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

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.

Hypokalaemia in patients with type 2 diabetes and chronic kidney disease: the effect of finerenone-a FIDELITY analysis

AIMS

Hypokalaemia is associated with cardiovascular events and mortality in patients with chronic kidney disease (CKD). This exploratory FIDELITY analysis, a prespecified pooled patient-dataset from FIDELIO-DKD and FIGARO-DKD, investigated the incidence and effect of hypokalaemia in patients with CKD and type 2 diabetes (T2D) treated with finerenone vs. placebo.

METHODS AND RESULTS

Outcomes include the incidence of treatment-emergent hypokalaemia (serum potassium <4.0 or <3.5 mmol/L) and the effect of finerenone on cardiovascular composite outcome (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, or hospitalization for heart failure) and arrhythmia composite outcome (new diagnosis of atrial fibrillation/atrial flutter, hospitalization due to arrhythmia, or sudden cardiac death) by baseline serum potassium subgroups. In the FIDELITY population, treatment-emergent hypokalaemia with serum potassium <4.0 and <3.5 mmol/L occurred in 41.1% and 7.5%, respectively. Hazards of cardiovascular and arrhythmia composite outcomes were higher in patients with baseline serum potassium <4.0 vs. 4.0-4.5 mmol/L [hazard ratio (HR) 1.16; 95% confidence interval (CI) 1.02-1.32, P = 0.022 and HR 1.20; 95% CI 1.00-1.44, P = 0.055, respectively]. Finerenone reduced the incidence of hypokalaemia with serum potassium <4.0 mmol/L (HR 0.63; 95% CI 0.60-0.66) and <3.5 mmol/L (HR 0.46; 95% CI 0.40-0.53) vs. placebo. Finerenone lessened the hazard of cardiovascular and arrhythmia events vs. placebo, irrespective of baseline serum potassium.

CONCLUSION

A substantial proportion of patients with CKD and T2D experienced hypokalaemia, which was associated with an increased hazard of adverse cardiovascular outcomes. Finerenone reduced the incidence of hypokalaemia. Finerenone reduced the hazard of cardiovascular and arrhythmia outcomes irrespective of serum potassium subgroups. Clinical trials registration: FIDELIO-DKD and FIGARO-DKD are registered with ClinicalTrials.gov, numbers NCT02540993 and NCT02545049, respectively (funded by Bayer AG).

Translating evidence into practice: Managing electrolyte imbalances and iron deficiency in heart failure

Mineral abnormalities are a common complication of heart failure (HF). In particular, dyskalaemia, hyponatraemia, and hypomagnesaemia are prevalent, with hypo- and hyperkalaemia observed in over 40 % of HF patients, hyponatraemia in 18-27 %, hypomagnesaemia in 7-52 %, and phosphate imbalance in 13 %. These abnormalities serve as indicators of the severity of HF and are strongly associated with an increased risk of morbidity and mortality. The neurohumoral activation, including the renin-angiotensin-aldosterone system (RAAS), the sympathetic nervous system, and vasopressin, HF medications such as diuretics and RAAS inhibitors, amd concomitant diseases such as chronic kidney disease, can disrupt mineral homeostasis. Iron deficiency (ID) is another of the most common mineral abnormalities, affecting up to 60 % of HF patients. ID is significantly associated with adverse clinical outcomes such as reduced quality of life and exercise capacity, HF re-hospitalization, and all-cause mortality. Various pathways contribute to the development of ID in HF, including reduced iron intake due to anorexia, increased hepcidin levels associated with chronic inflammation and hepatic congestion, and occult gastrointestinal bleeding due to the concomitant use of antithrombotic agents. The efficacy of iron replacement therapy has been demonstrated in clinical trials, particularly in heart failure with reduced ejection fraction (HFrEF), whilst more recently, it has also been shown to improve exercise capacity in patients with heart failure with preserved ejection fraction (HFpEF). This review focuses on potassium and phosphate abnormalities, hyponatraemia, hypomagnesaemia, and ID in HF, providing a comprehensive overview of the mechanisms, clinical significance, and intervention strategies with the latest findings.

The Efficacy and Safety of Patiromer for Heart Failure Patients: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the efficacy and safety of patiromer, a novel potassium binder, in reducing the risk of hyperkalemia in patients with heart failure and optimizing their RAASi therapy.

DESIGN

Systematic review and meta-analyses.

