Hyperkalemia in patients with heart failure: Incidence, prevalence, and management

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

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

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.

Impact of Hyperkalemia in Heart Failure and Reduced Ejection Fraction: A Retrospective Study

(1) Background: Hyperkalemia is a common finding in patients with heart failure and reduced ejection fraction (HFrEF), though its prognostic significance is controversial. There is no consensus on optimal potassium levels in these patients. The primary endpoint of this study was to determine the 5-year incidence of hyperkalemia in a cohort of patients with HFrEF. Secondary endpoints were to determine predictors of hyperkalemia and its impact on overall 5-year mortality; (2) Methods: retrospective, longitudinal, single-center observational study of patients with HFrEF followed-up in a specialized unit between 2011 and 2019. Hyperkalemia was considered as potassium concentration > 5.5 mEq/L; (3) Results: Hyperkalemia was observed in 170 (16.8%) of the 1013 patients. The 5-year hyperkalemia-free survival rate was 82.1%. Hyperkalemia was more frequent at the beginning of follow-up. Factors associated with hyperkalemia in the multivariate analysis were baseline potassium (HR 3.13, 95%CI 2.15-4.60; p < 0.001), creatinine clearance (HR 0.99, 95%CI 0.98-0.99; p = 0.013), right ventricular function (HR 0.95, 95%CI 0.91-0.99; p = 0.016) and diabetes mellitus (HR 1.40, 95%CI 1.01-1.96; p = 0.047). The overall survival rate at 5 years was 76.4%. Normal-high potassium levels (5-5.5 mEq/L) were inversely associated with mortality (HR 0.60, 95%CI 0.38-0.94; p = 0.025); (4) Conclusions: Hyperkalemia is a common finding in patients with HFrEF with an impact on the optimization of neurohormonal treatment. In our retrospective study, potassium levels in the normal-high range seem to be safe and are not associated with increased mortality.

In pursuit of balance: renin-angiotensin-aldosterone system inhibitors and hyperkalaemia treatment

Hyperkalaemia is a life-threatening condition leading to significant morbidity and mortality. It is common in heart failure (HF) patients due to the disease itself, which often co-exists with chronic kidney disease and diabetes mellitus, the fluctuations in renal function, and the use of some drugs [i.e. renin-angiotensin-aldosterone system (RAAS) inhibitors]. In particular, hyperkalaemia opposes to their administration or up-titration, thus impacting on mortality. New K+ binders, namely, patiromer and sodium zirconium cyclosilicate, are an intriguing option to manage hyperkalaemia in HF patients, both to reduce its fatal effects and to let clinicians up-titrate RAAS inhibitors. Even if their real impact on strong outcomes is still to be determined, we hereby provide an overview of hyperkalaemia in HF and its current management. New trials are welcome to fill the gap in knowledge.

Hyperkalemia and Electrocardiogram Manifestations in End-Stage Renal Disease

Hyperkalemia is one of the more common acute life-threatening metabolic emergencies. The aim of our study is to determine the correlation and accuracy of abnormal ECG parameters as a function of serum potassium concentration in the end-stage renal disease (ESRD) population. We performed a retrospective chart review of emergency department patients presenting with ESRD and receiving emergent hemodialysis treatment. A total of 96 patients, each with five independent ED visits, provided 480 sets of ECGs and electrolytes. Of these, four ECGs were excluded for inability to interpret, leaving a total of 476 patient encounters that met all inclusion criteria. Linear regression analysis on the limited data set for serum potassium versus T/R in V2, V3, and V4, PR, and QRS found weak correlations (r2 = 0.02 to 0.12) with statistical significance <0.05 level for T/R in V2, V3, and V4. In summary, we found that a QRS duration of 120 ms or greater is most predictive of hyperkalemia in the ESRD population. On the other hand, T/R ratio, PR interval and QRS duration have poor correlations with serum potassium and are not predictive of hyperkalemia in patients with ESRD.

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

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

Determinants of Hyperkalemia Progression Among Patients with Mild Hyperkalemia

Introduction

The progression of mild hyperkalemia and the predictors of progression have not been well characterized. In this study we aimed to characterize the progression of hyperkalemia and identify the risk factors for hyperkalemia progression.

Methods

Adults with mild hyperkalemia (at least one serum potassium measure > 5.0 and ≤ 5.5 mEq/L) were identified using electronic medical records from the Research Action for Health Network (2012–2018). Progression to moderate-to-severe and progression to severe hyperkalemia were defined as the first occurrences of a serum potassium measure > 5.5 and > 6.0 mEq/L, respectively. Kaplan–Meier analyses were conducted to estimate progression rates for all patients and by pre-specified patient subgroups. Hazard ratios (HR) of moderate-to-severe and severe hyperkalemia progression were estimated using Cox models.

