Hyperkalemia constitutes a constraint for implementing renin-angiotensin-aldosterone inhibition: the widening gap between mandated treatment guidelines and the real-world clinical arena

Guideline-Recommended Disease-Modifying Therapies for Patients with Cardiorenal Disease: A Call-to-Action Narrative Review

Substantial gaps exist between recommendations for guideline-directed medical therapy (GDMT) for chronic kidney disease (CKD) and its use in real-world clinical practice. This includes suboptimal dosing of renin-angiotensin system inhibitors (RASi), low uptake of sodium-glucose co-transporter 2 inhibitors (SGLT2i) for CKD, and low uptake and/or transient use of potassium binders to manage RASi-induced hyperkalemia. Suboptimal RASi therapy deprives patients of the full cardiorenal benefits associated with RASi, and increases the risk of cardiorenal adverse events and mortality. Hyperkalemia can be managed and optimal RASi dosing can be continued by using novel potassium binders, such as sodium zirconium cyclosilicate or patiromer. Similarly, low uptake of SGLT2i might be associated with the concern of an accelerated decline in estimated glomerular filtration rate and, therefore, disease progression when initiating SGLT2i. Numerous clinical trials have demonstrated that adding SGLT2i to RASi therapy can improve clinical outcomes and prolong patient survival in CKD. The recently published Kidney Disease: Improving Global Outcomes (KDIGO) 2024 clinical practice guideline for the evaluation and management of CKD extends the recommendation of SGLT2i to individuals with CKD without diabetes, reinforces the cardiorenal benefits of optimized RASi, recommends the addition of newer drug classes in suitable patients with CKD, and notes the use of novel potassium binders to manage hyperkalemia and enable optimal use of GDMT. In doing so, the guideline targets achievement of the "quadruple aim" of GDMT in CKD, i.e., enabling optimal use of RASi and SGLT2i in most patients, along with nonsteroidal mineralocorticoid receptor antagonists, and glucagon-like peptide-1 receptor agonists in diabetic kidney disease. This manuscript constitutes a call to action to raise awareness of the growing clinical and economic burdens of CKD and to promote a united approach to the early detection and optimal treatment of CKD through stricter adherence to GDMT.

Endothelial dysfunction in the kidney transplant population: Current evidence and management strategies

The endothelium modulates vascular homeostasis owing to a variety of vasoconstrictors and vasodilators. Endothelial dysfunction (ED), characterized by impaired vasodilation, inflammation, and thrombosis, triggers future cardiovascular (CV) diseases. Chronic kidney disease, a state of chronic inflammation caused by oxidative stress, metabolic abnormalities, infection, and uremic toxins damages the endothelium. ED is also associated with a decline in estimated glomerular filtration rate. After kidney transplantation, endothelial functions undergo immediate but partial restoration, promising graft longevity and enhanced CV health. However, the anticipated CV outcomes do not happen due to various transplant-related and unrelated risk factors for ED, culminating in poor CV health and graft survival. ED in kidney transplant recipients is an under-recognized and poorly studied entity. CV diseases are the leading cause of death among kidney transplant candidates with functioning grafts. ED contributes to the pathogenesis of many of the CV diseases. Various biomarkers and vasoreactivity tests are available to study endothelial functions. With an increasing number of transplants happening every year, and improved graft rejection rates due to the availability of effective immunosuppressants, the focus has now shifted to endothelial protection for the prevention, early recognition, and treatment of CV diseases.

Potassium levels and short-term outcomes in heart failure with mildly reduced ejection fraction

OBJECTIVE

The study investigates the prognostic impact of dyskalemias in patients hospitalized with heart failure with mildly reduced ejection fraction (HFmrEF).

BACKGROUND

Although dyskalemias represent a common complication in patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF), data concerning the prevalence and prognostic impact of dyskalemias in HFmrEF is limited.

METHODS

Consecutive patients with HFmrEF were retrospectively included at one institution from 2016 to 2022. The prognostic impact of potassium levels was assessed comparing patients with potassium levels > 3.3 to ≤4.5 mmol/L, ≤3.3 mmol/L and > 4.5 mmol/L. The primary endpoint was all-cause mortality at 30 days.

RESULTS

2079 patients with HFmrEF and potassium measurement were included (median potassium level: 4.4 mmol/L; mean 4.2 mmol/L). 84 % of patients hospitalized with HFmrEF presented with potassium levels in the norm range, 8 % with hypokalemia and 8 % with hyperkalemia, respectively. The risk of all-cause mortality at 30 days was higher in patients with hyperkalemia compared to patients with normokalemia (7 % vs 4 %; log rank p = 0.026), whereas the presence of hypokalemia (6 %; log rank p = 0.075) was not significantly associated with the risk of 30-days all-cause mortality. Compared to patients with normokalemia, the presence of hyperkalemia was still associated with an increased risk of 30-day all-cause mortality within a multivariable Cox regression analysis (HR = 2.002; 95 % CI 1.004-3.992; p = 0.049).

CONCLUSION

In patients hospitalized with HFmrEF, hyperkalemia - but not hypokalemia - was independently associated with an increased risk of all-cause mortality at 30 days.

New strategies for the treatment of hyperkalemia

Renin-angiotensin-aldosterone system inhibitors (RAASi) and mineralocorticoid receptor antagonists (MRAs) are key drugs in the management of patients with cardiovascular diseases (CVD), particularly those with hypertension, diabetes, chronic kidney disease and heart failure (HF), given their demonstrated effectiveness in reducing the risk of both surrogate and hard endpoints. Despite their positive impact on the outcome, patients with RAASi and MRAs are particularly vulnerable to hyperkalaemia, with approximately 50 % of these individuals experiencing two or more recurrences annually. The common practice of reducing the dose or discontinuing the treatment with RAASi and MRAs in conditions of hyperkalaemia results in suboptimal management of these patients, with a potential impact on their mortality and morbidity risk. Recent guidelines from cardiovascular and renal international societies increasingly recognize the need for alternative strategies to manage the risk of hyperkalaemia, allowing the continuation of RAASi and MRA therapies. In this review, we summarise the new potential options available to manage hyperkalaemia in patients with CVD and the recommendations of the most recent guidelines on the topic.

Cost-effectiveness of sodium zirconium cyclosilicate for the treatment of hyperkalemia in patients with chronic kidney disease or heart failure in Spain

BACKGROUND AND OBJECTIVE

Hyperkalemia (HK) is an electrolyte disturbance in the concentration of potassium ions (K+), whose risk increases in patients with chronic kidney disease (CKD) or heart failure (HF) and/or in patients being treated with renin-angiotensin-aldosterone system inhibitors (RAASi). The new oral K+ chelators offer a safe and effective treatment to maintain normokalemia in these patients. The objective of the analysis is to estimate the cost-effectiveness of sodium zirconium cyclosilicate (SZC) for the treatment of chronic HK in patients with CKD or HF versus standard treatment (calcium polystyrene sulfonate and lifestyle modifications) from the perspective of the Spanish National Health System.

MATERIALS AND METHODS

Two microsimulation models reflecting the natural history of CKD and HF were used. In both models, K+ levels were simulated individually. Based on efficacy (reduction of K+ levels), quality of life of patients (utilities according to health states, and disutilities of events derived from each pathology and adverse events [AEs] of treatment) and costs considered (cost of treatment for HK, of RAASi treatment and its modification, health states, management of events derived from each pathology, HK episodes, and AEs treatment) (, 2022), clinical benefit (quality-adjusted life years [QALYs]) and cost results were obtained. A time horizon of the patient's lifetime was used and a discount rate of 3% was applied for costs and outcomes.

