Dapagliflozin effects on lung fluid volumes in patients with heart failure and reduced ejection fraction: Results from the DEFINE-HF trial

Current Role of SLGT2 Inhibitors in the Management of the Whole Spectrum of Heart Failure: Focus on Dapagliflozin

Heart failure (HF) is associated with a high morbidity and mortality burden. In light of more recent evidence, SGLT2 inhibitors are currently recommended as first-line therapy in managing patients with HF, regardless of ejection fraction, to reduce HF burden. The DAPA-HF and DELIVER trials, and particularly, the pooled analysis of both studies, have shown that dapagliflozin significantly reduces the risk of cardiovascular death, all-cause death, total HF hospitalizations, and MACE in the whole spectrum of HF, with sustained benefits over time. Recent data have shown that the full implementation of dapagliflozin in clinical practice would translate into a robust reduction in hospitalizations for HF and death in real-life populations. Many pathophysiological mechanisms have been involved in these benefits, particularly the positive effects of dapagliflozin on reversing cardiac (atrial and ventricular) remodeling, reducing cardiac fibrosis and inflammation, and improving endothelial dysfunction. In this manuscript, we reviewed from a practical point of view the role of dapagliflozin in the management of the whole spectrum of patients with HF.

Lack of durable natriuresis and objective decongestion following SGLT2 inhibition in randomized controlled trials of patients with heart failure

Patients with heart failure have increased cardiac filling pressures, circulating natriuretic peptides, and physical signs of fluid retention, which are related to sodium retention by the kidneys and are alleviated by conventional diuretics. Sodium-glucose cotransporter 2 (SGLT2) inhibitors interfere with sodium and glucose reabsorption in the proximal renal tubule, but they evoke a marked counterregulatory activation of sodium and water reabsorption in distal nephron segments, which opposes and negates any diuretic effect. Nevertheless, it has been postulated that SGLT2 inhibitors modulate the volume set point, leading selectively to decongestion in patients with fluid overload. This hypothesis was tested in a review of 15 randomized controlled trials of SGLT2 inhibitors in patients with heart failure, with 7 trials focusing on urinary volume within the first week, and 8 trials focusing on objective decongestion at 12 weeks. In trials < 1 week, SGLT2 inhibition increased urine volume in the first 24 h, but typically without a change in urinary sodium excretion, and this diuresis was not sustained. In 8 trials of 12 weeks' duration, none reported alleviation of edema, ascites or pulmonary rales. The 2 trials that evaluated changes in left ventricular filling pressure noted no or small changes (1-2 mm Hg); the two trials that measured interstitial lung water or total blood volume found no effect; and 6 of the 7 trials found no decrease in circulating natriuretic peptides. Therefore, randomized controlled trials do not indicate that SGLT2 inhibitors produce a durable natriuresis or objective decongestion in patients with heart failure.

Clinical implications of remote dielectric sensing system to estimate lung fluid levels

The reduction of pulmonary congestion is an essential clinical target in the management of chronic heart failure. This proves to be challenging given the lack of a gold standard method to quantify the degree of pulmonary congestion both quickly and non-invasively. Remote dielectric sensing (ReDS) is a non-invasive electromagnetic energy-based technology to quantify lung fluid levels as a percentage within minutes. This technique, due to its high negative predictive value, may be a useful tool particularly to rule out primarily cardiac causes of dyspnea in ambulatory patients when the values are normal. Further studies are warranted to establish ReDS-guided management of congestive heart failure patients.

A new role for an old drug: acetazolamide in decompensated heart failure

INTRODUCTION

Mortality from heart failure remains high. Many subjects who have been hospitalized with acute decompensated heart failure leave hospital with residual congestion, despite treatment with loop diuretics. In an attempt to improve this, the Acetazolamide in Decompensated heart failure with Volume OveRload (ADVOR) trial was undertaken, where acetazolamide was added to the loop diuretic bumetanide.

AREAS COVERED

This article discusses ADVOR. The primary endpoint of ADVOR was the reversal of congestion, which was increased by adding acetazolamide to bumetanide. However, acetazolamide did not shorten hospital stay or the composite of rehospitalisation and death after three months.

