Patiromer in patients with kidney disease and hyperkalemia receiving RAAS inhibitors

Vinyl and methyl-ester groups in the insoluble polymer drug patiromer identified and quantified by solid-state NMR

Patiromer (Veltassa®) is a crosslinked, insoluble co-polymer drug used as a nonabsorbent potassium binder, approved for treatment of hyperkalemia. Quantitative solid-state 13C nuclear magnetic resonance (NMR) analysis with comprehensive peak assignment, component quantification, and calculation of mole and weight fractions of monomer units was performed on three doses of patiromer. The workflow is documented in detail. Spectrally edited solid-state 13C NMR spectra of patiromer show =CHn peaks of matching intensity at 116 and 141 ppm, characteristic of -CH=CH2 vinyl groups. Similar spectral features can be observed in earlier studies but were previously ignored. In this study, the vinyl signals are well-resolved in a 2-s direct polarization (DP) spectrum without and with dipolar dephasing, which confirms that these sp2-hybridized carbons are bonded to hydrogen and partially mobile, consistent with vinyl side groups from incompletely reacted divinyl crosslinkers. The vinyl groups account for 1.6% of all carbon, 3% of the monomer units, and nearly 1/3 of the crosslinkers. Furthermore, an unexpected OCH3 moiety accounting for ∼1.2% of all carbons was identified by spectral editing; its chemical shift of 54 ppm is more consistent with a methyl ester than with a methyl ether. It can originate from incomplete hydrolysis of ∼6% of methyl-2-fluoroacrylate, the main monomer of patiromer. Characteristic cross peaks in two-dimensional 1H-13C heteronuclear correlation NMR confirm the presence of the vinyl and OCH3 groups. Trace amounts of xanthan gum are also detected. The quantitative 13C NMR spectrum of patiromer has been matched in a simulation using a model with five monomer units.

Comparative effectiveness of an individualized model of hemodialysis vs conventional hemodialysis: a study protocol for a multicenter randomized controlled trial (the TwoPlus trial)

BACKGROUND

Most patients starting chronic in-center hemodialysis (HD) receive conventional hemodialysis (CHD) with three sessions per week targeting specific biochemical clearance. Observational studies suggest that patients with residual kidney function can safely be treated with incremental prescriptions of HD, starting with less frequent sessions and later adjusting to thrice-weekly HD. This trial aims to show objectively that clinically matched incremental HD (CMIHD) is non-inferior to CHD in eligible patients.

METHODS

An unblinded, parallel-group, randomized controlled trial will be conducted across diverse healthcare systems and dialysis organizations in the USA. Adult patients initiating chronic hemodialysis (HD) at participating centers will be screened. Eligibility criteria include receipt of fewer than 18 treatments of HD and residual kidney function defined as kidney urea clearance ≥3.5 mL/min/1.73 m2 and urine output ≥500 mL/24 h. The 1:1 randomization, stratified by site and dialysis vascular access type, assigns patients to either CMIHD (intervention group) or CHD (control group). The CMIHD group will be treated with twice-weekly HD and adjuvant pharmacologic therapy (i.e., oral loop diuretics, sodium bicarbonate, and potassium binders). The CHD group will receive thrice-weekly HD according to usual care. Throughout the study, patients undergo timed urine collection and fill out questionnaires. CMIHD will progress to thrice-weekly HD based on clinical manifestations or changes in residual kidney function. Caregivers of enrolled patients are invited to complete semi-annual questionnaires. The primary outcome is a composite of patients' all-cause death, hospitalizations, or emergency department visits at 2 years. Secondary outcomes include patient- and caregiver-reported outcomes. We aim to enroll 350 patients, which provides ≥85% power to detect an incidence rate ratio (IRR) of 0.9 between CMIHD and CHD with an IRR non-inferiority of 1.20 (α = 0.025, one-tailed test, 20% dropout rate, average of 2.06 years of HD per patient participant), and 150 caregiver participants (of enrolled patients).

DISCUSSION

Our proposal challenges the status quo of HD care delivery. Our overarching hypothesis posits that CMIHD is non-inferior to CHD. If successful, the results will positively impact one of the highest-burdened patient populations and their caregivers.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05828823. Registered on 25 April 2023.

Prevention of Chronic Kidney Disease and Its Complications in Older Adults

In an era marked by a global demographic shift towards an aging society, there is a heightened prevalence of chronic kidney disease (CKD) among older adults. The burden of CKD spans from kidney-related complications to impacting psychological well-being, giving rise to depressive symptoms and caregiver burnout. This article delves into CKD prevention strategies within the context of aging, contributing to the discourse by exploring its multifaceted aspects. The prevention of CKD in the older adults necessitates a comprehensive approach. Primary prevention is centered on the modification of risk factors, acknowledging the intricate interplay of various comorbidities. Secondary prevention focuses on early CKD identification. Tertiary prevention aims to address factors contributing to CKD progression and complications, emphasizing the importance of timely interventions. This comprehensive strategy aims to enhance the quality of life for individuals affected by CKD, decelerating the deterioration of functional status. By addressing CKD at multiple levels, this approach seeks to effectively and compassionately care for the aging population.

The significance of finerenone as a novel therapeutic option in diabetic kidney disease: a scoping review with emphasis on cardiorenal outcomes of the finerenone phase 3 trials

This scoping review prepared by endocrinology and nephrology experts aimed to address the significance of finerenone, as a novel therapeutic option, in diabetic kidney disease (DKD), based on the biological prospect of cardiorenal benefit due to non-steroidal mineralocorticoid receptor antagonist (MRA) properties, and the recent evidence from the finerenone phase 3 program clinical trials. The importance of finerenone in slowing DKD progression was critically reviewed in relation to the role of MR overactivation in the pathogenesis of cardiorenal disease and unmet needs in the current practice patterns. The efficacy and safety outcomes of finerenone phase III study program including FIDELIO-DKD, FIGARO-DKD and FIDELITY were presented. Specifically, perspectives on inclusion of patients with preserved estimated glomerular filtration rate (eGFR) or high albuminuria, concomitant use of sodium-glucose co-transporter-2 inhibitor (SGLT2i) or glucagon-like peptide 1 receptor agonist (GLP-1 RA), baseline glycated hemoglobin (HbA1c) level and insulin treatment, clinically meaningful heart failure outcomes and treatment-induced hyperkalemia were addressed. Finerenone has emerged as a new therapeutic agent that slows DKD progression, reduces albuminuria and risk of cardiovascular complications, regardless of the baseline HbA1c levels and concomitant treatments (SGLT2i, GLP-1 RA, or insulin) and with a favorable benefit-risk profile. The evolving data on the benefit of SGLT2is and non-steroidal MRAs in slowing or reducing cardiorenal risk seem to provide the opportunity to use these pillars of therapy in the management of DKD, after a long-period of treatment scarcity in this field. Along with recognition of the albuminuria as a powerful marker to detect those patients at high risk of cardiorenal disease, these important developments would likely to impact standard-of-care options in the setting of DKD.

Consensus statement on the management of hyperkalaemia-An Asia-Pacific perspective

Hyperkalaemia is an electrolyte imbalance that impairs muscle function and myocardial excitability, and can potentially lead to fatal arrhythmias and sudden cardiac death. The prevalence of hyperkalaemia is estimated to be 6%-7% worldwide and 7%-10% in Asia. Hyperkalaemia frequently affects patients with chronic kidney disease, heart failure, and diabetes mellitus, particularly those receiving treatment with renin-angiotensin-aldosterone system (RAAS) inhibitors. Both hyperkalaemia and interruption of RAAS inhibitor therapy are associated with increased risks for cardiovascular events, hospitalisations, and death, highlighting a clinical dilemma in high-risk patients. Conventional potassium-binding resins are widely used for the treatment of hyperkalaemia; however, caveats such as the unpalatable taste and the risk of gastrointestinal side effects limit their chronic use. Recent evidence suggests that, with a rapid onset of action and improved gastrointestinal tolerability, novel oral potassium binders (e.g., patiromer and sodium zirconium cyclosilicate) are alternative treatment options for both acute and chronic hyperkalaemia. To optimise the care for patients with hyperkalaemia in the Asia-Pacific region, a multidisciplinary expert panel was convened to review published literature, share clinical experiences, and ultimately formulate 25 consensus statements, covering three clinical areas: (i) risk factors of hyperkalaemia and risk stratification in susceptible patients; (ii) prevention of hyperkalaemia for at-risk individuals; and (iii) correction of hyperkalaemia for at-risk individuals with cardiorenal disease. These statements were expected to serve as useful guidance in the management of hyperkalaemia for health care providers in the region.

Physician perceptions, attitudes, and strategies towards implementing guideline-directed medical therapy in heart failure with reduced ejection fraction. A survey of the Heart Failure Association of the ESC and the ESC Council for Cardiology Practice

AIMS

Recent guidelines recommend four core drug classes (renin-angiotensin system inhibitor/angiotensin receptor-neprilysin inhibitor [RASi/ARNi], beta-blocker, mineralocorticoid receptor antagonist [MRA], and sodium-glucose cotransporter 2 inhibitor [SGLT2i]) for the pharmacological management of heart failure (HF) with reduced ejection fraction (HFrEF). We assessed physicians' perceived (i) comfort with implementing the recent HFrEF guideline recommendations; (ii) status of guideline-directed medical therapy (GDMT) implementation; (iii) use of different GDMT sequencing strategies; and (iv) barriers and strategies for achieving implementation.

