Hyperkalaemia in Cardiological Patients: New Solutions for an Old Problem.

Hyperkalaemia is one of the most common electrolyte disorders in patients with cardiovascular disease (CVD). The true burden of hyperkalaemia in the real-world setting can be difficult to assess, but in population-based cohort studies up to 4 in 10 patients developed hyperkalaemia. In addition to drugs interfering with potassium metabolism and food intake, several conditions can cause or worsen hyperkalaemia, such as advanced age, diabetes, and chronic kidney disease. Mortality, cardiovascular morbidity, and hospitalisation are higher in patients with hyperkalaemia. Hyperkalaemia represents a major contraindication or a withholding cause for disease-modifying therapies like renin-angiotensin-aldosterone inhibitors (RAASi), mainly mineralocorticoid receptor antagonists. Hyperkalaemia can be also classified as acute and chronic, according to the onset. Acute hyperkalaemia is often a life-threatening emergency requiring immediate treatment to avoid lethal arrhythmias. Therapy goal is cell membrane stabilisation by calcium administration, cellular intake, shift of extracellular potassium to the intracellular space (insulin, beta-adrenergic agents, sodium bicarbonate), and increased elimination with diuretics or dialysis. Chronic hyperkalaemia was often managed with dietary counselling to prevent potassium-rich food intake and tapering of potassium-increasing drugs, mostly RAASi. Sodium polystyrene sulphonate, a potassium binder, was the only therapeutic option. Recently, new drugs such as patiromer and sodium zirconium cyclosilicate give new opportunities for the treatment of hyperkalaemia, as they proved to be safe, well tolerated, and effective. Aim of this review is to describe the burden of hyperkalaemia in cardiovascular patients, its direct and indirect effects, and the therapeutic options now available in the acute and chronic setting.

Italian Association of Hospital Cardiologists position paper-obesity in adults: a clinical primer.

Obesity is a chronic and relapsing disease characterized by the interaction between individual predispositions and an obesogenic environment. Recent advances in understanding the mechanisms of energetic homoeostasis paved the way to more effective therapeutic approaches compared with traditional treatments. Since obesity is a complex disease, it necessitates a multi-disciplinary approach whose implementation remains challenging. Nonetheless, emerging pharmacological interventions appear promising. Currently, therapeutic success is discreet in the short term but often fails to maintain long-term weight loss due to a high likelihood of weight regain. Cardiologists play a key role in managing patients with obesity, yet often lack familiarity with its comprehensive management. The aim of this document is to summarize knowledge to consolidate essential knowledge for clinicians to effectively treat patients living with obesity. The paper emphasizes the pivotal role of a strong patient-clinician relationship in navigating successful treatment. We analyse the criteria commonly used to diagnose obesity and point out the strengths and limitations of different criteria. Furthermore, we discuss the role of obesiologists and the contributions of cardiologists. In addition, we detail key components of effective therapeutic strategies, including educational aspects and pharmacological options.

Diabetes leading to heart failure and heart failure leading to diabetes: epidemiological and clinical evidence.

Type 2 diabetes mellitus (T2DM) is a risk factor that plays a major role in the onset of heart failure (HF) both directly, by impairing cardiac function, and indirectly, through associated diseases such as hypertension, coronary disease, renal dysfunction, obesity, and other metabolic disorders. In a population of HF patients, the presence of T2DM ranged from 20 to 40%, according to the population studied, risk factor characteristics, geographic area, and age, and it is associated with a worse prognosis. Finally, patients with HF, when compared with those without HF, show an increased risk for the onset of T2DM due to several mechanisms that predispose the HF patient to insulin resistance. Despite the epidemiological data confirmed the relationship between T2DM and HF, the exact prevalence of HF in T2DM comes from interventional trials rather than from observational registries aimed to prospectively evaluate the risk of HF occurrence in T2DM population. This review is focused on the vicious cycle linking HF and T2DM, from epidemiological data to prognostic implications.

