Pharmacology of new treatments for hyperkalaemia: patiromer and sodium zirconium cyclosilicate

Use of Fludrocortisone for Hyperkalemia in Chronic Kidney Disease Not Yet on Dialysis

Background

Hyperkalemia is a frequent and potentially lethal complication of chronic kidney disease (CKD). We retrospectively examined the potassium-lowering effect of oral fludrocortisone and its adverse effects in hyperkalemic CKD patients not yet on dialysis.

Methods

Thirty-three patients (23 men and 10 women, ages 69±14 years) were included. To control hyperkalemia at the outpatient clinic, twenty-one patients (Group 1) received fludrocortisone (0.05-0.1 mg/day) without changes in angiotensin II receptor blockers (ARBs) and calcium polystyrene sulfonate (CPS), while twelve patients (Group 2) were treated with fludrocortisone in addition to stopping ARBs and/or adding low-dose CPS.

Results

Fludrocortisone was administered for a median of 169 days (interquartile range, 47-445). At the first follow-up after fludrocortisone administration, serum potassium dropped from 6.14±0.32 mEq/L to 4.52±1.06 mEq/L (p<0.001) in Group 1 and from 6.37±0.35 mEq/L to 4.08±0.74 mEq/L (p<0.01) in Group 2. Ten patients in Group 1 and five patients in Group 2 measured serum potassium levels at four outpatient visits before and after fludrocortisone administration, respectively. The frequency of serum potassium ≥6.0 mEq/L decreased from 19/40 (48%) to 2/40 (5%) (p<0.001) in Group 1 and from 11/20 (55%) to 0/20 (0%) (p<0.001) in Group 2. Eleven patients experienced sodium retention-related problems after fludrocortisone administration: 7 with worsening leg edema, 2 with pleural effusions, and 2 with pulmonary edema.

Conclusion

In pre-dialysis CKD patients, fludrocortisone at low doses effectively reduced serum potassium levels; however, sodium retention was a common adverse effect.

Managing hyperkalemia in patients with heart failure on guideline-directed medical therapy: challenges and opportunities

Heart failure is a chronic and invalidating syndrome that affects tens of millions of people worldwide with significant socio-economic ramifications for the health care systems. Significant progress in the understanding of the pathophysiology of heart failure has allowed the gradual introduction of several drug classes for the management of such patients. Beta-blockers, mineralocorticoid receptor antagonists, angiotensin receptor neprilysin inhibitors, and sodium-glucose-cotransporter 2 inhibitors are all considered pillars of the guideline-directed medical therapy for heart failure. Despite remarkable improvements in the morbidity and mortality of heart failure, however, many patients still develop clinically significant hyperkalemia during combined treatment with those four pharmacological pillars. The consequence is often a down-titration or discontinuation of one or more crucial drugs, which in turns leads to a considerable increase in the risk of cardiovascular events, dialysis, and all-cause mortality. This paper will explore novel approaches for the management of hyperkalemia in heart failure, including closer monitoring of potassium levels, early review of drugs that might increase the risk of hyperkalemia, and pharmacological treatment of hyperkalemia, with a special emphasis on sodium-glucose-cotransporter 2 inhibitors and potassium-binding agents, including patiromer and sodium zirconium cyclosilicate.

Understanding and Treatment Strategies of Hypertension and Hyperkalemia in Chronic Kidney Disease

Hypertension and potassium imbalance are commonly observed in chronic kidney disease (CKD) patients. The development of hypertension would be related to several mechanisms. Hypertension is related to body mass index, dietary salt intake, and volume overload and is treated with antihypertensives. In CKD patients, managing hypertension can provide important effects that can slow the progression of CKD or reduce complications associated with reduced glomerular filtration rate. The prevalence of hyperkalemia and hypokalemia in CKD patients was similar at 15-20% and 15-18%, respectively, but more attention needs to be paid to treating and preventing hyperkalemia, which is related to a higher mortality rate, than hypokalemia. Hyperkalemia is prevalent in CKD due to impaired potassium excretion. Serum potassium level is affected by renin-angiotensin-aldosterone system inhibitors and diuretics and dietary potassium intake and can be managed by potassium restriction dietary, optimized renin-angiotensin-aldosterone system inhibitor, sodium polystyrene sulfonate, patiromer, and hemodialysis. This review discussed strategies to mitigate and care for the risk of hypertension and hyperkalemia in CKD patients.