METHOD

The authors conducted a systematic search in Pubmed, Embase, Web of Science, and Cochrane Library for randomized controlled trials investigating the efficacy and safety of patiromer in heart failure patients from inception to 31 January 2023 and updated on 25 March 2023. The primary outcome was the association between the reduction of hyperkalemia and patiromer compared with placebo, and the secondary outcome was the association between optimization of RAASi therapy and patiromer.

RESULTS

A total of four randomized controlled trials (n = 1163) were included in the study. Patiromer was able to reduce the risk of hyperkalemia in heart failure patients by 44% (RR 0.56, 95% CI 0.36 to 0.87; I2 = 61.9%), improve tolerance to target doses of MRA in patients with heart failure (RR 1.15, 95% CI 1.02 to 1.30; I2 = 49.4%), and decrease the proportion of all-cause discontinuation of RAASi (RR 0.49, 95% CI 0.25 to 0.98; I2 = 48.4%). However, patiromer therapy was associated with an increased risk of hypokalemia (RR 1.51, 95% CI 1.07 to 2.12; I2 = 0%), while no other statistically significant adverse events were observed.

CONCLUSION

Patiromer appears to have a considerable effect on reducing the incidence of hyperkalemia in heart failure patients and on optimizing the therapy of RAASi in those patients.

Association between admission baseline blood potassium levels and all-cause mortality in patients with acute kidney injury combined with sepsis: A retrospective cohort study

INTRODUCTION

Imbalances in blood potassium (K) homeostasis is a significant contributor to the emergence of severe complications, especially among critically ill patients. Hypokalemia and hyperkalemia are both associated with an increased risk of adverse events. However, it is not known about the impact of blood K levels on risk of intensive care units (ICU) mortality for Acute kidney injury (AKI) combined with sepsis patients. This study aimed to explore the relationship between admission blood K levels and ICU 30-day mortality in patients with AKI combined with sepsis.

METHODS

We selected patients diagnosed with AKI and sepsis on their first ICU admission from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The first blood K levels within 24 hours of admission were categorized into three groups according to tertiles (T1 < 3.9 mmol/L, 3.9 ≤ T2 < 4.5 mmol/L, and T3 ≥ 4.5 mmol/L), with T2 serving as the reference. We examined the association between blood K levels and ICU 30-day mortality using accelerated failure time (AFT) models and survival analysis.

RESULTS

A total of 8,242 ICU patients with AKI combined with sepsis were included. In multivariate AFT models, each 1 mmol/L increase in blood K levels was associated with a 13% increase in the risk of ICU 30-day mortality (p < 0.001, 95% confidence interval (CI): 1.06-1.20). Extended multivariable AFT models showed that, compared to the middle category, patients with high blood K levels (≥ 4.5 mmol/L) were associated with all-cause mortality (p = 0.002, adjusted hazard ratio (HR) = 1.22, 95% CI: 1.08-1.38), whereas those with low blood K levels (< 3.9 mmol/L) showed no significant difference (p = 0.385, adjusted HR = 1.06, 95% CI: 0.93-1.21). Kaplan-Meier curves indicated that patients with high blood K levels had higher mortality, and those with middle blood potassium levels (3.9 ≤ K < 4.5 mmol/L) had the lowest mortality.

CONCLUSION

The admission baseline blood K levels were significantly associated with ICU 30-day mortality in intensive care patients suffering from AKI in conjunction with sepsis. Therefore, immediate and careful correction of blood potassium imbalances may prove to be a crucial approach in improving outcomes for these patients.

Recurrence of left ventricular systolic dysfunction and its risk factors in heart failure with improved ejection fraction patients receiving guideline-directed medical therapy: A trajectory analysis based on echocardiography

BACKGROUND

Despite the better prognosis of heart failure (HF) with improved ejection fraction (HFimpEF), remnant cardiovascular risks, including cardiovascular death, rehospitalization, and future deterioration of left ventricular (LV) systolic function, remain in HFimpEF. However, for HFimpEF patients, especially for those receiving guideline-directed medical therapy (GDMT), the recurrent LV systolic dysfunction and its risk factors is still unclear.

METHODS

A total of 1098 HF patients under HF follow-up management system were initially screened. Echocardiography was re-evaluated at 3-, 6-, and 12-month follow-up. After exclusion, a total of 203 HFimpEF patients on GDMT were enrolled in our final analysis. Cox regression analysis was conducted to select risk factors.