Renal effects of SGLT2 inhibitors in cardiovascular patients with and without chronic kidney disease: focus on heart failure and renal outcomes.

The kidney has a prominent role in maintaining glucose homeostasis by using glucose as a metabolic substrate. This occurs by generating glucose through gluconeogenesis, and by reuptaking filtered glucose through the sodium-glucose cotransporters SGLT1 and SGLT2 located in the proximal tubule. In recent studies, the administration of sodium-glucose cotransporters inhibitors demonstrated that inhibition of renal glucose reabsorption significantly reduces adverse renal events and heart failure exacerbations, in type 2 diabetic patients with and without cardiovascular damage as well as in advanced chronic kidney disease and heart failure patients with reduced ejection fraction with and without diabetes. The benefit was consistent throughout the different investigated clinical conditions, ameliorating overall patient outcome. The efficacy of sodium glucose cotransporters inhibitors was prominently linked to the limitation of renal damage as highlighted by the significant reduction on global mortality achieved in the studies investigating diabetic and not diabetic populations with advanced chronic kidney disease. Both studies were halted at the interim analysis because of unquestionable evidence of treatment benefit. In current review, we examine the role of SGLT2 and SGLT1 in the regulation of renal glucose reabsorption in health and disease and the effect of SGLT2 inhibition on clinical outcomes of populations with different cardiovascular conditions investigated with large-scale outcome trials.

The Evolving Phenotypes of Cardiovascular Disease during COVID-19 Pandemic.

COVID-19 pandemic has negatively impacted the management of patients with acute and chronic cardiovascular disease: acute coronary syndrome patients were often not timely reperfused, heart failure patients not adequately followed up and titrated, atrial arrhythmias not efficaciously treated and became chronic. New phenotypes of cardiovascular patients were more and more frequent during COVID-19 pandemic and are expected to be even more frequent in the next future in the new world shaped by the pandemic. We therefore aimed to briefly summarize the main changes in the phenotype of cardiovascular patients in the COVID-19 era, focusing on new clinical challenges and possible therapeutic options.

Atrial paced rhythm and heart rate-dependent worsening of left atrial and ventricular function.

BACKGROUND AND AIM OF THE STUDY: The response to the increase in heart rate (HR) could be characterized by failure in both left ventricular (LV) and left atrial (LA) functions. This study aimed to evaluate the relationship between the increase in paced HR and the changes in LV and LA functions, assessed by two-dimensional speckle tracking analysis. METHODS: In a group of patients with an implantable cardioverter defibrillator (ICD) or pacemaker, the atrial paced rhythm was progressively increased from 60 to 70, from 70 to 80, and from 80 to 90 beats per minute (bpm). For each paced HR, using two-dimensional speckle tracking analysis, LA reservoir (LAr), LA conduit (LAc), LA contraction (LAct), and LV global longitudinal strain (LV-GLS) were evaluated every 10 bpm. RESULTS: Of the 45 patients enrolled, a significant reduction in LAr was observed at higher HR. However, when the patients were dichotomized according to the HR-related response of LV-GLS, the worsening of LAr was observed in those with LV-GLS worsening and not in those without (maximum LAR absolute changes -2.7 ± 7.2% vs. +2.7 ± 7.2%, respectively, p .028). Moreover, the worsening of LA and LV strain measures was associated with an increase in the estimated filling pressures. CONCLUSIONS: In patients with atrial paced rhythm, the increase in HR could be associated with worsening of LA and LV functions, as assessed by two-dimensional speckle tracking analyses. These results offer new data on HR-related atrioventricular function and could be useful for guiding the optimal HR responsiveness of the implanted devices.

Relationship between the strain measures of left atrial function and heart failure worsening.

