SGLT2 Inhibitors and Their Mode of Action in Heart Failure-Has the Mystery Been Unravelled?

Safety and Efficacy of Dapagliflozin in Patients with Heart Failure with Reduced Ejection Fraction: Multicentre Retrospective Study on Echocardiographic Parameters and Biomarkers of Heart Congestion

Objectives: Dapagliflozin has shown efficacy in clinical trials in patients with heart failure and reduced ejection fraction (HFrEF). However, real-world data on its use and outcomes in routine clinical practice are limited. We aimed to evaluate the utilisation and safety profile of dapagliflozin in a real-world population of HFrEF patients within the Marche region. Methods: Nine cardiology departments within the Marche region retrospectively included HFrEF patients who were initiated on dapagliflozin therapy in an outpatient setting. Data on medical history, comorbidities, echocardiographic parameters, and laboratory tests were collected at baseline and after 6 months. Telephone follow-up interviews were conducted at 1 and 3 months to assess adverse events. We defined the composite endpoint score as meeting at least 50% of four objective measures of improvement among: weight loss, NYHA decrease, ≥50% Natriuretic peptides (NP) decrease, and guideline/directed medical therapy (GDMT) up titration. Results: We included 95 HFrEF patients aged 66 ± 12 years, 82% were men, 48% had ischemic heart disease, and 20% had diabetes. At six months, glomerular filtration rate declined (p = 0.03) and natriuretic peptides levels decreased, on average, by 23% (p < 0.001). Echocardiographic measurements revealed a decrease in pulmonary artery pressure (p < 0.001) and E/e' (p < 0.001). In terms of drug therapy, furosemide dosage decreased (p = 0.001), and the percentage of the target dose achieved for angiotensin receptor-neprilysin inhibitors increased (p = 0.003). By multivariable Cox regression, after adjustment for age, sex, the presence of diabetes/prediabetes, and HF duration, higher baseline Hb concentrations (HR 1.347, 95% CI 1.038-1.746, p = 0.025), and eGFR levels (HR 1.016, 95% CI 1.000-1.033, p = 0.46). Conclusions: In a real-life HFrEF population, dapagliflozin therapy is safe and well-tolerated, improves echocardiographic parameters and biomarkers of congestion, and can also facilitate the titration of drugs with a prognostic impact.

Empagliflozin Improves Diastolic Function in HFpEF by Restabilizing the Mitochondrial Respiratory Chain

BACKGROUND

Clinical studies demonstrated beneficial effects of sodium-glucose-transporter 2 inhibitors on the risk of cardiovascular death in patients with heart failure with preserved ejection fraction (HFpEF). However, underlying processes for cardioprotection remain unclear. The present study focused on the impact of empagliflozin (Empa) on myocardial function in a rat model with established HFpEF and analyzed underlying molecular mechanisms.

METHODS

Obese ZSF1 (Zucker fatty and spontaneously hypertensive) rats were randomized to standard care (HFpEF, n=18) or Empa (HFpEF/Empa, n=18). ZSF1 lean rats (con, n=18) served as healthy controls. Echocardiography was performed at baseline and after 4 and 8 weeks, respectively. After 8 weeks of treatment, hemodynamics were measured invasively, mitochondrial function was assessed and myocardial tissue was collected for either molecular and histological analyses or transmission electron microscopy.

RESULTS

In HFpEF Empa significantly improved diastolic function (E/é: con: 17.5±2.8; HFpEF: 24.4±4.6; P<0.001 versus con; HFpEF/Empa: 19.4±3.2; P<0.001 versus HFpEF). This was accompanied by improved hemodynamics and calcium handling and by reduced inflammation, hypertrophy, and fibrosis. Proteomic analysis demonstrated major changes in proteins involved in mitochondrial oxidative phosphorylation. Cardiac mitochondrial respiration was significantly impaired in HFpEF but restored by Empa (Vmax complex IV: con: 0.18±0.07 mmol O2/s/mg; HFpEF: 0.13±0.05 mmol O2/s/mg; P<0.041 versus con; HFpEF/Empa: 0.21±0.05 mmol O2/s/mg; P=0.012 versus HFpEF) without alterations of mitochondrial content. The expression of cardiolipin, an essential stability/functionality-mediating phospholipid of the respiratory chain, was significantly decreased in HFpEF but reverted by Empa (con: 15.9±1.7 nmol/mg protein; HFpEF: 12.5±1.8 nmol/mg protein; P=0.002 versus con; HFpEF/Empa: 14.5±1.8 nmol/mg protein; P=0.03 versus HFpEF). Transmission electron microscopy revealed a reduced size of mitochondria in HFpEF, which was restored by Empa.

CONCLUSIONS

The study demonstrates beneficial effects of Empa on diastolic function, hemodynamics, inflammation, and cardiac remodeling in a rat model of HFpEF. These effects were mediated by improved mitochondrial respiratory capacity due to modulated cardiolipin and improved calcium handling.

Tuberculosis-diabetes comorbidities: Mechanistic insights for clinical considerations and treatment challenges

Tuberculosis (TB) remains a leading cause of death among infectious diseases, particularly in poor countries. Viral infections, multidrug-resistant and ex-tensively drug-resistant TB strains, as well as the coexistence of chronic illnesses such as diabetes mellitus (DM) greatly aggravate TB morbidity and mortality. DM [particularly type 2 DM (T2DM)] and TB have converged making their control even more challenging. Two contemporary global epidemics, TB-DM behaves like a syndemic, a synergistic confluence of two highly prevalent diseases. T2DM is a risk factor for developing more severe forms of multi-drug resistant-TB and TB recurrence after preventive treatment. Since a bidirectional relationship exists between TB and DM, it is necessary to concurrently treat both, and promote recommendations for the joint management of both diseases. There are also some drug-drug interactions resulting in adverse treatment outcomes in TB-DM patients including treatment failure, and reinfection. In addition, autophagy may play a role in these comorbidities. Therefore, the TB-DM comorbidities present several health challenges, requiring a focus on multidisciplinary collaboration and integrated strategies, to effectively deal with this double burden. To effectively manage the comorbidity, further screening in affected countries, more suitable drugs, and better treatment strategies are required.