Results

Of 35,369 patients with mild hyperkalemia, 16.9% and 8.7% progressed to moderate-to-severe and severe hyperkalemia, respectively. Rates of hyperkalemia progression elevated with the severity of chronic kidney disease (CKD). The highest progression rates were seen in patients with CKD stage 5 (stage 5 vs. no CKD: moderate-to-severe, 50.2% vs. 12.0%; severe, 31.3% vs. 3.9%; p < 0.001). Higher progression rates were also observed in patients with heart failure, hypertension, and type II diabetes compared with patients without those conditions (all p < 0.001). The most prominent risk factors were CKD stage 5 (HR of progression to moderate-to-severe hyperkalemia, 3.32 [95% CI 3.03–3.64]; severe, 4.08 [3.55–4.69]), CKD stage 4 (2.19 [1.97–2.43], 2.28 [1.92–2.71]), CKD stage 3 (1.57 [1.46–1.68], 1.65 [1.46–1.87]), type I diabetes (1.37 [1.18–1.61], 1.54 [1.23–1.93]), and serum potassium (1.12 [1.10–1.15], 1.13 [1.10–1.17] per 0.1 mEq/L increase) (all p values < 0.05).

Conclusion

Hyperkalemia progression rates increased significantly with CKD stage and were also higher among patients with higher baseline potassium level, heart failure, hypertension, and diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01925-1.

Serum potassium levels provide prognostic information in symptomatic heart failure beyond traditional clinical variables

Aims

Despite of recent advances in the pharmacological treatment, heart failure (HF) maintains significant morbidity and mortality rates. While serum potassium disorders are common and associated with adverse outcomes, the exact recommended potassium level for patients with HF are not entirely established. We aimed to investigate the prognostic role of potassium levels on a cohort of patients with symptomatic chronic HF.

Methods and results

Patients with symptomatic chronic HF were identified at the referral to 6 min walking test (6MWT) and were prospectively followed up for cardiovascular events. Clinical and laboratorial data were retrospectively obtained. The primary endpoint was the composite of cardiovascular death, hospitalization due to HF, and heart transplantation. The cohort included 178 patients with HF with the mean age of 51 ± 12.76 years, 39% were female, 85% of non‐ischaemic cardiomyopathy, and 38% had New York Heart Association Class III with a relatively high Meta‐Analysis Global Group in Chronic Heart Failure (MAGGIC) score (12.91 ± 6.6). The mean left ventricular ejection fraction was 39.98 ± 15.79%, and the mean 6MWT distance was 353 ± 136 m. After a median follow‐up of 516 days, there were 22 major cardiovascular events (4 cardiovascular deaths, 13 HF admissions, and 5 heart transplants). Patients were stratified according to cut‐point level of serum potassium of 4.7 mmol/L to predict combined cardiac events based on receiver operating characteristic analysis. Individuals with higher potassium levels had worse renal function (glomerular filtration rate, K ≤ 4.7: 102.8 ± 32.2 mL/min/1.73 m² vs. K > 4.7: 85.42 ± 36.2 mL/min/1.73 m², P = 0.004), higher proportion of New York Heart Association Class III patients (K ≤ 4.7: 28% vs. K > 4.7: 48%, P = 0.0029), and also higher MAGGIC score (K ≤ 4.7: 12.08 ± 5.7 vs. K > 4.7: 14.9 ± 7.9, P = 0.0089), without significant differences on the baseline pharmacological HF treatment. Both potassium levels [hazard ratio (HR) 4.26, 95% confidence interval (CI) 1.59–11.421, P = 0.003] and 6MWT distance (HR 0.99, 95% CI 0.993–0.999, P = 0.01) were independently associated with the primary outcome. After adjustments for MAGGIC score and 6MWT distance, potassium levels > 4.7 mmol/L maintained a significant association with outcomes (HR 3.57, 95% CI 1.305–9.807, P = 0.013). Patients with K > 4.7 mmol/L were more likely to present clinical events during the follow‐up (log rank = 0.005). Adding potassium levels to the model including 6MWT and MAGGIC significantly improved the prediction of events over 2 years (integrated discrimination index 0.105, 95% CI 0.018–0.281, P = 0.012 and net reclassification index 0.447, 95% CI 0.077–0.703, P = 0.028).

Conclusions

Potassium levels were independently associated with worse outcomes in patients with chronic symptomatic HF, also improving the accuracy model for prognostic prediction when added to MAGGIC score and 6MWT distance. The potassium levels above 4.7 mmol/L might identify those patients at an increased risk of cardiovascular events.

