sodium Zirconium Cyclosilicate in Healthy Chinese Adults

Sodium zirconium cyclosilicate (SZC) is an effective potassium binder for patients with hyperkalemia. This single‐center, open‐label, phase I study (NCT03283267) characterized the pharmacodynamics and safety of SZC in Chinese individuals. Twenty‐two healthy Chinese adults (mean age, 33.5 years) randomized 1:1 received daily oral SZC 5 or 10 g for 4 days, following 4 days on a low‐sodium, high‐potassium diet (continued throughout the study). End points were mean change from baseline in 24‐hour urinary potassium (primary) and sodium excretion, and serum potassium concentration. Urinary potassium excretion significantly decreased with SZC 5 g (mean change [mmol], –13.0; P < .001) and 10 g (–15.4; P < .001). Although urinary sodium excretion decreased significantly with SZC 5 g (–11.5; P = .030), there was no significant change with SZC 10 g (–5.1; P = .299). Serum potassium concentrations decreased significantly with SZC 5 g (–0.14; P = .031) and 10 g (–0.20; P = .002). All treatment‐emergent adverse events were mild, and none were considered causally related to SZC. Over 4 days, the pharmacodynamics and safety of SZC were consistent in healthy Chinese adults with global studies and patients of Japanese ethnicity.

Assessment of Patiromer Monotherapy for Hyperkalemia in an Acute Care Setting

IMPORTANCE

Hyperkalemia is a common electrolyte disorder in hospitalized patients; however, the clinical usefulness of administering patiromer for reduction of serum potassium levels in this setting is unknown.

OBJECTIVE

To evaluate the outcomes associated with patiromer as monotherapy in patients with acute hyperkalemia in an acute care setting.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used electronic health record data from adult patients treated with patiromer for acute hyperkalemia in emergency departments, inpatient units, and intensive care units at an urban, academic medical center in the Bronx, New York, between January 30, 2018, and December 30, 2019. Data analysis was conducted between June 2020 and February 2021.

EXPOSURES

A single dose of oral patiromer (8.4 g, 16.8 g, or 25.2 g).

MAIN OUTCOMES AND MEASURE

The primary outcome was the mean absolute reduction in serum potassium level from baseline at 3 distinct time intervals after patiromer administration: 0 to 6 hours, greater than 6 to 12 hours, and greater than 12 to 24 hours. Key secondary outcomes were the incidence of hypokalemia and potassium reduction stratified by baseline potassium level and care setting.

RESULTS

Among 881 encounters of patiromer treatment, the mean (SD) age of patients was 67.4 (14.4) years; 463 encounters (52.6%) were for male patients, and most (338 [38.4%]) were for patients who identified as non-Hispanic Black. The mean (SD) baseline serum potassium level was 5.60 (0.35) mEq/L (to convert to mmol/L, multiply by 1.0), and within the first 6 hours after patiromer administration, the mean (SD) potassium reduction was 0.50 (0.56) mEq/L (P < .001). Both absolute and relative potassium reduction from baseline varied across baseline hyperkalemia severity but not by care setting. The lowest dose of patiromer (8.4 g) was used in 721 encounters (81.8%), and in 725 encounters (82.3%), no further doses of a potassium binder were required. Hypokalemia was noted in 2 encounters (0.2%) at 24 hours after patiromer administration.

CONCLUSIONS AND RELEVANCE

In this cohort study of patients with acute, non-life-threatening hyperkalemia, a single dose of patiromer was associated with a significant decrease in serum potassium levels and a low incidence of hypokalemia. These findings suggest that patiromer monotherapy may be useful in an institutional setting for managing elevated potassium levels and minimizing the risk of hypokalemia associated with other potassium control measures.

Management of hypertension and renin-angiotensin-aldosterone system blockade in adults with diabetic kidney disease: Association of British Clinical Diabetologists and the Renal Association UK guideline update 2021

People with type 1 and type 2 diabetes are at risk of developing progressive chronic kidney disease (CKD) and end-stage kidney failure. Hypertension is a major, reversible risk factor in people with diabetes for development of albuminuria, impaired kidney function, end-stage kidney disease and cardiovascular disease. Blood pressure control has been shown to be beneficial in people with diabetes in slowing progression of kidney disease and reducing cardiovascular events. However, randomised controlled trial evidence differs in type 1 and type 2 diabetes and different stages of CKD in terms of target blood pressure. Activation of the renin-angiotensin-aldosterone system (RAAS) is an important mechanism for the development and progression of CKD and cardiovascular disease. Randomised trials demonstrate that RAAS blockade is effective in preventing/ slowing progression of CKD and reducing cardiovascular events in people with type 1 and type 2 diabetes, albeit differently according to the stage of CKD. Emerging therapy with sodium glucose cotransporter-2 (SGLT-2) inhibitors, non-steroidal selective mineralocorticoid antagonists and endothelin-A receptor antagonists have been shown in randomised trials to lower blood pressure and further reduce the risk of progression of CKD and cardiovascular disease in people with type 2 diabetes. This guideline reviews the current evidence and makes recommendations about blood pressure control and the use of RAAS-blocking agents in different stages of CKD in people with both type 1 and type 2 diabetes.

OUP accepted manuscript

Background

Hyperkalaemia is frequent in haemodialysis (HD) patients and associated with increased cardiovascular mortality. Despite routine clinical use, evidence regarding the efficacy of potassium (K⁺) binders in HD is scant. We wished to compare the efficacy of patiromer (PAT) and sodium polystyrene sulfonate (SPS) on K⁺ levels in this setting.

Methods

We screened patients in three HD centres with pre-HD K⁺ value between 5.0 and 6.4 mmol/L, after an initial 2-week washout period for those previously on K⁺ binders. We included patients in an unblinded two-arm crossover trial comparing SPS 15 g before each meal on non-dialysis days with PAT 16.8 g once daily on non-dialysis days with randomized attribution order and a 2-week intermediate washout period. The primary outcome was the mean weekly K⁺ value.

Results

We included 51 patients and analysed 48 with mean age of 66.4 ± 19.4 years, 72.9% men and 43.4% diabetics. Mean weekly K⁺ values were 5.00 ± 0.54 mmol/L, 4.55 ± 0.75 mmol/L and 5.17 ± 0.64 mmol/L under PAT (P = .003), SPS (P < .001) and washout, respectively. In direct comparison, K⁺ values and prevalence of hyperkalaemia were lower under SPS as compared with PAT (P < .001). While the incidence of gastrointestinal side effects was similar between treatments, SPS showed lower subjective tolerability score (6.0 ± 2.4 and 6.9 ± 1.9) and compliance (10.8 ± 20.4% and 2.4 ± 7.3% missed doses) as compared with PAT (P < .001 for both).

Conclusion

Both PAT and SPS are effective in decreasing K⁺ levels in chronic HD patients. However, at the tested doses, SPS was significantly more effective in doing so as compared with PAT, despite lower tolerability and compliance. Larger randomized controlled trials should be conducted in order to confirm our findings and determine whether they would impact clinical outcomes.

Stopping renin-angiotensin system inhibitors after hyperkalemia and risk of adverse outcomes

BACKGROUND

Stopping renin-angiotensin system inhibitors (RASi) after an episode of hyperkalemia is common but may involve therapeutic compromises, in that the cessation of RASi deprives patients of their beneficial cardiovascular effects.