RESULTS

SZC is a more effective option in both pathologies, with a difference in QALYs of 0.476 in CKD and 0.978 in HF compared to standard treatment, and it represents an incremental cost of 3,616 and 14,749, respectively, obtaining an incremental cost-utility ratio of 7,605/QALY in CKD and 15,078/QALY in HF.

CONCLUSIONS

SZC is a cost-effective alternative for the treatment of HK in patients with CKD or HF, taking into account the reference efficiency values commonly used in Spain.

Aldosterone synthase inhibitor (BI 690517) therapy for people with diabetes and albuminuric chronic kidney disease: A multicentre, randomized, double-blind, placebo-controlled, Phase I trial

AIM

This Phase I study evaluated the safety and early efficacy of an aldosterone synthase inhibitor (BI 690517) in people with diabetes and albuminuric chronic kidney disease.

METHODS

Double-blind, placebo-controlled study (NCT03165240) at 40 sites across Europe. Eligible participants [estimated glomerular filtration rate ≥20 and <75 ml/min/1.73 m2; urine albumin/creatinine ratio (UACR) ≥200 and <3500 mg/g] were randomized 6:1 to receive once-daily oral BI 690517 3, 10 or 40 mg, or eplerenone 25-50 mg, or placebo, for 28 days. The primary endpoint was the proportion of participants with drug-related adverse events (AEs). Secondary endpoints included changes from baseline in the UACR.

RESULTS

Fifty-eight participants were randomized and treated from 27 November 2017 to 16 April 2020 (BI 690517: 3 mg, n = 18; 10 mg, n = 13; 40 mg, n = 14; eplerenone, n = 4; placebo, n = 9) for 28 days. Eight (13.8%) participants experienced drug-related AEs [BI 690517: 3 mg (two of 18); 10 mg (four of 13); 40 mg (two of 14)], most frequently constipation [10 mg (one of 13); 40 mg (one of 14)] and hyperkalaemia [3 mg (one of 18); 10 mg (one of 13)]. Most AEs were mild to moderate; one participant experienced severe hyperkalaemia (serum potassium 6.9 mmol/L; BI 690517 10 mg). UACR responses [≥20% decrease from baseline (first morning void urine) after 28 days] were observed for 80.0% receiving BI 690517 40 mg (eight of 10) versus 37.5% receiving placebo (three of eight). Aldosterone levels were suppressed by BI 690517, but not eplerenone or placebo.

CONCLUSIONS

BI 690517 was generally well tolerated, reduced plasma aldosterone and may decrease albuminuria in participants with diabetes and albuminuric chronic kidney disease.

Financial Implication of Sodium Zirconium Cyclosilicate Therapy in Patients with Systolic Heart Failure and Hyperkalemia

Sodium zirconium cyclosilicate (SZC), a newly-introduced potassium binder, can be used to manage hyperkalemia especially in patients with chronic kidney disease and in those on medical therapy which may raise serum potassium levels. The medication may incur additional costs but may in turn have a significant benefit in the effect of maintaining guideline-directed medical therapy for heart failure. We aimed to investigate the financial impact of SZC therapy in patients with systolic heart failure.Patients with systolic heart failure who received SZC for hyperkalemia between July 2020 and March 2023 were included. In-hospital medical costs were compared between the patients who discontinued SZC and those who continued SZC. For the continue group, the cost of SZC was added. All patients were followed for 2 years or until May 2023.A total of 36 patients (median age 81 years, 56% male, median left ventricular ejection fraction 43%) were included. Total medical costs were significantly lower in the continue group (n = 12) compared to the discontinue group (n = 24) (3.1 [3.1, 6.2] versus 12.1 [3.8, 48.6] × 104 JPY per month, P = 0.039). In the continue group, serum potassium levels were decreased, renin-angiotensin-aldosterone system inhibitor doses were up-titrated, and the left ventricular ejection fraction was increased, whereas these parameters remained unchanged or worsened in the discontinue group.SZC may have the potential to assist in the up-titration of potassium-sparing heart failure-specific medications, prevent readmissions, and minimize medical costs, by preventing recurrent hyperkalemia in patients with systolic heart failure.

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.

Chronic kidney disease in children: an update

Chronic kidney disease (CKD) is a major healthcare issue worldwide. However, the prevalence of pediatric CKD has never been systematically assessed and consistent information is lacking in this population. The current definition of CKD is based on glomerular filtration rate (GFR) and the extent of albuminuria. Given the physiological age-related modification of GFR in the first years of life, the definition of CKD is challenging per se in the pediatric population, resulting in high risk of underdiagnosis in this population, treatment delays and untailored clinical management. The advent and spreading of massive-parallel sequencing technology has prompted a profound revision of the epidemiology and the causes of CKD in children, supporting the hypothesis that CKD is much more frequent than currently reported in children and adolescents. This acquired knowledge will eventually converge in the identification of the molecular pathways and cellular response to damage, with new specific therapeutic targets to control disease progression and clinical features of children with CKD. In this review, we will focus on recent innovations in the field of pediatric CKD and in particular those where advances in knowledge have become available in the last years, with the aim of providing a new perspective on CKD in children and adolescents.

Primary Aldosteronism in Chronic Kidney Disease: Blood Pressure Control and Kidney and Cardiovascular Outcomes After Surgical Versus Medical Management

BACKGROUND

Diagnosis and treatment of primary aldosteronism (PA) in chronic kidney disease (CKD) may be deferred due to limited evidence supporting safety and efficacy of treatment. Our goal was to assess clinical outcomes in patients with PA and CKD who received surgical or medical management.

METHODS

We conducted a multicenter, retrospective cohort study of patients with PA and CKD who underwent adrenal vein sampling from 2009-2019. We characterized clinical outcomes and evaluated differences by surgical versus medical management. Primary outcomes were systolic blood pressure and number of antihypertensive medications. Secondary outcomes were diastolic blood pressure, serum potassium, estimated glomerular filtration rate (eGFR), and kidney and cardiovascular events. Analyses were adjusted for age, sex, race, cardiovascular disease, diabetes, and eGFR.

RESULTS

Of 239 participants with PA and CKD, 158 (66%) underwent adrenalectomy, and 81 (34%) were treated medically. Mean age was 57±10 years, 67% were female, mean eGFR was 45±12 mL/min per 1.73 m2, and 49% were on potassium supplementation. At 5 years, mean blood pressure decreased from 149±22/85±14 to 131±28/78±16 mm Hg and mean number of antihypertensive medications decreased from 4.0±1.5 to 2.4±1.4. Adrenalectomy, compared to medical management, was associated with similar systolic blood pressure (-0.90 mm Hg [95% CI, -6.99 to 5.07]) but fewer medications (1.7 [95% CI, -2.24 to -1.10]), and no difference in potassium levels or kidney or cardiovascular outcomes.

CONCLUSIONS

Patients with PA and CKD are likely to benefit from either surgical adrenalectomy or medical management. Detection and treatment of PA may help to reduce blood pressure and medication burden in patients with CKD.

Influence of SGLT2i and RAASi and Their Combination on Risk of Hyperkalemia in DKD: A Network Meta-Analysis

BACKGROUND

This network meta-analysis investigated the effect of various combined regimens of sodium-glucose cotransporter-2 inhibitors (SGLT2is) and renin-angiotensin-aldosterone system inhibitors (RAASis) on the occurrence of hyperkalemia in diabetic kidney disease.

METHODS

The risk of hyperkalemia was compared using the random-effects model of network meta-analysis, with results expressed as odds ratios (ORs) with 95% confidence intervals (CIs). The comparative effects of all medications and their combinations with placebo were ranked using the surface under the cumulative ranking probabilities.

