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.

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.

Does the Measurement of Ejection Fraction Still Make Sense in the HFpEF Framework? What Recent Trials Suggest.

Left ventricular ejection fraction (LVEF) is universally accepted as a cardiac systolic function index and it provides intuitive interpretation of cardiac performance. Over the last two decades, it has erroneously become the leading feature used by clinicians to characterize the left ventricular function in heart failure (HF). Notably, LVEF sets the basis for structural and functional HF phenotype classification in current guidelines. However, its diagnostic and prognostic role in patients with preserved or mildly reduced contractile function is less clear. This is related to several concerns due to intrinsic technical, methodological and hemodynamic limitations entailed in LVEF measurement that do not describe the chamber's real contractile performance as expressed by pressure volume loop relationship. In patients with HF and preserved ejection fraction (HFpEF), it does not reflect the effective systolic function because it is prone to preload and afterload variability and it does not account for both longitudinal and torsional contraction. Moreover, a repetitive measurement could be assessed over time to better identify HF progression related to natural evolution of disease and to the treatment response. Current gaps may partially explain the causes of negative or neutral effects of traditional medical agents observed in HFpEF. Nevertheless, recent pooled analysis has evidenced the positive effects of new therapies across the LVEF range, suggesting a potential role irrespective of functional status. Additionally, a more detailed analysis of randomized trials suggests that patients with higher LVEF show a risk reduction strictly related to overall cardiovascular (CV) events; on the other hand, patients experiencing lower LVEF values have a decrease in HF-related events. The current paper reports the main limitations and shortcomings in LVEF assessment, with specific focus on patients affected by HFpEF, and it suggests alternative measurements better reflecting the real hemodynamic status. Future investigations may elucidate whether the development of non-invasive stroke volume and longitudinal function measurements could be extensively applied in clinical trials for better phenotyping and screening of HFpEF patients.

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 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.

[The mechanisms mediating the favorable effects of sodium-glucose cotransporter 2 inhibitors on cardiorenal function]. / I meccanismi d'azione degli inibitori del cotrasportatore sodio-glucosio di tipo 2 ed i loro effetti benefici sull'assetto funzionale di cuore e rene.

In several clinical investigations performed in patients with type 2 diabetes mellitus and in diabetic and non-diabetic patients with heart failure or chronic kidney disease, sodium-glucose cotransporter 2 inhibitors (SGLT2i) proved their benefit on cardiac and renal adverse outcomes. Although there is clear evidence regarding the clinical benefits achieved, the pathophysiological mechanisms underlying their efficacy are still poorly understood. Some favorable mechanisms are likely related to the induced glycosuria and natriuresis. Both have been observed since the early stages of the molecule action and can drive beneficial hemodynamic changes, resulting in a decline of glomerular hyperfiltration and activation of the renin-angiotensin-aldosterone system. In addition to the improvement of cardiocirculatory regimen and renal performance, SGLT2i have an important role in cardio-renal protection by improving the metabolism of cardiomyocytes, carrying out anti-fibrotic and anti-inflammatory action and increasing the expression of cardio-protective adipokines. Further studies are needed to better understand the molecular mechanisms underlying the favorable effects of these drugs in diabetic and non-diabetic patients. The purpose of this review article is to analyze the molecular mechanisms underlying the cardiovascular benefits of SGLT2i in each of the main organs involved in the cardio-renal axis. Furthermore, the manuscript aims to analyze the extent of the beneficial effects of SGLT2i on heart failure in the different populations investigated in the most recent clinical studies.

ANMCO statement on the use of sodium-glucose cotransporter 2 inhibitors in patients with heart failure: a practical guide for a streamlined implementation.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors, dapagliflozin, and empagliflozin, first developed as glucose-lowering agents for the treatment of Type 2 diabetes, have been demonstrated to improve prognosis in patients with heart failure and reduced ejection fraction (HFrEF) regardless of the presence of diabetes. Since these drugs have only recently been included among the four pillars of HFrEF treatment, cardiologists are still unfamiliar with their use in this setting. This article provides an up-to-date practical guide for the initiation and monitoring of patients treated with SGLT2 inhibitors.