Compared effectiveness of sodium zirconium cyclosilicate and calcium polystyrene sulfonate on hyperkalemia in patients with chronic kidney disease

Hyperkalemia is a well-recognized electrolyte abnormality in patients with chronic kidney disease (CKD). Potassium binders are often used to prevent and treat hyperkalemia. However, few studies have evaluated the difference in serum potassium (K⁺) level-lowering effect during the post-acute phase between the novel potassium binder, sodium zirconium cyclosilicate (ZSC), and conventional agents. This retrospective study included patients who received potassium binders (either ZSC or calcium polystyrene sulfonate [CPS]) in our hospital between May 2020 and July 2022. The patients were divided into the ZSC and CPS groups. After propensity score matching, we compared changes from baseline to the first follow-up point, at least 4 weeks after initiating potassium binders, in electrolytes including K⁺ level between the two groups. Of the 132 patients, ZSC and CPS were administered in 48 and 84 patients, respectively. After matching, 38 patients were allocated to each group. The ZSC group showed greater reduction in K⁺ levels than did the CPS group (P < 0.05). Moreover, a significant increase in serum sodium minus chloride levels, a surrogate marker for metabolic acidosis, was observed in the ZSC group (P < 0.05). Our results demonstrated that ZSC could potentially improve hyperkalemia and metabolic acidosis in patients with CKD.

Potassium Derangements: A Pathophysiological Review, Diagnostic Approach, and Clinical Management

Potassium is an essential cation critical in fluid and electrolyte balance, acid–base regulation, and neuromuscular functions. The normal serum potassium is kept within a narrow range of 3.5–5.2 meq/L while the intracellular concentration is approximately 140–150 meq/L. The total body potassium is about 45–55 mmol/kg; thus, a 70 kg male has an estimated ~136 g and 60 kg female has ~117 g of potassium. In total, 98% of the total body potassium is intracellular. Skeletal muscle contains ~80% of body potassium stores. The ratio of intracellular to extracellular potassium concentration (Ki/Ke) maintained by Na+/K+ ATPase determines the resting membrane potential. Disturbances of potassium homeostasis lead to hypo- and hyperkalemia, which if severe, can be life-threatening. Prompt diagnosis and management of these problems are important.

2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC). With the special contribution of the Heart Failure Association (HFA) of the ESC

