Why do SGLT2 inhibitors reduce heart failure hospitalization? A differential volume regulation hypothesis

SGLT2i: beyond the glucose-lowering effect

Sodium/glucose cotransporter-2 inhibitors (SGLT2i) are a new type of glucose-lowering drug that can reduce blood glucose by inhibiting its reabsorption in proximal tubules and by promoting urinary glucose excretion. SGLT2i are widely used in the clinical treatment of type 2 diabetes mellitus (T2DM). In recent studies, SGLT2i were found to not only reduce blood glucose but also protect the heart and kidney, which can significantly reduce cardiovascular events, delay the progression of renal failure, greatly improve the quality of life of patients, and reduce medical expenses for families and society. As adverse cardiac and renal events are the most common and serious complications of T2DM, it is very important to understand the cardio- and renoprotective mechanisms of SGLT2i. This article reviews the historical development, pharmacological mechanism, heart and kidney protection and safety of SGLT2i. The information presented provides a theoretical basis for the clinical prevention and treatment of diabetes and its complications and for the development of new glucose-lowering drugs.

A novel strategy to reduce the readmission rates in congestive heart failure: intermittent empirical intravenous diuretics

Improvements in the medical management of heart failure have changed the course of the disease. However, mortality rates, hospitalization rates, and treatment costs are not at desired levels. Diuretics have been widely used in the treatment of congestion in heart failure patients. The following case reports represent a special patient group treated and followed by cardiology clinic. Treatment approach of each case report has been tailored on an individual basis depending on the clinical course and hospitalization rates of patients. Authors have highlighted and discussed the common aspects and future perspectives of their cases in which post-discharge intermittent empirical intravenous diuretic administration dramatically improved the clinical status and readmission number due to decompensated congestive heart failure. This is a relatively new and promising approach, which has been thought to cease the recycle of diuretic resistance and silent increase of fluid congestion in patients with congestive heart failure and frequent hospitalization.

[Advantages of therapy with sodium glucose cotransporter type 2 inhibitors in patients with type 2 diabetes mellitus in combination with hyperuricemia and gout]

Currently, only two drugs for reducing uric acid (UA), allopurinol and febuxostat, are registered in the Russian Federation, but their use does not allow to achieve the target level of UA in all cases. According to the results of numerous randomized trials, hyperuricemia and gout are associated with the corresponding components of the metabolic syndrome, including diabetes mellitus. The influence of factors is due to the need to search for new drugs that have a complex effect on several components of metabolic syndrome at once. Potentially attractive in this regard is a new group of drugs for the treatment of type 2 diabetes mellitus inhibitors of the sodium-glucose cotransporter of type 2, which, in addition to the main hypoglycemic actions, showed positive effects on the cardiovascular system, kidneys, as well as lowering UA.

Mechanisms of Cardiovascular Benefits of Sodium Glucose Co-Transporter 2 (SGLT2) Inhibitors: A State-of-the-Art Review

Recent clinical trials have shown that sodium glucose co-transport 2 (SGLT2) inhibitors have dramatic beneficial cardiovascular outcomes. These include a reduced incidence of cardiovascular death and heart failure hospitalization in people with and without diabetes, and those with and without prevalent heart failure. The actual mechanism(s) responsible for these beneficial effects are not completely clear. Several potential theses have been proposed to explain the cardioprotective effects of SGLT2 inhibition, which include diuresis/natriuresis, blood pressure reduction, erythropoiesis, improved cardiac energy metabolism, inflammation reduction, inhibition of the sympathetic nervous system, prevention of adverse cardiac remodeling, prevention of ischemia/reperfusion injury, inhibition of the Na+/H+-exchanger, inhibition of SGLT1, reduction in hyperuricemia, increasing autophagy and lysosomal degradation, decreasing epicardial fat mass, increasing erythropoietin levels, increasing circulating pro-vascular progenitor cells, decreasing oxidative stress, and improving vascular function. The strengths and weaknesses of these proposed mechanisms are reviewed in an effort to try to synthesize and prioritize the mechanisms as they relate to clinical event reduction.

Different effects of SGLT2 inhibitors according to the presence and types of heart failure in type 2 diabetic patients

Background

The effects of sodium-glucose cotransporter 2 inhibitor (SGLT2i) on cardiac function are not fully understood. We investigated the changes in cardiac function in diabetic patients according to the presence and types of heart failure (HF).

Methods

We retrospectively identified 202 diabetic patients who underwent echocardiography before, and 6 to 24 months after the initiation of SGLT2i. After propensity score matching with diabetic patients without SGLT2i, the study population (n = 304) were categorized into group 1 (without HF nor SGLT2i; n = 76), group 2 (without HF and received SGLT2i; n = 78), group 3 (with HF but without SGLT2i; n = 76), and group 4 (with HF and received SGLT2i; n = 74). Changes in echocardiographic parameters were compared between these 4 groups, and between HF patients with reduced versus preserved ejection fraction (EF).

Results

After a median 13 months of follow-up, HF patients with SGLT2i showed a significant decrease in left ventricular end-diastolic dimension (LV-EDD; from 57.4 mm [50.0–64.9] to 53.0 mm [48.0–60.0]; p < 0.001) and improvement in LV-EF (from 36.1% [25.6–47.5] to 45.0% [34.8–56.3]; p < 0.001). LV mass index and diastolic parameters also showed improvements in HF patients with SGLT2i. The SGLT2i-induced improvements in cardiac function were more prominent in HF patients than those without HF, and in HFrEF patients than HFpEF patients.

Conclusions

Use of SGLT2i improved cardiac function in diabetic patients, regardless of the presence of HF. The improvements were more prominent in HF patients, especially in those with HFrEF. These improvements in cardiac function would contribute to the clinical benefit of SGLT2i.

Sodium-Glucose Cotransporter-2 inhibitors are potential therapeutic agents for treatment of non-diabetic heart failure patients

Despite recent developments in various therapies, heart failure remains a leading cause of morbidity and mortality worldwide. New pharmacological approaches are therefore needed to improve the outcomes of patients with heart failure. Diabetes mellitus is an important risk factor for heart failure, but until recently there had been no evidence that hypoglycemic agents prevent heart failure. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have now been shown to prevent cardiovascular events, especially hospitalization for heart failure, in three large randomized clinical trials: EMPA-REG OUTCOME, the CANVAS program, and the DECLARE-TIMI58 trial. It is expected, therefore, that SGLT2 inhibitors will be useful therapeutic agents for the treatment of heart failure. The DAPA-HF trial recently demonstrated that dapagliflozin significantly reduces cardiovascular death and hospitalization for heart failure in patients with heart failure with reduced ejection fraction (HFrEF). Importantly, these benefits of dapagliflozin were similarly observed in patients with or without diabetes, suggesting the drug's efficacy is independent of glycemic reduction. The results of that study highlight the significance of SGLT2 inhibition as a novel therapeutic approach to treating HFrEF, irrespective of the presence or absence of diabetes. Findings of the DAPA-HF trial may also challenge current assumptions about the mechanisms underlying the cardioprotective action of SGLT2 inhibitors. It is anticipated that ongoing clinical trials, mainly using dapagliflozin and empagliflozin, will provide further insight into the clinical importance of these drugs for the treatment of heart failure, including heart failure with preserved ejection fraction (HFpEF), and also the mechanisms underlying those clinical benefits.