Prevalence and economic burden of hyperkalemia in the United States Medicare population

Objective: To estimate the prevalence and economic burden of hyperkalemia in the United States (US) Medicare population.Methods: Patients were selected from a 5% random sample of Medicare beneficiaries (01 January 2010-31 December 2014) to estimate the prevalence and economic burden of hyperkalemia. The prevalence for each calendar year was calculated as the number of patients with hyperkalemia divided by the total number of eligible patients per year. To estimate the economic burden of hyperkalemia, patients with hyperkalemia (cases) were matched 1:1 to patients without hyperkalemia (controls) on age group, chronic kidney disease [CKD] stage, dialysis treatment, and heart failure. The incremental 30-day and 1-year resource utilization and costs (2016 USD) associated with hyperkalemia were estimated.Results: The estimated prevalence of hyperkalemia was 2.6-2.7% in the overall population and 8.9-9.3% among patients with CKD and/or heart failure. Patients with hyperkalemia had higher 1-year rates of inpatient admissions (1.28 vs. 0.44), outpatient visits (30.48 vs. 23.88), emergency department visits (2.01 vs. 1.17), and skilled nursing facility admissions (0.36 vs. 0.11) than the matched controls (all p < .001). Patients with hyperkalemia incurred on average $7208 higher 30-day costs ($8894 vs. $1685) and $19,348 higher 1-year costs ($34,362 vs. $15,013) than controls (both p < .001). Among patients with CKD and/or heart failure, the 30-day and 1-year total cost differences between cohorts were $7726 ($9906 vs. $2180) and $21,577 ($41,416 vs. $19,839), respectively (both p < .001).Conclusions: Hyperkalemia had an estimated prevalence of 2.6-2.7% in the Medicare population and was associated with markedly high healthcare costs.

Sodium Zirconium Cyclosilicate among Individuals with Hyperkalemia: A 12-Month Phase 3 Study

BACKGROUND AND OBJECTIVES

Oral sodium zirconium cyclosilicate (formerly ZS-9) binds and removes potassium via the gastrointestinal tract. Sodium zirconium cyclosilicate-associated restoration and maintenance of normokalemia and adverse events were evaluated in a two-part, open label, phase 3 trial.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In the correction phase, adult outpatients with plasma potassium ≥5.1 mmol/L (i-STAT Point-of-Care) received sodium zirconium cyclosilicate 10 g three times daily for 24-72 hours until normokalemic (potassium =3.5-5.0 mmol/L). Qualifying participants entered the ≤12-month maintenance phase and received sodium zirconium cyclosilicate 5 g once daily titrated to maintain normokalemia without dietary or medication restrictions. Prespecified primary end points were restoration of normal serum potassium values (3.5-5.0 mmol/L) during the correction phase and maintenance of serum potassium ≤5.1 mmol/L during the maintenance phase. Adverse events were assessed throughout.

RESULTS

Of 751 participants, 746 (99%) achieved normokalemia during the correction phase (mean serum potassium =4.8 mmol/L; 95% confidence interval, 4.7 to 4.8) and entered the maintenance phase; 466 (63%) participants completed the 12-month trial. Participants were predominantly white, men, and age ≥65 years old; 74% had an eGFR<60 ml/min per 1.73 m², and 65% used renin-angiotensin-aldosterone system inhibitors. Mean time on sodium zirconium cyclosilicate was 286 days. Mean daily sodium zirconium cyclosilicate dose was 7.2 g (SD=2.6). Over months 3-12, mean serum potassium was 4.7 mmol/L (95% confidence interval, 4.6 to 4.7); mean serum potassium values ≤5.1 and ≤5.5 mmol/L were achieved by 88% and 99% of participants, respectively. Of 483 renin-angiotensin-aldosterone system inhibitor users at baseline, 87% continued or had their dose increased; 11% discontinued. Among 263 renin-angiotensin-aldosterone system inhibitor-naïve participants, 14% initiated renin-angiotensin-aldosterone system inhibitor therapy. Overall, 489 (66%) participants experienced adverse events during the maintenance phase, and 22% experienced a serious adverse event. Of eight (1%) deaths, none were considered related to sodium zirconium cyclosilicate. Nine (1%) and 34 (5%) participants experienced serum potassium <3.0 and 3.0-3.4 mmol/L, respectively.

CONCLUSIONS

After achieving normokalemia, individualized once daily sodium zirconium cyclosilicate was associated with maintenance of normokalemia without substantial renin-angiotensin-aldosterone system inhibitor changes for ≤12 months.

Epidemiology and health outcomes associated with hyperkalemia in a primary care setting in England

Background

Real-world incidence, clinical consequences, and healthcare resource utilization (HRU) of hyperkalemia (HK) remain poorly characterized, particularly in patients with specific comorbidities.