BACKGROUND: Two-dimensional speckle tracking evaluation (2D-STE) is a useful tool to evaluate the complexity of atrial function by the analysis of the different phases of atrial deformation and by the combination with Doppler measurements of diastolic function. AIM OF THE STUDY: To evaluate the role of the left atrial (LA) strain parameters to predict worsening chronic heart failure (CHF). METHODS: We enrolled outpatients affected by CHF referred to our heart failure unit. Each patient underwent a medical visit, an electrocardiogram (ECG), and an echocardiographic examination. LA function was assessed by 2D-STE. The three phases of LA strain, that is, the reservoir (LAr), the conduit (LAcd), and the contraction (LAct)-were evaluated. Moreover, the ratio between E and LAr (E/LAr) and those between LAr and septal (LAr/Ees), lateral (LAr/Eel), and septal-lateral (LAr/Eem) E/e' were measured. During follow-up, the events related to worsening of heart failure were evaluated. RESULTS: Two hundred eleven patients were enrolled. During a mean follow-up of 14 ± 7 months, 37 patients showed at least one event related to heart failure worsening. At univariate Cox regression analysis, LAr, LAcd, LAct, E/LAr, LAr/Ees, LAr/Eel, and LAr/Eem were all associated with events related to heart failure worsening, but at multivariate regression analyses, only LAr (Hazard Ratio, HR: .95; 95% Confidence Interval, CI: .92-.99; p: .031), LAct (HR: 1.06; 95% CI: 1.01-1.12; p: .027), E/LAr (HR: 1.10; 95%CI: 1.0-1.16; p < .001), LAr/Ees (HR: .57; 95% CI: .37-.87; p: .010), and LAr/Eem (HR: .71; 95% CI: .53-.96; p: .026) remained significantly associated with the events. Finally, in a predictive model including the other relevant echocardiographic parameters LAr < 18%, LAct > -10.0%, LAr/Ees < 1.28, and E/LAr > 3.70 were associated with a statistically significant overall net reclassification improvement. CONCLUSIONS: In CHF patients, the measure of the LA reservoir and contraction by 2D-STE is independently associated with heart failure worsening, but the accuracy in predicting the events is even greater when the reservoir is combined with the Doppler measures of diastolic function.

Metabolic Regulation in the Development of Cardiovascular Disease and Heart Failure.

The Special Issue "Metabolic Regulation in the Development of Cardiovascular Disease and Heart Failure" focused on how metabolic diseases could cause a predisposition to cardiovascular diseases and, in particular, heart failure due to systolic or diastolic dysfunction or a combination thereof [...].

Renal Oxygen Demand and Nephron Function: Is Glucose a Friend or Foe?

The kidneys and heart work together to balance the body's circulation, and although their physiology is based on strict inter dependence, their performance fulfills different aims. While the heart can rapidly increase its own oxygen consumption to comply with the wide changes in metabolic demand linked to body function, the kidneys physiology are primarily designed to maintain a stable metabolic rate and have a limited capacity to cope with any steep increase in renal metabolism. In the kidneys, glomerular population filters a large amount of blood and the tubular system has been programmed to reabsorb 99% of filtrate by reabsorbing sodium together with other filtered substances, including all glucose molecules. Glucose reabsorption involves the sodium-glucose cotransporters SGLT2 and SGLT1 on the apical membrane in the proximal tubular section; it also enhances bicarbonate formation so as to preserve the acid-base balance. The complex work of reabsorption in the kidney is the main factor in renal oxygen consumption; analysis of the renal glucose transport in disease states provides a better understanding of the renal physiology changes that occur when clinical conditions alter the neurohormonal response leading to an increase in glomerular filtration pressure. In this circumstance, glomerular hyperfiltration occurs, imposing a higher metabolic demand on kidney physiology and causing progressive renal impairment. Albumin urination is the warning signal of renal engagement over exertion and most frequently heralds heart failure development, regardless of disease etiology. The review analyzes the mechanisms linked to renal oxygen consumption, focusing on sodium-glucose management.

The Role of Genetics in the Management of Heart Failure Patients.