RESULTS

In total, 27 eligible studies involving 43,589 participants with diabetic kidney disease were included. Major findings showed that the use of mineralocorticoid receptor antagonists (MRAs) on top of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) prominently increased hyperkalemia incidence when compared with placebo (OR, 6.08; 95% CI, 2.30 to 16.08), ACEI (OR, 3.07; 95% CI, 1.14 to 8.31), ARB (OR, 2.57; 95% CI, 1.10 to 6.02), SGLT2i (OR, 9.22; 95% CI, 2.99 to 28.46), renin inhibitors+ACEI/ARB (OR, 2.23; 95% CI, 1.14 to 4.36), or SGLT2i+ACEI/ARB (OR, 4.10; 95% CI, 2.32 to 7.26). Subgroup analysis among different generations of MRA found that spironolactone had the strongest effect in combination with ACEI/ARB, even higher than the combined use of ACEI and ARB (OR, 2.89; 95% CI, 1.26 to 6.63). In addition, SGLT2i had a significantly lower incidence of hyperkalemia compared with ACEI (OR, 0.33; 95% CI, 0.12 to 0.91), ARB (OR, 0.28; 95% CI, 0.13 to 0.61), dual RAASi (ACEI combined with ARB; OR, 0.17; 95% CI, 0.06 to 0.47), or MRA or renin inhibitors combined with ACEI/ARB (OR, 0.11; 95% CI, 0.04 to 0.33; OR, 0.24; 95% CI, 0.08 to 0.76, respectively). Moreover, adding SGLT2i to the combination of MRA and ACEI/ARB, as well as the combinations of different RAASis, markedly reduced the occurrence of hyperkalemia.

CONCLUSIONS

Among the therapeutic drugs with the potential risk of increasing serum potassium in patients with diabetic kidney disease, MRA added an extra risk of hyperkalemia while SGLT2i had the opposite effect and could even reverse the elevation of serum potassium caused by the combined regimen, including MRAs.

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.

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.

Clinical outcomes following discontinuation of renin-angiotensin-system inhibitors in patients with type 2 diabetes and advanced chronic kidney disease: A prospective cohort study

Background

Renin-angiotensin-system inhibitors (RASi), that include angiotensin converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) reduce proteinuria, delay chronic kidney disease (CKD) progression, protect against cardiovascular events and heart failure hospitalizations. We examined the associations of discontinuation of ACEi/ARBs with risk of clinical outcomes in Chinese patients with type 2 diabetes (T2D) and advanced-CKD (estimated-glomerular filtration rate [eGFR] <30 ml/min/1.73 m2).

Methods

We conducted a prospective, population-based cohort study including 10,400 patients with T2D in Hong Kong stratified by continuation of ACEi/ARBs within 6 months after reaching eGFR <30 ml/min/1.73 m2 from January 01, 2002 to December 31, 2018 and observed until December 31, 2019. The primary outcomes were death, major-adverse cardiovascular events (MACE), heart failure, end-stage kidney disease (ESKD), and all-cause mortality. Cox-model with time-dependent exposure and covariates was used to estimate the hazard ratio (HR) of outcomes in a propensity-score overlap-weighted cohort. The risk of occurrence of hyperkalemia (plasma potassium >5.5 mmol/L) in discontinued-ACEi/ARBs versus continued-ACEi/ARBs users was assessed in a register-based cohort.

Findings

In the population-based cohort of 10,400 ACEi/ARBs users with new-onset eGFR<30 ml/min/1.73 m2, 1766 (17.0%) discontinued ACEi/ARBs and 8634 (83.0%) persisted with treatment. During a median follow-up of 3.6 (interquartile range, IQR: 2.11-5.8) years (41,623 person-years), 13.5%, 12.9%, and 27.6% had incident MACE, heart failure and ESKD respectively, and 35.8% died. Discontinued-ACEi/ARBs use was associated with higher risk of MACE (HR = 1.27, 95% CI: 1.08-1.49), heart failure (HR = 1.85, 95% CI: 1.53-2.25) and ESKD (HR = 1.30, 95% CI: 1.17-1.43), and neutral risk of all-cause mortality (HR = 0.93, 95% CI: 0.86-1.01) compared to counterparts with continued use. In the register-based cohort (583 discontinued-ACEi/ARBs users and 3817 continued-ACEi/ARBs users), discontinued-ACEi/ARBs had neutral risk of hyperkalemia (HR = 0.95, 95% CI: 0.84-1.08).

Interpretation

Discontinuation of ACEi/ARBs was associated with increased risk of cardiovascular-renal events supporting their continued use in patients with T2D and advanced-CKD.

Funding

CUHK Impact Research Fellowship Scheme.

Risk-Benefit Balance of Renin-Angiotensin-Aldosterone Inhibitor Cessation in Heart Failure Patients with Hyperkalemia

Background: Whether to continue renin−angiotensin−aldosterone system inhibitor (RAASi) therapy in patients with hyperkalemia remains a clinical challenge, particularly in patients with heart failure (HF), where RAASis remain the cornerstone of treatment. We investigated the incidence of dose reduction or the cessation of RAASis and evaluated the threshold of serum potassium at which cessation alters the risk−benefit balance. Methods: This retrospective analysis of a Japanese nationwide claims database investigated treatment patterns of RAASis over 12 months after the initial hyperkalemic episode. The incidences of the clinical outcomes of patients with RAASi (all ACEi/ARB/MRA) or MRA-only cessation (vs. non-cessation) were compared via propensity score-matched patients. A cubic spline regression analysis assessed the hazard of death resulting from treatment cessation vs. no cessation at each potassium level. Results: A total of 5059 hyperkalemic HF patients were identified; most received low to moderate doses of ACEis and ARBs (86.9% and 71.5%, respectively) and low doses of MRAs (76.2%). The RAASi and MRA cessation rates were 34.7% and 52.8% at 1 year post-diagnosis, while the dose reduction rates were 8.4% and 6.5%, respectively. During the mean follow-up of 2.8 years, patients who ceased RAASi or MRA therapies were at higher risk for adverse outcomes; cubic spline analysis found that serum potassium levels of <5.9 and <5.7 mmol/L conferred an increased mortality risk for RAASi and MRA cessation, respectively. Conclusions: Treatment cessation/dose reduction of RAASis are common among HF patients. The risks of RAASi/MRA cessation may outweigh the benefits in patients with mild to moderate hyperkalemia.

The Cost Effectiveness of Patiromer for the Treatment of Hyperkalaemia in Patients with Chronic Kidney Disease with and without Heart Failure in Ireland

BACKGROUND AND OBJECTIVE

Hyperkalaemia can be a life-threatening condition, particularly in patients with advanced chronic kidney disease with and without heart failure. Renin-angiotensin-aldosterone system inhibitor therapy offers cardiorenal protection in chronic kidney disease and heart failure; however, it may also cause hyperkalaemia subsequently resulting in down-titration or discontinuation of treatment. Hence, there is an unmet need for hyperkalaemia treatment in patients with chronic kidney disease with and without heart failure to enable renin-angiotensin-aldosterone system inhibitor use in this patient population. In this study, we develop a de novo disease progression and cost-effectiveness model to evaluate the clinical and economic outcomes associated with the use of patiromer for the treatment of hyperkalaemia in patients with chronic kidney disease with and without heart failure.

METHODS

A Markov model was developed using data from the OPAL-HK trial to assess the health economic impact of patiromer therapy in comparison to standard of care in controlling hyperkalaemia in patients with advanced chronic kidney disease with and without heart failure in the Irish setting. The model was designed to predict the natural history of chronic kidney disease and heart failure and quantify the costs and benefits associated with the use of patiromer for hyperkalaemia management over a lifetime horizon from a payer perspective.