METHODS AND RESULTS

A 26-question survey was disseminated via bulletin, e-mail and social channels directed to physicians with an interest in HF. Of 432 respondents representing 91 countries, 36% were female, 52% were aged <50 years, and 90% mainly practiced in cardiology (30% HF). Overall comfort with implementing quadruple therapy was high (87%). Only 12% estimated that >90% of patients with HFrEF without contraindications received quadruple therapy. The time required to initiate quadruple therapy was estimated at 1-2 weeks by 34% of respondents, 1 month by 36%, 3 months by 24%, and ≥6 months by 6%. The average respondent favoured traditional drug sequencing strategies (RASi/ARNi with/followed by beta-blocker, and then MRA with/followed by SGLT2i) over simultaneous initiation or SGLT2i-first sequences. The most frequently perceived clinical barriers to implementation were hypotension (70%), creatinine increase (47%), hyperkalaemia (45%) and patient adherence (42%).

CONCLUSIONS

Although comfort with implementing all four core drug classes in patients with HFrEF was high among physicians, a majority estimated implementation of GDMT in HFrEF to be low. We identified several important perceived clinical and non-clinical barriers that can be targeted to improve implementation.

Hyperkalemia in chronic kidney disease patients with and without heart failure: an Italian economic modelling study

BACKGROUND

Hyperkalemia (HK) is frequently present in chronic kidney disease (CKD). Risk factors for HK among CKD patients include comorbidities and renin-angiotensin-aldosterone system inhibitor (RAASi) treatment. Current standard of care (SoC) often necessitates RAASi down-titration or discontinuation, resulting in poorer cardiorenal outcomes, hospitalization and mortality. This study evaluates the cost-effectiveness of patiromer for HK in CKD patients with and without heart failure (HF) in an Italian setting.

METHODS

A lifetime Markov cohort model was developed based on OPAL-HK to assess the health economic impact of patiromer therapy in comparison to SoC after accounting for the effects of HK and RAASi use on clinical events. Outcomes included accumulated clinical events, number needed to treat (NNT) and the incremental cost-effectiveness ratio (ICER). Subgroup analysis was conducted in CKD patients with and without HF.

RESULTS

Patiromer was associated with an incremental discounted cost of €4,660 and 0.194 quality adjusted life years (QALYs), yielding an ICER of €24,004. Per 1000 patients, patiromer treatment prevented 275 moderate/severe HK events, 54 major adverse cardiovascular event, 246 RAASi discontinuation and 213 RAASi up-titration/restart. Subgroup analysis showed patiromer was more effective in preventing clinical events in CKD patients with HF compared to those without; QALY gains were greater in CKD patients without HF versus those with HF (0.267 versus 0.092, respectively). Scenario analysis and sensitivity analysis results support base-case conclusions.

CONCLUSION

Patiromer is associated with QALY gains in CKD patients with and without HF compared to SoC in Italy. Patiromer prevented HK events, enabled RAASi therapy maintenance and reduced cardiovascular event risk.

What to do with foundation therapies for heart failure for patients with end-stage kidney disease on haemodialysis

There is a significant burden of cardiovascular disease morbidity and mortality in the end-stage kidney disease population, driven by traditional and non-traditional risk factors. Despite its prevalence, heart failure is difficult to diagnose in the dialysis population due to overlapping clinical presentations, limitations of investigations, and the impact on the cardiorenal axis. 'Foundation therapies' are the key medications which improve patient outcomes in heart failure with reduced ejection fraction and include beta-blockers, renin-angiotensin-aldosterone system inhibitors and sodium-glucose cotransporter-2 inhibitors. They are underutilised in the dialysis population due to the exclusion of chronic kidney disease patients from major trials and legitimate clinical concerns e.g. hyperkalaemia, intradialytic hypotension and residual kidney function preservation. A coordinated cardiorenal multidisciplinary approach can guide appropriate diagnostic considerations (biomarkers interpretation, imaging, addressing unique complications of kidney disease), optimise dialysis management (prescription length, frequency and ultrafiltration targets) and when at euvolaemia facilitate the stepwise introduction of appropriate foundation therapies.

Incidence of hyperkalemia in anuric hemodialysis patients treated with sacubitril/valsartan

INTRODUCTION

Sacubitril/valsartan is increasingly used in hemodialysis patients due to its cardioprotective benefits. However, its impact on serum potassium levels in anuric patients undergoing hemodialysis remains controversial.

METHODS

We conducted a retrospective data from patients undergoing hemodialysis at two dialysis centers. A total of 71 out of 332 patients receiving hemodialysis treatment were enrolled. Mean serum potassium (mean value of 6-8 determinations), peak serum potassium (maximum K value observed during follow-up observations), and other biochemical parameters were recorded at baseline and during the follow-up period.

FINDINGS

After 6 months of follow-up, mean serum potassium increased from 4.84 ± 0.45 mmol/L at baseline to 5.07 ± 0.46 mmol/L at 3 months and 5.04 ± 0.46 mmol/L at 6 months (p < 0.001). Notably, no significant group differences were found in peak serum potassium concentrations between baseline and 6 months after sacubitril/valsartan therapy (5.69 ± 0.56 vs. 5.75 ± 0.41, p = 0.419). Prior to starting sacubitril/valsartan treatment, none of the patients had severe hyperkalemia; however, after 3 and 6 months of sacubitril/valsartan therapy, two (2.80%) and three (4.20%) patients experienced severe hyperkalemia, respectively; however, this difference was not statistically significant. Additionally, there was a significant reduction in blood pressure; however, serum sodium, bicarbonate, and Kt/V values did not change significantly during either period.

DISCUSSION

Sacubitril/valsartan therapy is associated with an increase in serum potassium levels in anuric hemodialysis patients. Nevertheless, the proportion of patients with severe hyperkalemia did not increase significantly. This suggests that the use of sacubitril/valsartan in anuric patients on hemodialysis is relatively safe.

Recommendations for the management of hyperkalemia in patients receiving renin-angiotensin-aldosterone system inhibitors

Hyperkalemia is common in clinical practice and can be caused by medications used to treat cardiovascular diseases, particularly renin-angiotensin-aldosterone system inhibitors (RAASis). This narrative review discusses the epidemiology, etiology, and consequences of hyperkalemia, and recommends strategies for the prevention and management of hyperkalemia, mainly focusing on guideline recommendations, while recognizing the gaps or differences between the guidelines. Available evidence emphasizes the importance of healthcare professionals (HCPs) taking a proactive approach to hyperkalemia management by prioritizing patient identification and acknowledging that hyperkalemia is often a long-term condition requiring ongoing treatment. Given the risk of hyperkalemia during RAASi treatment, it is advisable to monitor serum potassium levels prior to initiating these treatments, and then regularly throughout treatment. If RAASi therapy is indicated in patients with cardiorenal disease, HCPs should first treat chronic hyperkalemia before reducing the dose or discontinuing RAASis, as reduction or interruption of RAASi treatment can increase the risk of adverse cardiovascular and renal outcomes or death. Moreover, management of hyperkalemia should involve the use of newer potassium binders, such as sodium zirconium cyclosilicate or patiromer, as these agents can effectively enable optimal RAASi treatment. Finally, patients should receive education regarding hyperkalemia, the risks of discontinuing their current treatments, and need to avoid excessive dietary potassium intake.

Randomised, blinded, cross-over evaluation of the palatability of and preference for different potassium binders in participants with chronic hyperkalaemia in the USA, Canada and Europe: the APPETIZE study

OBJECTIVES

Traditional potassium (K+) binders for treating hyperkalaemia are unpalatable and poorly tolerated. Newer K+ binders are reportedly better tolerated; however, no published data describe their palatability, a determinant of long-term adherence. This study evaluated the palatability of and preference for three K+ binders: sodium and calcium polystyrene sulfonate (S/CPS), sodium zirconium cyclosilicate (SZC) and calcium patiromer sorbitex (patiromer).

DESIGN

Phase 4, randomised, participant-blinded, cross-over study. Participants were randomised to one of six taste sequences and, using a 'sip and spit' approach, tasted each K+ binder before completing a survey.

SETTING

17 centres across the USA, Canada and European Union.

PARTICIPANTS

144 participants with chronic kidney disease, hyperkalaemia and no recent use of K+ binders.

MAIN OUTCOME MEASURES

For the primary (USA) and key secondary (Canada and European Union) endpoints, participants rated palatability attributes (taste, texture, smell and mouthfeel) and willingness to take each K+ binder on a scale of 0-10 (rational evaluation). Feelings about each attribute, and the idea of taking the product once daily, were evaluated using a non-verbal, visual measure of emotional response. Finally, participants ranked the K+ binders according to palatability.

RESULTS

In each region, SZC and patiromer outperformed S/CPS on overall palatability (a composite of taste, texture, smell and mouthfeel), based on rational evaluation and emotional response. Taking the product once daily was more appealing for SZC and patiromer, creating greater receptivity than the idea of taking S/CPS. The emotional response to mouthfeel had the strongest influence on feelings about taking each product. In each region, a numerically greater proportion of participants ranked SZC as the most preferred K+ binder versus patiromer or S/CPS.