Document Reviewers: Rudolf A. de Boer (CPG Review Coordinator) (Netherlands), P. Christian Schulze (CPG Review Coordinator) (Germany), Magdy Abdelhamid (Egypt), Victor Aboyans (France), Stamatis Adamopoulos (Greece), Stefan D. Anker (Germany), Elena Arbelo (Spain), Riccardo Asteggiano (Italy), Johann Bauersachs (Germany), Antoni Bayes-Genis (Spain), Michael A. Borger (Germany), Werner Budts (Belgium), Maja Cikes (Croatia), Kevin Damman (Netherlands), Victoria Delgado (Netherlands), Paul Dendale (Belgium), Polychronis Dilaveris (Greece), Heinz Drexel (Austria), Justin Ezekowitz (Canada), Volkmar Falk (Germany), Laurent Fauchier (France), Gerasimos Filippatos (Greece), Alan Fraser (United Kingdom), Norbert Frey (Germany), Chris P. Gale (United Kingdom), Finn Gustafsson (Denmark), Julie Harris (United Kingdom), Bernard Iung (France), Stefan Janssens (Belgium), Mariell Jessup (United States of America), Aleksandra Konradi (Russia), Dipak Kotecha (United Kingdom), Ekaterini Lambrinou (Cyprus), Patrizio Lancellotti (Belgium), Ulf Landmesser (Germany), Christophe Leclercq (France), Basil S. Lewis (Israel), Francisco Leyva (United Kingdom), AleVs Linhart (Czech Republic), Maja-Lisa Løchen (Norway), Lars H. Lund (Sweden), Donna Mancini (United States of America), Josep Masip (Spain), Davor Milicic (Croatia), Christian Mueller (Switzerland), Holger Nef (Germany), Jens-Cosedis Nielsen (Denmark), Lis Neubeck (United Kingdom), Michel Noutsias (Germany), Steffen E. Petersen (United Kingdom), Anna Sonia Petronio (Italy), Piotr Ponikowski (Poland), Eva Prescott (Denmark), Amina Rakisheva (Kazakhstan), Dimitrios J. Richter (Greece), Evgeny Schlyakhto (Russia), Petar Seferovic (Serbia), Michele Senni (Italy), Marta Sitges (Spain), Miguel Sousa-Uva (Portugal), Carlo G. Tocchetti (Italy), Rhian M. Touyz (United Kingdom), Carsten Tschoepe (Germany), Johannes Waltenberger (Germany/Switzerland) All experts involved in the development of these guidelines have submitted declarations of interest. These have been compiled in a report and published in a supplementary document simultaneously to the guidelines. The report is also available on the ESC website www.escardio.org/guidelines For the Supplementary Data which include background information and detailed discussion of the data that have provided the basis for the guidelines see European Heart Journal online.

The importance of developing hyperkalaemia in heart failure during long-term follow-up

BACKGROUND

Hyperkalaemia is a potentially life-threatening condition. Furthermore, it is one of the main reasons for discontinuation and dose reduction of renin-angiotensin-aldosterone system inhibitors (RAASi) in clinical practice. However, exact data on the prevalence and consequences of occurrence of hyperkalaemia when taking RAASi in a dedicated heart failure care setting are scarce.

METHODS

Consecutive patients diagnosed with heart failure from a single tertiary hospital between August 2000 and May 2017 were retrospectively evaluated. Primary endpoint was the development of hyperkalaemia (≥5.5 mmol/L) at any moment during follow-up.

RESULTS

About 396 patients were included in the current analysis (mean follow-up 6.9 years). 26% (n = 104) and 12% (n = 46) of patients developed hyperkalaemia (≥5.5 mmol/L and ≥6.0 mmol/L, respectively). Diabetes mellitus (OR = 1.80, 95% CI = 1.03-3.19) and baseline creatinine (mg/dL) (OR = 2.37, 95% CI = 2.37-3.85) were independent risk factors for hyperkalaemia. Development of hyperkalaemia was associated with 6.5 higher odds for recurrence. Only 10% developed hyperkalaemia during up-titration of RAASi, while 90% developed during later follow-up on stable doses of RAASi. hyperkalaemia was not associated with worse outcome after multivariate adjustment for baseline co-morbidities. However, hyperkalaemia was associated with discontinuation and lower doses of MRAs during follow-up (p = 0.007). Discontinuation of MRA due to hyperkalaemia was associated with an increase in all-cause mortality in HFrEF patients (HR = 1.77, 95% CI = 1.05-2.99).

CONCLUSIONS

Approximately, one-fourth of patients developed hyperkalaemia during follow-up which was associated with a lower MRA dose during follow-up. Discontinuation of MRA, but not hyperkalaemia itself, was associated with an increased risk of all-cause mortality and heart failure admission in HFrEF patients.