Drug Therapy for Acute and Chronic Heart Failure with Preserved Ejection Fraction with Hypertension: A State-of-the-Art Review

In this comprehensive state-of-the-art review, we provide an evidence-based analysis of current drug therapies for patients with heart failure with preserved ejection fraction (HFpEF) in the acute and chronic phases with concurrent hypertension. Additionally, we explore the latest developments and emerging evidence on the efficacy, safety, and clinical outcomes of common and novel drug treatments in the management of HFpEF with concurrent hypertension. During the acute phase of HFpEF, intravenous diuretics, mineralocorticoid receptor antagonists (MRAs), and vasodilators are pivotal, while in the chronic phase, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have proven effective in enhancing clinical outcomes. However, the use of calcium channel blockers in HFpEF with hypertension should be approached with caution, owing to their potential negative inotropic effects. We also explored emerging drug therapies for HFpEF, such as sodium-glucose co-transporter 2 (SGLT2) inhibitors, angiotensin receptor-neprilysin inhibitor (ARNI), soluble guanylate cyclase (sGC) stimulators, novel MRAs, and ivabradine. Notably, SGLT2 inhibitors have shown promise in reducing heart failure hospitalizations and cardiovascular mortality in patients with HFpEF, regardless of their diabetic status. Additionally, ARNI and sGC stimulators have demonstrated potential in improving symptoms, functional capacity, and quality of life. Nonetheless, additional research is necessary to pinpoint optimal treatment strategies for HFpEF with concurrent hypertension. Furthermore, long-term studies are essential to assess the durability and sustained benefits of emerging drug therapies. Identification of novel targets and mechanisms underlying HFpEF pathophysiology will pave the way for innovative drug development approaches in the management of HFpEF with concurrent hypertension.

Novel Medical Treatments and Devices for the Management of Heart Failure with Reduced Ejection Fraction

Heart failure (HF) is a growing issue in developed countries; it is often the result of underlying processes such as ischemia, hypertension, infiltrative diseases or even genetic abnormalities. The great majority of the affected patients present a reduced ejection fraction (≤40%), thereby falling under the name of "heart failure with reduced ejection fraction" (HFrEF). This condition represents a major threat for patients: it significantly affects life quality and carries an enormous burden on the whole healthcare system due to its high management costs. In the last decade, new medical treatments and devices have been developed in order to reduce HF hospitalizations and improve prognosis while reducing the overall mortality rate. Pharmacological therapy has significantly changed our perspective of this disease thanks to its ability of restoring ventricular function and reducing symptom severity, even in some dramatic contexts with an extensively diseased myocardium. Notably, medical therapy can sometimes be ineffective, and a tailored integration with device technologies is of pivotal importance. Not by chance, in recent years, cardiac implantable devices witnessed a significant improvement, thereby providing an irreplaceable resource for the management of HF. Some devices have the ability of assessing (CardioMEMS) or treating (ultrafiltration) fluid retention, while others recognize and treat life-threatening arrhythmias, even for a limited time frame (wearable cardioverter defibrillator). The present review article gives a comprehensive overview of the most recent and important findings that need to be considered in patients affected by HFrEF. Both novel medical treatments and devices are presented and discussed.

Precision Cardiology: Phenotype-targeted Therapies for HFmrEF and HFpEF

Heart failure with mid-range ejection fraction (HFmrEF) and preserved ejection fraction (HFpEF) represent over half of heart failure cases but lack proven effective therapies beyond sodium-glucose cotransporter 2 inhibitor and diuretics. HFmrEF and HFpEF are heterogeneous conditions requiring precision phenotyping to enable tailored therapies. This review covers concepts on precision medicine approaches for HFmrEF and HFpEF. Areas discussed include HFmrEF mechanisms, anti-inflammatory and antifibrotic treatments for obesity-related HFpEF, If inhibition for HFpEF with atrial fibrillation, and mineralocorticoid receptor antagonism for chronic kidney disease-HFpEF. Incorporating precision phenotyping and matched interventions in HFmrEF and HFpEF trials will further advance therapy compared to blanket approaches.

Hypertrophic cardiomyopathy dysfunction mimicked in human engineered heart tissue and improved by sodium-glucose cotransporter 2 inhibitors

AIMS

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy, often caused by pathogenic sarcomere mutations. Early characteristics of HCM are diastolic dysfunction and hypercontractility. Treatment to prevent mutation-induced cardiac dysfunction is lacking. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a group of antidiabetic drugs that recently showed beneficial cardiovascular outcomes in patients with acquired forms of heart failure. We here studied if SGLT2i represent a potential therapy to correct cardiomyocyte dysfunction induced by an HCM sarcomere mutation.

METHODS AND RESULTS

Contractility was measured of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) harbouring an HCM mutation cultured in 2D and in 3D engineered heart tissue (EHT). Mutations in the gene encoding β-myosin heavy chain (MYH7-R403Q) or cardiac troponin T (TNNT2-R92Q) were investigated. In 2D, intracellular [Ca2+], action potential and ion currents were determined. HCM mutations in hiPSC-CMs impaired relaxation or increased force, mimicking early features observed in human HCM. SGLT2i enhance the relaxation of hiPSC-CMs, to a larger extent in HCM compared to control hiPSC-CMs. Moreover, SGLT2i-effects on relaxation in R403Q EHT increased with culture duration, i.e. hiPSC-CMs maturation. Canagliflozin's effects on relaxation were more pronounced than empagliflozin and dapagliflozin. SGLT2i acutely altered Ca2+ handling in HCM hiPSC-CMs. Analyses of SGLT2i-mediated mechanisms that may underlie enhanced relaxation in mutant hiPSC-CMs excluded SGLT2, Na+/H+ exchanger, peak and late Nav1.5 currents, and L-type Ca2+ current, but indicate an important role for the Na+/Ca2+ exchanger. Indeed, electrophysiological measurements in mutant hiPSC-CM indicate that SGLT2i altered Na+/Ca2+ exchange current.