RESULTS

During the 1-year follow-up, a total of 28 (13.8%) patients had recurrent LV systolic dysfunction. The trajectory analysis of echocardiographic parameters illustrated that persistent decline of left ventricular ejection fraction (LVEF) and worsening LV remodeling was observed in patients with recurrent LV systolic dysfunction. Multivariable Cox regression analysis identified that ischemic cardiomyopathy, atrial fibrillation, higher left ventricular end-diastolic diameter index (LVEDDI), elevated serum potassium, and a lack of sodium-glucose co-transporter-2 inhibitors (SGLT2i) treatment were confirmed as independent risk factors for recurrent LV systolic dysfunction. Recurrent LV systolic dysfunction was associated with higher rehospitalization rate.

CONCLUSION

In our longitudinal cohort study, almost 14% HFimpEF receiving GDMT suffered recurrent LV systolic dysfunction. Ischemic cardiomyopathy, atrial fibrillation, higher LVEDDI, higher serum potassium, and a lack of SGLT2i therapy were tightly associated with recurrence of LV systolic dysfunction. Relapse of LV systolic dysfunction correlated with poor prognosis.

Clinical outcomes of serum potassium in patients with percutaneous coronary intervention: insights from a large single-center registry

Background

Serum potassium homeostasis plays an important role in myocardial electrical stability, but the impact of altered serum potassium levels on the major adverse cardiovascular and cerebral events (MACCE) in patients with percutaneous coronary intervention (PCI) has not been evaluated.

Aim

To evaluate the association between serum potassium level and the risk of MACCE in PCI patients.

Materials and methods

This retrospective study involved 8,263 in-patients from a single-center registry who were successfully treated with PCI between January 2003 and December 2020. Clinical data were collected for 24 h after admission. Data were analyzed from June 2003 to December 2021. The primary outcome was MACCE, defined as a composite of all-cause death, myocardial infarction, revascularization, stroke, and heart failure-related hospitalization.

Results

The median [interquartile range (IQR)] follow-up for all patients was 4.0 (2.1, 5.8) years, and 1,632 patients (19.7%) were diagnosed with MACCE. High serum potassium levels were associated with a 20% increased risk of MACCE (hazard ratio [HR]: 1.20, 95% confidence interval [CI]: 1.05-1.38, P = 0.008) and 72% increased risk of all-cause death (HR: 1.72, 95% CI: 1.39-2.14, P < 0.001). Multivariate Cox analysis showed that the risk of MACCE was higher in patients at the highest quartile of serum potassium (Q4 vs. Q1: adjusted HR: 1.18, 95% CI: 1.02-1.35, P = 0.026). Moreover, a higher serum potassium level was always associated with a higher risk of all-cause death (Q4 vs. Q1: adjusted HR: 1.50, 95% CI: 1.17-1.91, P = 0.001). A U-shaped relationship between serum potassium levels, MACCE, and all-cause death was derived in patients undergoing PCI. Serum potassium levels, maintained within the range of 3.8-4.0 mmol/L before PCI, exhibited the lowest risk of associated MACCE and all-cause death.

Conclusion

Our results demonstrate that the serum potassium level could be associated with higher risks of MACCE and all-cause death in PCI patients. In particular, serum potassium levels maintained at 3.8-4.0 mmol/L before PCI could lower the risk of MACCE and all-cause death.

Serum potassium in elderly heart failure patients as a predictor of readmission within 1 year

Blood potassium levels are associated with adverse outcomes in patients with congestive heart failure (HF). However, it is unclear whether there are differences in outcome events in elderly patients with different blood potassium levels at the time of emergency readmission within 1 year. This study used data from patients hospitalized with HF, integrating electronic medical records from the PhysioNet restricted health data database and external outcome data. We conducted a retrospective study of HF patients aged 60 years and older, using baseline data, comorbidities, laboratory tests, and medication use as covariates to analyze the effect of serum potassium levels on outcome events, with the primary outcome being readmission within 1 year. A priori was used to calculate the sample size, and this retrospective cohort study included a total of 788 elderly HF patients, of whom 20.3% had hypokalaemia (K⁺  < 3.5 mmol/L) and 14.7% had hyperkalemia (K⁺  > 4.7 mmol/L). According to a multivariate Cox regression model, patients with hyperkalemia had a shorter time interval between readmissions within 1 year, with a hazard ratio (HR) and its 95% CI of 1.134 (1.006-1.279). Three models were used to analyze patients with different blood potassium levels and, after correction, the high potassium group was at high risk relative to the low and normal groups, with significant differences in outcome events, with HRs and their 95% CI of 1.266 (1.03-1.557), 1.245 (1.01-1.534), and 1.439 (1.142-1.812), respectively. The robustness of the model was also demonstrated by competing risk models with subgroup analysis, showing that blood potassium levels had a stable effect on outcome events and were not altered by covariates (age, sex, diabetes, chronic kidney disease, NT-proBNP, high-sensitivity troponin, and glomerular filtration rate). The results show that high blood potassium levels are associated with the outcome event of readmission within 1 year in elderly patients with HF. Blood potassium levels at the time of the first hospitalization may therefore be a valuable predictor.