RESULTS

Treatment with patiromer was associated with an increase in discounted life-years (8.62 vs 8.37) and an increase in discounted quality-adjusted life-years (6.15 vs 5.95). Incremental discounted costs were predicted at €4979 per patient, with an incremental cost-effectiveness ratio of €25,719 per quality-adjusted life-year gained. Patients remained taking patiromer treatment for an average of 7.7 months, with treatment associated with reductions in the overall clinical event incidence and a delay in chronic kidney disease progression. Furthermore, patiromer was associated with lower overall rates of hospitalisation, major adverse cardiovascular events, dialysis, renin-angiotensin-aldosterone system inhibitor discontinuation episodes and renin-angiotensin-aldosterone system inhibitor down-titration episodes. At a willingness-to-pay threshold of €45,000 per quality-adjusted life-year in Ireland, treatment with patiromer was estimated to have a 100% chance of cost effectiveness compared with standard of care.

CONCLUSIONS

This study has demonstrated an economic case for the reimbursement of patiromer for the treatment of hyperkalaemia in patients with chronic kidney disease with and without heart failure in Ireland. Patiromer was estimated to improve life expectancy and quality-adjusted life expectancy, whilst incurring marginal additional costs when compared with current standard of care. Results are predominantly attributed to the ability of patiromer to enable the continuation of renin-angiotensin-aldosterone system inhibitor treatment whilst also reducing potassium levels.

Cost effectiveness of sodium zirconium cyclosilicate for the treatment of hyperkalaemia in patients with CKD in Norway and Sweden

Background

Hyperkalaemia is common in patients with chronic kidney disease (CKD) and is associated with a range of adverse outcomes. Historically, options for management of chronic hyperkalaemia in the outpatient setting have been limited. Novel oral potassium binders provide a safe, effective therapy for maintenance of normokalaemia in patients with CKD, but despite being approved for reimbursement in many countries, prescription data indicate uptake has been slower than anticipated. This analysis aimed to demonstrate the value to patients and the healthcare system of the potassium binder sodium zirconium cyclosilicate (SZC) for treatment of hyperkalaemia in patients with CKD in Norway and Sweden.

Methods

A published simulation model reflecting the natural history of CKD was adapted to the Norwegian and Swedish settings and used to predict long-term health economic outcomes of treating hyperkalaemia with SZC versus usual care.

Results

SZC was highly cost effective compared to usual care in Norway and Sweden, with incremental cost-effectiveness ratios of €14,838/QALY in Norway and €14,352/QALY in Sweden, over a lifetime horizon. The acquisition cost of SZC was largely offset by cost savings associated with reductions in hyperkalaemia events and hospitalisations; a modest overall increase in costs was predominantly attributable to costs associated with gains in life years compared with usual care. SZC remained cost effective in all scenarios examined.

Conclusions

SZC was estimated to be cost effective for treating hyperkalaemia. Consequently, improving access to a clinically effective, safe and cost-effective therapy, such as SZC, may result in considerable benefits for CKD patients with hyperkalaemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02903-7.

Short-Term Changes in Serum Potassium and the Risk of Subsequent Vascular Events and Mortality: Results from a Randomized Controlled Trial of ACE Inhibitors

BACKGROUND AND OBJECTIVES

Hyperkalemia after starting renin-angiotensin system inhibitors has been shown to be subsequently associated with a higher risk of cardiovascular and kidney outcomes. However, whether to continue or discontinue the drug after hyperkalemia remains unclear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data came from the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial, which included a run-in period where all participants initiated angiotensin-converting enzyme inhibitor-based therapy (a fixed combination of perindopril and indapamide). The study population was taken as patients with type 2 diabetes with normokalemia (serum potassium of 3.5 to <5.0 mEq/L) at the start of run-in. Potassium was remeasured 3 weeks later when a total of 9694 participants were classified into hyperkalemia (≥5.0 mEq/L), normokalemia, and hypokalemia (<3.5 mEq/L) groups. After run-in, patients were randomized to continuation of the angiotensin-converting enzyme inhibitor-based therapy or placebo; major macrovascular, microvascular, and mortality outcomes were analyzed using Cox regression during the following 4.4 years (median).

RESULTS

During active run-in, 556 (6%) participants experienced hyperkalemia. During follow-up, 1505 participants experienced the primary composite outcome of major macrovascular and microvascular events. Randomized treatment of angiotensin-converting enzyme inhibitor-based therapy significantly decreased the risk of the primary outcome (38.1 versus 42.0 per 1000 person-years; hazard ratio, 0.91; 95% confidence interval, 0.83 to 1.00; P=0.04) compared with placebo. The magnitude of effects did not differ across subgroups defined by short-term changes in serum potassium during run-in (P for heterogeneity =0.66). Similar consistent treatment effects were also observed for all-cause death, cardiovascular death, major coronary events, major cerebrovascular events, and new or worsening nephropathy (P for heterogeneity ≥0.27).

CONCLUSIONS

Continuation of angiotensin-converting enzyme inhibitor-based therapy consistently decreased the subsequent risk of clinical outcomes, including cardiovascular and kidney outcomes and death, regardless of short-term changes in serum potassium.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE), NCT00145925.

Serum potassium variability as a predictor of clinical outcomes in patients with cardiorenal disease or diabetes: a retrospective UK database study

Background

Hyperkalaemia is an electrolyte abnormality associated with adverse clinical outcomes; however, few studies have investigated the relationship with patterns of hyperkalaemia over time. This study explored the impact of time spent in a hyperkalaemic state and variability of serum potassium (sK+) on major adverse cardiovascular events (MACE) and all-cause mortality in patients with chronic kidney disease (CKD), resistant hypertension, heart failure and diabetes.

Methods

Cohorts comprised adult patients diagnosed with CKD stage 3+, resistant hypertension, heart failure or diabetes, and/or renin-angiotensin-aldosterone system inhibitor prescription, between 1 January 2003 and 30 June 2018, from the UK Clinical Practice Research Datalink. Associations between percentage of follow-up spent in a hyperkalaemic state (sK+ ≥5.0 mmol/L, ≥5.5 mmol/L, ≥6.0 mmol/L) or sK+ variability (standard deviation above or below median standard deviation) and all-cause mortality or MACE were investigated.

Results

For sK+ ≥5.0 mmol/L, time spent in a hyperkalaemic state was associated with reduced risk of all-cause mortality across all cohorts. For higher sK+ thresholds, this trend was attenuated or reversed; for time spent in a hyperkalaemic state at sK+ ≥6.0 mmol/L, an increased risk of mortality was seen in the overall cohort and for patients with diabetes, resistant hypertension or prescribed renin-angiotensin-aldosterone system inhibitors, with no consistent association seen for patients with CKD or heart failure. Risk of MACE in the overall cohort and in patients with CKD, diabetes or resistant hypertension increased with time spent in a hyperkalaemic state at all sK+ thresholds; however, no correlation was seen in patients with heart failure or those receiving dialysis. High sK+ variability was associated with a higher risk of MACE compared with low sK+ variability across most sK+ categories in the overall population and in all disease cohorts, except patients on dialysis; however, no association between sK+ variability and all-cause mortality was observed.

Conclusions

Patterns of hyperkalaemia, including time spent in hyperkalaemia and sK+ variability, are associated with adverse clinical outcomes. Regular monitoring of sK+ in high-risk populations in broader community, primary care and outpatient settings may enable guideline-recommended management of hyperkalaemia and help avoid adverse events.

Mineralocorticoid Receptor Antagonists in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a major cause of end-stage kidney disease (ESKD) worldwide. Mineralocorticoid receptor (MR) plays an important role in the development of DKD. A series of preclinical studies revealed that MR is overactivated under diabetic conditions, resulting in promoting inflammatory and fibrotic process in the kidney. Clinical studies demonstrated the usefulness of MR antagonists (MRAs), such as spironolactone and eplerenone, on DKD. However, concerns regarding their selectivity for MR and hyperkalemia have remained for these steroidal MRAs. Recently, nonsteroidal MRAs, including finerenone, have been developed. These agents are highly selective and have potent anti-inflammatory and anti-fibrotic properties with a low risk of hyperkalemia. We herein review the current knowledge and future perspectives of MRAs in DKD treatment.