Hyperkalemia excursions are associated with an increased risk of mortality and hospitalizations in hemodialysis patients

BACKGROUND

Hyperkalemia is common among hemodialysis (HD) patients and has been associated with adverse clinical outcomes. Previous studies considered a single serum potassium (K) measurement or time-averaged values, but serum K excursions out of the target range may be more reflective of true hyperkalemia events. We assessed whether hyperkalemia excursions lead to an elevated risk of adverse clinical outcomes.

METHODS

Using data from 21 countries in Phases 4-6 (2009-18) of the Dialysis Outcomes and Practice Patterns Study (DOPPS), we investigated the associations between peak serum K level, measured monthly predialysis, over a 4-month period ('peak K') and clinical outcomes over the subsequent 4 months using Cox regression, adjusted for potential confounders.

RESULTS

The analysis included 62 070 patients contributing a median of 3 (interquartile range 2-6) 4-month periods. The prevalence of hyperkalemia based on peak K was 58% for >5.0, 30% for >5.5 and 12% for >6.0 mEq/L. The all-cause mortality hazard ratio for peak K (reference ≤5.0 mEq/L) was 1.15 [95% confidence interval (CI) 1.09, 1.21] for 5.1-5.5 mEq/L, 1.19 (1.12, 1.26) for 5.6-6.0 mEq/L and 1.33 (1.23, 1.43) for >6.0 mEq/L. Results were qualitatively consistent when analyzing hospitalizations and a cardiovascular composite outcome.

CONCLUSIONS

Among HD patients, we identified a lower K threshold (peak K 5.1-5.5 mEq/L) than previously reported for increased risk of hospitalization and mortality, with the implication that a greater proportion (>50%) of the HD population may be at risk. A reassessment of hyperkalemia severity ranges is needed, as well as an exploration of new strategies for effective management of chronic hyperkalemia.

Inpatient management and post-discharge outcomes of hyperkalemia

OBJECTIVES

Patients with hyperkalemia are commonly treated in the inpatient setting; however, real-world evidence is limited. The purpose of this study was to describe the inpatient management and post-discharge outcomes among patients with hyperkalemia.

METHODS

Electronic medical record data (2012-2018) were used to analyze US adult patients with an inpatient stay with hyperkalemia (≥1 potassium value >5.0mEq/L). Patient characteristics, treatments, and monitoring six months prior to and during the inpatient stay, and hyperkalemia recurrence and inpatient readmissions post-discharge were summarized and compared among patients with mild (>5.0-5.5mEq/L), moderate (>5.5-6.0), and severe (>6.0) hyperkalemia.

RESULTS

Of the 21,793 patients, 69.2% had mild, 19.0% had moderate, and 11.8% had severe hyperkalemia during inpatient care. The most common inpatient treatments were temporizing agents (mild: 28.9%; moderate: 46.0%; severe: 73.0%), diuretics (32.7%; 37.1%; 34.6%), and sodium-polystyrene sulfonate (11.7%; 27.8%; 45.3%). Almost no patients (0.1%) received a potassium binder at discharge. Most patients (86.8%) had their potassium levels return to ≤5.0mEq/L during the inpatient stay. Death during the inpatient stay occurred in 12.3% of mild, 15.5% of moderate, and 19.5% of severe hyperkalemic patients. Within 30 days of discharge, hyperkalemia recurred in 13.3%, 15.4%, and 18.4% of patients with mild, moderate, and severe hyperkalemia, respectively. Additionally, 19.7%, 21.5%, and 19.6% of patients were readmitted to inpatient care within 30 days post-discharge.

CONCLUSION

Among patients with hyperkalemia in the inpatient setting, treatment and normalization of serum potassium levels were common. However, death, readmission, and hyperkalemia recurrence were also fairly common across all cohorts. Future studies examining measures to reduce inpatient death, readmission, and hyperkalemia recurrence among patients with hyperkalemia in inpatient care are warranted.