CONCLUSIONS

Preference for more palatable K+ binders such as SZC and patiromer may provide an opportunity to improve adherence to long-term treatment of hyperkalaemia.

TRIAL REGISTRATION NUMBER

NCT04566653.

Real-world management of chronic and postprandial hyperkalemia in CKD patients treated with patiromer: a single-center retrospective study

INTRODUCTION

Hyperkalemia, one of the most important electrolyte abnormalities of chronic kidney disease (CKD), often limits the use of renin-angiotensin-aldosterone system inhibitors and can increase in the postprandial period. In this study we report a real-world experience with the new non-adsorbed potassium binder patiromer in stage 3b-4 CKD patients. Moreover, we performed a cross-sectional analysis to evaluate, for the first time, the efficacy of patiromer in the control of postprandial potassium concentrations.

METHODS

We retrospectively collected data of 40 patients at the time of patiromer initiation (T0), and after 2 (T2), 6 (T6) and 12 (T12) months of treatment. For cross sectional analysis, a blood sample was collected 2 h after the main meal for the evaluation of postprandial potassium concentrations.

RESULTS

Eighty-two point five percent of patients (33/40) reached normal potassium concentrations at T2. Serum potassium significantly decreased at T2 compared to T0 (5.13 ± 0.48 vs 5.77 ± 0.41 mmol/L, respectively; p < 0.001) and the reduction remained significant during the follow-up (5.06 ± 0.36 at T6 and 5.77 ± 0.41 at T12; p < 0.001 vs T0). Renin-angiotensin-aldosterone system inhibitors were continued by 93% of patients (27/29). Adverse events were reported in 27.5% of patients and were all mild-to-moderate. Postprandial potassium concentrations did not significantly change compared to fasting state potassium measured at T12 (4.53 ± 0.33 vs 5.06 ± 0.36 mmol/L; p = 0.15).

CONCLUSIONS

In a real-world setting of advanced CKD patients, patiromer is a useful treatment for hyperkalemia, since it significantly reduces serum potassium levels over the long term and is able to maintain potassium concentrations in the normal range even in the post-prandial period.

The role of a novel mineralocorticoid receptor antagonist, finerenone, in chronic kidney disease: mechanisms and clinical advances

BACKGROUND

Chronic kidney disease (CKD) poses a significant health risk in contemporary society. Current CKD treatments primarily involve renin-angiotensin-aldosterone system inhibitors and mineralocorticoid receptor antagonists, albeit associated with hyperkalemia risks. A novel selective mineralocorticoid receptor antagonist, finerenone, offers a promising, safer alternative for CKD therapy. This review comprehensively assesses the role and efficacy of finerenone in CKD treatment by analyzing clinical and animal studies. Emerging evidence consistently supports finerenone's ability to effectively slow the progression of CKD. By targeting the mineralocorticoid receptor, finerenone not only mitigates renal damage but also exhibits a favorable safety profile, minimizing hyperkalemia concerns.

CONCLUSION

Finerenone emerges as a valuable addition to CKD therapy, demonstrating potential benefits in delaying CKD progression while minimizing side effects. Nevertheless, further clinical trials are necessary to provide a comprehensive understanding of its safety and efficacy.

Strategies to prevent, diagnose and treat kidney disease related to systemic arterial hypertension: a narrative review from the Mexican Group of Experts on Arterial Hypertension

This narrative review highlights strategies proposed by the Mexican Group of Experts on Arterial Hypertension endorsed to prevent, diagnose, and treat chronic kidney disease (CKD) related to systemic arterial hypertension (SAH). Given the growing prevalence of CKD in Mexico and Latin America caused by SAH, there is a need for context-specific approaches to address the effects of SAH, given the diverse population and unique challenges faced by the region. This narrative review provides clinical strategies for healthcare providers on preventing, diagnosing, and treating kidney disease related to SAH, focusing on primary prevention, early detection, evidence-based diagnostic approaches, and selecting pharmacological treatments. Key-strategies are focused on six fundamental areas: 1) Strategies to mitigate kidney disease in SAH, 2) early detection of CKD in SAH, 3) diagnosis and monitoring of SAH, 4) blood pressure targets in patients living with CKD, 5) hypertensive treatment in patients with CKD and 6) diuretics and Non-Steroidal Mineralocorticoid Receptor Inhibitors in Patients with CKD. This review aims to provide relevant strategies for the Mexican and Latin American clinical context, highlight the importance of a multidisciplinary approach to managing SAH, and the role of community-based programs in improving the quality of life for affected individuals. This position paper seeks to contribute to reducing the burden of SAH-related CKD and its complications in Mexico and Latin America.

Evaluation of the introduction of novel potassium binders in routine care; the Stockholm CREAtinine measurements (SCREAM) project

BACKGROUND

The pharmacological management of hyperkalemia traditionally considered calcium or sodium polystyrene sulfonate and, since recently, the novel binders patiromer and sodium zirconium cyclosilicate. We evaluated their patterns of use, duration of treatment and relative effectiveness/safety in Swedish routine care.

METHODS

Observational study of adults initiating therapy with sodium polystyrene sulfonate or a novel binder (sodium zirconium cyclosilicate or patiromer) in Stockholm 2019-2021. We quantified treatment duration by repeated dispensations, compared mean achieved potassium concentration within 60 days, and potential adverse events between treatments.

RESULTS

A total of 1879 adults started treatment with sodium polystyrene sulfonate, and 147 with novel binders (n = 41 patiromer and n = 106 sodium zirconium cyclosilicate). Potassium at baseline for all treatments was 5.7 mmol/L. Sodium polystyrene sulfonate patients stayed on treatment a mean of 61 days (14% filled ≥3 consecutive prescriptions) compared to 109 days on treatment (49% filled ≥3 prescriptions) for novel binders. After 15 days of treatment, potassium similarly decreased to 4.6 (SD 0.6) and 4.8 (SD 0.6) mmol/L in the sodium polystyrene sulfonate and novel binder groups, respectively, and was maintained over the 60 days post-treatment. In multivariable regression, the odds ratio for novel binders (vs sodium polystyrene sulfonate) in reaching potassium ≤ 5.0 mmol/L after 15 days was 0.65 (95% CI 0.38-1.10) and after 60 days 0.89 (95% CI 0.45-1.76). Hypocalcemia, hypokalemia, and initiation of anti-diarrheal/constipation medications were the most-commonly detected adverse events. In multivariable analyses, the OR for these events did not differ between groups.

CONCLUSION

We observed similar short-term effectiveness and safety for all potassium binders. However, treatment duration was longer for novel binders than for sodium polystyrene sulfonate.

Long-term Patiromer Use and Outcomes Among US Veterans With Hyperkalemia and CKD: A Propensity-Matched Cohort Study

Rationale & Objective

Patiromer is a potassium binder approved for the long-term management of hyperkalemia. Although patiromer use among patients with advanced chronic kidney disease (CKD) has been shown to reduce the discontinuation of renin-angiotensin-aldosterone system inhibition therapy, it remains unclear whether patiromer can improve clinical outcomes. The aim of this study was to examine the association of long-term patiromer use with clinical outcomes among hyperkalemic patients with CKD.

Study Design

This was a longitudinal observational study.

Setting & Participants

We evaluated a national cohort of 854,217 US Veterans who had at least 1 serum potassium measurement of ≥5.1 mEq/L and were treated at US Department of Veterans Affairs health care facilities between January 2016 and September 2019.

Exposure

The exposure was long-term patiromer use.

Outcomes

The outcomes were as follows: (1) composite endpoint of kidney failure with replacement therapy (KFRT) or all-cause death and (2) all-cause death including the post-KFRT period.

Analytical Approach

Cox proportional Fine-Gray subdistribution hazard models were used in a propensity-matched cohort.

Results

Among 2,004 patients who ever used patiromer during the study period (0.2% of the cohort), 666 met the criteria for long-term patiromer use. We matched 308 long-term patiromer users to 308 nonusers based on propensity scores. The median estimated glomerular filtration rate was 23.5 mL/min/1.73m2, and the median potassium level was 5.2 mEq/L. Approximately 45% were on renin-angiotensin system inhibitor(s) at baseline. During follow-up, 93 patients developed KFRT, and 134 patients died. Long-term patiromer users, when compared to nonusers, experienced a 26% lower risk of the composite outcome (HR, 0.74; 95% CI, 0.53-1.01; P = 0.06) and a 41% lower risk of all-cause mortality (HR, 0.59; 95% CI, 0.41-0.84; P = 0.003).

Limitations

The study cohort included mostly male veterans with relatively short follow-up periods.

Conclusions

Long-term patiromer use was associated with a lower risk of all-cause mortality among patients with CKD and hyperkalemia. Long-term potassium binder use for hyperkalemia may improve clinical outcomes in CKD.