Triangulation of pharmacoepidemiology and laboratory science to tackle otic quinolone safety

Background

The scientific method requires studies with high internal and external validity. Though both are necessary, they do not go hand‐in‐hand: The more controlled a study is to enhance internal validity, the less applicable to real‐world clinical care, and vice versa. In the many instances where evidence from clinical trials is not available, scientific inference must rely on more extreme approaches on this spectrum, such as mechanistic (limited generalizability/strong bias control) and real‐world evidence (RWE) studies (higher generalizability/lesser bias control).

Objectives

Illustrate how triangulating mechanistic and RWE studies can enhance scientific inference by delivering the supporting evidence for both.

Methods

We describe our research on an unexpected and highly unlikely drug safety issue: the risk of tympanic membrane (TM) perforations resulting from otic quinolone therapy. Tightly controlled laboratory studies using cell culture and rodent models were complemented with pharmacoepidemiological studies of real‐world data to translate mechanistic findings and corroborate RWE.

Results

We present a cascade of mechanistic and RWE studies investigating fibroblast cytotoxicity, delayed healing of perforated TMs, and spontaneous TM perforations after otic quinolone exposure, all suggesting local tissue toxicity.

Conclusion

Triangulation of mechanistic and RWE studies allowed incremental progress toward robust evidence on otic quinolone toxicity.

Epidemiology of hyperkalemia in CKD patients under nephrological care: a longitudinal study

Hyperkalemia is a potential life-threatening condition among chronic kidney disease (CKD) patients. Available estimates of the burden of this alteration in CKD are mainly derived from large administrative databases. Since K measurements in patients in these databases are often dictated by clinical reasons, longitudinal studies including pre-planned measurements of potassium independently of clinical complication/symptoms may produce more reliable estimates of the frequency and the risk factors underlying hyperkalemia in CKD patients. We estimated the prevalence and the incidence of hyperkalemia in a longitudinal study in 752 stages 2-5 CKD patients lasting 3 years and including up to seven pre-planned assessment of key biochemical measurements including K. At baseline, 203 out of 752 patients (27%) had serum K > 5.0 mM/L and 33% had acidosis (HCO₃ ≤ 22 mmol/L). Among those without hyperkalemia at baseline (n = 549), 284 patients developed this alteration across the 3-year follow-up. The point prevalence of hyperkalemia rose from 27% (baseline) to 30% (last visit) (P = 0.001). In a multivariate model, hyperkalemia at baseline [odds ratio (OR):7.29, 95% CI 5.65-9.41, P < 0.001], venous bicarbonate levels [OR (1 mmol/l): 0.92, 0.89-0.96, P < 0.001], eGFR [OR (1 ml/min/1.73m²): 0.98, 0.97-0.99, P < 0.001], use of ACE inhibitors (OR: 1.68, 1.28-2.19, P < 0.001) and angiotensin II antagonists (OR: 1.30, 1.01-1.68, P = 0.045) were related to hyperkalemia over time. Of note, venous bicarbonate levels emerged as an independent risk factor of hyperkalemia over time also in a separate analysis of patients with and without hyperkalemia at baseline. In a cohort of CKD patients including pre-planned measurements of K, 27% of patients had hyperkalemia. Metabolic acidosis and the use of drugs interfering with renin-angiotensin system were the strongest modifiable risk factors for this potentially life-threatening alteration in CKD in longitudinal analyses in the whole study cohort and in patients developing de novo hyperkalemia over time.

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

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

Association Between Longitudinal Blood Pressure Trajectory and the Progression of Chronic Kidney Disease: Results From the KNOW-CKD

Studies on the longitudinal temporal trend of blood pressure (BP) and its impact on kidney function are scarce. Here, we evaluated the association of dynamic changes in systolic blood pressure (SBP) over time with adverse kidney outcomes. We analyzed 1837 participants from the KNOW-CKD (Korean Cohort Study for Outcomes in Patients With Chronic Kidney Disease). The main exposure was 3 distinct SBP trajectories determined by the latent class mixed model (decreasing, stable, and increasing) using 3 SBP measurements at 0, 6, and 12 months. The primary outcome was CKD progression, defined as a composite of halving estimated glomerular filtration rate from baseline value or onset of end-stage kidney disease. SBP declined from 144 to 120 mm Hg in the decreasing SBP trajectory group and rose from 114 to 136 mm Hg in the increasing trajectory group within 1 year. During 6576 person-years of follow-up (median, 3.7 years), the composite outcome occurred in 521 (28.4%) participants. There were fewer primary outcome events in the decreasing (30.6%) and stable (26.5%) SBP trajectory groups than in the increasing trajectory group (33.0%). In the multivariable-adjusted cause-specific hazards model, increasing SBP trajectory was associated with a 1.28-fold higher risk for adverse kidney outcome compared with stable SBP trajectory. However, the risk for the primary outcome did not differ between the decreasing and stable SBP trajectory groups. In this longitudinal CKD cohort study, compared with stable SBP trajectory, increasing SBP trajectory was associated with higher risk for adverse kidney outcome, whereas decreasing SBP trajectory showed similar risk.

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

Background

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

Methods

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

Results

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

Conclusion

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

Mineralcorticoid receptor blockers in chronic kidney disease

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

[Mineralcorticoid receptor blockers in chronic kidney disease]

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

Effects of hyperkalaemia and non-adherence to renin-angiotensin-aldosterone system inhibitor therapy in patients with heart failure in Italy: a propensity-matched study

Aims

The aims of this study were to evaluate if the risk of cardiovascular events and all‐cause mortality was higher in the presence of hyperkalaemia (HK) in patients with heart failure (HF) treated with renin–angiotensin–aldosterone system inhibitors (RAASi), and to investigate in this cohort the increased risk of cardiovascular events and all‐cause mortality among HK patients with non‐optimal adherence to RAASi therapy.

Methods and results

In this retrospective cohort study based on administrative databases of five Italian Local Health Units, all adult patients with a HF diagnosis between January 2010 and December 2017 were included only if they were prescribed RAASi therapy during the first 3 months after the index date, that corresponded to the date of first HF diagnosis during the inclusion period. Patients were considered to have HK if serum potassium level was ≥5.5 mmol/L. A propensity score matching was applied before evaluation of hazard ratios. Patients with HK were 37% (P < 0.001) and 70% (P < 0.001), respectively, more at risk of cardiovascular events and of dying for all‐cause mortality compared to non‐HK patients. Among the HK group, patients non‐adherent to RAASi therapy had a 39% (P = 0.105) higher risk of cardiovascular events and a twofold increased risk (P < 0.001) of all‐cause death.

Conclusion

Findings from this real‐world study showed that in a cohort of HF patients under RAASi therapy, subjects with HK had an enhanced risk of cardiovascular events or death compared to patients without HK. Moreover, in HK patients, sub‐optimal adherence to RAASi therapy was associated with an increased risk of all‐cause mortality.

Impact of CKD Progression on Cardiovascular Disease Risk in a Contemporary UK Cohort of Individuals With Diabetes

Introduction

It remains unclear whether an increased progression rate of chronic kidney disease (CKD) adds predictive information regarding cardiovascular disease (CVD) risk. The aim of this study was to evaluate the association between CKD progression, based on estimated glomerular filtration rate (eGFR) slope estimates and the risk for CVD.