Methods

Data from the Clinical Practice Research Datalink and Hospital Episode Statistics databases were analyzed to determine incidence of an index HK event, subsequent clinical outcomes, and HRU in the English population. Factors associated with index HK in a primary care setting were also identified for those with an index HK event during the study period (2009–2013) and matched controls.

Results

The overall incidence rate of an index HK event was 2.9 per 100 person-years. Use of renin–angiotensin–aldosterone system inhibitors was strongly associated with HK (odds ratio, 13.6–15.9). Few patients (5.8%) had serum potassium (K⁺) retested ≤ 14 days following the index event; among those retested, 32% had HK. Following an index HK event, all-cause hospitalization, HK recurrence, and kidney function decline were the most common outcomes (incidence rates per 100 person-years: 14.1, 8.1, and 6.7, respectively), with higher rates in those with comorbidities or K⁺ > 6.0 mmol/L. Mortality and arrhythmia rates were higher among those with K⁺ > 6.0 mmol/L. Older age, comorbid diabetes mellitus, and mineralocorticoid receptor antagonist use were associated with HK recurrence. Relatively few patients received testing or prescriptions to treat HK following an event.

Conclusions

Severe index HK events were associated with adverse outcomes, including arrhythmia and mortality. Despite this, retesting following an index event was uncommon, and incidence of recurrence was much higher than that of the index event.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1250-0) contains supplementary material, which is available to authorized users.

Hyperkalaemia: aetiology, epidemiology, and clinical significance

Disturbances in the potassium homeostasis are common among patients with heart failure (HF) and negatively affect clinical outcome. Patients with HF have a higher prevalence of common risk factors related to hyperkalaemia, including diabetes mellitus, hypertension, and chronic kidney disease. Furthermore, the use of renin-angiotensin-aldosterone system (RAAS) inhibitors, is an important risk factor for developing hyperkalaemia. The association between hyperkalaemia and mortality is not unequivocal, depends on the study type (trial vs. real-world setting) and is often confounded. More importantly, hyperkalaemia is an important cause of discontinuation or failure to uptitrate to guideline recommended dosages of RAAS inhibitors, which in turn may negatively impact clinical outcomes. The goal of this review is to discuss the epidemiology, aetiology, and clinical consequences of potassium disturbances in HF.

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.

Hyperkalaemia in people with diabetes: occurrence, risk factors and outcomes in a Danish population-based cohort study

AIMS

To examine the incidence, risk factors and clinical outcomes of hyperkalaemia in people with diabetes in a real-world setting.

METHODS

Using Danish health registries, we identified a population-based cohort of people with first-time drug-treated diabetes, in the period 2000-2012. First, the cumulative incidence of hyperkalaemia, defined as first blood test with potassium level >5.0 mmol/l after diabetes treatment initiation, was ascertained. Second, in a case-control analysis, risk factors were compared in people with vs without hyperkalaemia. Third, clinical outcomes were assessed among individuals with hyperkalaemia in a before-after analysis, and among people with and without hyperkalaemia in a matched cohort analysis.

RESULTS

Of 68 601 individuals with diabetes (median age 62 years, 47% women), 16% experienced hyperkalaemia (incidence rate 40 per 1000 person-years) during a mean follow-up of 4.1 years. People who developed hyperkalaemia had a higher prevalence of chronic kidney disease [prevalence ratio 1.74 (95% CI 1.68-1.81)], heart failure [prevalence ratio 2.35 (95% CI 2.18-2.54)], use of angiotensin-converting enzyme inhibitors [prevalence ratio 1.24 (95% CI 1.20-1.28)], use of spironolactone [prevalence ratio 2.68 (95% CI 2.48-2.88)] and potassium supplements [prevalence ratio 1.59 (95% CI 1.52-1.67)]. In people with diabetes who developed hyperkalaemia, 31% were acutely hospitalized within 6 months before hyperkalaemia, increasing to 50% 6 months after hyperkalaemia [before-after risk ratio 1.67 (95% CI 1.61-1.72)]. The 6-month mortality rate after hyperkalaemia was 20%. Compared with matched individuals without hyperkalaemia, the hazard ratio for death was 6.47 (95% CI 5.81-7.21).

CONCLUSIONS

One in six newly diagnosed people with diabetes experienced a hyperkalaemic event, which was associated with severe clinical outcomes and death.

The prevalence of hyperkalemia in the United States

OBJECTIVE

The retrospective study aimed to estimate prevalence of hyperkalemia using a large US commercial claims database.