Plain-Language Summary

Hyperkalemia is a common complication of chronic kidney disease (CKD) and can result in the discontinuation of renin-angiotensin-aldosterone system inhibition therapy, a cornerstone of CKD management. Patiromer is a new potassium binder approved for the long-term management of hyperkalemia, but it remains unclear whether patiromer can improve clinical outcomes. We examined a cohort of US Veterans with hyperkalemia between January 2016 and September 2019 and found that patiromer use was uncommon for treating hyperkalemia during this study period. We then matched 308 long-term patiromer users and 308 nonusers based on propensity scores. Long-term patiromer users, when compared to nonusers, experienced a 26% lower risk of the composite outcome and a 41% lower risk of all-cause mortality. These findings indicate that long-term potassium binder use for hyperkalemia may improve clinical outcomes in CKD.

Cost-effectiveness analysis of sodium zirconium cyclosilicate for hyperkalemia among patients with chronic kidney disease or heart failure in Kuwait

INTRODUCTION

Our model was conducted from Kuwaiti payer's perspective to provide evidence on the cost-effectiveness of Sodium zirconium cyclosilicate (SZC) versus patiromer to correct and maintain serum potassium (K+) in combination with renin-angiotensin-aldosterone system inhibitors (RAASis) with different dose titration in patients with chronic kidney disease/heart failure (CKD/HF) with/without renal replacement therapy (RRT).

METHODOLOGY

The model was developed as a patient-level, fixed-time increment stochastic simulation to simulate the complexity of disease, including multiple coexisting and competing conditional risks. This model was established to compare SZC versus patiromer as a treatment for hyperkalemia (HK) among adult populations with underlying conditions of advanced CKD stages 3a-5 or HF to correct and maintain serum K + over a lifetime horizon. The clinical outcomes of SZC and patiromer were demonstrated through arm-specific K + trajectories extracted from the HARMONIZE trial and OPAL-HK trial, respectively. The utility data was captured from different studies. Direct medical cost was captured from local data from Kuwaiti hospitals. Sensitivity analyses were conducted to assess the uncertainty in the model.

RESULTS

Within different scenarios of CKD/HF, SZC was a cost-saving option, with/without RRT, whether one-off administration or repeated administration, except for one-off treatment administration among the HF cohort, which generated an incremental cost effectiveness ratio of KWD 331/quality adjusted life year (QALY). The incremental QALY of SZC ranged from 0.007 to 0.202. In addition, the savings observed with SZC fall within a range of KWD -60 to KWD -1,235 at serum K+ ≥ 5.1 mmol/L.

CONCLUSION

The evidence generated by our model recommends the inclusion of SZC as a treatment option to correct HK and maintain normal serum K + level for CKD/HF patients within the Kuwaiti healthcare system. The costs saved from reducing frequent HK episodes, RAASis discontinuation/down titration, major cardiovascular events, and hospitalization offset the drug acquisition cost of SZC.

Potassium-lowering effects of sodium zirconium cyclosilicate in the early post-transplant period

PROBLEM

Hyperkalemia is a serious condition among intra-abdominal transplant recipients, and the safety and efficacy of sodium zirconium cyclosilicate (SZC) for its management during the early post-transplant period are not well-established.

METHODS

Adults who received at least one 10-g dose of SZC within 14 days after an intra-abdominal transplant between January 2020 and July 2022 were included in our study. The primary outcome was the change in potassium (K+) levels following the first SZC dose. Other analyses explored adjunctive potassium-lowering therapies, potential gastrointestinal complications, and patient subgroups based on therapy and transplant type.

RESULTS

Among the recipients (n = 46), 11 were kidney recipients, 26 were liver recipients, seven were simultaneous liver/kidney recipients, and two were simultaneous pancreas/kidney recipients. The mean time to first dose post-transplant was 7.6 (±4) days, and the mean change in serum K+ after the initial SZC dose was -.27 mEq (p = .001). No gastrointestinal complications were observed following the SZC dose. The mean increase in serum bicarbonate was .58 mEq (p = .41) following the first dose of SZC. Four kidney recipients required dialysis following the SZC dose.

CONCLUSION

This study represents the largest investigation on the use of SZC in transplant recipients. A single 10-g dose of SZC reduced serum K+ levels in all subgroups, while the use of adjunctive K+-lowering therapies did not provide additional reduction beyond the effects of SZC. Importantly, no gastrointestinal complications were observed. These findings suggest that SZC may be a safe and promising therapeutic option for hyperkalemia management following solid organ transplantation.

Hyperkalemia: Pharmacotherapies and Clinical Considerations

Hyperkalemia has been defined as a condition where a serum potassium level is >5.5 mmol/l. It is associated with fatal dysrhythmias and muscular dysfunction. Certain medical conditions, such as chronic kidney disease (CKD), diabetes mellitus, and others, can lead to hyperkalemia. Many of the signs of hyperkalemia are nonspecific. A history and physical examination can be beneficial in the diagnosis of the condition. In this regard, certain characteristic electrocardiogram findings are associated with hyperkalemia along with laboratory potassium levels. In acute and potentially lethal conditions, hyperkalemia treatments include glucose and insulin, bicarbonate, calcium gluconate, beta-2 agonists, hyperventilation, and dialysis. There are several drugs, both old and new, that can additionally aid in the reduction of serum potassium levels. The present investigation evaluated some of these different drugs, including sodium polystyrene sulfonate (SPS), sodium zirconium cyclosilicate (SZC), and patiromer. These drugs each have increased selectivity for potassium and work primarily in the gastrointestinal (GI) tract. Each of these medications has unique benefits and contraindications. Clinicians must be aware of these medications when managing patients with hyperkalemia.

Evaluation of longer- vs short-term use of patiromer on health care resource utilization in the patiromer longer-term use evaluation (VALUE) study

BACKGROUND

Studies suggest that continuous long-term use of patiromer by patients with hyperkalemia is associated with less health care resource utilization compared with not using potassium binders.

OBJECTIVE

To retrospectively evaluate health care resource utilization and costs with longer-term adherent vs short-term use of patiromer.

METHODS

Time-restricted extracts from Optum's de-identified Clinformatics® Data Mart Database (CDM; January 2016-May 2019) and Symphony Health (SHA; January 2016-September 2018) deidentified databases were analyzed. Both include participants enrolled in commercial and privatized public insurance programs (SHA includes some government programs). Both integrate health care claims data from medical and pharmacy claims. Patients aged 18 years or older with hyperkalemia and an index patiromer prescription were selected. Patiromer use was identified as short-term (<2 months) and any fill quantity or adherent longer-term with claims for at least 2 consecutive months and fill quantities of at least 80% of the total days. Groups were matched on multiple categorical covariates to control for demographic variables, baseline characteristics, and markers of disease severity. Random sampling without replacement was performed 50 times to identify 50 sets of patients matched from the short-term cohort to the longer-term cohort. Health care costs/charges and encounters were compared for a 6-month post-index period using t-tests.

RESULTS

Of the CDM patients, 1,267 (40.2%) vs 1,887 (59.8%) and of the SHA patients, 2,234 (35.1%) vs 4,132 (64.9%) experienced longer-term vs short-term patiromer use, respectively. Patient sampling selected 242 and 485 patient-matched pairs from CDM and SHA databases, respectively. At 6 months post-index in longer-term vs short-term patiromer groups (P < 0.0001 for all differences shown), respective mean medical and prescription costs/charges were $42,000 vs $54,311 (-$12,311) and $6,816 vs $4,786 (+$2,030), respectively, for CDM patients and $75,147 vs $84,414 (-$9,267) and $4,689 vs $3,736 (+$953) for SHA patients. In the CDM database, medical costs were lower for longer-term vs short-term cohorts for end-stage renal disease services charges ($10,342 vs $14,976 [-$4,634]), inpatient charges ($15,789 vs $21,473 [-$5,684]), and office visit charges ($10,152 vs $13,152 [-$3,000]). Patient out-of-pocket costs ($658 vs $420 [+$238]) and total prescription charges ($6,158 vs $4,366 [+$1,792]) were higher for the longer-term cohort of CDM patients, with similar findings in the SHA dataset.

CONCLUSIONS

Adherent, longer-term use of patiromer is associated with significantly lower medical costs offsetting higher prescription costs, driven by the largest changes in inpatient and clinic services at CDM and SHA, respectively. This illustrates an economic value of longer-term adherence to patiromer.

Therapeutic update on oral potassium exchange resin use in chronic kidney disease patients: a systematic review of randomized controlled clinical trials

Hyperkalemia is a common electrolyte disorder in patients with chronic kidney disease (CKD) that increases in prevalence with the decline of glomerular fltration rate (GFR). Another risk of hyperkalemia is the use of renin-angiotensin-aldosterone system inhibitors (RAASi) and/or mineralocorticoid receptor antagonists (MRAs) in managing CKD and proteinuria. The treatment of chronic hyperkalemia is challenging especially for outpatients. Treatment options for hyperkalemia include the potassium exchange resins of which two new potassium binders, Patiromer Sorbitex Calcium, and Sodium Zirconium Cyclosilicate (SZC) have demonstrated their clinical efficacy in reducing serum potassium with a positive safety profile. The old potassium exchange resin sodium polystyrene sulfonate (Kayexalate™) has some negative side effects including colonic necrosis, hypomagnesemia, and hypernatremia. In this review and literature search, we compare the available oral potassium exchange resins, highlight their advantages and disadvantages and comment on efficacy and safety parameters specifically in CKD patients.

Overview of research progress on the association of dietary potassium intake with serum potassium and survival in hemodialysis patients, does dietary potassium restriction really benefit hemodialysis patients?