METHODS AND RESULTS

Observational study from the Stockholm Creatinine Measurements (SCREAM) project including patients initiating RASi in routine care and surviving a first-detected episode of hyperkalemia (potassium >5.0 mmol/L). We used target trial emulation techniques based on cloning, censoring and weighting to compare stopping vs. continuing RASi within 6 months after hyperkalemia. Outcomes were 3-year risks of mortality, major adverse cardiovascular events (MACE, composite of cardiovascular death, myocardial infarction and stroke hospitalization) and recurrent hyperkalemia. Of 5669 new users of RASi who developed hyperkalemia (median age 72 years, 44% women), 1425 (25%) stopped RASi therapy within 6 months. Compared with continuing RASi, stopping therapy was associated with a higher 3-year risk of death (absolute risk difference 10.8%; HR 1.49, 95% CI 1.34-1.64) and MACE (risk difference 4.7%; HR 1.29, 1.14-1.45), but a lower risk of recurrent hyperkalemia (risk difference -9.5%; HR 0.76, 0.69-0.84). Results were consistent for events following potassium of >5.0 or >5.5 mmol/L, after censoring when the treatment decision was changed, across prespecified subgroups, and after adjusting for albuminuria.

CONCLUSION

These findings suggest that stopping RASi after hyperkalemia may be associated with a lower risk of recurrence of hyperkalemia, but higher risk of death and cardiovascular events.

Prescription Pattern of Cation Exchange Resins and Their Efficacy in Treating Chronic Hyperkalemia Among Patients With Chronic Kidney Diseases: Findings From a Population-Based Analysis in British Columbia, Canada

Background:

Little was known about how chronic hyperkalemia (cHK) in patients with chronic kidney disease (CKD) is managed in British Columbia, Canada.

Objective:

To investigate the trend in sodium polystyrene sulfonate (SPS) and calcium polystyrene sulfonate (CPS) utilization and their efficacy in treating cHK in CKD patients from British Columbia, Canada.

Study Design:

Retrospective cohort.

Setting & Patients:

CKD patients aged ≥18 years, followed in Kidney Care Clinic (KCC), who had at least 2 potassium values ≥5.0 mmol/L separated by no more than 91 days during the period of June 1, 2015, to July 31, 2021, were included. Index date was the first date of the 2 potassium values ≥5.0 mmol/L. Patients who received SPS or CPS within 90 days before index date were excluded. Patients who were on dialysis or received kidney transplantation on or before index date were also excluded.

Exposure:

Continuous exposure to SPS and CPS.

Outcome:

SPS/CPS prescription utilization trend was described by the proportion of patients ever treated with SPS/CPS, median time in days between cHK diagnosis and initiating treatment with SPS/CPS, total and median number of SPS/CPS prescriptions dispensed. Change in mean serum potassium concentration before and after a 90-day continuous treatment with SPS/CPS was estimated.

Analytical Approach:

Descriptive.

Results:

This study included 10 495 patients with cHK (median age 74 years, 60% were male). Median follow-up time was 625 days. Only 2864 (27%) patients were dispensed at least 1 prescription of either SPS or CPS. A total 7300 prescriptions were dispensed; median prescriptions dispensed per patients were 2 (interquartile range [IQR]: 1-3). Median time from index date to the first prescription dispensing date was 154 days (IQR: 36-455). Continuous 90-day treatment with SPS/CPS decreased the mean serum potassium concentration by 0.60 mmol/L, from 5.58 to 4.98 mmol/L.

Limitations:

Descriptive observational study without control group.

Conclusions:

In British Columbia, only 1 in 4 CKD patients with cHK were dispensed with SPS/CPS, mostly with higher degrees of hyperkalemia. These medications appeared to be moderately effective in reducing the serum potassium concentration. Future research is necessary to evaluate the comparative effectiveness of newer generation medications.

Multiple comorbid conditions and healthcare resource utilization among adult patients with hyperkalemia: A retrospective observational cohort study using association rule mining

Objectives

To estimate the prevalence of specific comorbid conditions (CCs) and multiple comorbid conditions (MCCs) among adult patients with hyperkalemia and examine the associations between MCCs and healthcare resource utilization (HRU) and costs.

Methods

This retrospective observational cohort study was conducted using a large administrative claims database. We identified patients with hyperkalemia (ICD-10-CM: E87.5; or serum potassium >5.0 mEq/L; or NDC codes for either patiromer or sodium polystyrene sulfonate) during the study period (1/1/2016–6/30/2019). The earliest service/claim date with evidence of hyperkalemia was identified as index date. Qualified patients had ≥12 months of enrolment before and after index date, ≥18 years of age. Comorbid conditions were assessed using all data within 12 months prior to the index date. Healthcare resource utilization and costs were estimated using all data within 12 months after the index date. Association rule mining was applied to identify MCCs. Generalized linear models were used to examine the associations between MCCs and HRU and costs.

Results

Of 22,154 patients with hyperkalemia, 94% had ≥3 CCs. The most common individual CCs were chronic kidney disease (CKD, 85%), hypertension (HTN, 83%), hyperlipidemia (HLD, 81%), and diabetes mellitus (DM, 47%). The most common dyad combination of CCs was CKD+HTN (71%). The most common triad combination was CKD+HTN+HLD (62%). The most common quartet combination was CKD+HTN+HLD+DM (36%). The increased number of CCs were significantly associated with increased ED visits, length of hospital stays, and total healthcare costs (all p-value < 0.0001).

Conclusions

MCCs are very prevalent among patients with hyperkalemia and are strongly associated with HRU and costs.

A cost-effectiveness analysis of patiromer for the treatment of hyperkalemia in chronic kidney disease patients with and without heart failure in Spain

AIMS

Renin-angiotensin-aldosterone system inhibitors (RAASi) therapy is commonly used to reduce the risk of death and to slow down disease progression in patients with chronic kidney disease (CKD), heart failure (HF) and hypertension. However, the cardio-renal benefits of RAASi therapy are also associated with an increased risk of hyperkalemia (HK), which may lead to dose reduction or discontinuation of therapy. Patiromer has demonstrated to reduce the risk of HK, which enables to maintain optimal doses of RAASi therapy. This study aimed to assess the cost-effectiveness of patiromer for the management of HK in CKD patients with and without HF in Spain.

METHODS

A Markov model was developed to evaluate the costs and benefits of patiromer for the management of HK in patients with CKD stages 3-4 with and without HF treated with RAASi over a lifetime horizon. The main outcomes included total direct costs (€2021), quality-adjusted life-years (QALYs), life-years gained (LYG) and incremental cost-effectiveness ratio (ICER). Deterministic one-way and probabilistic sensitivity analyses were performed to assess the robustness of the results.

RESULTS

Patiromer was more effective compared to no patiromer (5.76 vs 5.57 QALYs; 7.73 vs 7.50 LYG), and resulted in an incremental cost of €3,574, yielding an ICER of €19,092/QALY gained and of €15,236/LYG. Sensitivity analyses suggested that the results were robust to changes in most input parameters.

CONCLUSIONS

Patiromer is a cost-effective intervention in maintaining normokalemia and enabling optimal RAASi therapy in patients with CKD stages 3-4 with and without HF in Spain.

New Aspects in the Management of Hypertension in Patients with Chronic Kidney Disease not on Renal Replacement Therapy

With chronic kidney disease (CKD) being a global arising health problem, strategies for delaying kidney disease progression and reducing the high cardiovascular risk inherent to CKD, are the main objectives of the actual management of patients with kidney diseases. In these patients, the control of arterial hypertension is essential, as high blood pressure (BP) is a strong determinant of worst cardiovascular and renal outcomes. Achieving target blood pressures recommended by international guidelines is mandatory and often demands a multiple levels management, including several pharmacological and lifestyle measures. Even in the presence of adequate BP control, the residual cardiovascular risk remains high. In this respect, the recent demonstration that novel agents such as sodium glucose transporter 2 (SGLT2) inhibitors or the new non-steroidal mineralocorticoid antagonist finerenone can retard the progression of kidney diseases and reduce cardiovascular mortality on top of standard of care treatment with renin-angiotensin system inhibitors represent enormous progresses. These studies also demonstrate that cardiovascular and renal protection can be obtained beyond blood pressure control. Other promising novelties are still to come such as renal denervation and endothelin receptor antagonists in the setting of diabetic and non-diabetic kidney diseases. In the present review, we shall discuss the classic and the new aspects for the management of hypertension in CKD, integrating the new data from recent clinical studies.