Methods

We compared the updated eGFR slope calculated over multiple overlapping 2-year periods and the updated mean eGFR. Incident CKD subjects were selected from a prevalent population with diabetes (T2DM). Subjects from the UK Clinical Practice Research Data Link GOLD (CPRD) were followed from CKD diagnosis (n = 30,222) until heart failure (HF), myocardial infarction (MI), ischemic stroke (IS), or a composite end point including all 3 event types (MACE plus), mortality, database dropout, or end of study follow-up.

Results

Both the updated eGFR slope and updated mean eGFR were associated with MACE plus and HF. Updated eGFR slope decline of > –3 ml/min/1.73 m² increased the risk for MACE plus (adjusted hazard ratio [HR] = 1.45; 95% confidence interval [CI], 1.26–1.67), HF (HR = 1.50; 95% CI, 1.27–1.76), and MI (HR = 1.39; 95% CI, 1.01–1.91).

Conclusions

This study strongly supports current evidence that CKD is an independent risk factor for CVD. From a clinical perspective, both rate of progression and cumulative status of CKD describe distinct aspects of the cardiorenal risk among persons with diabetes. This evidence is essential to enable more timely and improved use of treatments in this population.

Tailoring treatment of hyperkalemia

Hyperkalemia is a common electrolyte disorder that may be rapidly life-threatening because of its cardiac toxicity. Hyperkalemia risk factors are numerous and often combined in the same patient. Most of the strategies to control serum potassium level in the short term have been used for decades. However, evidence for their efficacy and safety remains low. Treatment of hyperkalemia remains challenging, poorly codified, with a risk of overtreatment, including short-term side effects, and with the priority of avoiding unnecessary hospital stays or chronic medication changes. Recently, new oral treatments have been proposed for non-life-threatening hyperkalemia, with encouraging results. Their role in the therapeutic arsenal remains uncertain. Finally, a growing body of evidence suggests that hyperkalemia might negatively impact outcomes in the long term in patients with chronic heart failure or kidney failure through underdosing or withholding of cardiovascular medication (e.g. renin-angiotensin-aldosterone system inhibitors). Recognition of efficacy and potential side effects of treatment may help in tailoring treatments to the patient's status and conditions. In this review we discuss how treatment of hyperkalemia could be tailored to the patient's conditions and status, both on the short and mid term.

Potassium Binders for Hyperkalemia in Chronic Kidney Disease-Diet, Renin-Angiotensin-Aldosterone System Inhibitor Therapy, and Hemodialysis

Hyperkalemia is a potentially life-threatening complication of chronic kidney disease (CKD). The management of CKD requires balancing the benefits of specific treatments, which may exacerbate the potential for hyperkalemia, with the risks of hyperkalemia itself. Renin-angiotensin-aldosterone system (RAAS) inhibitors, which slow CKD progression and improve cardiovascular outcomes, are often discontinued if hyperkalemia develops. Patients with hyperkalemia are frequently advised to restrict dietary potassium (K⁺), depriving these patients of many heart-healthy foods. Patients receiving hemodialysis are particularly susceptible to hyperkalemia during long interdialytic intervals, and managing this risk without causing hypokalemia can be challenging. Recently, 2 K⁺-binding agents were approved for the treatment of hyperkalemia: sodium zirconium cyclosilicate and patiromer. These agents offer alternatives to sodium polystyrene sulfonate, which is associated with serious gastrointestinal adverse effects. For this review, PubMed was searched for English-language articles published in 2014-2018 using the terms patiromer, sodium zirconium cyclosilicate, sodium polystyrene sulfonate, hyperkalemia, renin-angiotensin-aldosterone, diet, and dialysis. In randomized controlled studies of patients with hyperkalemia, sodium zirconium cyclosilicate and patiromer effectively reduced serum K⁺ and were generally well tolerated. Furthermore, patients in these studies could maintain RAAS inhibitor therapy and, in some studies, were not required to limit dietary K⁺. There may also be a role for these agents in preventing hyperkalemia in patients receiving hemodialysis. Thus, K⁺-binding agents may allow patients with CKD at risk for hyperkalemia to optimize RAAS inhibitor therapy, receive benefits of a K⁺-rich diet, and experience improved hemodialysis outcomes. Additional long-term studies are necessary to confirm these effects.

Hyperkalemia in chronic kidney disease

Hyperkalemia is a frequent finding in patients with chronic kidney disease (CKD). This increase in serum potassium levels is associated with decreased renal ion excretion, as well as the use of medications to reduce the progression of CKD or to control associated diseases such as diabetes mellitus and heart failure. Hyperkalemia increases the risk of cardiac arrhythmia episodes and sudden death. Thus, the control of potassium elevation is essential for reducing the mortality rate in this population. Initially, the management of hyperkalemia includes orientation of low potassium diets and monitoring of patients' adherence to this procedure. It is also important to know the medications in use and the presence of comorbidities to guide dose reduction or even temporary withdrawal of any of the potassium retention-related drugs. And finally, the use of potassium binders is indicated in both acute episodes and chronic hyperkalemia.

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.

New mineralocorticoid receptor antagonists: update on their use in chronic kidney disease and heart failure

Aldosterone is a mineralocorticoid hormone with a well-known effect on the renal tubule leading to water retention and potassium reabsorption. Other major effects of the hormone include the induction of proinflammatory activity that leads to progressive fibrotic damage of the target organs, heart and kidney. Blocking the aldosterone receptor therefore represents an important pharmacological strategy to avoid the clinical conditions deriving from heart failure (CHF) and chronic kidney disease (CKD). However, steroidal mineralocorticoid receptor antagonists (MRA) have a low safety profile, especially in CKD patients due to the high incidence of hyperkalemia. A new generation of nonsteroidal MRA has recently been developed to obtain a selective receptor block avoiding side-effects like hyperkalemia and thereby making the drugs suitable for administration to CKD patients. This review summarizes the results of published preclinical and clinical studies on the nonsteroidal MRA, apararenone esaxerenone and finerenone. The trials showed a better safety profile with maintained drug efficacy compared with steroidal MRA. For this reason, nonsteroidal MRA represent an interesting new therapeutic approach for the prevention of CHF and CKD progression. Some basic research findings also yielded interesting results in acute clinical settings such as myocardial infarction and acute kidney injury.

The value of maintaining normokalaemia and enabling RAASi therapy in chronic kidney disease

Background

People with chronic kidney disease (CKD) are at an increased risk of developing hyperkalaemia due to their declining kidney function. In addition, these patients are often required to reduce or discontinue guideline-recommended renin-angiotensin-aldosterone system inhibitor (RAASi) therapy due to increased risk of hyperkalaemia. This original research developed a model to quantify the health and economic benefits of maintaining normokalaemia and enabling optimal RAASi therapy in patients with CKD.

Methods

A patient-level simulation model was designed to fully characterise the natural history of CKD over a lifetime horizon, and predict the associations between serum potassium levels, RAASi use and long-term outcomes based on published literature. The clinical and economic benefits of maintaining sustained potassium levels and therefore avoiding RAASi discontinuation in CKD patients were demonstrated using illustrative, sensitivity and scenario analyses.

Results

Internal and external validation exercises confirmed the predictive capability of the model. Sustained potassium management and ongoing RAASi therapy were associated with longer life expectancy (+ 2.36 years), delayed onset of end stage renal disease (+ 5.4 years), quality-adjusted life-year gains (+ 1.02 QALYs), cost savings (£3135) and associated net monetary benefit (£23,446 at £20,000 per QALY gained) compared to an absence of RAASi to prevent hyperkalaemia.

Conclusion

This model represents a novel approach to predicting the long-term benefits of maintaining normokalaemia and enabling optimal RAASi therapy in patients with CKD, irrespective of the strategy used to achieve this target, which may support decision making in healthcare.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1228-y) contains supplementary material, which is available to authorized users.