For the general population, increasing potassium intake can reduce the incidence of cardiovascular and cerebrovascular diseases. However, since hyperkalemia is a common and life-threatening complication in maintenance hemodialysis patients, which can increase the risk of malignant arrhythmia and sudden death, the current mainstream of management for hemodialysis patients is dietary potassium restriction in order to prevent hyperkalemia. Hemodialysis patients are usually advised to reduce dietary potassium intake and limit potassium-rich fruits and vegetables, but there is limited evidence to support this approach can reduce mortality and improve quality of life. There is still no consistent conclusion on the association between dietary potassium intake and serum potassium and survival in hemodialysis patients. According to the current small observational studies, there was little or even no association between dietary potassium intake and serum potassium in hemodialysis patients when assurance of adequate dialysis and specific dietary patterns (such as the plant-based diet mentioned in the article) are being followed, and excessive dietary potassium restriction may not benefit the survival of hemodialysis patients. Additionally, when assessing the effect of diet on serum potassium, researchers should not only focus on the potassium content of foods, but also consider the type of food and the content of other nutrients. However, more large-scale, multi-center clinical trials are required to provide high-quality evidence support. Besides, further research is also needed to determine the optimal daily potassium intake and beneficial dietary patterns for hemodialysis patients.

Effectiveness of Patiromer Versus Sodium Zirconium Cyclosilicate for the Management of Acute Hyperkalemia

BACKGROUND

Patiromer and sodium zirconium cyclosilicate (SZC) are 2 oral potassium binders approved for chronic hyperkalemia. It is unknown if one is more effective at reducing serum potassium than the other in acute hyperkalemia.

OBJECTIVE

The objective of this study was to determine if there was a difference between patiromer and SZC in the reduction of serum potassium in patients with acute hyperkalemia.

METHODS

This was a single-center, retrospective, observational study. Patients with a nonhemolyzed serum potassium level of 5.5 mEq/L or greater and received at least one dose of patiromer or SZC were included. The primary outcome was to determine the difference in effectiveness between patiromer and SZC in lowering of serum potassium 6 to 24 hours after administration. Secondary outcomes included description of total dosage received in 24 hours and incidence of electrolyte changes.

RESULTS

A total of 200 patients were included in this study, with 100 patients in each group. Serum potassium was significantly reduced by both patiromer (-1.2 mEq/L, 95% confidence interval [CI]: -2.3 to -0.2) and SZC (-0.8 mEq/L, 95% CI: -1.0 to -0.7), but there was no difference between the 2 medications in the amount of potassium reduction (P = 0.464). No clinically significant differences in electrolyte changes were seen.

CONCLUSIONS AND RELEVANCE

This study represents the first head-to-head comparison of patiromer and SZC in the setting of acute hyperkalemia. No difference in effectiveness between patiromer and SZC in reducing serum potassium was seen. Both agents can be considered in acute hyperkalemia management.

Practical patient care appraisals with use of new potassium binders in heart failure and chronic kidney diseases

Hyperkalaemia is a life-threatening condition leading to significant morbidity and mortality. It is common in heart failure and in chronic kidney disease (CKD) patients due to the diseases themselves, which often coexist, the high co-presence of diabetes, the fluctuations in renal function, and the use of some drugs [i.e. renin-angiotensin-aldosterone system (RAAS) inhibitors]. Hyperkalaemia limits their administration or uptitration, thus impacting on mortality. New K + binders, namely patiromer and sodium zirconium cyclosilicate (ZS-9), are an intriguing option to manage hyperkalaemia in heart failure and/or CKD patients, both to reduce its fatal effects and to let clinicians uptitrate RAAS inhibition. Even if their real impact on strong outcomes is still to be determined, we hereby provide a practical approach to favour their use in routine clinical practice in order to gain the correct confidence and provide an additive tool to heart failure and CKD patients' wellbeing. New trials are welcome to fill the gap in knowledge.

Managing Phosphate Burden in Patients Receiving Dialysis: Beyond Phosphate Binders and Diet

Most patients receiving dialysis rely on dietary restriction and phosphate binders to minimize the risk of hyperphosphatemia, which is associated with increased mortality. However, dietary restriction is difficult because of hidden phosphate additives in processed foods and medications. Restriction of dietary phosphate sources such as protein may increase the risk of malnutrition. Phosphate binders, the only pharmacologic option for phosphate management since aluminum salts were introduced several decades ago, are often insufficient for binding the 1400-2500 mg of phosphate potentially consumed daily. Over the last decade, serum phosphate levels in the United States have risen, and >69% of patients receiving dialysis exhibited a most recent phosphate level >4.5 mg/dl (above the normal range), indicating an urgent need for new, more effective therapies to manage phosphate burden. Novel, nonbinder therapies such as transcellular and paracellular phosphate absorption inhibitors may be used for phosphate management, and future studies should examine whether they allow fewer dietary restrictions for patients receiving dialysis, potentially improving patient quality of life and nutritional status. It is imperative that we collaborate to move beyond the restrictive approaches available today and provide patients and clinicians with an array of strategies so that they may choose the most appropriate patient-centered therapy.

Economic impact of the use of patiromer in chronic kidney disease or heart failure for the treatment of chronic hyperkalemia in Spain

INTRODUCTION

Chronic hyperkalemia has negative consequences in the medium and long term, and determines the suspension of nephro and cardioprotective drugs, such as renin-angiotensin-aldosterone system inhibitors (RAASi). There is an alternative to the suspension or dose reduction of these treatments: the administration of potassium chelators. The aim of this study is to estimate the economic impact of the use of patiromer in patients with chronic kidney disease (CKD) or heart failure (HF) and hyperkalemia in Spain.

MATERIALS AND METHOD

The annual economic impact of the use of patiromer has been estimated from the perspective of the Spanish society. Two scenarios were compared: patients with CKD or HF and hyperkalemia treated with and without patiromer. The costs have been updated to 2020 euros, using the Health Consumer Price Index. Direct healthcare costs related to the use of resources (treatment with RAASi, CKD progression, cardiovascular events and hospitalization due to hyperkalemia), direct non-healthcare costs (informal care: costs derived from time dedicated by patient's relatives), the indirect costs (productivity loss), as well as an intangible cost (due to premature mortality) were considered. A deterministic sensitivity analysis was performed to validate the robustness of the study results.

RESULTS

The mean annual cost per patient in the scenario without patiromer is €9,834.09 and €10,739.37 in CKD and HF, respectively. The use of patiromer would lead to cost savings of over 30% in both diseases. The greatest savings in CKD come from the delay in the progression of CKD. While in the case of HF, 80.1% of these savings come from premature mortality reduction. The sensitivity analyses carried out show the robustness of the results, obtaining savings in all cases.

CONCLUSIONS

The incorporation of patiromer allows better control of hyperkalemia and, as a consequence, maintain treatment with RAASi in patients with CKD or HF. This would generate a 32% of annual savings in Spain (€3,127 in CKD; €3,466 in HF). The results support the positive contribution of patiromer to health cost in patients with only CKD or in patients with only HF.

Sequencing Quadruple Therapy for Heart Failure with Reduced Ejection Fraction: Does It Really Matter?

The conventional sequence of guideline-directed medical therapy (GDMT) initiation in heart failure with reduced ejection fraction (HFrEF) assumes that the effectiveness and tolerability of GDMT agents mirror their order of discovery, which is not true. In this review, the authors discuss flexible GDMT sequencing that should be permitted in special populations, such as patients with bradycardia, chronic kidney disease, or atrial fibrillation. Moreover, the initiation of certain GDMT medications may enable tolerance of other GDMT medications. Most importantly, the achievement of partial doses of all four pillars of GDMT is better than achievement of target dosing of only a couple.

Management of Hyperkalemia in Patients with Chronic Kidney Disease Using Renin Angiotensin Aldosterone System Inhibitors

PURPOSE OF REVIEW

Use of renin-angiotensin-aldosterone system (RAAS) inhibiting medications is critical in the prevention of cardiovascular disease and kidney function decline in patients with chronic kidney disease (CKD); however, these agents can lead to hyperkalemia, an electrolyte disorder associated with risk of arrythmia, conduction disorders, and increased overall mortality. Discontinuation, or reduction of dose, of RAAS inhibitor therapy in hyperkalemic patients with CKD can lead to loss of kidney and cardiovascular protection afforded by these medications. Given the high prevalence of hyperkalemia among patients with CKD utilizing RAAS inhibitors, clear management principles are critical to minimize risk and maximize benefit when facing this clinical dilemma.

RECENT FINDINGS

Strategies to mitigate hyperkalemia that do not interfere with optimal RAAS inhibitor therapy should be prioritized when managing potassium elevation in patients with CKD. These strategies include discontinuing non-RAAS inhibitor medications known to cause hyperkalemia, correction of metabolic acidosis, and maximization of medication therapies that lower serum potassium, including diuretics and sodium-glucose cotransporter-2 (SGLT-2) inhibitors. Initiation of potassium exchange resins should also be considered to allow for sustained RAAS inhibitor utilization. An approach which employs multiple strategies concurrently is important to mitigate hyperkalemia and maintain long-term use of RAAS-inhibitors. Persistence of RAAS inhibitor use in patients with CKD is important to slow kidney function decline, delay onset of dialysis or the need for kidney transplant, and prevent adverse cardiovascular outcomes. When hyperkalemia develops among patients with CKD utilizing a RAAS inhibitor, a deliberate effort to reduce serum potassium levels using an approach that allows for continuation of maximally dosed RAAS inhibitor therapy is important. Patient education and engagement in the potassium management process is important for sustained success.