Optimization of RAASi Therapy with New Potassium Binders for Patients with Heart Failure and Hyperkalemia: Rapid Review and Meta-Analysis

(1) Background: The objective of this rapid review is to assess whether new potassium binders (NPBs) could enable the optimization of RAASi therapy more than usual care or placebo in patients with or at risk of heart failure and hyperkalemia. (2) Methods: We searched for RCTs that included patients with or at risk of hyperkalemia and patients treated with Patiromer or sodium zirconium cyclosilicate (ZSC). The comparators were placebo, usual care, and potassium binders with different doses or different treatment protocols. We searched the Cochrane CENTRAL, MEDLINE, and ClinicalTrials.gov databases. The risk of bias was assessed using the Cochrane risk of bias tool for RCTs. Data were pooled using the random effects model, and the fixed effects model was used for sensitivity analysis. (3) Results: We included 12 studies with 2800 enrolled patients. Only three of these trials (412 patients) were included in the meta-analysis. NPBs seemed to have an effect on the optimization of MRA therapy, with an RR (95% CI) of 1.24 (1.09, 1.42) (moderate certainty evidence); Patiromer seemed to have an effect on MRA optimization, with an RR (95% CI) or 1.25 (1.08, 1.45) (high certainty evidence). ZSC seemed to have no effect on enabling MRA therapy, with an RR (95% CI) of 1.19 (0.89, 1.59) (low certainty evidence). The AEs in HF patients with hyperkalemia treated with Patiromer were GI disorders and hypomagnesemia. ZSC The AEs included chronic cardiac failure, hypokalemia, and edema. (4) Conclusions: This meta-analysis included three studies with a small number of patients and a short follow-up period (1–3 months). The evidence of the effect of NPBs on MRA optimization had a moderate certainty for imprecision. Data on the effect on MRA optimization and less severe AEs in long-term treatment seem to suggest the use of Patiromer for the optimization of MRA therapy in patients with or at risk of heart failure and hyperkalemia. Future adequately powered RCTs are needed to assess the benefits and potential harms of potassium binders.

Development and outcomes of hyperkalemia in hospitalized patients: potential implications for care

INTRODUCTION

While severe hyperkalemia is commonly encountered, its manifestation in hospitalized patients and related outcomes are unclear. We aimed to examine development of hyperkalemia in hospitalized patients and associated outcomes.

METHODS

Data from a county hospital electronic health record were used to assess all inpatient admissions, 2012-2016, for non-dialysis-dependent patients with ≥1 K value for development of hyperkalemia. Unadjusted odds ratios (ORs) were calculated for associations of the maximum K value with in-hospital mortality and adjusted ORs were calculated for death associated with hyperkalemia.

RESULTS

In 47,018 individual patient hospitalizations, 1.3% had a maximum K ≥6.0 mEq/L and 4.2% <3.5 mEq/L. Fifth and 95th percentiles for maximum K values were 3.5 and 5.3 mEq/L. For high-K patients with a prior K value, the mean (SD) of the immediate pre-maximum K value was 5.0 ± 1.0 mEq/L, and the mean difference in K values (immediate pre-maximum to maximum) was 1.5 ± 1.1 mEq/L; mean duration between these two K tests was 10.7 ± 14.9 hours. Compared with maximum K values 3.5 to 4.0 mEq/L, ORs for death were 37.1 (95% confidence intervals, 25.8-53.3) for K 6.0 to <6.5, 88.6 (56.8-138.2) for K ≥7.0, and 18.9 (4.3-82.2) for K <3.0 mEq/L. In adjusted models, the OR for death for K ≥6.0 mEq/L was 4.9 (3.7-6.4).

DISCUSSION/CONCLUSIONS

Peak K values ≥6.0 mEq/L were associated with mortality. Values tended to increase rapidly, limiting opportunities for detection and treatment. Systems-based approaches to detect life-threatening hyperkalemia should be studied.

Hyperkalaemia management and related costs in chronic kidney disease patients with comorbidities in Spain

BACKGROUND

Hyperkalaemia (HK) is a common electrolyte disorder in patients with chronic kidney disease (CKD) and/or treated with renin-angiotensin-aldosterone system inhibitors (RAASis). The aim of this study is to determine the severity, current management and cost of chronic HK.

METHODS

We performed a retrospective cohort study of patients with chronic HK and CKD, heart failure or diabetes mellitus between 2011 and 2018. The study follow-up was 36 months.

RESULTS

A total of 1499 patients with chronic HK were analysed: 66.2% presented with mild HK, 23.4% with moderate HK and 10.4% with severe HK. The severity was associated with CKD stage. Most patients (70.4%) were on RAASi therapies, which were frequently discontinued (discontinuation rate was 39.8, 49.8 and 51.8% in mild, moderate and severe HK, respectively). This RAASi discontinuation was similar with or without resin prescription. Overall, ion-exchange resins were prescribed to 42.5% of patients with HK and prescriptions were related to the severity of HK, being 90% for severe HK. Adherence to resin treatment was very low (36.8% in the first year and 17.5% in the third year) and potassium remained elevated in most patients with severe HK. The annual healthcare cost per patient with HK was €5929, reaching €12 705 in severe HK. Costs related to HK represent 31.9% of the annual cost per HK patient and 58.8% of the specialized care cost.

CONCLUSIONS

HK was usually managed by RAASi discontinuation and ion-exchange resin treatment. Most patients with HK were non-adherent to resins and those with severe HK remained with high potassium levels, despite bearing elevated healthcare expenditures.

Possible Advantages Deriving from Patiromer Use in Hypertensive Patients Made Hyperkalemic by Renin-Angiotensin-Aldosterone Blocking Agents

Hyperkalemia is an elevated level of serum potassium (K⁺) and does represent a life-threatening condition. In clinical practice, hyperkalemia mainly derives from an impaired renal K⁺ excretion which, in turn, is usually caused by either acute or chronic renal failure. In concordance with this, hyperkalemia is very common in several chronic conditions, such as kidney disease, diabetes mellitus, heart failure, hypertension, and coronary heart disease. In all of these conditions the use of Renin-Angiotensin-Aldosterone System inhibitors (RAASIs), such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), and mineralocorticoid receptor antagonist is widely recommended and further increases the risk of hyperkalemia. As hypertension is concerned, clinical trials suggest that the risk of hyperkalemia associated with RAASIs ranges from 2 to 10%. This often leads to a reduction or complete cessation of RAASIs, leaving patients without protective medications. Patiromer, a new oral potassium-binding agent, has been approved for clinical use in several countries, including Europe and US. Clinical studies have demonstrated that patiromer is effective in inducing a rapid and sustained K⁺ reduction in various patient settings, including those where RAASIs are a fundamental component of cardiorenal protection. Patiromer is generally well tolerated and characterised by a good safety profile. Most importantly, patiromer use might allow the continuation of ACEIs and ARBs in hypertensive patients developing hyperkalemia during treatment and thereby favour a more effective and long-lasting cardiorenal protection.