CONCLUSION

SGLT2i (canagliflozin > dapagliflozin > empagliflozin) acutely enhance relaxation in human EHT, especially in HCM and upon prolonged culture. SGLT2i may represent a potential therapy to correct early cardiac dysfunction in HCM.

Identification of phytocompounds as potent inhibitors of sodium/glucose cotransporter-2 leading to diabetes treatment

Type-II diabetes, a major metabolic disorder has threatened the very existence of a healthy life since long ago. Commercially available antidiabetic drugs are known for several adverse effects. The present study attempted to identify potential phytocompounds as inhibitors of sodium/glucose cotransporter-2 (SGLT2), a major protein that helps in glucose re-absorption from renal tubules. A total of 28 phytocompounds were collected based on the literature survey. 3D co-ordinates of phytocompounds were collected from PubChem database. Molecular docking was carried out with SGLT2 protein and the best 3 docking complexes were subjected to molecular dynamics simulation for 100 ns. Free energy changes were also analyzed using MM/PBSA analysis. Phytocompounds were also analyzed for their drug-likeness and ADMET properties. Docking study observed a strong binding affinity of phytocompounds (> -7.0 kcal/mol). More than 10 phytocompounds showed better binding affinity compared to reference drugs. Further analysis of three best docking complexes when analyzed by MD simulation showed better stability and compactness of the complexes compared to reference drug, empagliflozin. MM/PBSA analysis also revealed that van der Waals force and electrostatic energy are the major binding energy involved in the complex formation. Like docking energy, free energy analysis also observed stronger binding energies (ΔGGAS) in SGLT2-phytocompound complexes compared to empagliflozin complex. All the phytocompounds showed drug-likeness and considerable ADMET properties. The study, therefore, suggests that Trifolirhizin-6'-monoacetate, Aspalathin, and Quercetin-3-glucoside could be a possible inhibitor of SGLT2 protein. However, further studies need to be carried out to reveal the exact mode of activity.Communicated by Ramaswamy H. Sarma.

Sodium-glucose co-transporter 2 inhibitor canagliflozin modulates myocardial metabolism and inflammation in a swine model for chronic myocardial ischemia

BACKGROUND

Inflammation and disruption of cardiac metabolism are prevalent in the setting of myocardial ischemia. Canagliflozin, a sodium-glucose costransporter-2 inhibitor, has beneficial effects on the heart, though the precise mechanisms are unknown. This study investigated the effects of canagliflozin therapy on metabolic pathways and inflammation in ischemic myocardial tissue using a swine model of chronic myocardial ischemia.

METHODS

Sixteen Yorkshire swine underwent placement of an ameroid constrictor to the left circumflex artery to induce chronic ischemia. Two weeks later, pigs received either no drug (n = 8) or 300 mg canagliflozin (n = 8) daily. Five weeks later, pigs underwent terminal harvest and tissue collection.

RESULTS

Canagliflozin treatment was associated with a trend toward decreased expression of fatty acid oxidation inhibitor acetyl-CoA carboxylase and decreased phosphorylated/inactivated acetyl-CoA carboxylase, a promotor of fatty acid oxidation, compared with control ischemic myocardium (P = .08, P = .03). There was also a significant modulation in insulin resistance markers p-IRS1, p-PKCα, and phosphoinositide 3-kinase in ischemic myocardium of the canagliflozin group compared with the control group (all P < .05). Canagliflozin treatment was associated with a significant increase in inflammatory markers interleukin 6, interleukin 17, interferon-gamma, and inducible nitric oxide synthase (all P < .05). There was a trend toward decreased expression of the anti-inflammatory cytokines interleukin 10 (P = .16) and interleukin 4 (P = .31) with canagliflozin treatment.

CONCLUSION

The beneficial effects of canagliflozin therapy appear to be associated with inhibition of fatty acid oxidation and enhancement of insulin signaling in ischemic myocardium. Interestingly, canagliflozin appears to increase the levels of several inflammatory markers, but further studies are required to better understand how canagliflozin modulates inflammatory signaling pathways.

SGLT2 Inhibition in Heart Failure: Clues to Cardiac Effects?

Following the publication of several landmark clinical trials such as dapagliflozin in patients with heart failure and reduced ejection fraction, dapagliflozin evaluation to improve the lives of patients with preserved ejection fraction heart failure, and empagliflozin outcome trial in patients with chronic heart failure with preserved ejection fraction, sodium-glucose cotransport 2 inhibitors have been rapidly incorporated as a guideline-directed therapy in the treatment of heart failure. Moreover, their benefits appear to extend across the spectrum of left ventricular dysfunction which in some respects, can be seen as the holy grail of heart failure pharmacotherapy. Despite its plethora of proven cardioprotective benefits, the mechanisms by which it exerts these effects remain poorly understood, however, it is clear that these extend beyond that of promotion of glycosuria and natriuresis. Several hypotheses have emerged over the years including modification of cardiovascular risk profile via weight reduction, improved glucose homeostasis, blood pressure control, and natriuretic effect; however, these mechanisms do not fully explain the potent effects of the drug demonstrated in large-scale randomized trials. Other mechanisms may be at play, specifically the down-regulation of inflammatory pathways, improved myocardial sodium homeostasis, modulation of profibrotic pathways, and activation of nutrient deprivation signaling pathways promoting autophagic flux. This review seeks to summarize the cardioprotective benefits demonstrated in major clinical trials and provide a succinct review of the current theories of mechanisms of action, based on the most recent evidence derived from both clinical and laboratory data.