Over the last decades, the relevance of genetics in cardiovascular diseases has expanded, especially in the context of cardiomyopathies. Its relevance extends to the management of patients diagnosed with heart failure (HF), given its capacity to provide invaluable insights into the etiology of cardiomyopathies and identify individuals at a heightened risk of poor outcomes. Notably, the identification of an etiological genetic variant necessitates a comprehensive evaluation of the family lineage of the affected patients. In the future, these genetic variants hold potential as therapeutic targets with the capability to modify gene expression. In this complex setting, collaboration among cardiologists, specifically those specializing in cardiomyopathies and HF, and geneticists becomes paramount to improving individual and family health outcomes, as well as therapeutic clinical results. This review is intended to offer geneticists and cardiologists an updated perspective on the value of genetic research in HF and its implications in clinical practice.

Network meta-analysis of medical therapy efficacy in more than 90,000 patients with heart failure and reduced ejection fraction.

BACKGROUND: Following the availability of new drugs for chronic heart failure (HF) with reduced ejection fraction (HFrEF), we sought to provide an updated and comparative synthesis of the evidence on HFrEF pharmacotherapy efficacy. METHODS: We performed a Bayesian network meta-analysis of phase 2 and 3 randomized controlled trials (RCTs) of medical therapy in HFrEF patient cohorts with more than 90% of the participants with left ventricular ejection fraction less than 45% and all-cause mortality reported. RESULTS: Sixty-nine RCTs, accounting for 91,741 subjects, were evaluated. The step-wise introduction of new drugs progressively decreased the risk of all-cause death, up to reaching a random-effects hazard ratio (HR) of 0.43 (95% credible intervals [CrI] 0.27-0.63) with beta blockers (BB), angiotensin-converting enzyme inhibitors (ACEi), and mineralocorticoid receptor antagonist (MRA) versus placebo. The risk was further reduced by adding sodium-glucose cotransporter-2 inhibitors (SGLT2i; HR 0.38, 95% CrI 0.22-0.60), ivabradine (HR 0.39, 95% CrI 0.21-0.64), or vericiguat (HR 0.40, 95% CrI 0.22-0.65) to neurohormonal inhibitors, and by angiotensin receptor-neprilysin inhibitor (ARNI), BB, and MRA (HR 0.36, 95% CrI 0.20-0.60). In a sensitivity analysis considering the ARNI and non-ARNI subgroups of SGLT2i RCTs, the combination SGLT2i + ARNI + BB + MRA was associated with the lowest HR (0.28, 95% CrI 0.16-0.45 vs. 0.40, 95% CrI 0.24-0.60 for SGLT2i + BB + ACEi + MRA). Consistent results were obtained in sensitivity analyses and by calculating surface under the cumulative ranking area, as well as for cardiovascular mortality (information available for 56 RCTs), HF hospitalization (45 RCTs), and all-cause hospitalization (26 RCTs). CONCLUSIONS: Combination medical therapy including neurohormonal inhibitors and newer drugs, especially ARNI and SGLT2i, confers the maximum benefit with regard to HFrEF prognosis.

Progressive right ventricular dysfunction and exercise impairment in patients with heart failure and diabetes mellitus: insights from the T.O.S.CA. Registry.