Pseudohyperkalemia and the Need for Imperative Caution With the Newly Introduced Potent Potassium Binders: Two Cases

Pseudohyperkalemia was first reported in 1955 by Hartmann and Mellinkoff, as a marked elevation of serum potassium in the absence of clinical evidence of electrolyte imbalance - simultaneous serum potassium exceeds plasma potassium by >0.4 mmol/L. We describe two patients with pseudohyperkalemia who inadvertently received inappropriate potassium binder therapy for weeks to months before the diagnosis of pseudohyperkalemia was entertained and subsequently confirmed. Potassium binders ultimately were promptly discontinued once the diagnosis of pseudohyperkalemia was confirmed. Physicians’ attention must be drawn to the availability of the new potent oral potassium binders, patiromer and sodium zirconium cyclosilicate. We strongly advocate for imperative caution with these new binders. Iatrogenic life-threatening hypokalemia remains a real concern and must be avoided. Our patients highlighted the importance of caution in the use of the newer potent potassium binders to mitigate against the causation of iatrogenic hypokalemia. Also as important is the observation that in the same patient, with changing clinical scenarios, a patient might exhibit true hyperkalemia that alternated with pseudohyperkalemia, the first of such a report.

Mineralocorticoid Receptor Antagonists-Use in Chronic Kidney Disease

Mineralocorticoid receptor antagonists (MRA) are drugs with a potentially broad spectrum of action. They have been reported to have healing effects in many diseases, such as chronic heart failure, hypertension, or nephrotic syndrome. Numerous studies suggest that mineralocorticoid receptor activation is pathogenic and a progression factor of chronic kidney disease (CKD); however, results of studies on the use of MRA in the treatment of CKD are inconclusive. Current guidelines recommend against the use of MRA in patients with advanced CKD. Although, there is growing interest on their use in this population due to treatment benefits. In this review, we summarize studies which were purposed to evaluate the impact of MRA therapy on CKD patients. Despite many benefits of this treatment e.g., reducing cardiovascular mortality or alleviating proteinuria, steroidal MRA (such as spironolactone or eplerenone) have a low safety profile. They often lead to hyperkalemia complications which are dangerous in patients with CKD, and diabetic nephropathy, especially in hemodialysis patients. Studies on recently developed nonsteroidal MRA showed that they have fewer side effects. In our review, we discuss steroidal and nonsteroidal MRA treatment effects on the estimated glomerular filtration rate (eGFR), proteinuria, the cardiovascular system, and hyperkalemia in CKD patients. We present new content and recent publications in this field.

The Role of Patiromer in Delaying the Onset of Renal Replacement Therapy in Patients with Advanced Renal Failure

Patients with chronic kidney disease (CKD) are at an increased risk of developing hyperkalemia, which can be potentially life threatening. Hyperkalemia is frequently encountered with renin-angiotensin-aldosterone system inhibitor (RAASi) therapy use in patients with CKD and often results in the underdosing or discontinuation of these drugs. RAASi therapy has been proven to delay the progression of CKD, ameliorate proteinuria, and reduce the overall risk of cardiovascular morbidity and mortality. Patiromer is a sodium-free, potassium-binding polymer used for the treatment of hyperkalemia. We present a case series of four patients with Stage 4 or 5 CKD in whom the initiation of dialysis was delayed with the use of patiromer. For one patient, dialysis was delayed by 18 months, whereas the remaining three patients, in whom hyperkalemia was one of the main complications, remain dialysis independent to date.

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.

Hyperkalemia with RAAS inhibition: Mechanism, clinical significance, and management

Renin-angiotensin-aldosterone system (RAAS) inhibitors are evidence-based treatments for a number of conditions including hypertension, diabetes mellitus, chronic kidney disease, and congestive heart failure. Among the most common adverse effects of RAAS inhibitors is hyperkalemia which results from either reduced secretion of aldosterone or increased resistance to aldosterone. Many of the conditions for which RAAS inhibitors are recommended further amplify the risk for hyperkalemia in and of themselves. RAAS inhibitor-related hyperkalemia is associated with an increased risk for cardiovascular events, hospitalizations, and death. Yet discontinuation of RAAS inhibitors for patients with chronic kidney disease and congestive heart failure is also associated with an increased risk for cardiovascular events, hospitalizations, and death. Therefore, clinicians are often left to struggle with the dilemma of the best management approach to RAAS inhibitor-related hyperkalemia. The ideal solution involves pharmacotherapies that are safe and effective in mitigating hyperkalemia and allow patients to continue to receive the beneficial effects from RAAS inhibitors. In this regard, modern pharmacologic agents such as patiromer and zirconium cyclosilicate are providing a mechanism whereby physicians are better equipped to maintain their patients on RAAS inhibitors.

A Rare Case of Patiromer Induced Hypercalcemia

Patiromer is a calcium (Ca)-potassium (K) exchange resin approved for the treatment of hyperkalemia. Disorders of Ca or acid base balance were not reported in pre-approval clinical trials. We present a case of a patient with chronic kidney disease (CKD) with an unusual picture of hypercalcemia, metabolic alkalosis and hypokalemia upon intensification of patiromer dosing. A 56-year-old white man with CKD stage 4 (baseline creatinine 2.8 mg/dL) due to type 1 diabetes mellitus, proteinuria (1.5 g/g) and persistently high serum potassium 5.9 mEq/L attributed to type 4 renal tubular acidosis was evaluated in clinic. Due to high risk of CKD progression, patiromer 8.4 g daily, followed by 16.8 g daily was prescribed to enable renin angiotensin aldosterone system (RAAS) inhibitor. After 5 months of being on patiromer 16.8 g daily, routine laboratory tests revealed serum potassium 2.5 mEq/L, serum calcium 12.8 mg/dL and carbon dioxide 34 mEq/L. Patiromer was discontinued and thorough investigation held was negative for other causes of hypercalcemia. Five days after patiromer discontinuation, serum calcium returned to normal. The role of secondary hyperparathyroidism in this case remains unclear. We, therefore recommend cautious vigilance of patients receiving patiromer and undergoing dose escalation.

Population Epidemiology of Hyperkalemia: Cardiac and Kidney Long-term Health Outcomes

RATIONALE & OBJECTIVE

The population burden and long-term implications of hyperkalemia have not been comprehensively studied. We studied how often and where hyperkalemia occurs as well as its independent association with survival and long-term cardiac and kidney health.

STUDY DESIGN

Population-based cohort study of adult residents of Grampian, United Kingdom.

SETTING & PARTICIPANTS

Among the 468,594 adult residents (2012-2014), 302,630 people with at least 1 blood test were followed until 2019.

EXPOSURE

Hyperkalemia was defined as serum potassium ≥ 5.5 mmol/L. Adjustment for comorbidities, demographics, measures of acute and chronic kidney function, and medications prescribed before measurement of serum potassium.

OUTCOME

All-cause mortality, cardiac events, and kidney failure.

ANALYTICAL APPROACH

Description of the annual incidence of hyperkalemia and the characteristics associated with its occurrence, and adjusted Cox proportional hazards (PH) analysis to evaluate the independent long-term association of hyperkalemia with all-cause mortality among people who survived ≥90 days after blood testing. Cause-specific PH models were fit to evaluate the association of hyperkalemia with cardiac events/death, noncardiac death, and kidney failure. Effect modification by level of estimated glomerular filtration rate (eGFR) at the time of blood testing was explored.

RESULTS

The annual population incidence of hyperkalemia was 0.96 per 100 person-years. This represented 2.3%, 2.1%, and 1.9% of people with at least one blood test in 2012, 2013, and 2014, respectively. Two-thirds of episodes of hyperkalemia occurred in the community. The hyperkalemia rate was 2-fold higher for each 10-year greater age. Those with hyperkalemia were 20 times more likely to have concurrent acute kidney injury (AKI), and 17 times more likely to have an eGFR of <30 mL/min/1.73 m². Throughout 5 years of follow-up evaluation (2,483,452 person-years), hyperkalemia was associated with poorer health outcomes. This association held across all levels of kidney function and was irrespective of concurrent AKI, but was stronger among those with a baseline eGFR of ≥60 mL/min/1.73 m² (P for interaction < 0.001). The adjusted HRs (hyperkalemia vs no hyperkalemia) for people with eGFR ≥60 mL/min/1.73 m² and eGFR <30 mL/min/1.73 m² were 2.3 (95% CI, 2.2-2.5) and 1.5 (95% CI, 1.3-1.6) for mortality; 1.8 (95% CI, 1.6-1.9) and 1.4 (95% CI, 1.2-1.6) for cardiac events; and 17.0 (95% CI, 9.3-31.1) and 2.0 (95% CI, 1.5-2.8) for kidney failure, respectively.