EXPERT OPINION

The limitations of ADVOR include that acetazolamide did not improve quality of life and that the testing was in white subjects only. During the hospital stay for decompensation, medicines that inhibit the angiotensin and mineralocorticoid systems were increased, which suggests that the treatment for heart failure was not ideal on hospitalization. As the death rates in ADVOR were lower than in previous studies, this suggests that the overall treatment of decompensated/heart failure is improving. However, in the author's opinion, although the addition of acetazolamide is a small improvement in the treatment of acute decompensated heart failure with volume overload, more options need to be considered.

Ketones: the double-edged sword of SGLT2 inhibitors?

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of medications used by individuals with type 2 diabetes that reduce hyperglycaemia by targeting glucose transport in the kidney, preventing its reabsorption, thereby inducing glucosuria. Besides improving HbA_1c and reducing body weight and blood pressure, the SGLT2 inhibitors have also been demonstrated to improve cardiovascular and kidney outcomes, an effect largely independent of their effect on blood glucose levels. Indeed, the mechanisms underlying these benefits remain elusive. Treatment with SGLT2 inhibitors has been found to modestly increase systemic ketone levels. Ketone bodies are an ancillary fuel source substituting for glucose in some tissues and may also possess intrinsic anti-oxidative and anti-inflammatory effects. Some have proposed that ketones may in fact mediate the cardio-renal benefits of this drug category. However, a rare complication of SGLT2 inhibition is ketoacidosis, sometimes with normal or near-normal blood glucose concentrations, albeit occurring more frequently in patients with type 1 diabetes who are treated (predominately off-label) with one of these agents. We herein explore the notion that an underpinning of one of the more serious adverse effects of SGLT2 inhibitors may, in fact, explain, at least in part, some of their benefits-a potential 'double-edged sword' of this novel drug category.

The current role of sodium-glucose cotransporter 2 inhibitors in type 2 diabetes mellitus management

Type 2 diabetes mellitus (T2DM) is a chronic, complex metabolic disease characterized by chronic hyperglycemia causing from insufficient insulin signaling because of insulin resistance or defective insulin secretion, and may induce severe complications and premature death. Sodium-glucose cotransporter-2 (SGLT2) inhibitors are oral drugs used to reduce hyperglycemia in patients with T2DM, including empagliflozin, ertugliflozin, dapagliflozin and canagliflozin. The primary objective of this article is to examine the clinical benefit, safety, and tolerability of the four SGLT2 inhibitors approved by the US FDA. SGLT2 inhibitors increase urinary glucose excretion via inhibiting SGLT2 to decrease renal reabsorption of filtered glucose and reduce the renal threshold for glucose. Rather than stimulating insulin release, SGLT2 inhibitors improve β-cell function by improving glucotoxicity, as well as reduce insulin resistance and increase insulin sensitivity. Early clinical trials have confirmed the beneficial effects of SGLT2 in T2DM with acceptable safety and excellent tolerability. In recent years, SGLT2 inhibitors has been successively approved by the FDA to decrease cardiovascular death and decrease the risk of stroke and cardiac attack in T2DM adults who have been diagnosed with cardiovascular disease, treating heart failure (HF) with reduced ejection fraction and HF with preserved ejection fraction, and treat diabetic kidney disease (DKD), decrease the risk of hospitalization for HF in T2DM and DKD patients. SGLT2 inhibitors are expected to be an effective treatment for T2DM patients with non alcoholic fatty liver disease. SGLT2 inhibitors have a similar safety profile to placebo or other active control groups, with major adverse events such as Ketoacidosis or hypotension and genital or urinary tract infections.

Sodium Glucose Cotransporter-2 Inhibitors: Spotlight on Favorable Effects on Clinical Outcomes beyond Diabetes

Sodium glucose transporter type 2 (SGLT2) molecules are found in proximal tubules of the kidney, and perhaps in the brain or intestine, but rarely in any other tissue. However, their inhibitors, intended to improve diabetes compensation, have many more beneficial effects. They improve kidney and cardiovascular outcomes and decrease mortality. These benefits are not limited to diabetics but were also found in non-diabetic individuals. The pathophysiological pathways underlying the treatment success have been investigated in both clinical and experimental studies. There have been numerous excellent reviews, but these were mostly restricted to limited aspects of the knowledge. The aim of this review is to summarize the known experimental and clinical evidence of SGLT2 inhibitors' effects on individual organs (kidney, heart, liver, etc.), as well as the systemic changes that lead to an improvement in clinical outcomes.