The impact of empagliflozin and metformin on cardiac parameters in patients with mid-range ejection fraction heart failure without diabetes

Heart failure (HF) remains a significant problem for healthcare systems, requiring the use of intervention and multimodal management strategies. We aimed to assess the short-term effect of empagliflozin (EMPA) and metformin on cardiac function parameters, including ventricular dimension-hypertrophy, septal thickness, ejection fraction (EF), and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in patients with HF and mildly reduced EF. A case-control study included 60 newly diagnosed patients with HF. Patients were divided into two groups: Group E received standard HF treatment (carvedilol, bumetanide, sacubitril-valsartan, spironolactone) plus EMPA 10 mg daily, and Group M received standard HF treatment plus metformin 500 mg daily. After three months of treatment, Group E had a significantly higher EF than Group M compared to initial measurements (a change of 9.2% versus 6.1%, respectively). We found similar results in the left ventricular end-systolic dimension (LVESD), with mean reductions of 0.72 mm for Group E and 0.23 mm for Group M. Regarding cardiac indicators, the level of NT-proBNP was considerably decreased in both groups. However, the reduction was significantly greater in group E than in group M compared to the initial level (mean reduction: 719.9 vs. 973.6, respectively). When combined with quadruple anti-heart failure therapy, metformin enhanced several echocardiographic parameters, showing effects similar to those of EMPA when used in the same treatment regimen. However, the benefits of EMPA were more pronounced, particularly regarding improvements in EF and LVESD.

Sodium Glucose Co-Transporter 2 Inhibitors and the Cardiovascular System: Current Knowledge and Future Expectations

Diabetic cardiomyopathy is a well-recognized clinical entity and reflects a complex relationship between metabolic substrates and myocardial function. Sodium glucose co-transporter 2 (SGLT2) inhibitors are antidiabetic agents that are found to exert multiple cardioprotective effects. Large clinical trials showed their beneficial effects on patients with heart failure, reducing the rates of rehospitalizations and improving kidney function. The aim of this review is to summarize the latest evidence in the literature regarding the multiple effects of SGLT2 inhibitors on patients across the spectrum of cardiovascular diseases.

Cornerstone Cellular Pathways for Metabolic Disorders and Diabetes Mellitus: Non-Coding RNAs, Wnt Signaling, and AMPK

Metabolic disorders and diabetes (DM) impact more than five hundred million individuals throughout the world and are insidious in onset, chronic in nature, and yield significant disability and death. Current therapies that address nutritional status, weight management, and pharmacological options may delay disability but cannot alter disease course or functional organ loss, such as dementia and degeneration of systemic bodily functions. Underlying these challenges are the onset of aging disorders associated with increased lifespan, telomere dysfunction, and oxidative stress generation that lead to multi-system dysfunction. These significant hurdles point to the urgent need to address underlying disease mechanisms with innovative applications. New treatment strategies involve non-coding RNA pathways with microRNAs (miRNAs) and circular ribonucleic acids (circRNAs), Wnt signaling, and Wnt1 inducible signaling pathway protein 1 (WISP1) that are dependent upon programmed cell death pathways, cellular metabolic pathways with AMP-activated protein kinase (AMPK) and nicotinamide, and growth factor applications. Non-coding RNAs, Wnt signaling, and AMPK are cornerstone mechanisms for overseeing complex metabolic pathways that offer innovative treatment avenues for metabolic disease and DM but will necessitate continued appreciation of the ability of each of these cellular mechanisms to independently and in unison influence clinical outcome.

The impact of aging and oxidative stress in metabolic and nervous system disorders: programmed cell death and molecular signal transduction crosstalk

Life expectancy is increasing throughout the world and coincides with a rise in non-communicable diseases (NCDs), especially for metabolic disease that includes diabetes mellitus (DM) and neurodegenerative disorders. The debilitating effects of metabolic disorders influence the entire body and significantly affect the nervous system impacting greater than one billion people with disability in the peripheral nervous system as well as with cognitive loss, now the seventh leading cause of death worldwide. Metabolic disorders, such as DM, and neurologic disease remain a significant challenge for the treatment and care of individuals since present therapies may limit symptoms but do not halt overall disease progression. These clinical challenges to address the interplay between metabolic and neurodegenerative disorders warrant innovative strategies that can focus upon the underlying mechanisms of aging-related disorders, oxidative stress, cell senescence, and cell death. Programmed cell death pathways that involve autophagy, apoptosis, ferroptosis, and pyroptosis can play a critical role in metabolic and neurodegenerative disorders and oversee processes that include insulin resistance, β-cell function, mitochondrial integrity, reactive oxygen species release, and inflammatory cell activation. The silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), AMP activated protein kinase (AMPK), and Wnt1 inducible signaling pathway protein 1 (WISP1) are novel targets that can oversee programmed cell death pathways tied to β-nicotinamide adenine dinucleotide (NAD+), nicotinamide, apolipoprotein E (APOE), severe acute respiratory syndrome (SARS-CoV-2) exposure with coronavirus disease 2019 (COVID-19), and trophic factors, such as erythropoietin (EPO). The pathways of programmed cell death, SIRT1, AMPK, and WISP1 offer exciting prospects for maintaining metabolic homeostasis and nervous system function that can be compromised during aging-related disorders and lead to cognitive impairment, but these pathways have dual roles in determining the ultimate fate of cells and organ systems that warrant thoughtful insight into complex autofeedback mechanisms.

The Negative Impact of Insulin Resistance/Hyperinsulinemia on Chronic Heart Failure and the Potential Benefits of Its Screening and Treatment

This opinion article highlights the potential alterations caused by insulin resistance and hyperinsulinemia on the cardiovascular system and their negative impact on heart failure (HF), and describes the potential benefits of an early screening with consequent prompt treatment. HF is the final event of several different cardiovascular diseases. Its incidence has been increasing over the last decades because of increased survival from ischemic heart disease thanks to improvements in its treatment (including myocardial revascularization interventions) and the increase in life span. In particular, incidence of HF with preserved ejection fraction (HFpEF) is significantly increasing, and patients with HFpEF often are also affected by diabetes mellitus and insulin resistance (IR), with a prevalence > 45%. Concentric left ventricular (LV) remodeling and diastolic dysfunction are the main structural abnormalities that characterize HFpEF. It is well documented in the literature that IR with chronic hyperinsulinemia, besides causing type 2 diabetes mellitus, can cause numerous cardiovascular alterations, including endothelial dysfunction and increased wall thicknesses of the left ventricle with concentric remodeling and diastolic dysfunction. Therefore, it is conceivable that IR might play a major role in the pathophysiology and the progressive worsening of HF. To date, several substances have been shown to reduce IR/hyperinsulinemia and have beneficial clinical effects in patients with HF, including SGLT2 inhibitors, metformin, and berberine. For this reason, an early screening of IR could be advisable in subjects at risk and in patients with heart failure, to promptly intervene with appropriate therapy. Future studies aimed at comparing the efficacy of the substances used both alone and in association are needed.