Consensus document on the management of hyperkalemia

Hyperkalaemia is a common electrolyte imbalance with potentially serious short-, medium- and long-term consequences on morbidity and mortality rates and the use of national health service resources. The fact that different medical specialities can manage hyperkalaemia makes it important to have a unified approach, and the recent availability of new specific drug treatments means that the approach needs to be updated. This consensus document from the scientific societies most directly involved in the management of hyperkalaemia (Sociedad Española de Cardiología [Spanish Society of Cardiology], Sociedad Española de Endocrinología y Nutrición [Spanish Society of Endocrinology and Nutrition], Sociedad Española de Medicina Interna [Spanish Society of Internal Medicine], Sociedad Española de Medicina de Urgencias y Emergencias [Spanish Society of Accident and Emergency Medicine] and Sociedad Española de Nefrología [Spanish Society of Nephrology]) first of all reviews basic aspects of potassium balance and blood potassium. Then it goes on to focus on the concept, epidemiology, pathophysiology and diagnostic and therapeutic approaches to hyperkalaemia. The available evidence and the main published studies have been reviewed with the aim of providing a useful tool in the multidisciplinary approach to patients with hyperkalaemia.

Management of Hypertension in Diabetic Kidney Disease

Hypertension is a critical component of cardiovascular disease progression in patients with chronic kidney disease, and specifically diabetic kidney disease (DKD). Causation versus correlation remains up for debate, but what has been confirmed is the delay of DKD progression when hypertension is controlled or moved to guideline drive ranges. Many medications have been studied and used in real world experience for best outcomes, and we discuss below the proven winners thus far making up the renin angiotensin aldosterone system. As well, we discuss guideline changing medications including sodium-glucose cotransporter 2 inhibitors and newer generation mineralocorticoid receptor antagonists. With the growing prevalence of diabetes and DKD in the population, newer agents are emerging in multiple drug class and will be highlighted below. Clinicians continue to search for the optimal care plans for this challenging patient population.

Novel Approaches in Chronic Renal Failure without Renal Replacement Therapy: A Review

Chronic kidney disease (CKD) is characterized by renal parenchymal damage leading to a reduction in the glomerular filtration rate. The inflammatory response plays a pivotal role in the tissue damage contributing to renal failure. Current therapeutic options encompass dietary control, mineral salt regulation, and management of blood pressure, blood glucose, and fatty acid levels. However, they do not effectively halt the progression of renal damage. This review critically examines novel therapeutic avenues aimed at ameliorating inflammation, mitigating extracellular matrix accumulation, and fostering renal tissue regeneration in the context of CKD. Understanding the mechanisms sustaining a proinflammatory and profibrotic state may offer the potential for targeted pharmacological interventions. This, in turn, could pave the way for combination therapies capable of reversing renal damage in CKD. The non-replacement phase of CKD currently faces a dearth of efficacious therapeutic options. Future directions encompass exploring vaptans as diuretics to inhibit water absorption, investigating antifibrotic agents, antioxidants, and exploring regenerative treatment modalities, such as stem cell therapy and novel probiotics. Moreover, this review identifies pharmaceutical agents capable of mitigating renal parenchymal damage attributed to CKD, targeting molecular-level signaling pathways (TGF-β, Smad, and Nrf2) that predominate in the inflammatory processes of renal fibrogenic cells.

Pathophysiology and clinical management of hyperkalemia in chronic kidney disease

Adaptive increases in kidney and gastrointestinal excretion of K+ help to prevent hyperkalemia in patients with chronic kidney disease (CKD) as long as the glomerular filtration rate (GFR) remains >15-20 mL/min. K+ balance is maintained by increased secretion per functioning nephron, which is mediated by elevated plasma K+ concentration, aldosterone, increased flow rate, and enhanced Na+-K+-ATPase activity. Fecal losses of potassium also increase in CKD. These mechanisms are effective in preventing hyperkalemia if urine output is in excess of 600 mL/day and the GFR exceeds 15 mL/min. Development of hyperkalemia with only mild to moderate reductions in GFR should prompt a search for intrinsic disease of the collecting duct, disturbances in mineralocorticoid activity, and/or decreased delivery of sodium to the distal nephron. The initial approach to treatment is to review the patient's medication profile and whenever possible discontinue drugs that impair kidney K+ excretion. Patients should be educated on sources of K+ in the diet and should be strongly encouraged to avoid the use of K+ containing salt substitutes as well as herbal remedies since herbs may be a hidden source of dietary K+. Effective diuretic therapy and correction of metabolic acidosis are effective strategies to minimize the potential for hyperkalemia. Discontinuation or use of submaximal doses of renin-angiotensin blockers should be discouraged given the cardiovascular protective effect these drugs provide. Potassium binding drugs can be useful to enable use of these drugs and potentially allow liberalization of the diet in CKD patients.

Maintaining Renin-Angiotensin-Aldosterone System Inhibitor Treatment with Patiromer in Hyperkalaemic Chronic Kidney Disease Patients: Comparison of a Propensity-Matched Real-World Population with AMETHYST-DN

INTRODUCTION

Guideline-directed renin-angiotensin-aldosterone system inhibitor (RAASi) therapy is rarely achieved in clinical settings, often due to hyperkalaemia. We assessed the potassium binder, patiromer, on continuation of RAASi therapy in hyperkalaemic patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM) in the AMETHYST-DN trial, propensity score-matched to a real-world cohort not receiving patiromer (Salford Kidney Study).

METHODS

The phase 2, open-label AMETHYST-DN trial (NCT01371747) randomized 304 adults with CKD on RAASi, T2DM, hyperkalaemia (serum potassium [sK+] >5.0 mEq/L), and hypertension to receive patiromer, 8.4-33.6 g/day for 12 months. Patients underwent propensity score matching for systolic blood pressure (BP), heart failure status, and estimated glomerular filtration rate (eGFR), with 321 patients with CKD, T2DM, hyperkalaemia, and on RAASi from a prospective CKD cohort (Salford Kidney Study). Changes in RAASi utilization, sK+, BP, proteinuria, and eGFR during 12-month follow-up were assessed by Mann-Whitney U or χ2 tests.

RESULTS

Matching produced 135:135 patients with no significant differences in age, sex, systolic BP, sK+, eGFR, or heart failure status, although differences in diastolic BP remained (p < 0.001). After 12 months, 100% of AMETHYST-DN patients receiving patiromer remained on RAASi therapy, whereas 38.5% of the Salford Kidney Cohort discontinued RAASi (p < 0.001); hyperkalaemia contributed in 16% of patients (42% of RAASi discontinuations). Significantly greater reductions in sK+ and BP, but not proteinuria or eGFR, were observed in AMETHYST-DN, compared with Salford Kidney Study patients (p < 0.05).

CONCLUSIONS

These results demonstrate the benefit of patiromer for sK+ management to enable RAASi use while revealing beneficial effects on BP.

Hyperkalemia in chronic kidney disease: a focus on potassium lowering pharmacotherapy

INTRODUCTION

Hyperkalemia is one of the most common electrolyte disorders in chronic kidney disease (CKD) and is associated with serious adverse outcomes. Hyperkalemia risk is even greater when CKD patients also have additional predisposing conditions such as diabetes or heart failure. Renin-angiotensin-aldosterone-system blockers are first-line treatments for cardio- and nephroprotection, but their use is often limited due to K+ elevation, resulting in high rates of discontinuation.

AREAS COVERED

This article provides an overview of factors interfering with K+ homeostasis and discusses recent data on newer therapeutic agents used for the treatment of hyperkalemia. A detailed literature search was performed in two major databases (PubMed/MEDLINE and Scopus) up to April 2023.

EXPERT OPINION

Major clinical trials have tested new and promising kidney protective therapies such as sodium/glucose-cotransporter-2 inhibitors and mineralocorticoid-receptor-antagonists, with promising results. Until recently, the only treatment option for hyperkalemia was the cation-exchanging resin sodium-polystyrene-sulfonate. However, despite its common use, the efficacy and safety data of this drug in the long-term management of hyperkalemia are scarce. During the last decade, two novel orally administered K+-exchanging compounds (patiromer and sodium-zirconium-cyclosilicate) have been approved for the treatment of adults with hyperkalemia, as they both effectively reduce elevated serum K+ and maintain chronically K+ balance within the normal range with an excellent tolerability and no serious adverse events.

Potassium homeostasis - Physiology and pharmacology in a clinical context

Membrane voltage controls the function of excitable cells and is mainly a consequence of the ratio between the extra- and intracellular potassium concentration. Potassium homeostasis is safeguarded by balancing the extra-/intracellular distribution and systemic elimination of potassium to the dietary potassium intake. These processes adjust the plasma potassium concentration between 3.5 and 4.5 mmol/L. Several genetic and acquired diseases but also pharmacological interventions cause dyskalemias that are associated with increased morbidity and mortality. The thresholds at which serum K+ not only associates but also causes increased mortality are hotly debated. We discuss physiologic, pathophysiologic, and pharmacologic aspects of potassium regulation and provide informative case vignettes. Our aim is to help clinicians, epidemiologists, and pharmacologists to understand the complexity of the potassium homeostasis in health and disease and to initiate appropriate treatment strategies in dyskalemic patients.