Effects of Glucagon-Like Peptide-1 Receptor Agonists, Sodium-Glucose Cotransporter-2 Inhibitors, and Their Combination on Endothelial Glycocalyx, Arterial Function, and Myocardial Work Index in Patients With Type 2 Diabetes Mellitus After 12-Month Treatment

Background We investigated the effects of insulin, glucagon-like peptide-1 receptor agonists (GLP-1RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i), and their combination on vascular and cardiac function of patients with type 2 diabetes mellitus. Methods and Results A total of 160 patients with type 2 diabetes mellitus were randomized to insulin (n=40), liraglutide (n=40), empagliflozin (n=40), or their combination (GLP-1RA+SGLT-2i) (n=40) as add-on to metformin. We measured at baseline and 4 and 12 months posttreatment: (a) perfused boundary region of the sublingual arterial microvessels (marker of endothelial glycocalyx thickness), (b) pulse wave velocity (PWV) and central systolic blood pressure, (c) global left ventricular longitudinal, circumferential, and radial strain, (d) myocardial work index (global work index) derived by pressure-myocardial strain loops using speckle tracking imaging. Twelve months posttreatment, all patients improved perfused boundary region, PWV, global longitudinal strain, global circumferential strain, and global radial strain (P<0.05). GLP-1RA, SGLT-2i, and their combination showed a greater reduction of perfused boundary region, PWV, and central systolic blood pressure than insulin, despite a similar glycosylated hemoglobin reduction (P<0.05). GLP-1RA or GLP-1RA+SGLT-2i provided a greater increase of global work index (12.7% and 17.4%) compared with insulin or SGLT-2i (3.1% and 2%). SGLT-2i or GLP-1RA and SGLT-2i showed a greater decrease of PWV (10.1% and 13%) and central and brachial systolic blood pressure than insulin or GLP-1RA (PWV, 3.6% and 8.6%) (P<0.05 for all comparisons). The dual therapy showed the greatest effect on measured markers in patients with left ventricular ejection fraction <55% (P<0.05). Conclusions Twelve-month treatment with GLP-1RA, SGLT-2i, and their combination showed a greater improvement of vascular markers and effective cardiac work than insulin treatment in type 2 diabetes mellitus. The combined therapy as second line was superior to either insulin or GLP-1RA and SGLT-2i separately. Registration URL: https://www.clini​caltr​ials.gov. Unique identifier: NCT03878706.

An Overview of Prospective Drugs for Type 1 and Type 2 Diabetes

Aims:

The aim of this study is to provide an overview of several emerging anti-diabetic molecules.

Background:

Diabetes is a complex metabolic disorder involving the dysregulation of glucose homeostasis at various levels. Insulin, which is produced by β-pancreatic cells, is a chief regulator of glucose metabolism, regulating its consumption within cells, which leads to energy generation or storage as glycogen. Abnormally low insulin secretion from β-cells, insulin insensitivity, and insulin tolerance lead to higher plasma glucose levels, resulting in metabolic complications. The last century has witnessed extraordinary efforts by the scientific community to develop anti-diabetic drugs, and these efforts have resulted in the discovery of exogenous insulin and various classes of oral anti-diabetic drugs.

Objective:

Despite these exhaustive anti-diabetic pharmaceutical and therapeutic efforts, long-term glycemic control, hypoglycemic crisis, safety issues, large-scale economic burden and side effects remain the core problems.

Method:

The last decade has witnessed the development of various new classes of anti-diabetic drugs with different pharmacokinetic and pharmacodynamic profiles. Details of their FDA approvals and advantages/disadvantages are summarized in this review.

Results:

The salient features of insulin degludec, sodium-glucose co-transporter 2 inhibitors, glucokinase activators, fibroblast growth factor 21 receptor agonists, and GLP-1 agonists are discussed.

Conclusion :

In the future, these new anti-diabetic drugs may have broad clinical applicability. Additional multicenter clinical studies on these new drugs should be conducted.

Effect of Dapagliflozin on Worsening Heart Failure and Cardiovascular Death in Patients With Heart Failure With and Without Diabetes

IMPORTANCE

Additional treatments are needed for heart failure with reduced ejection fraction (HFrEF). Sodium-glucose cotransporter 2 (SGLT2) inhibitors may be an effective treatment for patients with HFrEF, even those without diabetes.

OBJECTIVE

To evaluate the effects of dapagliflozin in patients with HFrEF with and without diabetes.

DESIGN, SETTING, AND PARTICIPANTS

Exploratory analysis of a phase 3 randomized trial conducted at 410 sites in 20 countries. Patients with New York Heart Association classification II to IV with an ejection fraction less than or equal to 40% and elevated plasma N-terminal pro B-type natriuretic peptide were enrolled between February 15, 2017, and August 17, 2018, with final follow-up on June 6, 2019.

INTERVENTIONS

Addition of once-daily 10 mg of dapagliflozin or placebo to recommended therapy.

MAIN OUTCOMES AND MEASURES

The primary outcome was the composite of an episode of worsening heart failure or cardiovascular death. This outcome was analyzed by baseline diabetes status and, in patients without diabetes, by glycated hemoglobin level less than 5.7% vs greater than or equal to 5.7%.

RESULTS

Among 4744 patients randomized (mean age, 66 years; 1109 [23%] women; 2605 [55%] without diabetes), 4742 completed the trial. Among participants without diabetes, the primary outcome occurred in 171 of 1298 (13.2%) in the dapagliflozin group and 231 of 1307 (17.7%) in the placebo group (hazard ratio, 0.73 [95% CI, 0.60-0.88]). In patients with diabetes, the primary outcome occurred in 215 of 1075 (20.0%) in the dapagliflozin group and 271 of 1064 (25.5%) in the placebo group (hazard ratio, 0.75 [95% CI, 0.63-0.90]) (P value for interaction = .80). Among patients without diabetes and a glycated hemoglobin level less than 5.7%, the primary outcome occurred in 53 of 438 patients (12.1%) in the dapagliflozin group and 71 of 419 (16.9%) in the placebo group (hazard ratio, 0.67 [95% CI, 0.47-0.96]). In patients with a glycated hemoglobin of at least 5.7%, the primary outcome occurred in 118 of 860 patients (13.7%) in the dapagliflozin group and 160 of 888 (18.0%) in the placebo group (hazard ratio, 0.74 [95% CI, 0.59-0.94]) (P value for interaction = .72). Volume depletion was reported as an adverse event in 7.3% of patients in the dapagliflozin group and 6.1% in the placebo group among patients without diabetes and in 7.8% of patients in the dapagliflozin group and 7.8% in the placebo group among patients with diabetes. A kidney adverse event was reported in 4.8% of patients in the dapagliflozin group and 6.0% in the placebo group among patients without diabetes and in 8.5% of patients in the dapagliflozin group and 8.7% in the placebo group among patients with diabetes.

CONCLUSIONS AND RELEVANCE

In this exploratory analysis of a randomized trial of patients with HFrEF, dapagliflozin compared with placebo, when added to recommended therapy, significantly reduced the risk of worsening heart failure or cardiovascular death independently of diabetes status.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03036124.

Critical examination of mechanisms underlying the reduction in heart failure events with SGLT2 inhibitors: identification of a molecular link between their actions to stimulate erythrocytosis and to alleviate cellular stress

Sodium-glucose co-transporter 2 (SGLT2) inhibitors reduce the risk of serious heart failure events, even though SGLT2 is not expressed in the myocardium. This cardioprotective benefit is not related to an effect of these drugs to lower blood glucose, promote ketone body utilization or enhance natriuresis, but it is linked statistically with their action to increase haematocrit. SGLT2 inhibitors increase both erythropoietin and erythropoiesis, but the increase in red blood cell mass does not directly prevent heart failure events. Instead, erythrocytosis is a biomarker of a state of hypoxia mimicry, which is induced by SGLT2 inhibitors in manner akin to cobalt chloride. The primary mediators of the cellular response to states of energy depletion are sirtuin-1 and hypoxia-inducible factors (HIF-1α/HIF-2α). These master regulators promote the cellular adaptation to states of nutrient and oxygen deprivation, promoting mitochondrial capacity and minimizing the generation of oxidative stress. Activation of sirtuin-1 and HIF-1α/HIF-2α also stimulates autophagy, a lysosome-mediated degradative pathway that maintains cellular homoeostasis by removing dangerous constituents (particularly unhealthy mitochondria and peroxisomes), which are a major source of oxidative stress and cardiomyocyte dysfunction and demise. SGLT2 inhibitors can activate SIRT-1 and stimulate autophagy in the heart, and thereby, favourably influence the course of cardiomyopathy. Therefore, the linkage between erythrocytosis and the reduction in heart failure events with SGLT2 inhibitors may be related to a shared underlying molecular mechanism that is triggered by the action of these drugs to induce a perceived state of oxygen and nutrient deprivation.