LIMITATIONS

The observational nature of this study limits evaluation of causal relationships.

CONCLUSIONS

There is a substantial burden of hyperkalemia in the general population. Hyperkalemia is associated with poorer long-term health outcomes, especially kidney outcomes, that are independent of other established risk factors.

Binding Potassium to Improve Treatment With Renin-Angiotensin-Aldosterone System Inhibitors: Results From Multiple One-Stage Pairwise and Network Meta-Analyses of Clinical Trials

This manuscript presents findings from the first dichotomous data pooling analysis on clinical trials (CT) regarding the effectiveness of binding potassium. The results emanated from pairwise and network meta-analyses aiming evaluation of response to commercial potassium-binding polymers, that is, to achieve and maintain normal serum potassium (n = 1,722), and the association between this response and an optimal dosing of renin-angiotensin-aldosterone system inhibitors (RAASi) needing individuals affected by heart failure (HF) or resistant hypertension, who may be consuming other hyperkalemia-inducing drugs (HKID) (e.g., β-blockers, heparin, etc.), and frequently are affected by chronic kidney disease (CKD) (n = 1,044): According to the surface under the cumulative ranking area (SUCRA), sodium zirconium cyclosilicate (SZC) (SUCRA >0.78), patiromer (SUCRA >0.58) and sodium polystyrene sulfonate (SPS) (SUCRA <0.39) were different concerning their capacity to achieve normokalemia (serum potassium level (sK+) 3.5-5.0 mEq/L) or acceptable kalemia (sK+ ≤ 5.1 mEq/L) in individuals with hyperkalemia (sK+ >5.1 mEq/L), and, when normokalemia is achieved, patiromer 16.8-25.2 g/day (SUCRA = 0.94) and patiromer 8.4-16.8 g/day (SUCRA = 0.41) can allow to increase the dose of spironolactone up to 50 mg/day in subjects affected by heart failure (HF) or with resistant hypertension needing treatment with other RAASi. The potential of zirconium cyclosilicate should be explored further, as no data exists to assess properly its capacity to optimize dosing of RAASi, contrarily as it occurs with patiromer. More research is also necessary to discern between benefits of binding potassium among all type of hyperkalemic patients, for example, patients with DM who may need treatment for proteinuria, patients with early hypertension, etc. Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42020185614, CRD42020185558, CRD42020191430.

Hyperkalemia in patients undergoing hemodialysis: its pathophysiology and management

Potassium is a major intracellular cation in the body, regulating membrane potential of excitable cells, such as cardiomyocytes and skeletal muscle cells. Because the kidney plays a critical role in controlling potassium balance, the elevation in serum potassium levels is one of the most common complications in patients with maintenance hemodialysis (MHD). In addition to reduced renal potassium excretion, the alteration in body potassium distribution owing to comorbid conditions may also contribute to dyskalemia. Besides potassium elimination through hemodialysis in MHD patients, accumulating data indicate the potential importance of extra‐renal elimination involving the gastrointestinal system, which can be affected by the inhibitors of the renin‐angiotensin‐aldosterone system. In this article, the literature on potassium physiology in MHD patients is reviewed with an emphasis on the changes from individuals with normal kidney function. This article also summarizes the findings of recent studies on dietary control, dialysate prescription, and pharmacological therapy.

New Drugs for Heart Failure: What is the Evidence in Older Patients?

Heart failure (HF) is a major public health concern, with a high prevalence in the older population. The majority of randomized clinical trials evaluating new emerging pharmacologic agents for HF (eg, angiotensin receptor-neprilysin inhibitors, sodium-glucose cotransporter 2 inhibitors, intravenous iron for deficiency treatment, transthyretin stabilizers, soluble guanylate cyclase stimulators, cardiac myosin activators, and new potassium binders) have found positive results on various clinical outcomes, particularly in patients with reduced ejection fraction. These treatments might have an important role in the management of older patients as well. Nevertheless, trials demonstrating benefit of these drugs have involved patients significantly younger (on average, approximately 10 years) and fewer comorbidities than those commonly encountered in clinical practice. We describe the recent evidence regarding the newest HF drugs and their applicability to older individuals in terms of efficacy and safety, and we discuss their effects on outcomes particularly valuable to older patients, such as preservation of cognitive function, functional status, independence, and quality of life. Although available subgroup analyses seem to confirm efficacy and safety across the age spectrum for some of these drugs, their effects on older patients centered outcomes often have been neglected. Future HF trials should be designed to include older patients more representative of the real clinical practice, to overcome generalizability biases.

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.

Cardiorenal Syndrome: An Important Subject in Nephrocardiology

Coexisting dysfunction of heart and kidney, the cardiorenal syndrome, is a common condition and is associated with worsening of outcomes and complexities of diagnostic, preventive, and therapeutic approaches. The knowledge of the physiology of heart and kidney and their interaction with each other and with other organ systems has progressed significantly in recent years, resulting in a better understanding of the pathogenesis of cardiorenal syndrome. A robust knowledge of the pathophysiology and of the latest practical advancements about cardiorenal syndrome is necessary for cardiologists, nephrologists, and other practitioners who provide medical care to the patients with heart and kidney diseases.

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.

Risk of hyperkalemia from renin-angiotensin-aldosterone system inhibitors and factors associated with treatment discontinuities in a real-world population

BACKGROUND

Hyperkalemia rates in renin-angiotensin-aldosterone system (RAAS) inhibitor users, and factors associated with treatment interruptions and cessations, have not been explored in a large, population-wide database.

METHODS

RAAS inhibitor users were identified in the linked UK Clinical Practice Research Datalink-Hospital Episodes Statistics data set, 2009-15. Treatment interruptions (no active prescription followed by reappearance) and cessations were determined. Hyperkalemia (serum K+>5.5 mmol/L) rates were calculated and factors associated with interruptions and cessations modeled using time-varying Cox regression, including hyperkalemia (as a time-dependent variable).

RESULTS

Among 434 027 RAAS inhibitor users, the hyperkalemia rate was 1.30 (95% confidence interval 1.28-1.32) per 100 patient-years. Of 73.7% of patients who experienced off-treatment periods, 57.6% experienced interruption only, 7.5% cessation only and 8.6% both. Within 1 year of initiating RAAS inhibitor treatment, approximately one-third of the patients experienced interruption or cessation. Hazard ratios for patients with severe hyperkalemia were 1.10 (10.5-1.16) for interruptions and 3.37 (3.25-3.50) for cessation. Compared with no chronic kidney disease (CKD), risk of interruption was 1.20 (1.16-1.25) and 1.57 (1.44-1.72) for Stages 4 and 5, respectively, and of cessation was 2.20 (2.07-2.33) and 2.87 (2.56-3.22). Risk of interruption increased for patients with heart failure or diabetes [1.04 (1.02-1.05); 1.13 (1.12-1.14), respectively] but the risk of cessation decreased [0.85 (0.82-0.87); 0.92 (0.90-0.94)].

CONCLUSIONS

Risk of RAAS inhibitor interruption and cessation increased as CKD stage progressed. Efforts targeting reasons for interruptions and, especially, cessations, such as hyperkalemia prevention, could decrease off-treatment periods for patients who would otherwise benefit, such as those with CKD, heart failure or diabetes.