Sodium polystyrene is unsafe and should not be prescribed for the treatment of hyperkalaemia: primum non nocere!

'Old-generation' potassium (K) binders [i.e. sodium (SPS) and calcium polystyrene sulfonate] are widely used, but with substantial heterogeneity across countries to treat hyperkalaemia (HK). However, there are no randomized data to support their chronic use to manage HK, nor have they been shown to have a renin-angiotensin-aldosterone system inhibitor (RAASi)-enabling effect. These compounds have poor tolerability and an unpredictable onset of action and magnitude of K lowering. Furthermore, SPS may induce fluid overload, owing to the fact that it exchanges K for sodium. Its use has also been associated with colonic necrosis, as emphasized by a black box warning from the US Food and Drug Administration. In contrast, two new K binders, patiromer and sodium zirconium cyclosilicate, have been shown to be safe and well tolerated for chronic management of HK, thereby enabling RAASi optimization, as acknowledged by the latest international cardiorenal guidelines. In view of the lack of reliable evidence regarding the efficacy and safety of the old-generation K binders compared with the placebo-controlled randomized and real-word evidence demonstrating the safety, efficacy and RAASi-enabling effect of the new K binders, clinicians should now use these new K binders to treat HK (primum non nocere!).

Pharmacological strategies to manage hyperkalaemia: out with the old, in with the new? Not so fast…

Since the 1950s, sodium polystyrene sulphonate (SPS) has been the dominant cation exchange agent prescribed for hyperkalaemia. Clinicians have had plenty of time to learn of SPS's advantages and limitations. The demands of drug regulatory agencies regarding the incorporation of medications into the market were not so stringent then as they are today, and the efficacy and safety of SPS have been questioned. In recent years, two novel cation exchangers, patiromer and sodium zirconium cyclosilicate, have received (or are in the process of receiving) regulatory approval in multiple jurisdictions globally, after scrutiny of carefully conducted trials regarding their short-term and mid-term efficacy. In this debate, we defend the view that all three agents are likely to have similar efficacy. Harms are much better understood for SPS than for newer agents, but currently there are no data to suggest that novel agents are safer than SPS. Drug choices need to consider costs, access and numbers-needed-to-treat to prevent clinically important events; for potassium exchangers, we need trials directly examining clinically important events.

Hyperkalemia in CKD: an overview of available therapeutic strategies

Hyperkalemia (HK) is a life-threatening condition that often occurs in patients with chronic kidney disease (CKD). High serum potassium (sKsK) is responsible for a higher risk of end-stage renal disease, arrhythmias and mortality. This risk increases in patients that discontinue cardio-nephroprotective renin-angiotensin-aldosterone system inhibitor (RAASi) therapy after developing HK. Hence, the management of HK deserves the attention of the clinician in order to optimize the therapeutic strategies of chronic treatment of HK in the CKD patient. The adoption in clinical practice of the new hypokalaemic agents patiromer and sodium zirconium cyclosilicate (SZC) for the prevention and chronic treatment of HK could allow patients, suffering from heart failure and chronic renal failure, to continue to benefit from RAASi therapy. We have updated a narrative review of the clear variables, correct definition, epidemiology, pathogenesis, etiology and classifications for HK among non-dialysis CKD (ND CKD) patients. Furthermore, by describing the prognostic impact on mortality and on the progression of renal damage, we want to outline the strategies currently available for the control of potassium (K+) plasma levels.

Managing Hyperkalemia in the Modern Era: A Case-Based Approach

The last decade has seen tremendous advances in the prevention and treatment of recurrent hyperkalemia. In this narrative review, we aim to highlight contemporary data on key areas in the epidemiology and management of hyperkalemia. Focusing on drug-induced hyperkalemia (the implications of renin-angiotensin-aldosterone system inhibitors [RAASi] discontinuation and the role of mineralocorticoid receptor antagonists), newer concurrent therapies that modify potassium handling (sodium-glucose transporter 2 inhibitors [SGLT2i]), the introduction of new treatment agents (oral potassium binding agents), and the controversial role of dietary potassium restriction, we apply recent research findings and review the evidence in a case-based format.

Patiromer Treatment in Patients With CKD, Hyperkalemia, and Hyperphosphatemia: A Post Hoc Analysis of 3 Clinical Trials

RATIONALE & OBJECTIVE

Patients with chronic kidney disease (CKD), hyperkalemia (serum potassium [sK+]>5.0 mEq/L), and hyperphosphatemia experience poor clinical outcomes. Patiromer, a potassium binder that uses calcium as the exchange ion, may also reduce serum phosphorus (sP). We characterized the effect of patiromer on sP in patients with CKD, hyperkalemia, and hyperphosphatemia.

STUDY DESIGN

A post hoc pooled analysis of individual-level data from the AMETHYST-DN, OPAL-HK, and TOURMALINE trials of patiromer.

SETTING & PARTICIPANTS

Patients with CKD and hyperkalemia.

EXPOSURE

Patients treated with patiromer (8.4-33.6 g/day).

OUTCOME

Mean changes from baseline in sP, sK+, serum calcium (sCa2+), and serum magnesium (sMg2+) after 2 and 4 weeks of treatment.

ANALYTICAL APPROACH

Descriptive statistics to summarize pooled data on the study outcomes from the 3 studies.

RESULTS

We included 578 patients in the analysis. Of these participants, 86 patients (14.9%) had baseline hyperphosphatemia of whom 75.6% (65 of 86) had CKD stage 4/5 and 31.1% (153 of 492) with sP≤4.5mg/dL had CKD stage 4/5. Among the patients with elevated sP and sK+at baseline, the mean±SD reduction in sP and sK+after 4 weeks of patiromer treatment was-0.62±1.09mg/dL and-0.71± 0.51 mEq/L, respectively. Additionally, the mean±SD reduction in sMg2+in these patients was -0.25±0.23mg/dL while sCa2+remained unchanged. Both sMg2+and sCa2+remained within the normal range. Patiromer was generally well tolerated, and no serious adverse events were considered related to patiromer.

LIMITATIONS

These were post hoc analyses, no placebo comparison was performed due to the design of the original studies, and the follow-up period was limited to 4 weeks.

CONCLUSIONS

Reductions in sP and sK+to the normal range were observed after 2 weeks of patiromer treatment, and the reduction was sustained during 4 weeks of treatment among patients with non-dialysis-dependent CKD, hyperkalemia, and hyperphosphatemia. Future controlled trials are needed to establish if patiromer is useful to reduce both sK+and sP in hyperkalemic patients with CKD and hyperphosphatemia.

Patiromer utility as an adjunct treatment in patients needing urgent hyperkalaemia management (PLATINUM): design of a multicentre, randomised, double-blind, placebo-controlled, parallel-group study

INTRODUCTION

Hyperkalaemia is common, life-threatening and often requires emergency department (ED) management; however, no standardised ED treatment protocol exists. Common treatments transiently reducing serum potassium (K+) (including albuterol, glucose and insulin) may cause hypoglycaemia. We outline the design and rationale of the Patiromer Utility as an Adjunct Treatment in Patients Needing Urgent Hyperkalaemia Management (PLATINUM) study, which will be the largest ED randomised controlled hyperkalaemia trial ever performed, enabling assessment of a standardised approach to hyperkalaemia management, as well as establishing a new evaluation parameter (net clinical benefit) for acute hyperkalaemia treatment investigations.

METHODS AND ANALYSIS

PLATINUM is a Phase 4, multicentre, randomised, double-blind, placebo-controlled study in participants who present to the ED at approximately 30 US sites. Approximately 300 adult participants with hyperkalaemia (K+ ≥5.8 mEq/L) will be enrolled. Participants will be randomised 1:1 to receive glucose (25 g intravenously <15 min before insulin), insulin (5 units intravenous bolus) and aerosolised albuterol (10 mg over 30 min), followed by a single oral dose of either 25.2 g patiromer or placebo, with a second dose of patiromer (8.4 g) or placebo after 24 hours. The primary endpoint is net clinical benefit, defined as the mean change in the number of additional interventions less the mean change in serum K+, at hour 6. Secondary endpoints are net clinical benefit at hour 4, proportion of participants without additional K+-related medical interventions, number of additional K+-related interventions and proportion of participants with sustained K+ reduction (K+ ≤5.5 mEq/L). Safety endpoints are the incidence of adverse events, and severity of changes in serum K+ and magnesium.

ETHICS AND DISSEMINATION

A central Institutional Review Board (IRB) and Ethics Committee provided protocol approval (#20201569), with subsequent approval by local IRBs at each site, and participants will provide written consent. Primary results will be published in peer-reviewed manuscripts promptly following study completion.

TRIAL REGISTRATION NUMBER

NCT04443608.

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.

Steroidal or non-steroidal MRAs: should we still enable RAASi use through K binders?