Second revolution in cardiovascular prevention

Type 2 diabetes has become a major disease burden in twenty-first century. Both incidence and prevalence of type 2 diabetes have quadrupled between 1980 and 2004 in the whole world. Atherosclerotic cardiovascular disease (ASCVD) is the major complication of type 2 diabetes. The introduction of statins in clinical settings is the first revolution in our battle against ASCVD. Most ASCVDs could be prevented or treated with statins. However, statin failed to reduce chronic kidney diseases (CKD) and heart failure (HF). Owing to a mandate from US Food and Drug Administration in 2008 that every new antidiabetic drug should be tested in clinical trials to demonstrate its safety, we now have a good opportunity to look for better antidiabetic drugs not only to decrease blood sugar but also to decrease CVD or renal disease. Among them, glucagon-like peptide-1 receptor agonists and sodium-glucose transport protein 2 inhibitors (SGLT-2 i) are two most extensively studied ones. SGLT-2 i, in particular, prevent CKD and end-stage renal disease, and prevent HF. In the recent CREDENCE trial, canagliflozin reduced renal endpoints by 34% and end-stage renal disease by 32%. Furthermore, in the recent DAPA-HF trial, dapagliflozin decreased hospitalization for HF/cardiovascular death by 26%, and total death by 17%, in patients with HF with reduced ejection fraction, irrespective of diabetes or nondiabetes. The beneficial effects of SGLT-2 i in CKD and HF are complementary to the effects of statins. The introduction of SGLT-2 i in clinical practice is the second revolution in cardiovascular prevention.

Basic and Clinical Pharmaco-Therapeutics of SGLT2 Inhibitors: A Contemporary Update

Clinical relevance of sodium/glucose cotransporter 2 (SGLT2) inhibitors has been rapidly evolving across several therapy areas, apart from type 2 diabetes mellitus. While some of these developments are based on recognized scientific explanations, unexpected study findings have also shaped much of our present understanding. As the role of these agents evolves in various facets of cardiology, nephrology, hepatology and endocrinology, their optimum clinical value propositions should be realized in line with the principles of personalized medicine. An updated pharmaco-ergonomic qualification tool, based on the present evidence with these agents, would be a step in this direction. This review describes the present evidence on diverse pharmacological and therapeutic aspects for various SGLT2 inhibitors, as an attempt to provide useful guidance for optimum application in clinical practice.

Current and future approaches to nonclinical cardiovascular safety assessment

Our goal is to accurately predict all types of cardiovascular events in patients utilising nonclinical cardiovascular safety data. In the past two decades, cardiovascular safety science has primarily focused on events associated with the electrocardiogram. Broadening out to other cardiovascular parameters, we share real-life case studies that highlight our progress towards improved and better-informed project progression based upon use of disease models, mechanism-based translation and structure-function relationships. To fulfil this goal, further advances in patient-relevant humanised models will be required to enable cardiovascular safety science to keep pace with the ever-changing landscape of novel therapeutic paradigms.

DAPA-HF trial: dapagliflozin evolves from a glucose-lowering agent to a therapy for heart failure

Heart failure (HF) continues to be a major global health problem with a notable impact in terms of morbidity and mortality and so, in consequence, with a large unmet necessity for new therapies. The inhibition of sodium-glucose cotransporter 2 (SGLT2) causes glycosuria and natriuresis, leading to reductions in hyperglycemia (antidiabetic effect), body weight, and blood pressure. In this context, outcome trials have been shown to reduce hospitalizations for HF in patients with type 2 diabetes mellitus treated with SGLT2 inhibitors. The underlying protective cardiovascular (CV) mechanisms of these agents are complex, multifactorial, and not entirely understood as, in addition to a diuretic-like function, SGLT2 inhibitors may mitigate glycemic-related toxicity, promote ketogenesis, increase hematocrit, and exert antihypertrophic, antifibrotic, and antiremodeling properties. The DAPA-HF (Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure) trial enrolled 4744 patients with HF and reduced ejection fraction (EF) who were receiving excellent guideline-directed treatment before the addition of dapagliflozin (a SGLT2 inhibitor) or placebo. The DAPA-HF trial clearly showed that dapagliflozin was superior to placebo at preventing CV deaths and HF events. The relative and absolute risk reductions in death and hospitalizations were consistent across subgroups including patients with and without diabetes; so, in consequence, dapagliflozin represents the first in a new class of drug for HF with reduced EF. The recently published Dapagliflozin Effects on Biomarkers, Symptoms, and Functional Status in Patients With Heart Failure With Reduced Ejection Fraction (DEFINE-HF) trial is also described in this review as well as the thought-to-be mechanisms of action of SGLT2 inhibitors beyond their known glucose-lowering effects. There is a vast, ambitious, and promising ongoing clinical investigation program with dapagliflozin and other SGLT2 inhibitors, which may result in changes to the therapeutic approach to HF in a relatively short time.

SGLT-2 inhibitors and GLP-1 receptor agonists for nephroprotection and cardioprotection in patients with diabetes mellitus and chronic kidney disease. A consensus statement by the EURECA-m and the DIABESITY working groups of the ERA-EDTA

Chronic kidney disease (CKD) in patients with diabetes mellitus (DM) is a major problem of public health. Currently, many of these patients experience progression of cardiovascular and renal disease, even when receiving optimal treatment. In previous years, several new drug classes for the treatment of type 2 DM have emerged, including inhibitors of renal sodium-glucose co-transporter-2 (SGLT-2) and glucagon-like peptide-1 (GLP-1) receptor agonists. Apart from reducing glycaemia, these classes were reported to have other beneficial effects for the cardiovascular and renal systems, such as weight loss and blood pressure reduction. Most importantly, in contrast to all previous studies with anti-diabetic agents, a series of recent randomized, placebo-controlled outcome trials showed that SGLT-2 inhibitors and GLP-1 receptor agonists are able to reduce cardiovascular events and all-cause mortality, as well as progression of renal disease, in patients with type 2 DM. This document presents in detail the available evidence on the cardioprotective and nephroprotective effects of SGLT-2 inhibitors and GLP-1 analogues, analyses the potential mechanisms involved in these actions and discusses their place in the treatment of patients with CKD and DM.

Autophagy stimulation and intracellular sodium reduction as mediators of the cardioprotective effect of sodium-glucose cotransporter 2 inhibitors

In five large-scale trials involving >40 000 patients, sodium-glucose cotransporter 2 (SGLT2) inhibitors decreased the risk of serious heart failure events by 25-40%. This effect cannot be explained by control of hyperglycaemia, since it is not observed with antidiabetic drugs with greater glucose-lowering effects. It cannot be attributed to ketogenesis, since it is not causally linked to ketone body production, and the benefit is not enhanced in patients with diabetes. The effect cannot be ascribed to a natriuretic action, since SGLT2 inhibitors decrease natriuretic peptides only modestly, and they reduce cardiovascular death, a benefit that diuretics do not possess. Although SGLT2 inhibitors increase red blood cell mass, enhanced erythropoiesis does not favourably influence the course of heart failure. By contrast, experimental studies suggest that SGLT2 inhibitors may reduce intracellular sodium, thereby preventing oxidative stress and cardiomyocyte death. Additionally, SGLT2 inhibitors induce a transcriptional paradigm that mimics nutrient and oxygen deprivation, which includes activation of adenosine monophosphate-activated protein kinase, sirtuin-1, and/or hypoxia-inducible factors-1α/2α. The interplay of these mediators stimulates autophagy, a lysosomally-mediated degradative pathway that maintains cellular homeostasis. Autophagy-mediated clearance of damaged organelles reduces inflammasome activation, thus mitigating cardiomyocyte dysfunction and coronary microvascular injury. Interestingly, the action of hypoxia-inducible factors-1α/2α to both stimulate erythropoietin and induce autophagy may explain why erythrocytosis is strongly correlated with the reduction in heart failure events. Therefore, the benefits of SGLT2 inhibitors on heart failure may be mediated by a direct cardioprotective action related to modulation of pathways responsible for cardiomyocyte homeostasis.