BACKGROUND: Findings from the T.O.S.CA. Registry recently reported that patients with concomitant chronic heart failure (CHF) and impairment of insulin axis (either insulin resistance-IR or diabetes mellitus-T2D) display increased morbidity and mortality. However, little information is available on the relative impact of IR and T2D on cardiac structure and function, cardiopulmonary performance, and their longitudinal changes in CHF. METHODS: Patients enrolled in the T.O.S.CA. Registry performed echocardiography and cardiopulmonary exercise test at baseline and at a patient-average follow-up of 36 months. Patients were divided into three groups based on the degree of insulin impairment: euglycemic without IR (EU), euglycemic with IR (IR), and T2D. RESULTS: Compared with EU and IR, T2D was associated with increased filling pressures (E/e'ratio: 15.9 ± 8.9, 12.0 ± 6.5, and 14.5 ± 8.1 respectively, p < 0.01) and worse right ventricular(RV)-arterial uncoupling (RVAUC) (TAPSE/PASP ratio 0.52 ± 0.2, 0.6 ± 0.3, and 0.6 ± 0.3 in T2D, EU and IR, respectively, p < 0.05). Likewise, impairment in peak oxygen consumption (peak VO2) in TD2 vs EU and IR patients was recorded (respectively, 15.8 ± 3.8 ml/Kg/min, 18.4 ± 4.3 ml/Kg/min and 16.5 ± 4.3 ml/Kg/min, p < 0.003). Longitudinal data demonstrated higher deterioration of RVAUC, RV dimension, and peak VO2 in the T2D group (+ 13% increase in RV dimension, - 21% decline in TAPSE/PAPS ratio and - 20% decrease in peak VO2). CONCLUSION: The higher risk of death and CV hospitalizations exhibited by HF-T2D patients in the T.O.S.CA. Registry is associated with progressive RV ventricular dysfunction and exercise impairment when compared to euglycemic CHF patients, supporting the pivotal importance of hyperglycaemia and right chambers in HF prognosis. Trial registration ClinicalTrials.gov identifier: NCT023358017.

Switch to SGLT2 Inhibitors and Improved Endothelial Function in Diabetic Patients with Chronic Heart Failure.

PURPOSE: The use of sodium-glucose-cotransporter-type-2 inhibitors (SGLT2i) was associated in previous studies with an improved vascular function in non-human experimental models. We therefore sought to evaluate possible changes in endothelial function assessed by flow-mediated dilation (FMD) in patients with chronic heart failure (CHF) and type-2 diabetes mellitus (T2DM), switching from other oral hypoglycemic agents to SGLT2i in an observational study. METHODS: Twenty-two consecutive outpatients with CHF and T2DM were enrolled after switching to SGLT2i therapy, and compared with 23 consecutive controls from the same registry comparable for principal clinical characteristics. In all patients, endothelial function was assessed by FMD at baseline and after 3 months of follow-up. RESULTS: Three months of therapy with SGLT2i were associated with a statistically significant improvement in endothelial function (19.0 ± 5.7% vs 8.5 ± 4.1%, p < 0.0001); baseline levels of FMD were comparable between groups (p n.s.). Therapy with SGLT2i was significantly associated to improved FMD levels even at multivariable stepwise regression analysis (p < 0.001). CONCLUSIONS: Switch to SGLT2i in patients with CHF and T2DM was associated in an observational non-randomized study with an improved endothelial function.

Respiratory failure and bioelectrical phase angle are independent predictors for long-term survival in acute heart failure.

Background. The assessment of long-term mortality in acute decompensated heart failure (ADHF) is challenging. Respiratory failure and congestion play a fundamental role in risk stratification of ADHF patients. The aim of this study was to investigate the impact of arterial blood gases (ABG) and congestion on long-term mortality in patients with ADHF. Methods and results. We enrolled 252 patients with ADHF. Brain natriuretic peptide (BNP), blood urea nitrogen (BUN), phase angle as assessed by means of bioimpedance vector analysis, and ABG analysis were collected at admission. The endpoint was all-cause mortality. At a median follow-up of 447 d (interquartile range [IQR]: 248-667), 72 patients died 1-840 d (median 106, IQR: 29-233) after discharge. Respiratory failure types I and II were observed in 78 (19%) and 53 (20%) patients, respectively. The ROC analyses revealed that the cut-off points for predicting death were: BNP > 441 pg/mL, BUN > 1.67 mmol/L, partial pressure in oxygen (PaO2) ≤69.7 mmHg, and phase angle ≤4.9°. Taken together, these four variables proved to be good predictors for long-term mortality in ADHF (area under the curve [AUC] 0.78, 95% CI 0.72-0.78), thus explaining 60% of all deaths. A multiparametric score based on these variables was determined: each single-unit increase promoted a 2.2-fold augmentation of the risk for death (hazard ratio [HR] 2.2, 95% CI 1.8-2.8, p< .0001). Conclusions. A multiparametric approach based on measurements of BNP, BUN, PaO2, and phase angle is a reliable approach for long-term prediction of mortality risk in patients with ADHF.