METHODS

Adults with serum potassium lab data (2010 to 2014) and ≥1 calendar year of data were included from a large US commercial claims database. Hyperkalemia was defined as ≥2 serum potassium measurements >5.0 mEq/L or one hyperkalemia diagnosis code (ICD-9-CM, 276.7) or one sodium polystyrene sulfonate fill. Hyperkalemia prevalence was estimated for the overall population and subgroups with hyperkalemia-related comorbidities by calendar year. Hyperkalemia prevalence was also standardized to the US population to estimate the number of US adults with hyperkalemia.

RESULTS

The analysis included 2,270,635 patients (2010-2014). The annual prevalence of hyperkalemia in the overall population was 1.57% in 2014, with higher rates observed in patients with chronic kidney disease (CKD), heart failure, diabetes and hypertension. Among patients with CKD and/or heart failure, the 2014 annual prevalence was 6.35%. Among patients with hyperkalemia, 48.43% had CKD and/or heart failure in 2014. The prevalence of hyperkalemia was higher in patients with more severe CKD, as well as older patients and men. Extrapolating those results to the US population supports that 1.55% or 3.7 million US adults had hyperkalemia in 2014.

CONCLUSIONS

An estimated 3.7 million US adults had hyperkalemia in 2014, and this prevalence rate has increased since 2010. In patients with CKD and/or heart failure, the annual prevalence of hyperkalemia was 6.35% in 2014, and about half of all patients with hyperkalemia have either CKD and/or heart failure.

Elevated Potassium Levels in Patients With Congestive Heart Failure: Occurrence, Risk Factors, and Clinical Outcomes: A Danish Population-Based Cohort Study

Background

Data on the true burden of hyperkalemia in patients with heart failure (HF) in a real‐world setting are limited.

Methods and Results

Incidence rates of hyperkalemia (first blood test with a potassium level >5.0 mmol/L) in primary or hospital care were assessed in a population‐based cohort of patients with incident HF diagnoses in northern Denmark from 2000 to 2012. Risk factors and clinical outcomes were compared in patients with HF with versus without hyperkalemia. Of 31 649 patients with HF, 39% experienced hyperkalemia (mean follow‐up, 2.2 years). Risks of experiencing a second, third, or fourth event were 43%, 54%, and 60%, respectively. Among patients with HF with stage 3A, 3B, 4, or 5 kidney dysfunction, 26%, 35%, 44%, and 48% experienced hyperkalemia within the first year. Important hyperkalemia risk factors included chronic kidney disease (prevalence ratio, 1.46; 95% confidence interval [CI], 1.43−1.49), diabetes mellitus (prevalence ratio, 1.38; 95% CI, 1.32−1.45), and spironolactone use (prevalence ratio, 1.48; 95% CI, 1.42−1.54). In patients with HF who developed hyperkalemia, 53% had any acute‐care hospitalization 6 months before the hyperkalemia event, increasing to 74% 6 months after hyperkalemia (before‐after risk ratio, 1.41; 95% CI, 1.38−1.44). Compared with matched patients with HF without hyperkalemia, adjusted 6‐month hazard ratios in patients with hyperkalemia were 2.75‐fold (95% CI, 2.65–2.85) higher for acute‐care hospitalization and 3.39‐fold (95% CI, 3.19–3.61) higher for death.

Conclusions

Almost 4 in 10 patients with HF develop hyperkalemia, and many patients have recurrent hyperkalemia episodes. Hyperkalemia risk is strongly associated with degree of reduced kidney function and use of spironolactone. Hyperkalemia is associated with severe clinical outcomes and death in HF.

Incident Hyperkalemia, Hypokalemia, and Clinical Outcomes During Spironolactone Treatment of Heart Failure With Preserved Ejection Fraction: Analysis of the TOPCAT Trial

BACKGROUND

In patients with heart failure and preserved ejection fraction (HF-PEF) randomized in the Americas as part of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial, treatment with spironolactone enhanced the risk of hyperkalemia but reduced the risk of hypokalemia. We examined the clinical correlates and prognostic implications of incident hypo- and hyperkalemia during study follow-up.

METHODS

We defined the region-specific incidence of hypokalemia (potassium [K⁺] <3.5 mmol/l) and hyperkalemia (K⁺ ≥5.5 mmol/l) among both placebo- and spironolactone-assigned patients in TOPCAT. Factors associated with incident hypokalemia and hyperkalemia and the relationship between incident K⁺ abnormalities and the risk of subsequent mortality were analyzed in multivariable regression models restricted to the Americas.

RESULTS

In the Americas, assignment to spironolactone increased risk for hyperkalemia (hazard ratio 3.21, 95% confidence interval 2.46-4.20, P < .001) and reduced risk of hypokalemia (hazard ratio 0.43, 95% confidence interval 0.34-0.55, P < .001). Assignment to spironolactone, lower estimated glomerular filtration rate, higher baseline K⁺, diabetes, and lower hemoglobin were associated with incident hyperkalemia, whereas assignment to placebo, lower K⁺, younger age, lower estimated glomerular filtration rate, and use of diuretics at baseline were associated with hypokalemia. The combination of spironolactone and an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker was associated with incremental risk for hyperkalemia and protection from hypokalemia. Independent of region, both hypokalemia and hyperkalemia, were associated with higher risk for cardiovascular and all-cause mortality in multivariable-adjusted Cox regression models.