Enhancement of the serum chloride concentration by administration of sodium-glucose cotransporter-2 inhibitor and its mechanisms and clinical significance in type 2 diabetic patients: a pilot study

BACKGROUND

Chloride is a key electrolyte that regulates the body fluid distribution. Accordingly, manipulating chloride kinetics by selecting a suitable diuretic could be an attractive strategy for correcting body fluid dysregulation. Therefore, this study examined the effects and contributing factors of a sodium-glucose cotransporter-2 inhibitor (SGLT2i) on the serum chloride concentration in type 2 diabetic (T2DM) patients without heart failure (HF).

METHODS

This study was a retrospective single-center observational study that enrolled 10 T2DM/non-HF outpatients for whom the SGLT2i empagliflozin (daily oral dose of 10 mg) was prescribed. Among these 10 patients, 6 underwent detailed clinical testing that included hormonal and metabolic blood tests.

RESULTS

Empagliflozin treatment for 1-2 months decreased body weight (- 2.69 ± 1.9 kg; p = 0.002) and HbA1c (- 0.88 ± 0.55%; p = 0.0007). The hemoglobin (+ 0.27 ± 0.36 g/dL; p = 0.04) and hematocrit (+ 1.34 ± 1.38%; p = 0.014) values increased, but the serum creatinine concentration remained unchanged. The serum chloride concentration increased from 104 ± 3.23 to 106 ± 2.80 mEq/L (p = 0.004), but the sodium and potassium concentrations did not change. The spot urinary sodium concentration decreased from 159 ± 43 to 98 ± 35 mEq/L (p < 0.02) and the spot urinary chloride tended to decrease (from 162 ± 59 to 104 ± 36 mEq/L, p < 0.08). Both renin and aldosterone tended to be activated (5/6, 83%). The strong organic acid metabolite concentrations of serum acetoacetate (from 42 ± 25 to 100 ± 45 μmol/L, p < 0.02) and total ketone bodies (from 112 ± 64 to 300 ± 177 μmol/L, p < 0.04) increased, but the actual HCO3 - concentration decreased (from 27 ± 2.5 to 24 ± 1.6 mEq/L, p < 0.008).

CONCLUSIONS

The present study demonstrated that SGLT2i enhances the serum chloride concentration in T2DM patients and suggests that the effect is mediated by the possible following mechanisms: (1) enhanced reabsorption of urinary chloride by aldosterone activation due to blood pressure lowering and blood vessel contraction effects, (2) reciprocal increase in the serum chloride concentration by reducing the serum HCO3 - concentration via a buffering effect of strong organic acid metabolites, and (3) reduced NaHCO3 reabsorption and concurrently enhanced chloride reabsorption in the urinary tubules by inhibiting Na+-H+ exchanger 3 in the renal proximal tubules. Thus, the diuretic SGLT2i induces excessive extravascular fluid to drain into the vascular space by the enhanced vascular "tonicity" caused by the elevated serum chloride concentration.

Dapagliflozin Activates Neurons in the Central Nervous System and Regulates Cardiovascular Activity by Inhibiting SGLT-2 in Mice

PURPOSE

This study investigates the possible effect and central mechanism of novel antidiabetic medication sodium glucose transporter-2 (SGLT-2i) on the cardiovascular activity.

MATERIAL AND METHODS

Thirty-four normal male C57BL/6 mice were randomly assigned to 2 groups to receive single Dapagliflozin (1.52mg/kg) dose via intragastric gavage or a comparable dose of saline. Glycemic level (BG), blood pressure (BP) and heart rate (HR) were measured 2 hours after administration of the respective treatments. Immunohistochemical tests were performed to determine the effect of SGLT-2i on neural localization of SGLT-2 and c-Fos, a neural activator. The distributional relationships of SGLT-2 and c-Fos were examined by immunofluorescence.

RESULTS

Administration of SGLT-2i significantly decreased BP but did not affect the HR. There was no difference in BG between the two groups. Results showed that SGLT-2 was localized to specific regions involved in autonomic control. Expression of c-Fos was significantly higher in major critical nuclei in the aforementioned regions in groups treated with Dapagliflozin.

CONCLUSION

This study demonstrates that SGLT-2 is expressed in CNS tissues involved in autonomic control and possibly influence cardiovascular function. Dapagliflozin influences central autonomic activity via unidentified pathways by inhibiting central or peripheral SGLT-2. These results provide a new concept that sympathetic inhibition by SGLT-2i can be mediated by central autonomic system, a mechanism that explains how SGLT-2i improves the cardiovascular function.

Important Considerations for the Treatment of Patients with Diabetes Mellitus and Heart Failure from a Diabetologist's Perspective: Lessons Learned from Cardiovascular Outcome Trials

Heart failure (HF) represents an important cardiovascular complication of type 2 diabetes mellitus (T2DM) associated with substantial morbidity and mortality, and is emphasized in recent cardiovascular outcome trials (CVOTs) as a critical outcome for patients with T2DM. Treatment of T2DM in patients with HF can be challenging, considering that these patients are usually elderly, frail and have extensive comorbidities, most importantly chronic kidney disease. The complexity of medical regimens, the high risk clinical characteristics of patients and the potential of HF therapies to interfere with glucose metabolism, and conversely the emerging potential of some antidiabetic agents to modulate HF outcomes, are only some of the challenges that need to be addressed in the framework of a team-based personalized approach. The presence of established HF or the high risk of developing HF in the future has influenced recent guideline recommendations and can guide therapeutic decision making. Metformin remains first-line treatment for overweight T2DM patients at moderate cardiovascular risk. Although not contraindicated, metformin is no longer considered as first-line therapy for patients with established HF or at risk for HF, since there is robust scientific evidence that treatment with other glucose-lowering agents such as sodium-glucose cotransporter 2 inhibitors (SGLT2i) should be prioritized in this population due to their strong and remarkably consistent beneficial effects on HF outcomes.

SGLT-2 Inhibitors in Heart Failure and Type-2 Diabetes: Hitting Two Birds with One Stone?

Type 2 diabetes mellitus (T2DM) and heart failure (HF) have a tremendous impact worldwide, markedly reducing life-expectancy and quality of life. It is now known that each disease represents a risk factor for the other. Moreover, when they are combined, the prognosis is significantly worse. Until recently, these pathologies have been managed independently. However, their treatment paradigm is rapidly changing, with recent cardiovascular outcome trials showing that sodium-glucose cotransporter-2 inhibitors (SGLT-2i) are effective in the management of both diseases. This article explores the interactions between T2DM and HF and the concept of diabetic cardiomyopathy and summarizes recent data regarding the effects of SGLT-2i on HF hospitalization and the proposed pathophysiological mechanisms involved.