Sodium zirconium cyclosilicate for the management of chronic hyperkalemia in kidney disease, a novel agent

INTRODUCTION

Hyperkalemia is a common finding in patients with advanced kidney disease for multiple reasons. Renin-Angiotensin-Aldosterone-System Inhibitors (RAASi) that are indicated for slowing down progression of kidney disease are often associated with hyperkalemia which becomes a limiting factor in their use and titration to the maximum dose. Having a safe, effective, tolerable, and affordable potassium binder can help optimize RAAS inhibition in the setting of kidney disease.

AREAS COVERED

Although sodium polystyrene sulfonate has been a mainstay of acute management of hyperkalemia for decades, evidence regarding its efficacy is limited, and its chronic use is not routinely recommended for concerns regarding toxicity. The concern of gastrointestinal (GI) adverse effects with sodium polystyrene sulfonate has spurred the development of alternatives. Sodium zirconium cyclosilicate (SZC) is a promising agent that selectively binds potassium in the gut and eliminates it, while being safe for chronic use based on 1 year of data. Even though we do not have head-to-head studies among the three currently available binders, SZC stands out in rapidity of onset and efficacy.

EXPERT OPINION

In this review, we summarize the general management of hyperkalemia, including new agents. We review the pre-clinical and clinical data relating to sodium zirconium cyclosilicate.

Patiromer and Sodium Zirconium Cyclosilicate in Treatment of Hyperkalemia: A Systematic Review and Meta-Analysis

Background

Patiromer and sodium zirconium cyclosilicate (SZC) are newer options for hyperkalemia treatment. This systematic review and meta-analysis were conducted to assess the safety and side effect profile of patiromer and SZC compared with placebo or other standards of care in the management of hyperkalemia.

Methods

We searched electronic databases for relevant articles. The screening was performed independently and data were extracted among the selected studies. We performed a statistical analysis on Revman 5.4 software. The odds ratio (OR) was used for outcome estimation with a 95% CI.

Results

Patiromer had lower rates of hyperkalemia (OR = 0.44; 95% CI, 0.22–0.89) compared with standard of care. The analysis showed no significant differences between the 2 groups in terms of overall adverse effects, any serious/specific adverse effects, or treatment discontinuation as a result of adverse effects. Comparing the SZC-10 group with standard of care showed no significant differences in the occurrence of hyperkalemia during treatment, overall adverse effects, any serious/specific adverse effects, or treatment discontinuation as a result of adverse effects but showed a higher rate of edema in the treatment group (OR = 6.77; 95% CI, 1.03–44.25). Similarly, no significant differences were seen between the 2 SZC doses for the occurrence of any adverse effects, hyperkalemia, constipation, diarrhea, or urinary tract infection, whereas edema was higher among patients receiving SZC-10 (OR = 3.13; 95% CI, 1.19–8.27).

Conclusions

In patients with acute hyperkalemia, SZC is the drug of choice due to its more rapid reduction of serum potassium level, whereas in patients with chronic hyperkalemia, patiromer appears to be the drug of choice because SZC is associated with an increase in edema, likely due to an increase in sodium absorption, which could have important adverse consequences in patients with chronic kidney disease and or heart failure. Thus, both drugs were found to be safe while treating hyperkalemia. (Curr Ther Res Clin Exp. 2021; 82:XXX–XXX)

Tailoring the management of hypertension to comorbidities

PURPOSE OF REVIEW

In this article, we review the most current evidence for initiation and maintenance of various antihypertension (HTN) drug classes, including other misconceptions with respect to common comorbidities in patients with HTN.

RECENT FINDINGS

Although the currently available anti-HTN agents have broad applicability in treating HTN, additional agents, such as angiotensin receptor-neprilysin inhibitors and novel nonsteroidal mineralocorticoid antagonists, have recently gained clinical significance. In addition, there have been some anecdotal concerns regarding the adverse effects, indications, and risks of COVID-19 infection/mortality when using certain anti-HTN agents.

SUMMARY

Current guidelines currently address the treatment of primary HTN. However, isolated HTN is uncommon and often involves comorbid diseases that require specific regimentation. Several experimental medications are currently in late-stage trials showing potential superiority over current drugs that are available in the market.

Dietary Potassium Intake and Mortality in a Prospective Hemodialysis Cohort

OBJECTIVES

Among hemodialysis patients, clinical practice guidelines recommend dietary potassium restriction given concerns about potential hyperkalemia leading to malignant arrhythmias and mortality. However, there are sparse data informing recommendations for dietary potassium intake in this population. We thus sought to examine the relationship between dietary potassium intake and death risk in a prospective cohort of hemodialysis patients.

DESIGN AND METHODS

Among 415 hemodialysis patients from the prospective "Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease" cohort recruited across 16 outpatient dialysis clinics, information regarding dietary potassium intake was obtained using Food Frequency Questionnaires administered over October 2011 to March 2015. We first examined associations of baseline dietary potassium intake categorized as tertiles with mortality risk using Cox regression. We then examined clinical characteristics associated with low dietary potassium intake (defined as the lowest tertile) using logistic regression.

RESULTS

In expanded case-mix Cox analyses, patients whose dietary potassium intake was in the lowest tertile had higher mortality (ref: highest tertile) (adjusted hazard ratio 1.74, 95% confidence interval 1.14-2.66). These associations had even greater magnitude of risk following adjustment for laboratory and nutritional covariates (adjusted hazard ratio 2.65, 95% confidence interval 1.40-5.04). In expanded case-mix restricted cubic spline analyses, there was a monotonic increase in mortality risk with incrementally lower dietary potassium intake. In expanded case-mix logistic regression models, female sex; higher serum bicarbonate; and lower dietary energy, protein, and fiber intake were associated with low dietary potassium intake.

CONCLUSIONS

In a prospective cohort of hemodialysis patients, lower dietary potassium intake was associated with higher mortality risk. These findings suggest that excessive dietary potassium restriction may be deleterious in hemodialysis patients, and further studies are needed to determine the optimal dietary potassium intake in this population.

Patiromer in a Patient with Severe Hyperkalemia on Incremental Hemodialysis with 1 Session per Week: A Case Report and Literature Review

Hyperkalemia is common in patients with ESRD, undergoing hemodialysis (HD), and is associated with an increase in hospitalization and mortality. Residual kidney function in long-term dialysis patients is associated with lower morbidity and mortality in HD patients. Although the 2015 National Kidney Foundation-Kidney Disease Outcomes Quality Initiate (NKD-KDOQI) guidelines allow the reduction in the weekly HD dose for patients with a residual kidney urea clearance (Kur) >3 mL/min/1.73 m², very few centers adjust the dialysis dose based on these criteria. In our center, the pattern of incremental hemodialysis (iHD) with once-a-week schedule (1 HD/W) has been an option for a group of patients showing very good results. This pattern is maintained as long as residual diuresis is >1,000 mL/24 h, Kur is >4 mL/min, and there is no presence of edema or volume overload, as well as no analytical parameters persistently outside the advisable range (serum phosphorus >6 mg/dL or potassium [K⁺] >6.5 mmol/L). Management of hyperkalemia in HD patients includes reduction of dietary intake, dosing of medications that contribute to hyperkalemia, and use of cation-exchange resins such as calcium or sodium polystyrene sulfonate. Two newer potassium binders, patiromer sorbitex calcium and sodium zirconium cyclosilicate, have been safely used for potassium imbalance treatment in patients with ESRD in HD with a conventional regimen of thrice weekly, but has not yet been studied in 1 HD/W schedules. We present the case of a 76-year-old woman in iHD (1 HD/W) treated with patiromer for severe HK and describe her clinical characteristics and outcomes. In addition, we review the corresponding literature. Based on these data, it can be anticipated that the use of patiromer may overcome the risk of hyperkalemia in patients with incident ESRD treated with less-frequent HD regimens.