Serum potassium and clinical outcomes in heart failure patients: results of risk calculations in 21 334 patients in the UK

Aims

At present, the clinical burden of hypokalaemia and hyperkalaemia among European heart failure patients, and relationships between serum potassium and adverse clinical outcomes in this population, is not well characterized. The aim of this study was to investigate associations between mortality, major adverse cardiac events, and renin–angiotensin–aldosterone system inhibitor (RAASi) discontinuation across serum potassium levels, in a UK cohort of incident heart failure patients.

Methods and results

This was a retrospective observational cohort study of newly diagnosed heart failure patients listed in the Clinical Practice Research Datalink, with a first record of heart failure (index date) between 2006 and 2015. Hypokalaemia and hyperkalaemia episodes were defined as the number of serum potassium measurements exceeding each threshold (<3.5, ≥5.0, ≥5.5, and ≥6.0 mmol/L), without such a measurement in the preceding 7 days. Risk equations developed using Poisson generalized estimating equations were utilized to estimate adjusted incident rate ratios (IRRs) relating serum potassium and clinical outcomes (death, major adverse cardiac event, and RAASi discontinuation). Among 21,334 eligible heart failure patients, 1969 (9.2%), 7648 (35.9%), 2725 (12.8%), and 763 (3.6%) experienced episodes of serum potassium <3.5, ≥5.0, ≥5.5, and ≥6.0 mmol/L, respectively. The adjusted IRRs for mortality exhibited a U‐shaped association pattern with serum potassium. Relative to the reference category (4.5 to <5.0 mmol/L), adjusted IRRs for mortality were estimated as 1.98 (95% confidence interval: 1.69–2.33), 1.23 (1.12–1.36), 1.35 (1.14–1.60), and 3.02 (2.28–4.02), for patients with serum potassium <3.5, ≥5.0 to <5.5, ≥5.5 to <6.0, and ≥6.0 mmol/L, respectively. The adjusted IRRs for major adverse cardiac events demonstrated a non‐statistically significant relationship with serum potassium. Discontinuation of RAASi therapy exhibited a J‐shaped trend in association with serum potassium. Compared with the reference category (4.5 to <5.0 mmol/L), adjusted IRRs were estimated as 1.07 (0.89–1.28) in patients with serum potassium <3.5 mmol/L, increasing to 1.32 (1.14–1.53) and 2.19 (1.63–2.95) among those with serum potassium ≥5.5 to <6.0 and ≥6.0 mmol/L, respectively.

Conclusions

In UK patients with new onset heart failure, both hypokalaemia and hyperkalaemia were associated with increased mortality risk, and hyperkalaemia was associated with increased likelihood of RAASi discontinuation. Our results demonstrate the potential importance of serum potassium monitoring for heart failure outcomes and management.

Cecum perforation associated with a calcium polystyrene sulfonate bezoar - a rare entity

Hyperkalemia is one of the most common electrolyte disorders, responsible for a high number of adverse outcomes, including life-threatening arrhythmias. Potassium binders are largely prescribed drugs used for hyperkalemia treatment but unfortunately, there are many adverse events associated with its use, mostly gastrointestinal. Identification of patients at highest risk for the serious complications associated with the current potassium binders, such as colon necrosis and perforation, could prevent fatal outcomes. The authors present a case of a 56-year-old man with secondary diabetes and chronic renal disease that was treated for hyperkalemia with Calcium Polystyrene Sulfonate (CPS). He later presented with acute abdomen due to cecum perforation and underwent ileocecal resection but ultimately died from septic shock a week later. During surgery, a solid white mass was isolated in the lumen of the colon. The mass was identified as a CPS bezoar, a rare drug-mass formed in the gastrointestinal tract that contributed to the perforation. A previous history of partial gastrectomy and vagothomy was identified as a probable risk factor for the CPS bezoar development. Hopefully, the two new potassium binders patiromer and (ZS-9) Sodium Zirconium Cyclosilicate will help treat such high-risk patients, in the near future.

Development of a health economic model to evaluate the potential benefits of optimal serum potassium management in patients with heart failure

AIMS

Patients with heart failure are at increased risk of hyperkalemia, particularly when treated with renin-angiotensin-aldosterone system inhibitor (RAASi) agents. This study developed a model to quantify the potential health and economic value associated with sustained potassium management and optimal RAASi therapy in heart failure patients.

MATERIALS AND METHODS

A patient-level, fixed-time increment stochastic simulation model was designed to characterize the progression of heart failure through New York Heart Association functional classes, and predict associations between serum potassium levels, RAASi use, and consequent long-term outcomes. Following internal and external validation exercises, model analyses sought to quantify the health and economic benefits of optimizing both serum potassium levels and RAASi therapy in heart failure patients. Analyses were conducted using a UK payer perspective, independent of costs and utilities related to pharmacological potassium management.

RESULTS

Validation against multiple datasets demonstrated the predictive capability of the model. Compared to those who discontinued RAASi to manage serum potassium, patients with normokalemia and ongoing RAASi therapy benefited from longer life expectancy (+1.38 years), per-patient quality-adjusted life year gains (+0.53 QALYs), cost savings (£110), and associated net monetary benefit (£10,679 at £20,000 per QALY gained) over a lifetime horizon. The predicted value of sustained potassium management and ongoing RAASi treatment was largely driven by reduced mortality and hospitalization risks associated with optimal RAASi therapy.

LIMITATIONS

Several modeling assumptions were made to account for a current paucity of published literature; however, ongoing refinement and validation of the model will ensure its continued accuracy as the clinical landscape of hyperkalemia evolves.

CONCLUSIONS

Predictions generated by this novel modeling approach highlight the value of sustained potassium management to avoid hyperkalemia, enable RAASi therapy, and improve long-term health economic outcomes in patients with heart failure.

Serum potassium as a predictor of adverse clinical outcomes in patients with chronic kidney disease: new risk equations using the UK clinical practice research datalink

BACKGROUND

To address a current paucity of European data, this study developed equations to predict risks of mortality, major adverse cardiac events (MACE) and renin angiotensin-aldosterone system inhibitor (RAASi) discontinuation using time-varying serum potassium and other covariates, in a UK cohort of chronic kidney disease (CKD) patients.

METHODS

This was a retrospective observational study of adult CKD patients listed on the Clinical Practice Research Datalink, with a first record of CKD (stage 3a-5, pre-dialysis) between 2006 and 2015. Patients with heart failure at index were excluded. Risk equations developed using Poisson Generalized Estimating Equations were utilised to estimate adjusted incident rate ratios (IRRs) between serum potassium and adverse outcomes, and identify other predictive clinical factors.

RESULTS

Among 191,964 eligible CKD patients, 86,691 (45.16%), 30,629 (15.96%) and 9440 (4.92%) experienced at least one hyperkalaemia episode, when defined using serum potassium concentrations 5.0-< 5.5 mmol/L, 5.5-< 6.0 mmol/L and ≥ 6.0 mmol/L, respectively. Relative to the reference category (4.5 to < 5.0 mmol/L), adjusted IRRs for mortality and MACE exhibited U-shaped associations with serum potassium, with age being the most important predictor of both outcomes (P < 0.0001). A J-shaped association between serum potassium and RAASi discontinuation was observed; estimated glomerular filtration rate was most predictive of RAASi discontinuation (P < 0.0001).

CONCLUSIONS

Hyperkalaemia was associated with increased mortality and RAASi discontinuation risk. These risk equations represent a valuable tool to predict clinical outcomes among CKD patients; and identify those likely to benefit from strategies that treat hyperkalaemia, prevent RAASi discontinuation, and effectively manage serum potassium levels.