Mechanisms of action of SGLT2 inhibitors and their beneficial effects on the cardiorenal axis.

Large clinical studies conducted with sodium-glucose co-transporter 2 inhibitors (SGLT2i) in patients with type 2 diabetes and heart failure with reduced ejection fraction have demonstrated their ability to achieve both cardiac and kidney benefits. Although there is huge evidence on SGLT2i-mediated clinical benefits both in diabetic and non-diabetic patients, the pathophysiological mechanisms underlying their efficacy are still poorly understood. Some favorable mechanisms are likely due to the prompt glycosuric action which is associated with natriuretic effects leading to hemodynamic benefits as well as a reduction in glomerular hyperfiltration and renin-angiotensin-aldosterone system activation. In addition to the renal mechanisms, SGLT2i may play a relevant role in cardiorenal axis protection by improving the cardiomyocyte metabolism, by exerting anti-fibrotic and anti-inflammatory actions, and by increasing cardioprotective adipokine expression. New studies will be needed to better understand the specific molecular mechanisms that mediate the SGLT2i favorable effects in patients suffering diabetes. Our aim is to first discuss about the molecular mechanisms underlying the cardiovascular benefits of SGLT2i in each of the main organs involved in the cardiorenal axis. Furthermore, we update on the most recent clinical trials evaluating the beneficial effects of SGLT2i in treatment of both diabetic and non-diabetic patients suffering heart failure.

Noncardiac comorbidity clustering in heart failure: an overlooked aspect with potential therapeutic door.

Heart failure is associated with a range of comorbidities that have the potential to impair both quality of life and clinical outcome. Unfortunately, noncardiac diseases are underrepresented in large randomized clinical trials, and their management remains poorly understood. In clinical practice, the prevalence of comorbidities in heart failure is high. Although the prognostic impact of comorbidities is well known, their prevalence and impact in specific heart failure settings have been overlooked. Many studies have described specific single noncardiac conditions, but few have examined their overall burden and grading in patients with multiple comorbidities. The risk of comorbidities in patients with heart failure rises with more advanced disease, older age, and increased frailty-three conditions that are poorly represented in clinical trials. The pathogenic links between comorbidities and heart failure involve many pathways and include neurohormonal overdrive, inflammatory activation, oxidative stress, and endothelial dysfunction. Such interactions may worsen prognoses, but details of these relationships are still under investigation. We propose a shift from cardiac-focused care to a more systemic approach that considers all noncardiac diseases and related medications. Some new drugs class such as ARNI or SGLT2 inhibitors could change prognosis by acting directly or indirectly on metabolic disorders and related vascular consequences.

Combining home monitoring temporal trends from implanted defibrillators and baseline patient risk profile to predict heart failure hospitalizations: results from the SELENE HF study.

AIMS: We developed and validated an algorithm for prediction of heart failure (HF) hospitalizations using remote monitoring (RM) data transmitted by implanted defibrillators. METHODS AND RESULTS: The SELENE HF study enrolled 918 patients (median age 69 years, 81% men, median ejection fraction 30%) with cardiac resynchronization therapy (44%), dual-chamber (38%), or single-chamber defibrillators with atrial diagnostics (18%). To develop a predictive algorithm, temporal trends of diurnal and nocturnal heart rates, ventricular extrasystoles, atrial tachyarrhythmia burden, heart rate variability, physical activity, and thoracic impedance obtained by daily automatic RM were combined with a baseline risk-stratifier (Seattle HF Model) into one index. The primary endpoint was the first post-implant adjudicated HF hospitalization. After a median follow-up of 22.5 months since enrolment, patients were randomly allocated to the algorithm derivation group (n = 457; 31 endpoints) or algorithm validation group (n = 461; 29 endpoints). In the derivation group, the index showed a C-statistics of 0.89 [95% confidence interval (CI): 0.83-0.95] with 2.73 odds ratio (CI 1.98-3.78) for first HF hospitalization per unitary increase of index value (P < 0.001). In the validation group, sensitivity of predicting primary endpoint was 65.5% (CI 45.7-82.1%), median alerting time 42 days (interquartile range 21-89), and false (or unexplained) alert rate 0.69 (CI 0.64-0.74) [or 0.63 (CI 0.58-0.68)] per patient-year. Without the baseline risk-stratifier, the sensitivity remained 65.5% and the false/unexplained alert rates increased by ≈10% to 0.76/0.71 per patient-year. CONCLUSION: With the developed algorithm, two-thirds of first post-implant HF hospitalizations could be predicted timely with only 0.7 false alerts per patient-year.