Management of Chronic Hyperkalemia in Patients With Chronic Kidney Disease: An Old Problem With News Options

Hyperkalemia is one of the main electrolyte disorders in patients with chronic kidney disease (CKD). The prevalence of hyperkalemia increases as the Glomerular Filtration Rate (GFR) declines. Although chronic hyperkalemia is not a medical emergency, it can have negative consequences for the adequate cardio-renal management in the medium and long term. Hyperkalemia is common in patients on renin-angiotensin-aldosterone system inhibitors (RAASi) or Mineralocorticoid Receptor Antagonists (MRAs) and can affect treatment optimization for hypertension, diabetes mellitus, heart failure (HF), and CKD. Mortality rates are higher with suboptimal dosing among patients with CKD, diabetes or HF compared with full RAASi dosing, and are the highest among patients who discontinue RAASis. The treatment of chronic hyperkalemia is still challenging. Therefore, in the real world, discontinuation or reduction of RAASi therapy may lead to adverse cardiorenal outcomes, and current guidelines differ with regard to recommendations on RAASi therapy to enhance cardio and reno-protective effects. Treatment options for hyperkalemia have not changed much since the introduction of the cation exchange resin over 50 years ago. Nowadays, two new potassium binders, Patiromer Sorbitex Calcium, and Sodium Zirconium Cyclosilicate (SZC) already approved by FDA and by the European Medicines Agency, have demonstrated their clinical efficacy in reducing serum potassium with a good safety profile. The use of the newer potassium binders may allow continuing and optimizing RAASi therapy in patients with hyperkalemia keeping the cardio-renal protective effect in patients with CKD and cardiovascular disease. However, further research is needed to address some questions related to potassium disorders (definition of chronic hyperkalemia, monitoring strategies, prediction score for hyperkalemia or length for treatment).

A Predictive Model for Progression of Chronic Kidney Disease to Kidney Failure Using a Large Administrative Claims Database

Background

To create an appropriate chronic kidney disease (CKD) management program, we developed a predictive model to identify patients in a large administrative claims database with CKD stages 3 or 4 who were at high risk for progression to kidney failure.

Methods

The predictive model was developed and validated utilizing a subset of patients with CKD stages 3 or 4 derived from a large Aetna claims database. The study spanned 36 months, comprised of a 12-month (2015) baseline period and a 24-month (2016-2017) prediction period. All patients were ≥18 years of age and continuously enrolled for 36 months. Multivariate logistic regression was used to develop models. Prediction model performance measures included area under the receiver operating characteristic curve (AUROC), calibration, and gain and lift charts.

Results

Of the 74,114 patients identified as having CKD stages 3 or 4 during the baseline period, 2476 (3.3%) had incident kidney failure during the prediction period. The predictive model included the effect of numerous variables, including age, gender, CKD stage, hypertension (HTN), diabetes mellitus (DM), congestive heart failure, peripheral vascular disease, anemia, hyperkalemia (HK), prospective episode risk group score, and poor adherence to renin-angiotensin-aldosterone system inhibitors. The strongest predictors of progression to kidney failure were CKD stage (4 vs 3), HTN, DM, and HK. The ROC and calibration analyses in the validation sample demonstrated good predictive accuracy (AUROC=0.844) and calibration. The top two prediction deciles identified 70.8% of patients who progressed to kidney failure during the prediction period.

Conclusion

This novel predictive model had good accuracy for identifying, from a large national database, patients with CKD who were at high risk of progressing to kidney failure within 2 years. Early identification using this model could potentially lead to improved health outcomes and reduced healthcare expenditures in this at-risk population.

The dietary management of potassium in children with CKD stages 2-5 and on dialysis-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

Dyskalemias are often seen in children with chronic kidney disease (CKD). While hyperkalemia is common, with an increasing prevalence as glomerular filtration rate declines, hypokalemia may also occur, particularly in children with renal tubular disorders and those on intensive dialysis regimens. Dietary assessment and adjustment of potassium intake is critically important in children with CKD as hyperkalemia can be life-threatening. Manipulation of dietary potassium can be challenging as it may affect the intake of other nutrients and reduce palatability. The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric renal dietitians and pediatric nephrologists, has developed clinical practice recommendations (CPRs) for the dietary management of potassium in children with CKD stages 2-5 and on dialysis (CKD2-5D). We describe the assessment of dietary potassium intake, requirements for potassium in healthy children, and the dietary management of hypo- and hyperkalemia in children with CKD2-5D. Common potassium containing foods are described and approaches to adjusting potassium intake that can be incorporated into everyday practice discussed. Given the poor quality of evidence available, a Delphi survey was conducted to seek consensus from international experts. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs, based on the clinical judgment of the treating physician and dietitian. These CPRs will be regularly audited and updated by the PRNT.

Medical treatment of heart failure with reduced ejection fraction: the dawn of a new era of personalized treatment?

Recent trials have shown the efficacy of new drugs for the medical therapy of heart failure and reduced ejection fraction (HFrEF). Sodium-glucose cotransporter 2 inhibitors (SGLT2i) reduced hospitalizations for HF, HF events, and cardiovascular death in patients with HFrEF or hospitalized for HF. Iron repletion with ferric carboxymaltose (FCM) improved symptoms, functional capacity, and quality of life in chronic HFrEF patients, and decreased the risk of subsequent HF hospitalizations in subjects with acutely decompensated HF. New-generation potassium binders may allow initiation and up-titration of renin-angiotensin-aldosterone system inhibitors (RASi). Lastly, the guanylate cyclase stimulator vericiguat and the myosin activator omecamtiv mecarbil reduced the primary endpoint in two major controlled trials. These results open novel pathways for the treatment of HFrEF. This review discusses new opportunities of an individualized approach to HFrEF pharmacotherapy, where new compounds expand a spectrum of drugs that target primarily neuroendocrine activation. SGLT2i can be safely applied once daily at a fixed dose to the vast majority of patients with HFrEF, including those with moderate renal dysfunction and/or systolic blood pressure as low as 95-100 mmHg. Additional medications are suitable for more specific phenotypes, with ivabradine providing benefit in patients with sinus rhythm and heart rates ≥70 beats per minute, FCM in the presence of iron deficiency, and potassium-lowering agents to implement RASi when hyperkalaemia occurs. Vericiguat and omecamtiv mecarbil also have potential for tailored approaches towards the hemodynamic status. Thus, a new era is starting for a more personalized medical treatment of HFrEF.

Renal replacement treatment initiation with twice-weekly versus thrice-weekly haemodialysis in patients with incident dialysis-dependent kidney disease: rationale and design of the TWOPLUS pilot clinical trial

INTRODUCTION

The optimal haemodialysis (HD) prescription-frequency and dose-for patients with incident dialysis-dependent kidney disease (DDKD) and substantial residual kidney function (RKF)-that is, renal urea clearance ≥2 mL/min/1.73 m2 and urine volume ≥500 mL/day-is not known. The aim of the present study is to test the feasibility and safety of a simple, reliable prescription of incremental HD in patients with incident DDKD and RKF.

METHODS AND ANALYSIS

This parallel-group, open-label randomised pilot trial will enrol 50 patients from 14 outpatient dialysis units. Participants will be randomised (1:1) to receive twice-weekly HD with adjuvant pharmacological therapy for 6 weeks followed by thrice-weekly HD (incremental HD group) or outright thrice-weekly HD (standard HD group). Age ≥18 years, chronic kidney disease progressing to DDKD and urine output ≥500 mL/day are key inclusion criteria; patients with left ventricular ejection fraction <30% and acute kidney injury requiring dialysis will be excluded. Adjuvant pharmacological therapy (ie, effective diuretic regimen, patiromer and sodium bicarbonate) will complement twice-weekly HD. The primary feasibility end points are recruitment rate, adherence to the assigned HD regimen, adherence to serial timed urine collections and treatment contamination. Incidence rate of clinically significant volume overload and metabolic imbalances in the first 3 months after randomisation will be used to assess intervention safety.