Serum potassium and heart failure: association, causation, and clinical implications

Dyskalemia (hypo- and hyperkalemia) is a common clinical encounter in patients with heart failure (HF), linked to underlying pathophysiologic alterations, pharmacological treatments, and concomitant comorbidities. Both hypo- and hyperkalemia have been associated with a poor outcome in HF. However, it is not known if this association is causal. In order to investigate this relation, we implemented the Bradford Hill criteria for causation examining the available literature. Of note, hypokalemia and low-normal potassium levels (serum potassium < 4.0 mmol/L) appear to be associated with adverse clinical outcomes in HF in a cause-and-effect manner. Conversely, a cause-and-effect relationship between hyperkalemia (serum potassium > 5.0 mmol/L) and adverse clinical outcomes in HF appears unlikely. We also examined the benefits of renin-angiotensin-aldosterone system inhibitors (RAASi) therapy uptitration in patients with HF and reduced ejection fraction. In fact, hyperkalemia often limits RAASi use, thereby negating or mitigating their clinical benefits. Finally, serum potassium levels in HF should be maintained within the range of 4.0-5.0 mmol/L, and although the correction of hyperkalemia does not appear to improve clinical outcomes per se, it may enable the optimal titration of RAASi, offering indirect clinical benefit.

Clinical and Economic Burden of Hyperkalemia: A Nationwide Hospital-Based Cohort Study in Japan

Rationale & Objective

Hyperkalemia is a common electrolyte abnormality of chronic kidney disease and heart failure associated with increased mortality and morbidity. We aimed to assess the long-term economic burden of hyperkalemia.

Design

Observational cohort study using a Japanese nationwide hospital claims database (April 1, 2008, to September 30, 2018).

Setting & Population

: Patients 18 years or older with at least 1 serum potassium value (N = 1,208,894).

Exposures

Hyperkalemia defined with the presence of at least 2 serum potassium values ≥ 5.1 mmol/L.

Outcome Measures

Direct health care costs and resource use in patients with hyperkalemia within and after 12 months from first hyperkalemia episodes.

Analytical Approach

Health care costs and resource use were compared with propensity score–matched or nonmatched normokalemic controls. Multivariable regression analysis was performed to examine factors associated with health care costs.

Results

27,534 patients with hyperkalemia and 233,098 normokalemic controls were studied. Mean ± SD age was 73±13 years in patients with hyperkalemia; among them, 59% and 35% had chronic kidney disease and heart failure, respectively. In the propensity score–matched cohort (n = 5,859 in each group), average numbers of hospitalizations per patient per year in patients with hyperkalemia within and after 12 months were 1.2 and 1.6 times higher, respectively, compared with those in patients with normokalemia. The total cost per patient in patients with hyperkalemia was higher than for controls, with mean differences of $8,611 (95% CI, $8,046-$9,175) within 12 months and $5,150 (95% CI, $4,733-$5,566) after 12 months. The number of repeat hyperkalemic episodes was the factor with the strongest association with long-term health care costs, whereas severity of hyperkalemia was not associated.

Limitations

This study used secondary data; therefore, residual confounders may not be fully excluded.

Conclusions

Hyperkalemia was associated with significant long-term economic burden with frequent hospitalizations due to recurrent episodes, indicating the importance of hyperkalemia treatment for the sake of reducing health economic burdens and clinical complications.

Management of Acute Kidney Injury in Coronavirus Disease 2019

Acute kidney injury is a common complication in hospitalized patients with coronavirus disease 2019. Similar to acute kidney injury associated with other conditions such as sepsis and cardiac surgery, morbidity and mortality are much higher in patients with coronavirus disease 2019 who develop acute kidney injury, especially in the intensive care unit. Management of coronavirus disease 2019-associated acute kidney injury with kidney replacement therapy should follow existing recommendations regarding modality, dose, and timing of initiation. However, patients with coronavirus disease 2019 are very hypercoagulable, and close vigilance to anticoagulation strategies is necessary to prevent circuit clotting. During situations of acute surge, where demand for kidney replacement therapy outweighs supplies, conservative measures have to be implemented to safely delay kidney replacement therapy. A collaborative effort and careful planning is needed to conserve dialysis supplies, to ensure that treatment can be safely delivered to every patient who will benefit for kidney replacement therapy.