CONCLUSIONS

Both hyperkalemia and hypokalemia are associated with heightened risk for mortality in HF-PEF. Use of spironolactone in this population requires careful laboratory surveillance of K⁺ and creatinine, particularly in high-risk groups.

Prevalence and incidence of hyperkalaemia in the Spanish population with heart failure with reduced ejection fraction: a systematic review and populational relevance

BACKGROUND AND OBJECTIVES

Hyperkalaemia (K⁺ levels≥5.5mmol/L) is a severe ion imbalance that occurs in patients who have heart failure (HF) with reduced ejection fraction (HFrEF) and increases the risk of ventricular fibrillation. Given that there are no estimates on the number of patients with this complication, the aim of this study was to estimate the prevalence and incidence of hyperkalaemia in patients with HFrEF in Spain.

MATERIAL AND METHODS

Based on a systematic literature search and through a meta-analysis, we calculated an HFrEF prevalence of ≤40% in the European and U.S.

POPULATION

Based on another systematic literature search, we calculated the prevalence of hyperkalaemia in patients with HF and its annual incidence rate. Considering the previous values and the Spanish population pyramid in 2016, we estimated the number of individuals with HFrEF who currently have hyperkalaemia and those who develop it each year in Spain.

RESULTS

Approximately 17,100 (10,000 men and 7100 women) of the 508,000 patients with HFrEF in Spain have hyperkalaemia. Furthermore, approximately 14,900 patients with HFrEF (9500 men and 5400 women) develop hyperkalaemia each year.

CONCLUSIONS

Approximately 1 of every 30 patients with HFrEF has plasma potassium values >5.5 mmol/L.

Treatment of Hyperkalemia in Heart Failure

PURPOSE OF REVIEW

The aim of this paper is to discuss strategies for prevention and management of hyperkalemia in patients with heart failure, including the role of novel therapies.

RECENT FINDINGS

Renin-angiotensin-aldosterone system (RAAS) antagonists, including angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARB), and mineralocorticoid receptor antagonists (MRA) decrease mortality and morbidity in heart failure but increase the risk of hyperkalemia, especially when used in combination. Prevention of hyperkalemia and its associated complications requires careful patient selection, counseling regarding dietary potassium intake, awareness of drug interactions, and regular laboratory surveillance. Recent data suggests that the risk of hyperkalemia may be further moderated through the use of combined angiotensin-neprilysin inhibitors, novel MRAs, and novel potassium binding agents. Clinicians should be mindful of the risk of hyperkalemia when prescribing RAAS inhibitors to patients with heart failure. In patients at highest risk, such as those with diabetes, the elderly, and advanced chronic kidney disease, more intensive laboratory surveillance of potassium and creatinine may be required. Novel therapies hold promise for reducing the risk of hyperkalemia and enhancing the tolerability of RAAS antagonists.

How to Improve Adherence to Life-saving Heart Failure Treatments with Potassium Binders

Medications that affect the renin-angiotensin-aldosterone system (RAAS) form the mainstay of current heart failure (HF) therapy in patients with reduced ejection fraction. Concerns about the risk of hyperkalaemia have created a significant barrier to optimal RAAS inhibitor therapy in patients with HF, however, and many patients are discontinuing or receiving suboptimal doses of these lifesaving therapies. This has serious health and economic implications due to adverse renal and cardiovascular events. There is therefore an important unmet need for novel therapeutic options for the long-term management of patients with, and at risk for, hyperkalaemia. Two new potassium-binding agents, patiromer and ZS-9, have been shown to be effective and safe for the treatment of hyperkalaemia, as well as the maintenance of normokalaemia, without dose reduction or discontinuation of RAAS inhibitors. In addition, the fast onset of ZS-9 action suggests that it may be useful in the treatment of acute hyperkalaemia. These agents may allow for dose optimisation of RAAS inhibitors for the long-term maintenance and protection of the renal and cardiovascular system.