Mechanisms of benefits of sodium-glucose cotransporter 2 inhibitors in heart failure with preserved ejection fraction

For decades, heart failure with preserved ejection fraction (HFpEF) proved an elusive entity to treat. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have recently been shown to reduce the composite of heart failure hospitalization or cardiovascular death in patients with HFpEF in the landmark DELIVER and EMPEROR-Preserved trials. While improvements in blood sugar, blood pressure, and attenuation of kidney disease progression all may play some role, preclinical and translational research have identified additional mechanisms of these agents. The SGLT2 inhibitors have intriguingly been shown to induce a nutrient-deprivation and hypoxic-like transcriptional paradigm, with increased ketosis, erythropoietin, and autophagic flux in addition to altering iron homeostasis, which may contribute to improved cardiac energetics and function. These agents also reduce epicardial adipose tissue and alter adipokine signalling, which may play a role in the reductions in inflammation and oxidative stress observed with SGLT2 inhibition. Emerging evidence also indicates that these drugs impact cardiomyocyte ionic homeostasis although whether this is through indirect mechanisms or via direct, off-target effects on other ion channels has yet to be clearly characterized. Finally, SGLT2 inhibitors have been shown to reduce myofilament stiffness as well as extracellular matrix remodelling/fibrosis in the heart, improving diastolic function. The SGLT2 inhibitors have established themselves as robust, disease-modifying therapies and as recent trial results are incorporated into clinical guidelines, will likely become foundational in the therapy of HFpEF.

Efficacy of sacubitril-valsartan and SGLT2 inhibitors in heart failure with reduced ejection fraction: A systematic review and meta-analysis

BACKGROUND

Sacubitril-valsartan (SV) monotherapy has been shown to help patients with Heart failure with reduced ejection fraction (HFrEF), but whether adding a sodium-glucose cotransporter-2 inhibitor (SGLT2i) improves treatment results even more is unknown.

HYPOTHESIS

The goal of this study was to look at the efficacy of SV with additional SGLT2i in HFrEF patients.

METHODS

For this study, several databases, such as PubMed, EMBASE, Web of Science, and the Cochrane Library, were searched. A coherent search approach was used for data extraction. Review Manager 5.2 and MedCalc were used for conducting the meta-analysis and bias analysis. A meta-regression study correlates patient mean age with primary and secondary outcomes.

RESULTS

Seven trials totaling 16 100 patients were included in this meta-analysis. All-cause mortality, cardiovascular mortality, and improvement in mean left ventricular ejection fraction (LVEF) were the study's major objectives, while hospitalization for heart failure (HF) was calculated to be its secondary outcome. Our analysis showed that HFrEF patients receiving the combination of SV and SGLT2i had better treatment outcomes than the standard SV monotherapy, with risk ratios of 0.76 (0.65-0.88) for all-cause mortality, 0.65 (0.49-0.86) for cardiovascular mortality, 1.41 (-0.59 to 3.42) for change in mean LVEF, and 0.80 (0.64-1.01) for hospitalization for HF. According to the regression analysis, older HFrEF patients have higher rates of hospitalization, cardiovascular disease, and overall death.

CONCLUSIONS

The combination of SV and SGLT2i may have a greater cardiovascular protective effect and minimize the risk of death or hospitalization due to heart failure in HFrEF.

The use of sodium-glucose cotransporter 2 inhibitors in heart failure with reduced or preserved ejection fraction: new guidelines hot off the press and directly into guidelines!

It is well known that the prevalence of heart failure (HF) is high and continues to grow. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, although initially developed as a therapy for type 2 diabetes, have been found to be beneficial in patients with HF, regardless of diabetic status. Given the clinical benefit demonstrated in recent large randomized clinical trials in those with HF, they have been rapidly incorporated into clinical practice and adopted by the national guidelines hot off the press. SGLT2 inhibitors are now recommended for patients with symptomatic HF, with any ejection fraction. These medications are generally very well tolerated by patients, and adverse effects include genital and soft tissue infections, euglycemic ketoacidosis, and volume depletion. SGLT2 inhibitors have now become a pillar of the pharmacologic treatment of HF, thus providers should be familiar with their use for not only those with type 2 diabetes, but also those with HF.

Effect of Dapagliflozin in Patients with Heart Failure: A Systematic Review and Meta-Analysis

Background

Heart failure (HF) is a major cause of recurrent hospitalization and death worldwide. Sodium-glucose cotransporter-2 inhibitors including dapagliflozin are anti-diabetic drugs with promising cardiovascular (CV) effects. We performed systematic review and meta-analysis of randomized controlled trials investigating the effects of dapagliflozin in heart failure patients.

Methods

We searched PubMed, Scopus and ScienceDirect databases. A total of 1,567 studies from January 2017 to September 10, 2022, were screened. After applying exclusion criteria, 22 studies were retrieved for full-text screening, and nine of them were eligible for this meta-analysis. Effect estimates for dichotomous variables were expressed as risk ratio (RR) and 95% CI. The primary outcomes were the incidence of all-cause mortality, hospitalization due to HF, and CV death. This review was registered on PROSPERO with ID CRD42022347793.

Results

A total of 14,032 patients were included. The overall risk ratio of all-cause mortality favored the dapagliflozin group over the placebo/standard therapy group (RR = 0.89, 95% CI: 0.82-0.97, P = 0.006) and the pooled studies were not heterogenous (I2 = 0%). Additionally, dapagliflozin significantly reduced the hospitalization due to heart failure (RR = 0.76, 95% CI: 0.70-0.84, P > 0.00001, I2 = 0%), cardiovascular death (RR = 0.87, 95% CI: 0.78-0.97, P = 0.01, I2 = 0%) and their composite outcomes.