Potential Mechanisms of Sodium-Glucose Co-Transporter 2 Inhibitor-Related Cardiovascular Benefits

The findings of recent clinical trials have shown that sodium-glucose co-transporter 2 (SGLT2) inhibitors produce effects beyond glucose lowering and have demonstrated beneficial cardiovascular effects that have been observed across a broad range of patients with type 2 diabetes mellitus. In particular, the cardiovascular benefit results largely from substantial and early effects of SGLT2 inhibition on cardiovascular death and hospitalization for heart failure. Recent cardiovascular outcomes trials (CVOTs) have also shown that relative risk reductions in cardiovascular outcomes were observed with SGLT2 inhibition both in patients with current and prior heart failure. Since the observed reductions of cardiovascular outcomes with SGLT2 inhibitor therapy were observed much earlier than would be expected by an anti-atherosclerotic effect, these results have led to speculation about the potential underlying pathways. Suggested mechanisms include natriuresis and osmotic diuresis; reductions in inflammation, oxidative stress, and arterial stiffness; reductions in blood pressure and body weight; and possible renoprotective effects. These effects could produce cardiovascular benefits through a range of cardiac effects, including reduction in left ventricular load, attenuation of cardiac fibrosis and inflammation, and improved myocardial energy production. Other possible mechanisms include inhibition of sodium-hydrogen exchange, increases in erythropoietin levels, and reduction in myocardial ischemia or reperfusion injury. It is likely that a range of mechanisms underlie the observed cardiovascular benefits of SGLT2 inhibitors; further elucidation of these mechanisms will be answered by ongoing research.

Sodium Glucose Co-transporter 2 Inhibitors and Heart Failure

Sodium-glucose co-transporter 2 (SGLT2) receptors are primarily located in the proximal convoluted tubule of the nephron. These receptors are responsible for almost 90% to 95% of tubular reabsorption of the glucose in the nephron. In patients with diabetes mellitus, due to upregulation of SGLT2 receptors, glucose reabsorption is further increased. The Food and Drug Administration approved SGLT2 inhibitors, such as canagliflozin, empagliflozin, dapagliflozin, and ertugliflozin, for the treatment of type 2 diabetes. In addition to their positive effect on blood glucose, additional cardioprotective and renoprotective functions have been demonstrated in major trials such as EMPA-REG OUTCOME, CANVAS, DECLARE-TIMI-58, and CREDENCE. Unlike other antihyperglycemic drugs, reduction in hospitalization for heart failure (HF) was also seen as a class effect with this group, mechanisms of which are probably multifactorial. Subgroup analysis from these major trials indicated a reduction in progression of nephropathy and HF readmission with SGLT2 inhibitors. Although this unique property of canagliflozin was further analyzed in the CREDENCE trial, similar trials for empagliflozin (EMPERIAL-Reduced and EMPERIAL-Preserved) and dapagliflozin (DAPA-HF) are currently underway. Recently released phase III results from DAPA-HF trial indicate that dapagliflozin shows significant reduction in death due to cardiovascular causes and hospitalization in HF compared with the placebo, in both diabetics and nondiabetics. In this review article, the authors attempt to explore the possible underlying molecular mechanisms and data from existing trials pertaining to the HF related outcomes associated with SGLT2 inhibitors.

Effects of the sodium-glucose co-transporter-2 inhibitor dapagliflozin on estimated plasma volume in patients with type 2 diabetes

AIMS

To compare the effects of the sodium-glucose co-transporter-2 (SGLT2) inhibitor dapagliflozin on estimated (ePV) and measured plasma volume (mPV) and to characterize the effects of dapagliflozin on ePV in a broad population of patients with type 2 diabetes.

MATERIALS AND METHODS

The Strauss formula was used to calculate changes in ePV. Change in plasma volume measured with ¹²⁵ I-human serum albumin (mPV) was compared with change in ePV in 10 patients with type 2 diabetes randomized to dapagliflozin 10 mg/d or placebo. Subsequently, changes in ePV were measured in a pooled database of 13 phase 2b/3 placebo-controlled clinical trials involving 4533 patients with type 2 diabetes who were randomized to dapagliflozin 10 mg daily or matched placebo.

RESULTS

The median change in ePV was similar to the median change in mPV (-9.4% and -9.0%) during dapagliflozin treatment. In the pooled analysis of clinical trials, dapagliflozin decreased ePV by 9.6% (95% confidence interval 9.0 to 10.2) compared to placebo after 24 weeks. This effect was consistent in various patient subgroups, including subgroups with or without diuretic use or established cardiovascular disease.

CONCLUSIONS

ePV may be used as a proxy to assess changes in plasma volume during dapagliflozin treatment. Dapagliflozin consistently decreased ePV compared to placebo in a broad population of patients with type 2 diabetes.

Safety and effectiveness of empagliflozin in Japanese patients with type 2 diabetes: interim analysis from a post-marketing surveillance study

Background: Sodium-glucose cotransporter-2 (SGLT2) inhibitors are effective treatments for type 2 diabetes mellitus (T2DM). We present the interim findings of an ongoing post-marketing surveillance (PMS) study in Japanese patients with T2DM receiving empagliflozin.Research design and methods: This 3-year, prospective, observational, multicenter PMS evaluated the safety and effectiveness of empagliflozin in Japanese clinical practice. Patients with T2DM who had not been treated with empagliflozin before enrollment were eligible. Assessments, including the primary endpoint of incidence of adverse drug reactions (ADRs), were based on electronic case report forms (eCRF).Results: Of 8,180 registered patients from 1,103 sites, 7,618 patients had an eCRF including a follow-up visit and were treated (mean age, 58.8 years; 10.5% aged ≥75 years; 63.2% male; mean HbA1c, 8.01%; 41.8% with HbA1c ≥8.0%; 24.8% and 61.8% with at least mild hepatic and renal impairment, respectively). Mean treatment duration was 98.4 weeks; 644 (8.5%) patients had ≥1 ADR, including 8.5% of patients aged ≥75 years. Hypoglycemia, urinary tract infection, genital infections, volume depletion, diabetic ketoacidosis, and lower limb amputation occurred in 0.28%, 0.62%, 0.53%, 0.33%, 0%, and 0.03% of patients, respectively.Conclusions: The reported ADRs were consistent with the known safety profile of empagliflozin.Trial registration: ClinicalTrials.gov identifier: NCT02489942.

The Changing Landscape of Pharmacotherapy for Diabetes Mellitus: A Review of Cardiovascular Outcomes

The prevention of cardiovascular morbidity and mortality has always been a primary concern in patients with type 2 diabetes. Modern trials of glucose-lowering therapies now assess major adverse cardiac events as an endpoint in addition to the effects on glycaemic control. Whilst the data on the efficacy of intensive glucose lowering on reducing cardiovascular risk are limited, there are now increasing numbers of glucose-lowering therapies that have proven cardiovascular benefit independent of glucose lowering. This review will summarise the available literature on cardiovascular outcomes in relation to metformin, sulphonylureas, di-peptidyl peptidase-4 inhibitors, glucagon-like peptide receptor agonists, sodium-glucose co-transporter 2 inhibitors, thiazolidinediones, acarbose and insulin. In addition, new paradigms in diabetes management and the importance of treatment selection based on considerations including but not limited to glycaemic control will be discussed.