ANMCO POSITION PAPER: on administration of type 2 sodium-glucose co-transporter inhibitors to prevent heart failure in diabetic patients and to treat heart failure patients with and without diabetes.

This ANMCO (Associazione Nazionale Medici Cardiologi Ospedalieri) position paper aims to analyse the complex action of sodium-glucose co-transporter 2 inhibitors at the level of the kidney and cardiovascular system, focusing on the effect that these molecules have shown in the prevention and treatment of heart failure in diabetic and non-diabetic subjects. The goal was pursued by comparing the data generated with pathophysiology studies and with multicentre controlled studies in large populations. In accordance with the analysis carried out in the document, the following recommendations are issued: (i) canagliflozin, dapagliflozin, empagliflozin, and ertugliflozin are molecules recommended for the prevention of heart failure hospitalizations in type 2 diabetic subjects; (ii) canagliflozin and dapagliflozin are recommended for the prevention of heart failure hospitalizations in type 2 diabetic subjects with severe chronic kidney disease, dapagliflozin proved to be safe and effective also in diabetic subjects; and (iii) dapagliflozin and empagliflozin are recommended to reduce the combined risk of heart failure and cardiovascular death in diabetic and non-diabetic subjects with heart failure and reduced ejection fraction.

[ANMCO Position paper: Sodium-glucose co-transporter 2 inhibitors for the prevention of heart failure in diabetic patients and for the treatment of heart failure patients with and without diabetes]. / Position paper ANMCO: L'impiego degli inibitori del co-trasportatore sodio-glucosio di tipo 2 nella prevenzione e cura dell'insufficienza cardiaca nei soggetti diabetici e nei portatori di insufficienza cardiaca, diabetici e non diabetici.

This ANMCO position paper aims to analyze the complex action of sodium-glucose co-transporter 2 inhibitors at the level of the kidney and cardiovascular system, focusing on the effect that these molecules have shown in the prevention and treatment of heart failure in diabetic and non-diabetic subjects. The goal was pursued by comparing the data generated with pathophysiology studies and with multicenter controlled studies in large populations. In accordance with the analysis carried out in the document, the following recommendations are issued: (i) canagliflozin, dapagliflozin, empagliflozin and ertugliflozin are molecules recommended for the prevention of heart failure hospitalizations in type 2 diabetic subjects; (ii) canagliflozin and dapagliflozin are recommended for the prevention of heart failure hospitalizations in type 2 diabetic subjects with severe chronic kidney disease, dapagliflozin proved to be safe and effective also in diabetic subjects; and (iii) dapagliflozin and empagliflozin are recommended to reduce the combined risk of heart failure and cardiovascular death in diabetic and non-diabetic subjects with heart failure and reduced ejection fraction.

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.

Thromboembolic Complications in Covid-19: From Clinical Scenario to Laboratory Evidence.

SARS-Cov-2 infection, a pandemic disease since March 2020, is associated with a high percentage of cardiovascular complications mainly of a thromboembolic (TE) nature. Although clinical patterns have been described for the assessment of patients with increased risk, many TE complications occur in patients with apparently moderate risk. Notably, a recent statement from the European Society of Cardiology (ESC) atherosclerosis and vascular biology working group pointed out the key role of vascular endothelium for the recruitment of inflammatory and thrombotic pathways responsible for both disseminated intravascular coagulation and cardiovascular complications. Therefore, a better understanding of the pathophysiological process linking infection to increased TE risk is needed in order to understand the pathways of this dangerous liaison and possibly interrupt it with appropriate treatment. In this review, we describe the histological lesions and the related blood coagulation mechanisms involved in COVID-19, we define the laboratory parameters and clinical risk factors associated with TE events, and propose a prophylactic anticoagulation treatment in relation to the risk category. Finally, we highlight the concept that a solid risk assessment based on prospective multi-center data would be the challenge for a more precise risk stratification and more appropriate treatment.