Conclusion

Dapagliflozin reduces the risk of all-cause mortality, heart failure hospitalizations and cardiovascular death in a wide range of heart failure patients.

Efficacy and Safety of Sodium-Glucose Cotransporter 2 Inhibitors to Decrease the Risk of Cardiovascular Diseases: A Systematic Review

Cardiovascular disorders are one of the most frequent causes of death in people throughout the world. These disorders can account for the deaths of 31% of people worldwide. This systematic review examines the effectiveness of sodium-glucose cotransporter 2 (SGLT2) inhibitors in lowering the likelihood of cardiovascular diseases. The study aimed to evaluate various types of research, including randomized controlled trials and observational studies, to analyze how SGLT2 inhibitors impact cardiovascular disorders and establish evidence-based recommendations for clinical practice. The data in this research study were collected from 19 relevant published research articles. The key findings emphasized the potential advantages of SGLT2 inhibitors in reducing major cardiovascular disorders, such as myocardial infarction and stroke. Nonetheless, the study had certain limitations, including reliance on existing literature, exclusion of articles published prior to 2018, and restriction to English-language studies. Despite these limitations, this study contributed significantly to understanding the role of SGLT2 inhibitors in decreasing cardiovascular risk.

Innovative therapeutic strategies for cardiovascular disease

As a significant non-communicable disease, cardiovascular disease is the leading cause of death for both men and women, comprises almost twenty percent of deaths in most racial and ethnic groups, can affect greater than twenty-five million individuals worldwide over the age of twenty, and impacts global economies with far-reaching financial challenges. Multiple factors can affect the onset of cardiovascular disease that include high serum cholesterol levels, elevated blood pressure, tobacco consumption and secondhand smoke exposure, poor nutrition, physical inactivity, obesity, and concurrent diabetes mellitus. Yet, addressing any of these factors cannot completely eliminate the onset or progression of cardiovascular disorders. Novel strategies are necessary to target underlying cardiovascular disease mechanisms. The silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), a histone deacetylase, can limit cardiovascular injury, assist with stem cell development, oversee metabolic homeostasis through nicotinamide adenine dinucleotide (NAD+) pathways, foster trophic factor protection, and control cell senescence through the modulation of telomere function. Intimately tied to SIRT1 pathways are mammalian forkhead transcription factors (FoxOs) which can modulate cardiac disease to reduce oxidative stress, repair microcirculation disturbances, and reduce atherogenesis through pathways of autophagy, apoptosis, and ferroptosis. AMP activated protein kinase (AMPK) also is critical among these pathways for the oversight of cardiac cellular metabolism, insulin sensitivity, mitochondrial function, inflammation, and the susceptibility to viral infections such as severe acute respiratory syndrome coronavirus that can impact cardiovascular disease. Yet, the relationship among these pathways is both intricate and complex and requires detailed insight to successfully translate these pathways into clinical care for cardiovascular disorders.

Cognitive Impairment in Multiple Sclerosis

Almost three million individuals suffer from multiple sclerosis (MS) throughout the world, a demyelinating disease in the nervous system with increased prevalence over the last five decades, and is now being recognized as one significant etiology of cognitive loss and dementia. Presently, disease modifying therapies can limit the rate of relapse and potentially reduce brain volume loss in patients with MS, but unfortunately cannot prevent disease progression or the onset of cognitive disability. Innovative strategies are therefore required to address areas of inflammation, immune cell activation, and cell survival that involve novel pathways of programmed cell death, mammalian forkhead transcription factors (FoxOs), the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), the silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), and associated pathways with the apolipoprotein E (APOE-ε4) gene and severe acute respiratory syndrome coronavirus (SARS-CoV-2). These pathways are intertwined at multiple levels and can involve metabolic oversight with cellular metabolism dependent upon nicotinamide adenine dinucleotide (NAD+). Insight into the mechanisms of these pathways can provide new avenues of discovery for the therapeutic treatment of dementia and loss in cognition that occurs during MS.

Guideline-Directed Medical Therapy for the Treatment of Heart Failure with Reduced Ejection Fraction

Guideline-directed medical therapy (GDMT) is the cornerstone of pharmacological therapy for patients with heart failure with reduced ejection fraction (HFrEF) and consists of the four main drug classes: renin-angiotensin system inhibitors, evidence-based β-blockers, mineralocorticoid inhibitors and sodium glucose cotransporter 2 inhibitors. The recommendation for use of GDMT is based on the results of multiple major randomized controlled trials demonstrating improved clinical outcomes in patients with HFrEF who are maintained on this therapy. The effect is most beneficial when medications from the four main drug classes are used in conjunction. Despite this, there is an underutilization of GDMT, partially due to lack of awareness of how to safely and effectively initiate and titrate these medications. In this review article, we describe the different drug classes included in GDMT and offer an approach to initiation and effective titration in both the inpatient as well as outpatient setting.

Sodium-Glucose Co-Transporter 2 Inhibitors in Heart Failure-Current Evidence in Special Populations

Sodium-glucose co-transporter 2 (SGLT2) inhibitors, originally used for diabetes mellitus, are gaining more popularity for other indications, owing to their positive cardiovascular and renal effects. SGLT2 inhibitors reduce heart failure (HF) hospitalization and improve cardiovascular outcomes in patients with type 2 diabetes. Later, SGLT2 inhibitors were evaluated in patients with HF with reduced ejection fraction (HFREF) and had beneficial effects independent of the presence of diabetes. Recently, reductions in cardiovascular outcomes were also observed in patients with HF with preserved ejection fraction (HFPEF). SGLT2 inhibitors also reduced renal outcomes in patients with chronic kidney disease. Overall, these drugs have an excellent safety profile with a negligible risk of genitourinary tract infections and ketoacidosis. In this review, we discuss the current data on SGLT2 inhibitors in special populations, including patients with acute myocardial infarction, acute HF, right ventricular (RV) failure, left ventricular assist device (LVAD), and type 1 diabetes. We also discuss the potential mechanisms behind the cardiovascular benefits of these medications.