Arrhythmic myocarditis in an adolescent male: A unique presentation of multi-organ inflammatory syndrome (MIS-C).

Although children with Covid-19 generally present with mild symptoms or are often asymptomatic, there is increasing recognition of a delayed multi-organ inflammatory syndrome (MIS-C) following SARS-CoV-2 infection. We report the case of MIS-C associated arrhythmic myocarditis which recovered after anti-inflammatory therapy and immunoglobulin infusion.

The PONTE (PDTA FOR INTEGRATED FOLLOW-UP TERRITORY HOSPITAL OF THE PATIENT WITH CARDIAC HEART FAILURE) (BRIDGE) Heart Failure project: increased adherence to guideline-recommended therapies through web-based shared clinical database.

The aim of this study was to evaluate the effects on the adherence of drug prescription to the guideline recommendations of a chronic care model based on the close interaction between hospital and local healthcare district cardiologists through a shared web-based database. From 2018 to 2021, patients hospitalized for an episode of acute decompensated heart failure (HF) (de novo or worsening) in cardiology wards from the healthcare district of Bari, Italy, were enrolled. The follow-up programme was based on a first visit after discharge within 1 month; patients were therefore addressed to the local health district cardiologist outpatient clinics when not requiring further invasive investigations and haemodynamically stable and followed-up with at least one visit every 6 months. In order to share in-hospital patients' data with outpatient clinics, at discharge, they were entered in a web-based database accessible for all cardiologists and centres participating in the Ponte Project. The group of patients affected by HF with reduced ejection fraction (HFrEF) were considered for the analyses. Drug prescription rates at 1-year follow-up were analysed as endpoint, as well as the re-admission for HF worsening. Out of 1200 HF patients enrolled in the project until December 2021, 56% were affected by HFrEF. At 1-year follow-up, 91% of patients were assuming beta-blockers, 86% mineralocorticoid receptor antagonists, 98% angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists/neprilysin angiotensin receptor antagonists, and 13% ARNI. Compared to patients enrolled before 2020, ARNI prescription increased in 2021 (60% vs. 13%, respectively, P < 0.001). In 30% of patients, ARNI were prescribed before hospital discharge. Furthermore, in 10% of the population (most diabetics), sodium-glucose cotransporter 2 inhibitors were also prescribed. The implementation of the PONTE project was associated with an improved adherence to guidelines recommendations.

Optimization of Drug Therapy for Heart Failure With Reduced Ejection Fraction Based on Gender.

PURPOSE OF REVIEW: Over the last decades, several classes of drugs have been introduced for the treatment of patients with heart failure with reduced ejection fraction (HFrEF). Their use has been supported by randomized controlled trials that have demonstrated improved patient outcomes. However, these trials enrolled a small number of female patients and sometimes have reported gender-related differences regarding the efficacy of the treatments. The aim of this review is to revise the available data about the influence of gender on the optimal treatment and drug dose in patients with HFrEF. RECENT FINDINGS: Several gender-related differences in terms of pharmacokinetic and pharmacodynamic characteristics of the drugs have been described. These characteristics could be responsible for a different response and tolerability in men and women also when current recommended treatment of HFrEF is considered. Some studies have shown that, in women, lower doses of beta-blockers and inhibitors of renin angiotensin aldosterone system could be equally effective than higher doses in men, whereas sacubitril/valsartan could exert its favorable effect at greater values of left ventricular ejection fraction. Although there is evidence about differences in the response to treatment of HFrEF in men and women, this has not been sufficient for differentiating current recommended therapy. Further studies should better clarify if the treatment of HFrEF should be based also on the patients' gender.