The potassium regulator patiromer affects serum and stool electrolytes in patients receiving hemodialysis

Hyperkalemia is a common and an important cause of death in maintenance hemodialysis patients. Here we investigated the effect of patiromer, a synthetic cation exchanger, to regulate potassium homeostasis. Serum and stool electrolytes were measured in 27 anuric patients with hyperkalemia receiving hemodialysis (mainly 2 mEq/L dialysate) during consecutive two weeks of no-treatment, 12 weeks of treatment with patiromer (16.8g once daily), and six weeks of no treatment. The serum potassium decreased from a mean of 5.7 mEq/L pre-treatment to 5.1 mEq/L during treatment and rebounded to 5.4 mEq/L post-treatment. During the treatment phase, serum calcium significantly increased (from 8.9 to 9.1 mg/dL) and serum magnesium significantly decreased (from 2.6 to 2.4 mg/dL) compared to pre-treatment levels. For each one mEg/L increase in serum magnesium, serum potassium increased by 1.07 mEq/L. Stool potassium significantly increased during treatment phase from pre-treatment levels (4132 to 5923 μg/g) and significantly decreased post-treatment to 4246 μg/g. For each one μg/g increase in stool potassium, serum potassium significantly declined by 0.05 mEq/L. Stool calcium was significantly higher during the treatment phase (13017 μg/g) compared to pre-treatment (7874 μg/g) and post-treatment (7635 μg/g) phases. We estimated that 16.8 g of patiromer will increase fecal potassium by 1880 μg/g and reduce serum potassium by 0.5 mEq/L. Thus, there is a complex interaction between stool and blood potassium, calcium and magnesium during patiromer treatment. Long term consequence of patiromer-induced changes in serum calcium and magnesium remains to be studied.

Hyperkalemia in Real-World Patients Under Continuous Medical Care in Japan

Introduction

An abnormal serum potassium (S-K) level is an important electrolyte disturbance. However, its relation to clinical outcomes in real-world patients, particularly hyperkalemia burden, is not extensively studied.

Methods

An observational retrospective cohort study using a Japanese hospital claims database was done (April 2008–September 2017; N = 1,022,087). Associations between index S-K level and 3-year survival were modeled using cubic spline regression. Cox regression model was applied to estimate the time to death according to different S-K levels. Prevalence, patient characteristics, treatment patterns, and management of patients with hyperkalemia from first episode were assessed.

Results

Hyperkalemia prevalence was 67.9 (95% confidence interval [CI]: 67.1–68.8) per 1000 and increased in patients with chronic kidney disease (CKD) (227.9; 95% CI: 224.3–231.5), heart failure (134.0; 95% CI: 131.2–136.8), and renin-angiotensin-aldosterone system inhibitor (RAASi) use (142.2; 95% CI: 139.6–144.7). U-shaped associations between S-K level and 3-year survival were observed with nadir 4.0 mEq/l. The risk of death was increased at S-K 5.1–5.4 mEq with hazard ratio of 7.6 (95% CI: 7.2–8.0). The 3-year mortality rate in patients with CKD stages 3a, 3b, 4, and 5 with normokalemia were 1.51%, 3.93%, 10.86%, and 12.09%, whereas that in patients with CKD stage 3a at S-K 5.1–5.4, 5.5–5.9, and ≥6.0 mEq/l increased to 10.31%, 11.43%, and 22.64%, respectively. Despite treatment with loop diuretics (18.5%) and potassium binders (5.8%), >30% of patients had persistently high S-K (≥5.1 mEq/l).

Conclusion

This study provides real-world insight on hyperkalemia based on a large number of patients with various medical backgrounds.