Mechanisms of Protective Effects of SGLT2 Inhibitors in Cardiovascular Disease and Renal Dysfunction

Type 2 diabetes mellitus is one of the most common forms of the disease worldwide. Hyperglycemia and insulin resistance play key roles in type 2 diabetes mellitus. Renal glucose reabsorption is an essential feature in glycaemic control. Kidneys filter 160 g of glucose daily in healthy subjects under euglycaemic conditions. The expanding epidemic of diabetes leads to a prevalence of diabetes-related cardiovascular disorders, in particular, heart failure and renal dysfunction. Cellular glucose uptake is a fundamental process for homeostasis, growth, and metabolism. In humans, three families of glucose transporters have been identified, including the glucose facilitators GLUTs, the sodium-glucose cotransporter SGLTs, and the recently identified SWEETs. Structures of the major isoforms of all three families were studied. Sodium-glucose cotransporter (SGLT2) provides most of the capacity for renal glucose reabsorption in the early proximal tubule. A number of cardiovascular outcome trials in patients with type 2 diabetes have been studied with SGLT2 inhibitors reducing cardiovascular morbidity and mortality. The current review article summarises these aspects and discusses possible mechanisms with SGLT2 inhibitors in protecting heart failure and renal dysfunction in diabetic patients. Through glucosuria, SGLT2 inhibitors reduce body weight and body fat, and shift substrate utilisation from carbohydrates to lipids and, possibly, ketone bodies. These pleiotropic effects of SGLT2 inhibitors are likely to have contributed to the results of the EMPA-REG OUTCOME trial in which the SGLT2 inhibitor, empagliflozin, slowed down the progression of chronic kidney disease and reduced major adverse cardiovascular events in high-risk individuals with type 2 diabetes. This review discusses the role of SGLT2 in the physiology and pathophysiology of renal glucose reabsorption and outlines the unexpected logic of inhibiting SGLT2 in the diabetic kidney.

Protective effect of sodium-glucose cotransporter 2 inhibitors in patients with rapid renal function decline, stage G3 or G4 chronic kidney disease and type 2 diabetes

AIMS/INTRODUCTION

The risk of end-stage kidney disease increases in proportion to the decline in the estimated glomerular filtration rate (eGFR). Although protective effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) on the eGFR decline were shown in several large-scale clinical trials, there are no studies investigating patients with a high risk of end-stage kidney disease. We investigated the efficacy and safety of SGLT2i in advanced renal dysfunction patients (stage G3 or G4 of chronic kidney disease) with a rapid decline in eGFR.

MATERIALS AND METHODS

This retrospective, longitudinal study enrolled patients with type 2 diabetes who were treated with SGLT2i, and whose eGFR was <60 mL/min/1.73 m2 and had declined >20% over 2 years (%ΔeGFR-2y) before initiating SGLT2i. The primary end-point was the change in eGFR 2 years after initiation (%ΔeGFR+2y) compared with %ΔeGFR-2y.

RESULTS

A total of 17 patients among 553 patients treated with SGLT2i for ≥2 years were included in the study. The average age, glycated hemoglobin and eGFR at SGLT2i initiation were 68.5 years, 7.3% and 38.3 mL/min/1.73 m2 , respectively. %ΔeGFR+2y in patients who were treated with SGLT2i was significantly increased compared with the patients not treated with SGLT2i (2.3 and -21.7%, respectively; P < 0.0001). A multiple regression analysis showed that only the proportion of the rate of eGFR decline was the independent factor associated with improvement of %ΔeGFR+2y. There was no increase in serious adverse events including acute kidney injury.

CONCLUSIONS

SGLT2i was safe, and prevented further eGFR decline in patients with type 2 diabetes and advanced renal dysfunction.

Effects of exenatide and open-label SGLT2 inhibitor treatment, given in parallel or sequentially, on mortality and cardiovascular and renal outcomes in type 2 diabetes: insights from the EXSCEL trial

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1 RA) improve cardiovascular and renal outcomes in patients with type 2 diabetes through distinct mechanisms. However, evidence on clinical outcomes in patients treated with both GLP-1 RA and SGLT2i is lacking. We aim to provide insight into the effects of open-label SGLT2i use in parallel with or shortly after once-weekly GLP-1 RA exenatide (EQW) on cardiorenal outcomes.

METHODS

In the EXSCEL cardiovascular outcomes trial EQW arm, SGLT2i drop-in occurred in 8.7% of participants. These EQW+SGLT2i users were propensity-matched to: (1) placebo-arm participants not taking SGLT2i (n = 572 per group); and to (2) EQW-arm participants not taking SGLT2i (n = 575), based on their last measured characteristics before SGLT2i initiation, and equivalent study visit in comparator groups. Time-to-first major adverse cardiovascular event (MACE) and all-cause mortality (ACM) were compared using Cox regression analyses. eGFR slopes were quantified using mixed model repeated measurement analyses.

RESULTS

In adjusted analyses, the risk for MACE with combination EQW+SGLT2i use was numerically lower compared with both placebo (adjusted hazard ratio 0.68, 95% CI 0.39-1.17) and EQW alone (0.85, 0.48-1.49). Risk of ACM was nominally significantly reduced compared with placebo (0.38, 0.16-0.90) and compared with EQW (0.41, 0.17-0.95). Combination EQW+SGLT2i use also nominally significantly improved estimated eGFR slope compared with placebo (+ 1.94, 95% CI 0.94-2.94 mL/min/1.73 m2/year) and EQW alone (+ 2.38, 1.40-3.35 mL/min/1.73 m2/year).

CONCLUSIONS

This post hoc analysis supports the hypothesis that combinatorial EQW and SGLT2i therapy may provide benefit on cardiovascular outcomes and mortality. Trial registration Clinicaltrials.gov, Identifying number: NCT01144338, Date of registration: June 15, 2010.

Consensus recommendations for management of patients with type 2 diabetes mellitus and cardiovascular diseases

The recent American Diabetes Association and the European Association for the Study of Diabetes guideline mentioned glycaemia management in type 2 diabetes mellitus (T2DM) patients with cardiovascular diseases (CVDs); however, it did not cover the treatment approaches for patients with T2DM having a high risk of CVD, and treatment and screening approaches for CVDs in patients with concomitant T2DM. This consensus guideline undertakes the data obtained from all the cardiovascular outcome trials (CVOTs) to propose approaches for the T2DM management in presence of CV comorbidities. For patients at high risk of CVD, metformin is the drug of choice to manage the T2DM to achieve a patient specific HbA1c target. In case of established CVD, a combination of glucagon-like peptide-1 receptor agonist with proven CV benefits is recommended along with metformin, while for chronic kidney disease or heart failure, a sodium-glucose transporter proteins-2 inhibitor with proven benefit is advised. This document also summarises various screening and investigational approaches for the major CV events with their accuracy and specificity along with the treatment guidance to assist the healthcare professionals in selecting the best management strategies for every individual. Since lifestyle modification and management plays an important role in maintaining the effectiveness of the pharmacological therapies, authors of this consensus recommendation have also briefed on the patient-centric non-pharmacological management of T2DM and CVD.

Evaluation of the effects of sodium-glucose co-transporter 2 inhibition with empagliflozin on morbidity and mortality in patients with chronic heart failure and a preserved ejection fraction: rationale for and design of the EMPEROR-Preserved Trial

BACKGROUND

The principal biological processes that characterize heart failure with a preserved ejection fraction (HFpEF) are systemic inflammation, epicardial adipose tissue accumulation, coronary microcirculatory rarefaction, myocardial fibrosis and vascular stiffness; the resulting impairment of left ventricular and aortic distensibility (especially when accompanied by impaired glomerular function and sodium retention) causes increases in cardiac filling pressures and exertional dyspnoea despite the relative preservation of left ventricular ejection fraction. Independently of their actions on blood glucose, sodium-glucose co-transporter 2 (SGLT2) inhibitors exert a broad range of biological effects (including actions to inhibit cardiac inflammation and fibrosis, antagonize sodium retention and improve glomerular function) that can ameliorate the pathophysiological derangements in HFpEF. Such SGLT2 inhibitors exert favourable effects in experimental models of HFpEF and have been found in large-scale trials to reduce the risk for serious heart failure events in patients with type 2 diabetes, many of whom were retrospectively identified as having HFpEF.

STUDY DESIGN

The EMPEROR-Preserved Trial is enrolling ≈5750 patients with HFpEF (ejection fraction >40%), with and without type 2 diabetes, who are randomized to receive placebo or empagliflozin 10 mg/day, which is added to all appropriate treatments for HFpEF and co-morbidities.

