Relationship of Dapagliflozin With Serum Sodium: Findings From the DAPA-HF Trial

Evaluation and Management of Hyponatremia in Heart Failure

PURPOSE OF REVIEW

To provide a contemporary overview of the pathophysiology, evaluation, and treatment of hyponatremia in heart failure (HF).

RECENT FINDINGS

Potassium and magnesium losses due to poor nutritional intake and treatment with diuretics cause an intracellular sodium shift in HF that may contribute to hyponatremia. Impaired renal blood flow leading to a lower glomerular filtration rate and increased proximal tubular reabsorption lead to an impaired tubular flux through diluting distal segments of the nephron, compromising electrolyte-free water excretion. Hyponatremia in HF is typically a condition of impaired water excretion by the kidneys on a background of potassium and magnesium depletion. While those cations can and should be easily repleted, further treatment should mainly focus on improving the underlying HF and hemodynamics, while addressing congestion. For decongestive treatment, proximally acting diuretics such as sodium-glucose co-transporter-2 inhibitors, acetazolamide, and loop diuretics are the preferred options.

Chronic heart failure with reduced EF: A decade of major pharmacological innovations

BACKGROUND AND OBJECTIVES

Because of its severity, prevalence, and medical economic importance, heart failure is a chronic disease that is the subject of intense medical research. The aim of this article was to review the therapeutic innovations of the last decade that have been incorporated into the latest international recommendations for the treatment of heart failure.

METHOD

Review of literature and current guidelines.

CONCLUSION

The results of the clinical trials reviewed here represent major advances that will have a significant impact on quality of life, survival, rehospitalisation and, for certain treatments, a beneficial joint effect on commonly associated comorbidities such as diabetes and chronic renal failure.

Similarities and distinctions between acetazolamide and sodium-glucose cotransporter 2 inhibitors in patients with acute heart failure: Key insights into ADVOR and EMPULSE

Both acetazolamide and sodium-glucose cotransporter 2 (SGLT2) inhibitors block sodium reabsorption in the proximal renal tubule primarily through inhibition of sodium-hydrogen exchanger isoform 3 (NHE3), but neither SGLT2 inhibitors nor acetazolamide produce a sustained natriuresis due to compensatory upregulation of sodium reabsorption at distal nephron sites. Nevertheless, acetazolamide and SGLT2 inhibitors have been used as adjunctive therapy to loop diuretics in states where NHE3 is upregulated, e.g. acute heart failure. Two randomized controlled trials have been carried out with acetazolamide in acute heart failure (DIURESIS-CHF and ADVOR). In ADVOR, acetazolamide improved physical signs of fluid retention, but this finding could not be explained by the modest observed diuretic effect. Acetazolamide did not produce a natriuresis in the DIURESIS-CHF trial, and in ADVOR, immediate effects on symptoms and body weight were not reported, and the drug had no effect on morbidity or mortality after 90 days. Three randomized controlled trials have been carried out with empagliflozin (EMPAG-HF, EMPA-RESPONSE-AHF and EMPULSE) in acute heart failure. The EMPULSE trial did not report effects on diuresis or in changes in physical signs of congestion during the first week of treatment, but in EMPAG-HF and EMPA-RESPONSE-AHF, empagliflozin had no effect of dyspnoea, urinary sodium excretion or body weight during the first 4 days. In the EMPULSE trial, empagliflozin improved health status at 15 days and reduced the risk of worsening heart failure events at 90 days, but these effects are similar in magnitude and time course to the early statistical significance on the risk of heart failure hospitalizations achieved within 14-30 days in the major trials of SGLT2 inhibitors in patients with chronic heart failure. Neurohormonal inhibitors produce this early effect in the absence of a diuresis. Additionally, in numerous randomized controlled trials, in-hospital diuretic intensification has not reduced the risk of major heart failure events, even when treatment is sustained. These findings, taken collectively, suggest that any immediate diuretic effects of acetazolamide and SGLT2 inhibitors in acute heart failure are not likely to influence the short- or long-term clinical course of patients.

Critical Analysis of the Effects of SGLT2 Inhibitors on Renal Tubular Sodium, Water and Chloride Homeostasis and Their Role in Influencing Heart Failure Outcomes