ETHICS AND DISSEMINATION

The study has been reviewed and approved by the Institutional Review Board of Wake Forest School of Medicine in North Carolina, USA. Patient recruitment began on 14 June 2019, was paused between 13 March 2020 and 31 May 2020 due to COVID-19 pandemic, resumed on 01 June 2020 and will last until the required sample size has been attained. Participants will be followed in usual care fashion for a minimum of 6 months from last individual enrolled. All regulations and measures of ethics and confidentiality are handled in accordance with the Declaration of Helsinki.

TRIAL REGISTRATION NUMBER

NCT03740048; Pre-results.

Sudden cardiac death in dialysis patients: different causes and management strategies

Sudden cardiac death (SCD) represents a major cause of death in end-stage kidney disease (ESKD). The precise estimate of its incidence is difficult to establish because studies on the incidence of SCD in ESKD are often combined with those related to sudden cardiac arrest (SCA) occurring during a haemodialysis (HD) session. The aim of the European Dialysis Working Group of ERA-EDTA was to critically review the current literature examining the causes of extradialysis SCD and intradialysis SCA in ESKD patients and potential management strategies to reduce the incidence of such events. Extradialysis SCD and intradialysis SCA represent different clinical situations and should be kept distinct. Regarding the problem, numerically less relevant, of patients affected by intradialysis SCA, some modifiable risk factors have been identified, such as a low concentration of potassium and calcium in the dialysate, and some advantages linked to the presence of automated external defibrillators in dialysis units have been documented. The problem of extra-dialysis SCD is more complex. A reduced left ventricular ejection fraction associated with SCD is present only in a minority of cases occurring in HD patients. This is the proof that SCD occurring in ESKD has different characteristics compared with SCD occurring in patients with ischaemic heart disease and/or heart failure and not affected by ESKD. Recent evidence suggests that the fatal arrhythmia in this population may be due more frequently to bradyarrhythmias than to tachyarrhythmias. This fact may partly explain why several studies could not demonstrate an advantage of implantable cardioverter defibrillators in preventing SCD in ESKD patients. Electrolyte imbalances, frequently present in HD patients, could explain part of the arrhythmic phenomena, as suggested by the relationship between SCD and timing of the HD session. However, the high incidence of SCD in patients on peritoneal dialysis suggests that other risk factors due to cardiac comorbidities and uraemia per se may contribute to sudden mortality in ESKD patients.

[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.

Mineralcorticoid receptor blockers in chronic kidney disease

There are many experimental data supporting the involvement of aldosterone and mineralcorticoid receptor (MR) activation in the genesis and progression of chronic kidney disease (CKD) and cardiovascular damage. Many studies have shown that in diabetic and non-diabetic CKD, blocking the renin-angiotensin-aldosterone (RAAS) system with conversion enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARBs) decreases proteinuria, progression of CKD and mortality, but there is still a significant residual risk of developing these events. In subjects treated with ACEi or ARBs there may be an aldosterone breakthrough whose prevalence in subjects with CKD can reach 50%. Several studies have shown that in CKD, the aldosterone antagonists (spironolactone, eplerenone) added to ACEi or ARBs, reduce proteinuria, but increase the risk of hyperkalemia. Other studies in subjects treated with dialysis suggest a possible beneficial effect of antialdosteronic drugs on CV events and mortality. Newer potassium binders drugs can prevent/decrease hyperkalemia induced by RAAS blockade, and may reduce the high discontinuation rates or dose reduction of RAAS-blockers. The nonsteroidal MR blockers, with more potency and selectivity than the classic ones, reduce proteinuria and have a lower risk of hyperkalemia. Several clinical trials, currently underway, will determine the effect of classic MR blockers on CV events and mortality in subjects with stage 3b CKD and in dialysis patients, and whether in patients with type 2 diabetes mellitus and CKD, optimally treated and with high risk of CV and kidney events, the addition of finerenone to their treatment produces cardiorenal benefits. Large randomized trials have shown that sodium glucose type 2 cotransporter inhibitors (SGLT2i) reduce mortality and the development and progression of diabetic and nondiabetic CKD. There are pathophysiological arguments, which raise the possibility that the triple combination ACEi or ARBs, SGLT2i and aldosterone antagonist provide additional renal and cardiovascular protection.

Practical guidance for the use of potassium binders in the management of hyperkalaemia in patients with heart failure and/or chronic kidney disease

Given the critical physiological role of potassium, it is understandable that the development of severe hyperkalaemia requires effective management to reduce its effects, which include muscle weakness, paralysis and cardiac arrhythmias. Hyperkalaemia most often results from the failure of renal adaptation to potassium imbalance. Patients who are most susceptible to the development of hyperkalaemia include those with chronic kidney disease and those with heart failure. These patients are often treated with renin-angiotensin-aldosterone system (RAAS) inhibitors, such as angiotensin-converting enzyme inhibitors and angiotensin II-receptor blockers, but the development of hyperkalaemia can require down-titration or cessation of RAAS inhibitors. This presents a significant challenge to nephrologists, cardiologists and healthcare professionals treating these patients as this can prevent them from receiving maximum guideline-directed RAAS inhibitor therapy. Panellists in this roundtable discussion shared their clinical experiences of using potassium binders to manage hyperkalaemia in patients with chronic kidney disease and patients with heart failure (illustrated with case studies) in Northern Ireland and considered recommendations for the implementation and maintenance of chronic potassium-lowering treatment.

Sodium zirconium cyclosilicate increases serum bicarbonate concentrations among patients with hyperkalaemia: exploratory analyses from three randomized, multi-dose, placebo-controlled trials

BACKGROUND

Sodium zirconium cyclosilicate (SZC) binds potassium and ammonium in the gastrointestinal tract. In addition to serum potassium reduction, Phase 2 trial data have shown increased serum bicarbonate with SZC, which may be clinically beneficial because maintaining serum bicarbonate ≥22 mmol/L preserves kidney function. This exploratory analysis examined serum bicarbonate and urea, and urine pH data from three SZC randomized, placebo-controlled Phase 3 studies among patients with hyperkalaemia [ZS-003 (n = 753), HARMONIZE (n = 258) and HARMONIZE-Global (n = 267)].

METHODS

In all studies, patients received ≤10 g SZC 3 times daily (TID) for 48 h to correct hyperkalaemia, followed by randomization to maintenance therapy with SZC once daily (QD) versus placebo for ≤29 days among those achieving normokalaemia.

RESULTS

Significant dose-dependent mean serum bicarbonate increases from baseline of 0.3 to 1.5 mmol/L occurred within 48 h of SZC TID in ZS-003 (all P < 0.05), which occurred regardless of chronic kidney disease (CKD) stage. Similar acute increases in HARMONIZE and HARMONIZE-Global were maintained over 29 days. With highest SZC maintenance doses, patient proportions with serum bicarbonate <22 mmol/L fell from 39.4% at baseline to 4.9% at 29 days (P = 0.005) in HARMONIZE and from 87.9% to 70.1%, (P = 0.006) in HARMONIZE-Global. Path analyses demonstrated that serum urea decreases (but not serum potassium or urine pH changes) were associated with SZC effects on serum bicarbonate.

CONCLUSIONS

SZC increased serum bicarbonate concentrations and reduced patient proportions with serum bicarbonate <22 mmol/L, likely due to SZC-binding of gastrointestinal ammonium. These SZC-induced serum bicarbonate increases occurred regardless of CKD stage and were sustained during ongoing maintenance therapy.