Serum Potassium Levels and Outcome in Acute Heart Failure (Data from the PROTECT and COACH Trials)

Serum potassium is routinely measured at admission for acute heart failure (AHF), but information on association with clinical variables and prognosis is limited. Potassium measurements at admission were available in 1,867 patients with AHF in the original cohort of 2,033 patients included in the Patients Hospitalized with acute heart failure and Volume Overload to Assess Treatment Effect on Congestion and Renal FuncTion trial. Patients were grouped according to low potassium (<3.5 mEq/l), normal potassium (3.5 to 5.0 mEq/l), and high potassium (>5.0 mEq/l) levels. Results were verified in a validation cohort of 1,023 patients. Mean age of patients was 71 ± 11 years, and 66% were men. Low potassium was present in 115 patients (6%), normal potassium in 1,576 (84%), and high potassium in 176 (9%). Potassium levels increased during hospitalization (0.18 ± 0.69 mEq/l). Patients with high potassium more often used angiotensin-converting enzyme inhibitors and mineralocorticoid receptor antagonists before admission, had impaired baseline renal function and a better diuretic response (p = 0.005), independent of mineralocorticoid receptor antagonist usage. During 180-day follow-up, a total of 330 patients (18%) died. Potassium levels at admission showed a univariate linear association with mortality (hazard ratio [log] 2.36, 95% confidence interval 1.07 to 5.23; p = 0.034) but not after multivariate adjustment. Changes of potassium levels during hospitalization or potassium levels at discharge were not associated with outcome after multivariate analysis. Results in the validation cohort were similar to the index cohort. In conclusion, high potassium levels at admission are associated with an impaired renal function but a better diuretic response. Changes in potassium levels are common, and overall levels increase during hospitalization. In conclusion, potassium levels at admission or its change during hospitalization are not associated with mortality after multivariate adjustment.

Potassium and Its Discontents: New Insight, New Treatments

Hyperkalemia is common in patients with impaired kidney function or who take drugs that inhibit the renin-angiotensin-aldosterone axis. During the past decade, substantial advances in understanding how the body controls potassium excretion have been made, which may lead to improved standard of care for these patients. Renal potassium disposition is primarily handled by a short segment of the nephron, comprising part of the distal convoluted tubule and the connecting tubule, and regulation results from the interplay between aldosterone and plasma potassium. When dietary potassium intake and plasma potassium are low, the electroneutral sodium chloride cotransporter is activated, leading to salt retention. This effect limits sodium delivery to potassium secretory segments, limiting potassium losses. In contrast, when dietary potassium intake is high, aldosterone is stimulated. Simultaneously, potassium inhibits the sodium chloride cotransporter. Because more sodium is then delivered to potassium secretory segments, primed by aldosterone, kaliuresis results. When these processes are disrupted, hyperkalemia results. Recently, new agents capable of removing potassium from the body and treating hyperkalemia have been tested in clinical trials. This development suggests that more effective and safer approaches to the prevention and treatment of hyperkalemia may be on the horizon.

Serum potassium decline during hospitalization for acute decompensated heart failure is a predictor of 6-month mortality, independent of N-terminal pro-B-type natriuretic peptide levels: An individual patient data analysis

BACKGROUND

Limited data exist for the role of serum potassium changes during hospitalization for acute decompensated heart failure (ADHF). The present study investigated the long-term prognostic value of potassium changes during hospitalization in patients admitted for ADHF.

METHODS

Our study is a pooled individual patient data analysis assembled from 3 prospective cohorts comprising 754 patients hospitalized for ADHF. The endpoint was all-cause mortality within 180 days after discharge. Serum potassium levels and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured at admission and at discharge.

RESULTS

A percentage decrease >15% in serum potassium levels occurred in 96 (13%) patients, and an absolute decrease of >0.7 mmol/L in serum potassium levels occurred in 85 (12%) patients; and both were predictors of poor outcome independent of admission or discharge serum potassium. After the addition of other strong predictors of mortality-a 30% change in NT-proBNP during hospitalization, discharge levels of NT-proBNP, renal markers, and other relevant clinical variables-the multivariate hazard ratio of serum potassium percentage reduction of >15% remained an independent predictor of 180-day mortality (hazard ratio 2.06, 95% CI 1.14-3.73).

CONCLUSIONS

A percentage serum potassium decline of >15% is an independent predictor of 180-day all-cause mortality on top of baseline potassium levels, NT-proBNP levels, renal variables, and other relevant clinical variables. This suggest that patients hospitalized for ADHF with a decline of >15% in serum potassium levels are at risk and thus monitoring and regulating of serum potassium level during hospitalization are needed in these patients.

Renal tubular acidosis type IV in hyperkalaemic patients--a fairy tale or reality?

OBJECTIVE

Hyperkalaemia is a common feature in hospitalized patients and often attributed to drugs antagonizing the renin-angiotensin-aldosterone system (RAAS) and/or acute kidney injury (AKI), despite significantly preserved glomerular filtration rate (GFR). The objective of this study was to determine the prevalence and role of renal tubular acidosis type IV (RTA IV) in the development of significant hyperkalaemia.