Hypokalemia-Induced Life-Threatening Arrhythmia in a Patient With Congestive Heart Failure

Ventricular tachyarrhythmias are common in patients with heart failure. It is one of the important preventable causes of death in these patient populations. Hypokalemia is prevalent in patients with heart failure due to various reasons. Hypokalemia can trigger ventricular arrhythmias through different mechanisms. In this case report, we present a middle-aged man with congestive heart failure (CHF) and an automated intracardiac defibrillator (AICD) on multiple diuretic medications (unintended) who presented with acute chest pain. He was found to have severe hypokalemia, hyponatremia, and an acute kidney injury. Interrogation of the AICD revealed multiple episodes of ventricular fibrillation. The patient was managed by holding his diuretic medications, cautious volume repletion, and potassium replacement. Fortunately, the patient showed rapid clinical improvement and his plasma potassium level improved. On discharge, we reconciled the patient's medications to avoid the recurrence of hypokalemia from over-diuresis and arranged a close follow-up outpatient visit with his cardiologist.

Assessing potassium levels in critically ill patients with heart failure: application of a group-based trajectory model

AIMS

Abnormalities in potassium homeostasis are frequently seen in hospitalized patients. A poor outcome in heart failure (HF) has been linked to both hypokalaemia and hyperkalaemia. The studies on the connection between variations in potassium levels and all-cause mortality remain scarce. We delineated trajectories of potassium levels and investigated the association of these trajectories with all-cause mortality of critically ill patients with HF.

METHODS AND RESULTS

A retrospective analysis of blood potassium levels (9 times) in patients with HF after being admitted to the intensive care unit (ICU). Potassium levels were divided into three groups according to the first serum potassium level in ICU and thereafter categorized as follows: hypokalaemia group (n = 336) (<3.5 mmol/L), normal blood potassium-level group (n = 3322) (3.5-5.0 mmol/L), and hyperkalaemia group (n = 395) (>5.0 mmol/L). According to the group-based trajectory modelling (GBTM), the hyperkalaemia group and the normal blood potassium-level group can be divided into three trajectory groups: the low-level stable group, the medium-level stable group, and the high-level decline group. The hypokalaemia group can be divided into two trajectory groups: the low-level rise group and the high-level rise group. A total of 4053 HF patients were included (mean age 71.81 ± 13.12 years, 54.90% males, 45.10% females). After adjusting for possible confounding variables, in the hyperkalaemia group, the low-level stable group had lower 28 day [high-level decline group vs. low-level stable group hazard ratio (HR), 95% confidence interval (CI): 2.917, 1.555-5.473; P < 0.05] and 365 day (high-level decline group vs. low-level stable group HR, 95% CI: 2.854, 1.820-4.475; P < 0.05) all-cause mortality. In the normal blood potassium-level group, the medium-level stable group had lower 28 day (medium-level stable group vs. low-level stable group HR, 95% CI: 0.776, 0.657-0.918; P < 0.05) and 365 day (medium-level stable group vs. low-level stable group HR, 95% CI: 0.827, 0.733-0.934; P < 0.05) all-cause mortality. In the hypokalaemia group, the cumulative survival of the high-level rise group and the low-level rise group did not differ significantly.

CONCLUSIONS

Critically ill patients with HF have blood potassium trajectories. And the trajectories are associated with all-cause mortality for hyperkalaemia and normal blood potassium-level patients. GBTM is a granular method to describe the evolution of blood potassium, which may increase the current knowledge of blood potassium-level adjustment.