STUDY AIMS

The primary endpoint is the time-to-first-event analysis of the combined risk for cardiovascular death or hospitalization for heart failure. The trial will also evaluate the effects of empagliflozin on renal function, cardiovascular death, all-cause mortality and recurrent hospitalization events, and will assess a wide range of biomarkers that reflect important pathophysiological mechanisms that may drive the evolution of HFpEF. The EMPEROR-Preserved Trial is well positioned to determine if empagliflozin can have a meaningful impact on the course of HFpEF, a disorder for which there are currently few therapeutic options.

Mechanisms and Evidence for Heart Failure Benefits from SGLT2 Inhibitors

PURPOSE OF REVIEW

To review the clinical trial data and underlying mechanistic principles in support of the robust cardiovascular (CV) benefits, in particular, heart failure (HF) outcomes association with sodium-glucose co-transporter-2 (SGLT2) inhibitors.

RECENT FINDINGS

Several large CV outcome trials in patients with type 2 diabetes mellitus (T2DM) and with either established atherosclerotic CV disease (ASCVD) or at high risk for ASCVD reveal that SGLT2 inhibitors cause reductions in CV and HF endpoints. The reduction in ASCVD appears to be confined to those with established ASCVD on the order of ≈ 14%, as does the mortality benefit-all-cause and CV-related. However, hospitalization for HF are reduced by ≈ 33% and occur regardless of baseline patient characteristics. The unprecedented HF outcomes are theorized to occur via several possible mechanisms and include optimization of conventional ASCVD risk factors, improvement in hemodynamics, prevention of cardiac and renal remodeling, inhibition of hormone dysregulation, use of more efficient metabolic substrates, ion channel inhibition, anti-inflammatory effects, and anti-oxidant effects. Recent evidence has unveiled the irrefutable data that SGLT2 inhibitors reduce CV events in patients with T2DM, with a profound effect on reductions in hospitalization for HF. Though several mechanisms conveying this benefit are suggested, most are based in limited data requiring further validation. Nonetheless, the arrival of SGLT2 inhibitors has ushered in a new era of CV risk reductions therapies.

Sodium-glucose cotransporter 2 inhibition as a potential treatment for idiopathic oedema

Idiopathic oedema is a syndrome affecting primarily women that is characterized by frustrating intermittent fluid retention, with hallmarks of obesity, periodic oedema, anxiety, and a susceptibility to develop type 2 diabetes. Management is typically reassurance and weight control, with no known drug class proven to provide consistent relief. We hypothesise that sodium-glucose cotransporter 2 inhibition is a logical intervention in the treatment of idiopathic oedema, having effects on obesity, blood pressure, impaired glucose tolerance, sympathetic overdrive, and reduction in swelling - the most common and distressing complaint. Sodium-glucose cotransporter 2 inhibition by promoting greater electrolyte-free, but glucose driven, water clearance with preferential fluid clearance from the interstitial space, without compromising intravascular volume, may provide symptomatic relief of swelling and bloating. The consequent weight reduction secondary to caloric loss from renal glycosuria and decreased adiposity would prevent disease progression of type 2 diabetes or pre-diabetes. With diminished adrenergic output from central and peripheral autonomic influences, reduction of blood pressure occurs, and by similar mechanisms, anxiety may be reduced.

Rationale and Design of the CANONICAL Study - Randomized, Open-Label Study to Evaluate the Efficacy and Safety of Canagliflozin for Heart Failure With Preserved Ejection Fraction With Type 2 Diabetes Mellitus

Background: Sodium-glucose cotransporter 2 inhibitors (SGLT2-I) have beneficial cardiovascular effects, including reduction in hospitalization for heart failure (HF). The aim of this study is to explore the efficacy and safety of canagliflozin compared with standard diabetes treatment in elderly patients with type 2 diabetes (T2DM) and HF with preserved ejection fraction (HFpEF).

Methods and Results: This is a multicenter, randomized, open-label, parallel-group comparison study designed to evaluate the effects of canagliflozin on fluid retention and cardiac function in T2DM patients with HFpEF. Eligible participants are patients aged ≥65 years with insufficient glycemic control. Qualified patients will be randomly assigned to treatment with 100 mg of canagliflozin or standard diabetic treatment other than SGLT2-I; both groups will be treated for 24 weeks. The primary endpoints are changes in body weight as an indicator of fluid retention and plasma brain natriuretic peptide as an indicator of cardiac function. The secondary endpoints include cardiovascular event rates, changes in the dose of loop diuretics, echocardiographic left ventricular function, and nutritional status.

Conclusions: This study is expected to provide valuable findings regarding the mechanisms of canagliflozin on cardiac function and a potential new therapeutic approach for HFpEF. (UMIN000028668 and jRCTs051180030)

Mechanistic insights regarding the role of SGLT2 inhibitors and GLP1 agonist drugs on cardiovascular disease in diabetes

The treatment landscape for patients with established or at high risk for cardiovascular disease and type 2 diabetes mellitus has entirely changed over the past decade, with the introduction of several anti-hyperglycemic agents. Sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) agonists are two anti-hyperglycemic classes which have been of special interest after multiple large cardiovascular disease (CVD) outcomes studies have demonstrated superiority of these agents compared to placebo for major adverse CVD events and in some cases, hospitalization for heart failure. Despite the dramatic results of these trials, only recently have we began to understand the mechanisms underlying these CVD benefits. Here we review the underlying mechanisms which have the greatest plausibility for both of these agents including the impact of ventricular loading conditions, direct effects on cardiac structure and function, myocardial energetics and sodium/hydrogen exchange for SGLT2 inhibitors, and the anti-atherosclerotic, anti-inflammatory, and modulation of endothelial function for GLP-1 agonists.

Navigating the "MACE" in Cardiovascular Outcomes Trials and decoding the relevance of Atherosclerotic Cardiovascular Disease benefits versus Heart Failure benefits

The publication of results from recent cardiovascular outcome trials (CVOTs) has transformed the landscape of diabetes treatment. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium glucose co-transporter-2 (SGLT2) inhibitors have demonstrated CV benefits in large, well-conducted, randomized studies. Today, empagliflozin, canagliflozin and liraglutide are US Food and Drug Administration-approved not only for glucose-lowering, but also to reduce the risk of cardiovascular (CV) events/CV mortality in people with type 2 diabetes (T2DM) and established CV disease (CVD)/high CVD risk. Although the CVOTs were primarily powered for CV safety (non-inferiority), they also demonstrated CV efficacy (superiority). This initially surprised many in the diabetes community, but the replication of the CV benefits with different compounds in the same class alleviated concerns about the CV benefits being chance findings. However, many questions remain. While the heterogeneity in the CV benefits in the various CVOTs can be attributed to the variability in CV risk in the different studies, the reason(s) for the differences in the CV benefits between the GLP-1RA class and the SGLT2 inhibitor class appear to be more complex. An analysis of major adverse cardiovascular events (MACE) in the CVOTs shows that the CV benefits of GLP-1RAs are predominantly specific to atherosclerotic CV events (non-fatal myocardial infarction [MI], non-fatal stroke and CV death). By contrast, the SGLT2 inhibitors do not have any significant effects on atherosclerotic CV events (non-fatal MI/stroke). Their benefits are predominantly on hospitalization for heart failure (HF), suggesting effects primarily on myocardial function ("the pump"), and not on the "pipes" (coronary arteries). In the present review, we discuss the rationale for the conduct of CVOTs, highlight the inability of the classic three-point MACE to capture the entire spectrum of atherosclerotic and non-atherosclerotic CVD morbidity, especially HF in T2DM, and discuss the results of the CVOTs with a focus on the clinical significance of atherosclerotic CVD (ASCVD) versus HF, which develops in a sizeable proportion of people with diabetes and without prior ASCVD.