Renin-angiotensin-aldosterone system inhibitors (RAASi) and mineralocorticoid receptor antagonists (MRAs) are important interventions to improve outcomes in patients with chronic kidney disease and heart failure, but their use is limited in some patients by the development of hyperkalemia. The risk of hyperkalemia may differ between agents, with one trial showing lower risk of hyperkalemia with the novel non-steroidal MRA finerenone compared with steroidal MRA spironolactone. Novel potassium binders, including patiromer and sodium zirconium cyclosilicate, are available interventions to manage hyperkalemia and enable continuation of RAASi and MRAs in patients who could benefit from these treatments. These agents bind free potassium ions in the lumen of the gastrointestinal tract to prevent the absorption of dietary potassium and increase potassium secretion. Several studies showed that potassium binders are effective compared with placebo for preventing hyperkalemia or steroidal MRA discontinuation, but none has evaluated whether this strategy impacts clinically important endpoints such as cardiovascular events. Due to this and other limitations related to cost, clinical availability, pill burden and patient selection, alternative potential strategies to mitigate hyperkalemia may be more practical. Conservative strategies include increased monitoring and use of loop or thiazide diuretics to increase urinary potassium excretion. Non-steroidal MRAs may have a lower risk of hyperkalemia than steroidal MRAs and have stronger anti-inflammatory and anti-fibrotic effects with resultant reduced risk of kidney disease progression. Sodium-glucose cotransporter-2 inhibitors also decrease hyperkalemia risk in patients on MRAs and decrease cardiovascular events and kidney disease progression. These may be better first-line interventions to obviate the need for potassium binders and offer additional benefits.

Medical Treatment in Heart Failure with Reduced Ejection Fraction: A Proposed Algorithm Based on the Patient's Electrolytes and Congestion Status

In heart failure (HF) with reduced ejection fraction (HFrEF), four classes of drugs (β-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor neprilysin inhibitors, mineralocorticoid receptor antagonists, and the most recent Sodium-Glucose Co-Transporters 2 Inhibitors) have demonstrated positive results in randomized controlled trials (RCTs). Nevertheless, the latest RCTs are not proper for comparison since they were carried out at various times with dissimilar background therapies and the patients enrolled did not have the same characteristics. The difficulty of extrapolating from these trials and proposing a common framework appropriate for all cases is thus obvious. Despite the fact that these four agents are now the fundamental pillars of HFrEF treatment, the built-up algorithm of initiation and titration is a matter of debate. Electrolyte disturbances are common in HFrEF patients and can be attributed to several factors, such as the use of diuretics, renal impairment, and neurohormonal activation. We have identified several HFrEF phenotypes according to their sodium (Na+) and potassium (K+) status in a "real world" setting and suggest an algorithm on how to introduce the most appropriate drug and set up therapy based on the patients' electrolytes and the existence of congestion.

A randomized study to compare oral potassium binders in the treatment of acute hyperkalemia

BACKGROUND

The KBindER (K⁺ Binders in Emergency Room and hospitalized patients) clinical trial is the first head-to-head evaluation of oral potassium binders (cation-exchange resins) for acute hyperkalemia therapy.

METHODS

Emergency room and hospitalized patients with a blood potassium level ≥ 5.5 mEq/L are randomized to one of four study groups: potassium binder drug (sodium polystyrene sulfonate, patiromer, or sodium zirconium cyclosilicate) or nonspecific laxative (polyethylene glycol). Exclusion criteria include recent bowel surgery, ileus, diabetic ketoacidosis, or anticipated dialysis treatment within 4 h of treatment drug. Primary endpoints include change in potassium level at 2 and 4 h after treatment drug. Length of hospital stay, next-morning potassium level, gastrointestinal side effects and palatability will also be analyzed. We are aiming for a final cohort of 80 patients with complete data endpoints (20 per group) for comparative statistics including multivariate adjustment for kidney function, diabetes mellitus, congestive heart failure, metabolic acidosis, renin-angiotensin-aldosterone system inhibitor prescription, and treatment with other agents to lower potassium (insulin, albuterol, loop diuretics).

DISCUSSION

The findings from our study will inform decision-making guidelines on the role of oral potassium binders in the treatment of acute hyperkalemia.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04585542 . Registered 14 October 2020.

[Mineralocorticoid receptor antagonists: A new therapeutic option for diabetic kidney disease]

Diabetic kidney disease (DKD) and its associated cardiovascular morbidity represent a major complication in diabetic patients. Over the past two decades, several experimental studies have shown benefits of mineralocorticoid receptor (MR) antagonists on the cardiorenal outcomes in animal models of non-diabetic or diabetic kidney diseases. Here, we summarize the role of MR activation in promoting inflammatory and fibrotic mechanisms that contribute to DKD pathophysiology. We also review the key findings of two recent large clinical trials FIDELIO-DKD and FIGARO-DKD which showed for the first time a major benefit of the non-steroidal MR antagonist, finerenone, on renal and cardiac specific outcomes across the spectrum of DKD severity. We finally discuss the place of finerenone compared to other DKD therapeutic approaches.

A cost-effectiveness analysis of patiromer in the UK: evaluation of hyperkalaemia treatment and lifelong RAASi maintenance in chronic kidney disease patients with and without heart failure

BACKGROUND

Chronic kidney disease (CKD) patients with and without heart failure (HF) often present with hyperkalaemia (HK) leading to increased risk of hospitalisations, cardiovascular related events and cardiovascular-related mortality. Renin-angiotensin-aldosterone system inhibitor (RAASi) therapy, the mainstay treatment in CKD management, provides significant cardiovascular and renal protection. Nevertheless, its use in the clinic is often suboptimal and treatment is frequently discontinued due to its association with HK. We evaluated the cost-effectiveness of patiromer, a treatment known to reduce potassium levels and increase cardiorenal protection in patients receiving RAASi, in the UK healthcare setting.

METHODS

A Markov cohort model was generated to assess the pharmacoeconomic impact of patiromer treatment in regulating HK in patients with advanced CKD with and without HF. The model was generated to predict the natural history of both CKD and HF and quantify the costs and clinical benefits associated with the use of patiromer for HK management from a healthcare payer's perspective in the UK.

RESULTS

Economic evaluation of patiromer use compared to standard of care (SoC) resulted in increased discounted life years (8.93 versus 8.67) and increased discounted quality-adjusted life years (QALYs) (6.36 versus 6.16). Furthermore, patiromer use resulted in incremental discounted cost of £2,973 per patient and an incremental cost-effectiveness ratio (ICER) of £14,816 per QALY gained. On average, patients remained on patiromer therapy for 7.7 months, and treatment associated with a decrease in overall clinical event incidence and delayed CKD progression. Compared to SoC, patiromer use resulted in 218 fewer HK events per 1,000 patients, when evaluating potassium levels at the 5.5-6 mmol/l; 165 fewer RAASi discontinuation episodes; and 64 fewer RAASi down-titration episodes. In the UK, patiromer treatment was predicted to have a 94.5% and 100% chance of cost-effectiveness at willingness-to-pay thresholds (WTP) of £20,000/QALY and £30,000/QALY, respectively.

CONCLUSION

This study highlights the value of both HK normalisation and RAASi maintenance in CKD patients with and without HF. Results support the guidelines which recommend HK treatment, e.g., patiromer, as a strategy to enable the continuation of RAASi therapy and improve clinical outcomes in CKD patients with and without HF.

Assessing patiromer utilization and associated serum potassium changes in US veterans with prior sodium polystyrene sulfonate exposure

Untreated chronic hyperkalemia is associated with an increased risk of mortality. Novel potassium binders (e.g., patiromer) are new additions to the clinician's armamentarium. Prior to their approval, clinicians often considered trialing sodium polystyrene sulfonate. The study objective was to assess patiromer utilization and associated changes in serum potassium (K+) in US veterans with prior sodium polystyrene sulfonate exposure. This was a real-world observational study of US veterans with chronic kidney disease and a baseline K+ ≥ 5.1 mEq/L, initiated on patiromer between January 1, 2016, and February 28, 2021. The primary endpoints were patiromer utilization (dispensations and treatment courses), and K+ change at 30-, 91-, and 182-day follow-up (FU) intervals. Patiromer utilization was described using Kaplan-Meier probabilities and the proportion of days covered. Descriptive changes in population average K+ were obtained from a pre-post design using single-arm within-patient pre-post lab pairs and paired t tests. Two hundred five veterans met the study criteria. We observed an average of 1.25 (95% CI, 1.19-1.31) treatment courses and a median treatment duration of 64 days. Fifty veterans (24.4%) had >1 course, and 17.6% of patients remained on their initial patiromer treatment course until the end of the 180-day FU. The mean K+ value was 5.73 mEq/L (5.66-5.79) at baseline, 4.95 mEq/L (95% CI, 4.86-5.05) at the 30-day interval, 4.93 mEq/L (95% CI, 4.84-5.03) at the 91-day interval, and 4.9 mEq/L (95% CI, 4.8-4.99) at the 182-day interval. Novel potassium binders (e.g., patiromer) are newer chronic hyperkalemia management tools for clinicians. The average population K+ decreased to <5.1 mEq/L at all follow-up intervals. Patiromer appeared to be well tolerated with nearly 18% of patients remaining on their initial treatment course during the entire 180-day FU period. The median treatment duration was 64 days and approximately 24% of patients initiated a second course during FU.