The Benefit of Sodium-Glucose Co-Transporter Inhibition in Heart Failure: The Role of the Kidney.

In the essential homeostatic role of kidney, two intrarenal mechanisms are prominent: the glomerulotubular balance driving the process of Na+ and water reabsorption in the proximal tubule, and the tubuloglomerular feedback which senses the Na+ concentration in the filtrate by the juxtaglomerular apparatus to provide negative feedback on the glomerular filtration rate. In essence, the two mechanisms regulate renal oxygen consumption. The renal hyperfiltration driven by increased glomerular filtration pressure and by glucose diuresis can affect renal O2 consumption that unleashes detrimental sympathetic activation. The sodium-glucose co-transporters inhibitors (SGLTi) can rebalance the reabsorption of Na+ coupled with glucose and can restore renal O2 demand, diminishing neuroendocrine activation. Large randomized controlled studies performed in diabetic subjects, in heart failure, and in populations with chronic kidney disease with and without diabetes, concordantly address effective action on heart failure exacerbations and renal adverse outcomes.

Recent advances in pharmacological treatment of heart failure.

BACKGROUND: Over the last years, several trials offered new evidence on heart failure (HF) treatment. DESIGN AND RESULTS: For HF with reduced left ventricular ejection fraction, type 2 sodium-glucose cotransporter inhibitors, aside from sacubitril-valsartan, demonstrated extraordinary efficacy in ameliorating patients' prognosis. Some new molecules (eg vericiguat, omecamtiv mecarbil and ferric carboxymaltose) correct iron deficiency and have shown to be capable of furthering reducing the burden of HF hospitalisation. Finally, there is new evidence on the possible therapeutic approaches of HF patients with mid-range or preserved left ventricular ejection fraction. CONCLUSIONS: This review aimed to revise the main novelties in the field of HF therapy and focus on how the daily clinical approach to patient treatment is changing.

Prevalence, clinical impact and costs of hyperkalaemia: Special focus on heart failure.

BACKGROUND: Hyperkalaemia is a potential life-threatening electrolyte abnormality. Although renin-angiotensin-aldosterone system inhibitors (RAASi) are potentially life-saving, they may contribute to hyperkalaemia. METHODS: The prevalence, comorbidities, comedications and 1-year outcomes of patients admitted or treated for hyperkalaemia were investigated in a large healthcare administrative database including 12 533 230 general population inhabitants. A similar analysis was performed in the Italian Network on Heart Failure (IN-HF), a cardiology registry of 1726 acute and 7589 chronic HF patients, stratified by serum potassium. General practice healthcare costs related to hyperkalaemia were also assessed. Hyperkalaemia was defined by hospital coding, potassium-binder prescription or serum levels (mild: 5-5.4, moderate-severe: ≥5.5 mmol/L). RESULTS: In the general population, the prevalence of hyperkalaemia was 0.035%. After excluding patients on haemodialysis, hyperkalaemia in the community (n = 2314) was significantly and directly associated with diabetes, chronic kidney disease, HF, RAASi prescriptions, 1-year hospitalisations and threefold annual healthcare costs, compared to age- and sex-matched non-hyperkalaemic subjects (n = 2314). In the IN-HF registry, hyperkalaemia affected 4.3% of acute and 3.6% of chronic patients and was significantly associated with diabetes, kidney disease and lesser use of RAASi, compared to normokalaemic patients. Among patients hospitalised for acute HF, those with hyperkalaemia at entry had significantly higher 1-year all-cause mortality compared with normokalaemic patients, even after adjustment for available confounders. CONCLUSIONS: Hyperkalaemia in the general population, although uncommon, was associated with increased hospitalisations and tripling of healthcare costs. Among HF patients, hyperkalaemia was common and associated with underuse of RAASi; in acutely decompensated patients, it remained independently associated with 1-year all-cause mortality.