Evaluation of the effect of sodium-glucose co-transporter 2 inhibition with empagliflozin on morbidity and mortality of patients with chronic heart failure and a reduced ejection fraction: rationale for and design of the EMPEROR-Reduced trial

Drugs that inhibit the sodium-glucose co-transporter 2 (SGLT2) have been shown to reduce the risk of hospitalizations for heart failure in patients with type 2 diabetes. In populations that largely did not have heart failure at the time of enrolment, empagliflozin, canagliflozin and dapagliflozin decreased the risk of serious new-onset heart failure events by ≈30%. In addition, in the EMPA-REG OUTCOME trial, empagliflozin reduced the risk of both pump failure and sudden deaths, the two most common modes of death among patients with heart failure. In none of the three trials could the benefits of SGLT2 inhibitors on heart failure be explained by the actions of these drugs as diuretics or anti-hyperglycaemic agents. These observations raise the possibility that SGLT2 inhibitors could reduce morbidity and mortality in patients with established heart failure, including those without diabetes. The EMPEROR-Reduced trial is enrolling ≈3600 patients with heart failure and a reduced left ventricular ejection fraction (≤ 40%), half of whom are expected not to have diabetes. Patients are being randomized to placebo or empagliflozin 10 mg daily, which is added to all appropriate treatment with inhibitors of the renin-angiotensin system and neprilysin, beta-blockers and mineralocorticoid receptor antagonists. The primary endpoint is the time-to-first event analysis of the combined risk of cardiovascular death and hospitalization for heart failure, but the trial will also evaluate the effects of empagliflozin on renal function, cardiovascular death, all-cause mortality, and recurrent hospitalization events. By adjusting eligibility based on natriuretic peptide levels to the baseline ejection fraction, the trial will preferentially enrol high-risk patients. A large proportion of the participants is expected to have an ejection fraction < 30%, and the estimated annual event rate is expected to be at least 15%. The EMPEROR-Reduced trial is well-positioned to determine if the addition of empagliflozin can add meaningfully to current approaches that have established benefits in the treatment of chronic heart failure with left ventricular systolic dysfunction.

A Potential Mechanism of Cardio-Renal Protection with Sodium-Glucose Cotransporter 2 Inhibitors: Amelioration of Renal Congestion

Background: This review considers anew the etiology of the cardio-renal protective effect of sodium-glucose cotransporter 2 (SGLT2) inhibitors by extending the discussion to renal congestion, inherent in diabetic kidney disease (DKD) even at an early stage of nephropathy in which heart failure (HF) or salt and water accumulation is asymptomatic. Summary: The interstitial fluid (IF) space of the kidney space plays a crucial role for tubulointerstitial inflammation, renal hypoxia, and ischemic injury, which often leads to renal progression. In DKD, as a result of hyperglycemic milieu, excessive salt and water can be accumulated in the IF space, creating renal congestion. I hypothesize that SGLT2 inhibitors cause a shift in extracellular water from the IF space to the intravascular space to compensate for the SGLT2 inhibitor-induced hypovolemia. This decrease in IF volume ameliorates the IF space milieu and may reduce inflammation, hypoxia, and ischemic injury. Message: The present review proposes a novel theory; unlike other hypoglycemic agents or diuretics, SGLT2 inhibitor could protect DKD from failing by improving latent renal congestion even without symptomatic HF.

Empagliflozin in heart failure patients with reduced ejection fraction: a randomized clinical trial (Empire HF)

Background

Data from recent cardiovascular outcome trials in patients with type 2 diabetes (T2D) suggest that sodium-glucose cotransporter 2 (SGLT2) inhibitors can prevent development of heart failure (HF) and prolong life in patients without HF. Ongoing event-driven trials are investigating whether the same effect is present in patients with well-defined HF. The mechanism behind the effect of SGLT2 inhibitors in patients with T2D and the potential effect in patients with overt HF is presently unknown.

Methods

This is a randomized, double-blinded, placebo-controlled, parallel group, clinical trial including HF patients with reduced left ventricular ejection fraction (HFrEF) with an ejection fraction ≤ 40% on optimal therapy recruited from specialized HF clinics in Denmark. The primary aim is to investigate the effect of the SGLT2 inhibitor empagliflozin on N-terminal pro-brain natriuretic peptide (NT-proBNP). Secondary endpoints include cardiac biomarkers, function and hemodynamics, metabolic and renal parameters, daily activity level, and quality of life. Patients are assigned 1:1 to 90 days treatment with empagliflozin 10 mg daily or placebo. Patients with T2D are required to be on recommended doses of anti-glycemic therapy with a hemoglobin A1c (HbA1c) of 6.5–10.0% (48–86 mmol/mol). To show a between-group difference in the change of NT-proBNP of 30%, a total of 189 patients will be included.

Discussion

The Empire HF trial will elucidate the effects and modes of action of empagliflozin in HFrEF patients with and without T2D and provide important mechanistic data which will complement ongoing event-driven trials.

Trial registration

Clinicaltrialsregister.eu, EudraCT Number 2017-001341-27. Registered on 29 May 2017.

ClinicalTrials.gov, NCT03198585. Registered on 26 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3474-5) contains supplementary material, which is available to authorized users.

Quantitative Systems Pharmacology: An Exemplar Model-Building Workflow With Applications in Cardiovascular, Metabolic, and Oncology Drug Development

Quantitative systems pharmacology (QSP), a mechanistically oriented form of drug and disease modeling, seeks to address a diverse set of problems in the discovery and development of therapies. These problems bring a considerable amount of variability and uncertainty inherent in the nonclinical and clinical data. Likewise, the available modeling techniques and related software tools are manifold. Appropriately, the development, qualification, application, and impact of QSP models have been similarly varied. In this review, we describe the progressive maturation of a QSP modeling workflow: a necessary step for the efficient, reproducible development and qualification of QSP models, which themselves are highly iterative and evolutive. Furthermore, we describe three applications of QSP to impact drug development; one supporting new indications for an approved antidiabetic clinical asset through mechanistic hypothesis generation, one highlighting efficacy and safety differentiation within the sodium‐glucose cotransporter‐2 inhibitor drug class, and one enabling rational selection of immuno‐oncology drug combinations.

Empagliflozin Improves Kidney Outcomes in Patients With or Without Heart Failure

Background In EMPA-REG OUTCOME (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) empagliflozin significantly reduced the risk of cardiovascular and kidney outcomes in patients with type 2 diabetes mellitus and established cardiovascular disease. Post hoc, we evaluated empagliflozin on kidney outcomes in patients with or without heart failure (HF). Methods and Results Individuals were randomized to empagliflozin 10 mg, 25 mg, or placebo. Prespecified analyses by baseline HF status included risk of incident or worsening nephropathy and estimated glomerular filtration rate slope analyses. Cox proportional hazards models assessed consistency of treatment effect across subgroups. Safety evaluations included kidney-related adverse events. At baseline, 244 (10.5%) and 462 (9.9%) patients had HF in the placebo and empagliflozin groups, respectively. Overall, the incidence of kidney outcome events was numerically higher in patients with than without HF. In the HF group, empagliflozin reduced risk of incident or worsening nephropathy or cardiovascular death by 43% (hazard ratio, 0.57 [95% CI, 0.42-0.77]) and progression to macroalbuminuria by 50% (hazard ratio, 0.50 [0.33-0.75]). After an initial transient decrease, estimated glomerular filtration rate stabilized over time with empagliflozin but gradually declined with placebo. Kidney effects in patients with HF were consistent with those in the overall study population (all P values for interaction >0.05). Across groups, the incidence rate of kidney-related adverse events/100 patient-years was higher in patients with than without HF; however, overall rates were comparable between groups. Conclusions These findings from EMPA-REG OUTCOME support the hypothesis that empagliflozin could reduce the risk of clinically relevant kidney events and may slow progression of chronic kidney disease in individuals with type 2 diabetes mellitus regardless of HF status. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT01131676.