Sacubitril/valsartan, sodium‐glucose cotransporter 2 inhibitors, and vericiguat for congestive heart failure therapy

Heart failure is associated with notable morbidity and mortality, and therefore, novel therapies are needed. This minireview focused on the effects and mechanisms of action of sacubitril/valsartan, sodium‐glucose cotransporter 2 inhibitors and vericiguat in heart failure patients. A systematic review of the current literature was conducted. Seventeen randomised clinical trials regarding the effects of these drug classes were included. The mechanism of action of each treatment could improve pathophysiological imbalances present in heart failure. All three drug classes revealed a reduction in hospitalisations for heart failure or death from cardiovascular causes in patients with reduced ejection fraction. Sacubitril/valsartan also reduced hospitalisations and death from cardiovascular causes in patients with mid‐range ejection fraction, but not in patients with preserved ejection fraction. The sodium‐glucose cotransporter 2 inhibitors, sotagliflozin and empagliflozin, reduced hospitalisations and death from cardiovascular causes in heart failure patients with preserved ejection fraction. None of the three drug classes was associated with a higher prevalence of treatment discontinuation due to increases in adverse effects in large‐scale randomised clinical trials compared with placebo. Further studies are required to clarify the extent of effects of these medications in different subpopulations—especially in patients with mid‐range and preserved ejection fraction.

Understanding the protective effects of SGLT2 inhibitors in type 2 diabetes patients with chronic kidney disease

INTRODUCTION

Sodium-glucose co-transporter type 2 inhibitors (SGLT2is) were developed as glucose-lowering agents for the management of type 2 diabetes (T2D). Unexpectedly, they showed a significant reduction in hospitalization for heart failure and hard renal outcomes in patients with and without T2D. Underlying mechanisms remain a matter of debate.

AREAS COVERED

We summarize the protective renal effects of SGLT2is in patients with cardiovascular disease, chronic kidney disease (CKD, especially with albuminuria) or heart failure; a description of the safety of SGLT2is, with a special focus on the risk/benefit balance in people with stage 3 CKD; a comprehensive discussion of mechanisms that could explain nephro-protection; a reappraisal of the positioning of SGLT2is in recent international guidelines.

EXPERT OPINION

Several mechanisms could contribute to improved renal prognosis with SGLT2is, among which a reduction in intraglomerular pressure by restoring the tubuloglomerular feedback, a diuretic effect that contributes to lower albuminuria and renal decongestion, especially if fluid overload is present, a reduction in renal oxygen consumption, an improvement of heart failure status with less cardiorenal syndrome and a lower risk of acute renal injury. All these effects may be mutually not exclusive, and their respective contribution may differ according to patient characteristics.

Acute renal injury events in diabetic patients treated with SGLT2 inhibitors: A comprehensive review with a special reference to RAAS blockers

Renin-angiotensin-aldosterone system (RAAS) blockers and sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are two pharmacological classes that proved a remarkable nephroprotective effect, yet a risk of acute kidney injury (AKI) was also pointed out. In 2016, the US Food and Drug Administration recommended caution with the concomitant use of these medications. While the literature devoted to RAAS blockers remained surprisingly limited, numerous articles were published in recent years with SGLT2is. Safety analyses of large prospective cardiorenal trials showed a reduced rather than an increased number of AKI events in patients with type 2 diabetes treated with SGLT2is compared with those treated with placebo, despite the fact that a majority of patients received RAAS blockers at baseline. Interestingly, retrospective observational studies confirmed these reassuring findings in real-life conditions in more heterogeneous and possibly more frailty populations also commonly treated with RAAS blockers by showing a reduced risk of AKI with SGLT2is compared with other glucose-lowering drugs. Currently, there are no evidence of an increased risk of AKI with RAAS blocker-SGLT2i combinations in absence of haemodynamic instability. Several underlying mechanisms could explain a decreased rather than an increased risk of AKI with SGLT2is, including in patients treated with RAAS blockers.