SGLT2 (sodium-glucose cotransporter 2) inhibitors interfere with the reabsorption of glucose and sodium in the early proximal renal tubule, but the magnitude and duration of any ensuing natriuretic or diuretic effect are the result of an interplay between the degree of upregulation of SGLT2 and sodium-hydrogen exchanger 3, the extent to which downstream compensatory tubular mechanisms are activated, and (potentially) the volume set point in individual patients. A comprehensive review and synthesis of available studies reveals several renal response patterns with substantial variation across studies and clinical settings. However, the common observation is an absence of a large acute or chronic diuresis or natriuresis with these agents, either when given alone or combined with other diuretics. This limited response results from the fact that renal compensation to these drugs is rapid and nearly complete within a few days or weeks, preventing progressive volume losses. Nevertheless, the finding that fractional excretion of glucose and lithium (the latter being a marker of proximal sodium reabsorption) persists during long-term treatment with SGLT2 inhibitors indicates that pharmacological tolerance to the effects of these drugs at the level of the proximal tubule does not meaningfully occur. This persistent proximal tubular effect of SGLT2 inhibitors can be hypothesized to produce a durable improvement in the internal set point for volume homeostasis, which may become clinically important during times of fluid expansion. However, it is difficult to know whether a treatment-related change in the volume set point actually occurs or contributes to the effect of these drugs to reduce the risk of major heart failure events. SGLT2 inhibitors exert cardioprotective effects by a direct effect on cardiomyocytes that is independent of the presence of or binding to SGLT2 or the actions of these drugs on the proximal renal tubule. Nevertheless, changes in the volume set point mediated by SGLT2 inhibitors might potentially act cooperatively with the direct favorable molecular and cellular effects of these drugs on cardiomyocytes to mediate their benefits on the development and clinical course of heart failure.

A profile of SGLT-2 inhibitors in hyponatremia: The evidence to date

Hyponatremia is the most common electrolyte disorder in clinical practice, which may lead to life-threatening complications. Several lines of evidence suggest that hyponatremia is associated not only with significant increases in length of stay, cost, and financial burden, but also with increased morbidity and mortality. Hyponatremia is also considered to be a negative prognostic factor in patients with heart failure and cancer. Although multiple therapeutic methods are available for treating hyponatremia, most have some limitations, such as poor compliance, rapid correction of serum Na⁺, other negative side effects and high cost. Given these limitations, identifying novel therapies for hyponatremia is essential. Recent clinical studies have shown that SGLT-2 inhibitors (SGLT 2i) significantly increased serum Na⁺ levels and were well tolerated by patients who underwent this treatment. Therefore, oral administration of SGLT 2i appears to be an effective treatment for hyponatremia. This article will briefly review the etiology of hyponatremia and integrated control of sodium within the kidney, current therapies for hyponatremia, potential mechanisms and efficacy of SGLT 2i for hyponatremia, and the benefits in cardiovascular, cancer, and kidney disease by regulating sodium and water balance.

Diabetic Ketoacidosis Management: Updates and Challenges for Specific Patient Population

Diabetic ketoacidosis (DKA) is the most common hyperglycemic emergency and causes the greatest risk for death that could be prevented in patients with diabetes mellitus. DKA occurs more commonly among patients with type-1 diabetes with a thirty percent of the cases take place in patients with type 2 diabetes. DKA is characterized by sever hyperglycemia, metabolic acidosis and ketosis. Proper management of DKA requires hospitalization for aggressive replacement and monitoring of fluids, electrolytes and insulin therapy. Management of DKA has been updated with guidelines, to help standardize care, and reduce mortality and morbidity. The major precipitating factors for DKA include new diagnosis of diabetes, non-adherence to insulin therapy as well as infection in patients with diabetes. Discharge plans should include appropriate selection of insulin dosing and regimens as well as patient education to prevent recurrence of DKA. Further, definition and management of euglycemic DKA in patients prescribed sodium-glucose co-transporter 2 inhibitors are discussed. Special consideration is reviewed for specific patient population including pregnancy, renal replacement, acute pancreatitis, and insulin pump users as well as patients with COVID-19.

Role of Sodium-Glucose Co-Transporter 2 Inhibitors in the Regulation of Inflammatory Processes in Animal Models

Sodium-glucose co-transporter 2 inhibitors, also known as gliflozins, were developed as a novel class of anti-diabetic agents that promote glycosuria through the prevention of glucose reabsorption in the proximal tubule by sodium-glucose co-transporter 2. Beyond the regulation of glucose homeostasis, they resulted as being effective in different clinical trials in patients with heart failure, showing a strong cardio-renal protective effect in diabetic, but also in non-diabetic patients, which highlights the possible existence of other mechanisms through which gliflozins could be exerting their action. So far, different gliflozins have been approved for their therapeutic use in T2DM, heart failure, and diabetic kidney disease in different countries, all of them being diseases that have in common a deregulation of the inflammatory process associated with the pathology, which perpetuates and worsens the disease. This inflammatory deregulation has been observed in many other diseases, which led the scientific community to have a growing interest in the understanding of the biological processes that lead to or control inflammation deregulation in order to be able to identify potential therapeutic targets that could revert this situation and contribute to the amelioration of the disease. In this line, recent studies showed that gliflozins also act as an anti-inflammatory drug, and have been proposed as a useful strategy to treat other diseases linked to inflammation in addition to cardio-renal diseases, such as diabetes, obesity, atherosclerosis, or non-alcoholic fatty liver disease. In this work, we will review recent studies regarding the role of the main sodium-glucose co-transporter 2 inhibitors in the control of inflammation.