Systematic and state-of the science review of the role of environmental factors in Amyotrophic Lateral Sclerosis (ALS) or Lou Gehrig's Disease

The etiology of sporadic amyotrophic lateral sclerosis (ALS) is still unclear. We evaluate environmental factors suspected to be associated with ALS for their potential linkage to disease causality and to model geographic distributions of susceptible populations and expected cases worldwide. A PRISMA systematic literature review was performed 2021. Bradford Hill criteria were used to identify and rank environmental factors and a secondary review of ALS diagnoses in population studies and ALS case or cohort studies was conducted. Prevalence rate projection informed estimates of impacted regions and populations. Among 1710 papers identified, 258 met the inclusion criteria, of which 173 responded to at least one of nine Bradford Hill criteria among 83 literature-identified ALS environmental factors. Environmental determinants of ALS in order of decreasing significance were β-N-methylamino-L-alanine (BMAA), formaldehyde, selenium, and heavy metals including manganese, mercury, zinc, and copper. Murine animal models were the most common methodology for exploring environmental factors. Another line of investigation of 62 population exposure studies implicated the same group of environmental agents (mean odds ratios): BMAA (2.32), formaldehyde (1.54), heavy metals (2.99), manganese (3.85), mercury (2.74), and zinc (2.78). An age-adjusted incidence model estimated current total ALS cases globally at ~85,000 people compared to only ~1600 cases projected from the reported ALS incidence in the literature. Modeling with the prevalence microscope equation forecasted an increase in U.S. ALS cases from 16,707 confirmed in 2015 to ~22,650 projected for 2040. Two orthogonal methods employed implicate BMAA, formaldehyde, manganese, mercury, and zinc as environmental factors with strong ALS associations. ALS cases likely are significantly underreported globally, and high vulnerability exists in regions with large aging populations. Recent studies on other diseases with environmental determinants suggest the need to consider additional potential triggers and mechanisms, including exposures to microbial agents and epigenetic modifications.

Cardiovascular and kidney outcomes with finerenone in patients with type 2 diabetes and chronic kidney disease: the FIDELITY pooled analysis

AIMS

The complementary studies FIDELIO-DKD and FIGARO-DKD in patients with type 2 diabetes and chronic kidney disease (CKD) examined cardiovascular and kidney outcomes in different, overlapping stages of CKD. The purpose of the FIDELITY analysis was to perform an individual patient-level prespecified pooled efficacy and safety analysis across a broad spectrum of CKD to provide more robust estimates of safety and efficacy of finerenone compared with placebo.

METHODS AND RESULTS

For this prespecified analysis, two phase III, multicentre, double-blind trials involving patients with CKD and type 2 diabetes, randomized 1:1 to finerenone or placebo, were combined. Main time-to-event efficacy outcomes were a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, or hospitalization for heart failure, and a composite of kidney failure, a sustained ≥57% decrease in estimated glomerular filtration rate from baseline over ≥4 weeks, or renal death. Among 13 026 patients with a median follow-up of 3.0 years (interquartile range 2.3-3.8 years), the composite cardiovascular outcome occurred in 825 (12.7%) patients receiving finerenone and 939 (14.4%) receiving placebo [hazard ratio (HR), 0.86; 95% confidence interval (CI), 0.78-0.95; P = 0.0018]. The composite kidney outcome occurred in 360 (5.5%) patients receiving finerenone and 465 (7.1%) receiving placebo (HR, 0.77; 95% CI, 0.67-0.88; P = 0.0002). Overall safety outcomes were generally similar between treatment arms. Hyperkalaemia leading to permanent treatment discontinuation occurred more frequently in patients receiving finerenone (1.7%) than placebo (0.6%).

CONCLUSION

Finerenone reduced the risk of clinically important cardiovascular and kidney outcomes vs. placebo across the spectrum of CKD in patients with type 2 diabetes.

KEY QUESTION

Does finerenone, a novel selective, nonsteroidal mineralocorticoid receptor antagonist, added to maximum tolerated renin-angiotensin system inhibition reduce cardiovascular disease and kidney disease progression over a broad range of chronic kidney disease in patients with type 2 diabetes?

KEY FINDING

In a prespecified, pooled individual-level analysis from two randomized trials, we found reductions both in cardiovascular events and kidney failure outcomes with finerenone. Because 40% of the patients had an estimated glomerular filtration rate of >60 mL/min/1.73m2 they were identified solely on the basis of albuminuria.

TAKE HOME MESSAGE

Finerenone reduces the risk of clinical cardiovascular outcomes and kidney disease progression in a broad range of patients with chronic kidney disease and type 2 diabetes. Screening for albuminuria to identify at-risk patients among patients with type 2 diabetes facilitates reduction of both cardiovascular and kidney disease burden.