DESIGN

A single-centre retrospective study.

PATIENTS

Patients admitted to a University Hospital over 12 months.

MEASUREMENTS

Patients with a potassium value > 6·0 mm were identified. Clinical and laboratory data were revisited, and patients with a normal anion gap metabolic acidosis were evaluated for the existence of RTA IV.

RESULTS

A total of 57 patients having significant hyperkalaemia (>6·0 mm) were identified. Twelve patients had end-stage renal disease, while 21 patients had solely AKI or progressive chronic renal failure. RTA IV was present in 24 patients (42%), of whom 71% had pre-existing renal insufficiency because of diabetic nephropathy or tubulointerstitial nephritis. All hyperkalaemic patients with urinary/serum electrolytes suggestive of RTA IV had evidence of AKI, but creatinine levels were significantly lower (P < 0·05), while the number of drugs antagonizing the RAAS was comparable.

CONCLUSION

We demonstrated that RTA IV (i) is very common in patients with hyperkalaemia; (ii) should always be suspected in hyperkalaemic patients with only moderately impaired GFR; and (iii) may result in significant hyperkalaemia in the presence of both AKI and drugs antagonizing the RAAS.

Hyperkalemia secondary to renal hypoperfusion in a dog with third-degree atrioventricular block

OBJECTIVE

To demonstrate a critical role of artificial cardiac pacing to normalize severe bradyarrhythmia-induced hyperkalemia in a dog with third-degree atrioventricular (AV) block.

CASE SUMMARY

A dog was presented for evaluation of severe hyperkalemia and bradyarrhythmia. ECG revealed third-degree AV block with heart rate of 10-20 min, which was lower than usual ventricular escape rate. The etiology of severe hyperkalemia was considered secondary to significantly decreased renal perfusion and potassium excretion as a result of poor cardiac output caused by the AV block. Since potassium disorders may lead to life-threatening conditions such as cardiopulmonary arrest, artificial cardiac pacing was immediately pursued. Within 1 hour, serum potassium concentration was normalized, which confirmed that severe hyperkalemia occurred primarily due to third-degree AV block. The dog was then treated with permanent pacemaker implantation. A recheck evaluation 3-month post pacemaker implantation showed normal serum potassium concentration and the dog was clinically healthy.

NEW OR UNIQUE INFORMATION PROVIDED

This report describes hyperkalemia secondary to significantly decreased cardiac output and renal hypoperfusion caused by third-degree AV block. The authors propose that artificial cardiac pacing must be considered as an emergency treatment for bradyarrhythmia-induced hyperkalemia, which ultimately restores cardiac output and renal perfusion and normalizes serum potassium concentration.

Predictors of hyperkalemia and death in patients with cardiac and renal disease

Predictors of hyperkalemia in patients with cardiovascular disease (CVD; defined as patients with hypertension and heart failure) and associated chronic kidney disease (CKD) are not well established. The aim of this study was to ascertain risk factors of hyperkalemia (defined as serum potassium concentration >5.0 mEq/L) and associated all-cause mortality in patients with CVD treated with antihypertensive drugs that impair potassium homeostasis. In a retrospective analysis using a logistic regression model, risk factors for hyperkalemia and all-cause mortality were analyzed in 15,803 patients with CVD treated with antihypertensive drugs. The mean estimated glomerular filtration rate and mean serum potassium concentration were 55.55 ml/min/1.73 m(2) and 4.06 mEq/L, respectively. Hyperkalemia was observed in 24.5% of study patients and 1.7% of total hospital admissions. Compared to patients with normokalemia, those with hyperkalemia had a higher percentage of death (6.25% vs 2.92%, p = 0.0001) and admissions (7.80% vs 5.04%, p = 0.0001). Predictors of hyperkalemia were CKD stage (odds ratio [OR] 2.14, 95% confidence interval [CI] 2.02 to 2.28), diabetes mellitus (OR 1.59, 95% CI 1.47 to 1.72), coronary artery disease (OR 1.32, 95% CI 1.21 to 1.43), and peripheral vascular disease (OR 1.55, 95% CI 1.36 to 1.77). Predictors of all-cause mortality were CKD stage (OR 1.26, 95% CI 1.12 to 1.43), hyperkalemic event (OR 1.56, 95% CI 1.30 to 1.88), age (OR 1.04, 95% CI 1.03 to 1.05), and hospitalization (OR 1.04, 95% CI 1.04 to 1.05). In conclusion, hyperkalemia is encountered frequently in patients with established CVD who are taking antihypertensive drugs and is associated with increases in all-cause mortality and hospitalizations. Advanced CKD, diabetes mellitus, coronary artery disease, and peripheral vascular disease are independent predictors of hyperkalemia.