Intersection Between Diabetes and Heart Failure: Is SGLT2i the "One Stone for Two Birds" Approach?

Purpose of Review

Diabetes mellitus (DM) is a major comorbidity of heart failure (HF). Comparing the similarities and differences in disease characteristics and treatment between the HF patients with and without DM, this review was to investigate whether and how the novel class of sodium-glucose transport protein 2 inhibitors (SGLT2i) would benefit both populations.

Recent Findings

Despite the obviously different clinical profiles, patients of HF with reduced ejection fraction (HFrEF) should be treated the same with guideline directed medical therapy, irrespective of DM status. Upon the mounting evidence that supported its use in diabetic patients at high risk of HF, recent large clinical trials demonstrated that SGLT2i could further reduce HF hospitalization or cardiovascular mortality and improve quality of life in diabetic and non-diabetic HFrEF patients who were optimally managed.

Summary

SGLT2i expands the foundation of HFrEF therapy. Whether it is equally effective in HF with preserved ejection fraction awaits more evidence.

Dapagliflozin Mediates Plin5/PPARα Signaling Axis to Attenuate Cardiac Hypertrophy

Objective: The purpose of this study was to investigate the effect of dapagliflozin (DAPA), a sodium-glucose cotransporter 2 inhibitor, on relieving cardiac hypertrophy and its potential molecular mechanism.

Methods: Cardiac hypertrophy induced by abdominal aortic constriction (AAC) in mice, dapagliflozin were administered in the drinking water at a dose of 25 mg/kg/d for 12 weeks was observed. Echocardiography was used to detect the changes of cardiac function, including LVEF, LVFS, LVEDd, LVEDs, HR and LV mass. Histological morphological changes were evaluated by Masson trichrome staining and wheat germ agglutinin (WGA) staining. The enrichment of differential genes and signal pathways after treatment was analyzed by gene microarray cardiomyocyte hypertrophy was induced by AngII (2 μM) and the protective effect of dapagliflozin (1 μM) was observed in vitro. The morphological changes of myocardial cells were detected by cTnI immunofluorescence staining. ELISA and qRT-PCR assays were performed to detect the expressions levels of cardiac hypertrophy related molecules.

Results: After 12 weeks of treatment, DAPA significantly ameliorated cardiac function and inhibited cardiac hypertrophy in AAC-induced mice. In vitro, DAPA significantly inhibited abnormal hypertrophy in AngII-induced cardiacmyocytes. Both in vivo and in vitro experiments have confirmed that DAPA could mediate the Plin5/PPARα signaling axis to play a protective role in inhibiting cardiac hypertrophy.

Conclusion: Dapagliflozin activated the Plin5/PPARα signaling axis and exerts a protective effect against cardiac hypertrophy.

The diuretic effects of SGLT2 inhibitors: A comprehensive review of their specificities and their role in renal protection

Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are new oral glucose-lowering agents that provide cardiovascular and renal protection in both patients with and without type 2 diabetes. Because of their unique mechanism of action, increased glucosuria is associated with osmotic diuresis and some natriuresis, yet the latter seems mostly transient. The potential role of the diuretic effect in overall cardiovascular and renal protection by SGLT2is remains a matter of debate. Precise evaluation of the diuretic effect is not so easy and most studies relied upon indirect estimations that led to divergent results, presumably also explained by different study designs and population characteristics. Everybody agrees upon the fact that SGLT2is are different from other classical diuretics (thiazides and loop diuretics) as they present some favourable properties, i.e. reduced sympathetic activity, preserved potassium balance, lower risk of acute renal injury, decrease of serum uric acid level. The potential role of the diuretic effect of SGLT2is on renal outcomes is still unclear, yet their ability to reduce albuminuria and dampen the risk of heart failure may contribute to improve renal prognosis besides other complex underlying mechanisms. In this comprehensive review we first critically analyse the results obtained with indirect methods that assess a diuretic effect of SGLT2is, second we describe the specificities of the diuretic activity of SGLT2is compared with other classical diuretics, and third we discuss the potential mechanisms by which the diuretic effect of SGLT2is could contribute to the improvement of renal outcomes consistently reported with this innovative amazing pharmacological class.