[Sodium-glucose co-transporter 2 inhibitors: mechanisms of renal action. Implications for diabetes and heart failure]. / Inibitori del co-trasportatore sodio-glucosio di tipo 2: meccanismi d'azione renale. Le implicazioni nel diabete e nello scompenso cardiaco.

The liver is not the exclusive site of glucose production in humans in the post-absorption state. Experimental data showed that the kidney is able of carrying out gluconeogenesis. Renal glucose production accounts for 20% of systemic glucose production. Evidence indicates that the kidney is able to reabsorb glucose from the glomerular filtrate through the sodium-glucose co-transporters (SGLT) 1 and 2 placed under the Bowman's capsule, in the thick portion of the proximal convoluted tubule, preserving this essential energy substrate for the organism. The maximal renal glucose reabsorption capacity (TmG), as well as the threshold for the spillover of glucose in the urine, are higher in diabetics than normal subjects and contribute to the hyperglycemic state in the absence of glycosuria. The administration of SGLT2 inhibitors in diabetics improves the excretion of sodium and glucose, reducing the threshold of glycosuria and TmG. This also restores the sodium concentration in the filtrate that reaches the macula densa (juxtaglomerular apparatus), which signals the appropriate perfusion of the kidney, defusing the secretion of renin and the activation of the neurohormonal axis that leads to the production of angiotensin II.Large clinical trials conducted with SGLT2 inhibitors in subjects with type 2 diabetes mellitus have demonstrated the great ability of this new class of drugs to achieve cardiac and renal benefits. All studies have shown SGLT2 inhibitors reduce the risk of hospitalizations for heart failure and the progression of kidney damage. A part of the favorable mechanisms is mediated by the natriuretic effect that is associated with the glycosuric effect, which reduces the activation of the renin-angiotensin-aldosterone system together with glomerular hyperfiltration.The aim of this review is to expand the knowledge among general cardiologists on the role of SGLT2 and SGLT1 in renal glucose homeostasis in healthy and diabetic subjects in the light of a potent class of drugs counteracting heart failure.

Glucose Metabolism in the Kidney: Neurohormonal Activation and Heart Failure Development.

The liver is not the exclusive site of glucose production in humans in the postabsorptive state. Robust data support that the kidney is capable of gluconeogenesis and studies have demonstrated that renal glucose production can increase systemic glucose production. The kidney has a role in maintaining glucose body balance, not only as an organ for gluconeogenesis but by using glucose as a metabolic substrate. The kidneys reabsorb filtered glucose through the sodium-glucose cotransporters sodium-glucose cotransporter (SGLT) 1 and SGLT2, which are localized on the brush border membrane of the early proximal tubule with immune detection of their expression in the tubularized Bowman capsule. In patients with diabetes mellitus, the renal maximum glucose reabsorptive capacity, and the threshold for glucose passage into the urine, are higher and contribute to the hyperglycemic state. The administration of SGLT2 inhibitors to patients with diabetes mellitus enhances sodium and glucose excretion, leading to a reduction of the glycosuria threshold and tubular maximal transport of glucose. The net effects of SGLT2 inhibition are to drive a reduction in plasma glucose levels, improving insulin secretion and sensitivity. The benefit of SGLT2 inhibitors goes beyond glycemic control, since inhibition of renal glucose reabsorption affects blood pressure and improves the hemodynamic profile and the tubule glomerular feedback. This action acts to rebalance the dense macula response by restoring adenosine production and restraining renin-angiotensin-aldosterone activation. By improving renal and cardiovascular function, we explain the impressive reduction in adverse outcomes associated with heart failure supporting the current clinical perspective.