Cellular Metabolism: A Fundamental Component of Degeneration in the Nervous System

It is estimated that, at minimum, 500 million individuals suffer from cellular metabolic dysfunction, such as diabetes mellitus (DM), throughout the world. Even more concerning is the knowledge that metabolic disease is intimately tied to neurodegenerative disorders, affecting both the central and peripheral nervous systems as well as leading to dementia, the seventh leading cause of death. New and innovative therapeutic strategies that address cellular metabolism, apoptosis, autophagy, and pyroptosis, the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), growth factor signaling with erythropoietin (EPO), and risk factors such as the apolipoprotein E (APOE-ε4) gene and coronavirus disease 2019 (COVID-19) can offer valuable insights for the clinical care and treatment of neurodegenerative disorders impacted by cellular metabolic disease. Critical insight into and modulation of these complex pathways are required since mTOR signaling pathways, such as AMPK activation, can improve memory retention in Alzheimer's disease (AD) and DM, promote healthy aging, facilitate clearance of β-amyloid (Aß) and tau in the brain, and control inflammation, but also may lead to cognitive loss and long-COVID syndrome through mechanisms that can include oxidative stress, mitochondrial dysfunction, cytokine release, and APOE-ε4 if pathways such as autophagy and other mechanisms of programmed cell death are left unchecked.

Impact of dapagliflozin on cardiac function following anterior myocardial infarction in non-diabetic patients - DACAMI (a randomized controlled clinical trial)

BACKGROUND

The role of Sodium-glucose co-transporter 2 inhibitors (SGLT2i) in heart failure is established. Early data also suggests their favorable role in patients with acute coronary syndromes, but more evidence is still needed.

METHODS

In this dual center, double-blinded randomized controlled trial, non-diabetic patients (N = 100) who presented with anterior ST- elevation myocardial infarction (STEMI) & had undergone successful primary percutaneous coronary intervention, but their left ventricular ejection fraction was below 50%, were randomized to dapagliflozin 10 mg or a placebo once daily. The primary endpoint was a change in cardiac function assessed by N-terminal pro-Brain Natriuretic Peptide - NT-proBNP measured at baseline & 12 weeks post the cardiac event &/or echocardiographic parameters (left ventricular ejection fraction, left ventricular diastolic dimension & left ventricular mass index) assessed at baseline, 4-weeks & 12-weeks post the cardiac event.

RESULTS

From October 2021 to April 2022, 100 patients were randomized. The mean drop of NT- proBNP in the study group was more significant compared to the control group by 10.17% (95% CI: -3.28-19.67, p-value 0.034). In addition, the decrease in the left ventricular mass index (LV mass index) was also significant in the study group compared to the control group by 11.46% (95% CI: -19.37 to -3.56, p-value 0.029).

CONCLUSIONS

Dapagliflozin seems to have a role in preventing left ventricular dysfunction & maintaining cardiac function following anterior ST-elevation myocardial infarction. More Large-scale trials need to be done to confirm these findings further. This trial is locally registered at the National Heart Institute, Cairo - Egypt, and Faculty of Medicine, Ain Shams University, with reference numbers CTN1012021 & MS-07/2022, respectively. It is also registered retrospectively at the US National Institutes of Health (ClinicalTrial.gov) with identifier number: NCT05424315 - June 16th,2022.

Clinical pharmacology of SGLT-2 inhibitors in heart failure

INTRODUCTION

Sodium-glucose cotransporter 2 (SGLT2) inhibitors constitute a class of oral antiglycemic agents that have emerged as a new therapeutic strategy for heart failure (HF) with reduced ejection fraction (HFrEF) and, potentially, for HF with preserved ejection fraction (HFpEF).

AREAS COVERED

Ongoing efforts to clarify the exact mechanisms of action of SGLT2 inhibitors (SGLT2i) reveal that glycosuria and osmotic diuresis, resulting from the blockade of renal receptors, is not the sole pathophysiological mechanism. Nevertheless, the underlying mechanisms, accounting for their cardiovascular beneficial effects which have been clearly demonstrated in clinical trials, remain unclear. The aim of this review is to summarize the primary outcomes of large-scale studies regarding the use of SGLT2i in HF and provide an overview of the potential pathways involved in the SGLT2i-mediated cardioprotection.

EXPERT OPINION

SGLT2i exhibit favorable pleiotropic effects, which extend beyond their primary indication as pharmaceutical agents intended for glycemic control. Given their unique pathophysiological profile, these agents have revolutionized the management of HF, while in the near future, it is possible that evolving research in the field may unfold further perspectives on their potential use in the treatment of other chronic conditions.

Effects of Sodium-Glucose Cotransporter Inhibitor Use in Type 2 Diabetes Mellitus Patients With Heart Failure

The advances in the development of sodium-glucose cotransporter 2 inhibitors (SGLT2i) have expanded the variety of favorable approaches to treating diabetes mellitus. It is possible to have an improvement in insulin resistance and natriuresis by inhibiting the reabsorption of sodium and glucose at the proximal tubules in the kidney, and a decrease in cardiovascular mortality in patients with diabetes mellitus (DM). In addition, SGLT2i provides renoprotection by reducing intraglomerular higher blood pressure. The usage of SGLT2i also provides hemodynamic and metabolic benefits. SGLT2i demonstrates large cardiovascular benefits in patients both with and without diabetes, as well as in existing heart failure patients. These SGLT2i have direct and indirect effects on the kidney, likely contributing to stated cardiovascular benefits. Here we review the literature on the direct effects of SGLT2 inhibitors in diabetic patients with heart failure (HF). We assume that the benefit in cardiac cells modulated by SGLT2i is due to the inhibition of sodium transporters affecting intracellular sodium homeostasis. In conclusion, the sodium transporters in cardiac cells provide, at least partly, an example of the clinical benefits of SGLT2i observed in HF patients.