Association of Serum Potassium with All-Cause Mortality in Patients with and without Heart Failure, Chronic Kidney Disease, and/or Diabetes

BACKGROUND

The relationship between serum potassium, mortality, and conditions commonly associated with dyskalemias, such as heart failure (HF), chronic kidney disease (CKD), and/or diabetes mellitus (DM) is largely unknown.

METHODS

We reviewed electronic medical record data from a geographically diverse population (n = 911,698) receiving medical care, determined the distribution of serum potassium, and the relationship between an index potassium value and mortality over an 18-month period in those with and without HF, CKD, and/or DM. We examined the association between all-cause mortality and potassium using a cubic spline regression analysis in the total population, a control group, and in HF, CKD, DM, and a combined cohort.

RESULTS

27.6% had a potassium <4.0 mEq/L, and 5.7% had a value ≥5.0 mEq/L. A U-shaped association was noted between serum potassium and mortality in all groups, with lowest all-cause mortality in controls with potassium values between 4.0 and <5.0 mEq/L. All-cause mortality rates per index potassium between 2.5 and 8.0 mEq/L were consistently greater with HF 22%, CKD 16.6%, and DM 6.6% vs. controls 1.2%, and highest in the combined cohort 29.7%. Higher mortality rates were noted in those aged ≥65 vs. 50-64 years. In an adjusted model, all-cause mortality was significantly elevated for every 0.1 mEq/L change in potassium <4.0 mEq/L and ≥5.0 mEq/L. Diuretics and renin-angiotensin-aldosterone system inhibitors were related to hypokalemia and hyperkalemia respectively.

CONCLUSION

Mortality risk progressively increased with dyskalemia and was differentially greater in those with HF, CKD, or DM.

Effectiveness of patiromer in the treatment of hyperkalemia in chronic kidney disease patients with hypertension on diuretics

OBJECTIVE

Recurrent hyperkalemia frequently limits use of renin-angiotensin-aldosterone system inhibitors (RAASi) in chronic kidney disease (CKD) patients with hypertension, diabetes, and/or heart failure. Patiromer is a sodium-free, nonabsorbed potassium (K)-binding polymer approved by the US Food and Drug Administration for the treatment of hyperkalemia. This post-hoc analysis of OPAL-HK examined the effectiveness and safety of patiromer in reducing serum K in hyperkalemic CKD patients on RAASi, with hypertension, receiving diuretic therapy versus those not on diuretics.

METHODS

Depending on the degree of hyperkalemia at baseline, CKD patients with serum K from 5.1 to less than 6.5 mmol/l on RAASi (n = 243) were assigned to a patiromer of total dose 8.4 or 16.8 g, divided twice daily. Changes in serum K, and tolerability and safety were assessed over 4 weeks in patients on and not on diuretics.

RESULTS

At baseline, 132 patients used diuretics and 111 were not on diuretics, mean age was 64.3 and 64.0 years, respectively, and 63 and 51% were men. Similar reductions in serum K were seen over 4 weeks in both subgroups. At week 4, serum K fell by -0.95 ± 0.04 mmol/l with any diuretic and -1.04 ± 0.05 mmol/l with no diuretic. Patiromer was well tolerated, with mild-to-moderate constipation reported as the most common adverse event (7.6 and 14.4% of patients on any diuretic or no diuretic, respectively). Hypokalemia (s-K <3.5 mEq/l) was reported in 2.3% of patients on any diuretic and in 3.7% not on diuretics.

CONCLUSION

The serum K-lowering efficacy and safety profile of patiromer in hyperkalemia patients with CKD was not compromised by diuretic therapy.

Emergency Department Use among Patients with CKD: A Population-Based Analysis

BACKGROUND AND OBJECTIVES

Although prior studies have observed high resource use among patients with CKD, there is limited exploration of emergency department use in this population and the proportion of encounters related to CKD care specifically.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We identified all adults (≥18 years old) with eGFR<60 ml/min per 1.73 m2 (including dialysis-dependent patients) in Alberta, Canada between April 1, 2010 and March 31, 2011. Patients with CKD were linked to administrative data to capture clinical characteristics and frequency of emergency department encounters and followed until death or end of study (March 31, 2013). Within each CKD category, we calculated adjusted rates of overall emergency department use as well as rates of potentially preventable emergency department encounters (defined by four CKD-specific ambulatory care-sensitive conditions: heart failure, hyperkalemia, volume overload, and malignant hypertension).

RESULTS

During mean follow-up of 2.4 years, 111,087 patients had 294,113 emergency department encounters; 64.2% of patients had category G3A CKD, and 1.6% were dialysis dependent. Adjusted rates of overall emergency department use were highest among patients with more advanced CKD; 5.8% of all emergency department encounters were for CKD-specific ambulatory care-sensitive conditions, with approximately one third resulting in hospital admission. Heart failure accounted for over 80% of all potentially preventable emergency department events among patients with categories G3A, G3B, and G4 CKD, whereas hyperkalemia accounted for almost one half (48%) of all ambulatory care-sensitive conditions among patients on dialysis. Adjusted rates of emergency department events for heart failure showed a U-shaped relationship, with the highest rates among patients with category G4 CKD. In contrast, there was a graded association between rates of emergency department use for hyperkalemia and CKD category.

CONCLUSIONS

Emergency department use is high among patients with CKD, although only a small proportion of these encounters is for potentially preventable CKD-related care. Strategies to reduce emergency department use among patients with CKD will, therefore, need to target conditions other than CKD-specific ambulatory care-sensitive conditions.

Potassium homeostasis and dyskalemias: the respective roles of renal, extrarenal, and gut sensors in potassium handling

Integrated mechanisms controlling the maintenance of potassium homeostasis are well established and are defined by the classic "feedback control" of potassium balance. Recently, increasing investigative attention has focused on novel physiological paradigms that increase the complexity and precision of homeostasis. This review briefly considers the classic and well-established feedback control of potassium and then considers subsequent investigations that inform on an intriguing and not widely recognized complementary paradigm: the "feed-forward control of potassium balance." Feed-forward control refers to a pathway in a homeostatic system that responds to a signal in the environment in a predetermined manner, without responding to how the system subsequently reacts (i.e., without responding to feedback). Studies in several animal species, and recently in humans, have confirmed the presence of a feed-forward control mechanism that is capable of mediating potassium excretion independent of changes in serum potassium concentration and aldosterone. Knowledge imparted by this update of potassium homeostasis hopefully will facilitate the clinical management of hyperkalemia in patients with chronic and recurrent hyperkalemia. Awareness of this updated integrative control mechanism for potassium homeostasis is more relevant today when the medical community is increasingly focused on leveraging and expanding established renin-angiotensin-aldosterone system inhibitor treatment regimens and on successfully coping with the challenges of managing hyperkalemia provoked by renin-angiotensin-aldosterone system inhibitors. These new insights are relevant to the future design of clinical trials delineating renal potassium handling.

Current and future treatment options for managing hyperkalemia

Hyperkalemia is associated with life-threatening cardiac arrhythmias and increased mortality. Hyperkalemia is most often observed in patients with chronic kidney disease and/or in those with congestive heart failure being treated with drugs that limit renal potassium excretion, especially drugs that inhibit the renin-angiotensin-aldosterone system. Treatment of hyperkalemia may be either acute, as needed during rapid changes in serum potassium, which are associated with cardiac arrhythmia, or chronic, which stabilizes serum potassium levels and limits the development of life-threatening arrhythmias. There are a number of both acute and chronic treatments available for the treatment of hyperkalemia, but some are limited by complex administration requirements and/or serious side effects. Hyperkalemia remains a vexing problem for clinicians, particularly in the care of patients with chronic kidney disease and cardiovascular disease.