Emerging concepts in heart failure management and treatment: focus on SGLT2 inhibitors in heart failure with preserved ejection fraction

The role of sodium-glucose cotransporter 2 inhibitors (SLTG2i), developed initially as glucose-lowering agents, has represented a novelty in patients with heart failure (HF) and reduced ejection fraction (HFrEF) since dapagliflozin (DAPA-HF study) and empagliflozin (EMPEROR-Reduced study) were able to reduce morbidity and mortality in this setting regardless of the presence or absence of diabetes. In previous large clinical trials (EMPA-REG OUTCOME study, CANVAS, DECLARE-TIMI 58), SGLT2i have been shown to attenuate HF progression expressed by reducing the risk of HF hospitalizations in patients with type 2 diabetes mellitus mostly without HF at baseline. This benefit was then corroborated with positive results in HF outcomes (cardiovascular mortality and HF hospitalizations) in patients with HF with preserved ejection fraction (HFpEF) in the EMPEROR-Preserved (empagliflozin) and DELIVER (dapagliflozin) trials. Several biological mechanisms apart from the glycosuria are attributed to these agents in this last context, including anti-inflammatory effects, reduction of fibrosis and apoptosis, improvement of myocardial metabolism, mitochondrial function optimization, and oxidative stress protection. Moreover, SGLT2i can also improve ventricular loading conditions by forcing diuresis and natriuresis, and by enhancing vascular and renal function. In addition, SGLT2i can reduce myocardial passive stiffness (diastolic function) by enforcing the phosphorylation of myofilament modulatory proteins. This article provided an overview of the main pathophysiological characteristics of HFpEF and of the diverse mechanisms of action of SGLT2i in this setting. The supporting clinical evidence of SGLT2i in HFpEF (EMPEROR-Preserved and DELIVER trials) is also reviewed. This article is part of the Emerging concepts in heart failure management and treatment Special Issue: https://www.drugsincontext.com/special_issues/emerging-concepts-in-heart-failure-management-and-treatment.

Sodium-glucose Cotransporter 2 Inhibitors and Pathological Myocardial Hypertrophy

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new type of oral hypoglycemic drugs that exert a hypoglycemic effect by blocking the reabsorption of glucose in the proximal renal tubules, thus promoting the excretion of glucose from urine. Their hypoglycemic effect is not dependent on insulin. Increasing data shows that SGLT2 inhibitors improve cardiovascular outcomes in patients with type 2 diabetes. Previous studies have demonstrated that SGLT2 inhibitors can reduce pathological myocardial hypertrophy with or without diabetes, but the exact mechanism remains to be elucidated. To clarify the relationship between SGLT2 inhibitors and pathological myocardial hypertrophy, with a view to providing a reference for the future treatment thereof, this study reviewed the possible mechanisms of SGLT2 inhibitors in attenuating pathological myocardial hypertrophy. We focused specifically on the mechanisms in terms of inflammation, oxidative stress, myocardial fibrosis, mitochondrial function, epicardial lipids, endothelial function, insulin resistance, cardiac hydrogen and sodium exchange, and autophagy.

Assessing clinical and biomarker characteristics to optimize the benefits of sacubitril/valsartan in heart failure

Of the various medical therapies for heart failure (HF), sacubitril/valsartan is a first-in-class angiotensin receptor-neprilysin inhibitor that combines sacubitril, a pro-drug that is further metabolized to the neprilysin inhibitor sacubitrilat, and the angiotensin II type 1 receptor blocker valsartan. Inhibition of neprilysin and blockade of the angiotensin II type 1 receptor with sacubitril/valsartan increases vasoactive peptide levels, increasing vasodilation, natriuresis, and diuresis. Left ventricular ejection fraction (LVEF) is widely used to classify HF, to assist with clinical decision-making, for patient selection in HF clinical trials, and to optimize the benefits of sacubitril/valsartan in HF. However, as HF is a complex syndrome that occurs on a continuum of overlapping and changing phenotypes, patient classification based solely on LVEF becomes problematic. LVEF measurement can be imprecise, have low reproducibility, and often changes over time. LVEF may not accurately reflect inherent disease heterogeneity and complexity, and the addition of alternate criteria to LVEF may improve phenotyping of HF and help guide treatment choices. Sacubitril/valsartan may work, in part, by mechanisms that are not directly related to the LVEF. For example, this drug may exert antifibrotic and neurohumoral modulatory effects through inhibition or activation of several signaling pathways. In this review, we discuss markers of cardiac remodeling, fibrosis, systemic inflammation; activation of neurohormonal pathways, including the natriuretic system and the sympathetic nervous system; the presence of comorbidities; patient characteristics; hemodynamics; and HF signs and symptoms that may all be used to (1) better understand the mechanisms of action of sacubitril/valsartan and (2) help to identify subsets of patients who might benefit from treatment, regardless of LVEF.

Skeletal muscle phenotypic switching in heart failure with preserved ejection fraction

Background

Skeletal muscle (SkM) phenotypic switching is associated with exercise intolerance in heart failure with preserved ejection fraction (HFpEF). Patients with HFpEF have decreased type-1 oxidative fibers and mitochondrial dysfunction, indicative of impaired oxidative capacity. The SAUNA (SAlty drinking water/Unilateral Nephrectomy/Aldosterone) mice are commonly used in HFpEF pre-clinical studies and demonstrate cardiac, lung, kidney, and white adipose tissue impairments. However, the SkM (specifically the oxidative-predominant, soleus muscle) has not been described in this preclinical HFpEF model. We sought to characterize the soleus skeletal muscle in the HFpEF SAUNA mice and investigate its translational potential.

Methods

HFpEF was induced in mice by uninephrectomy, d-aldosterone or saline (Sham) infusion by osmotic pump implantation, and 1% NaCl drinking water was given for 4 weeks. Mice were euthanized, and the oxidative-predominant soleus muscle was collected. We examined fiber composition, fiber cross-sectional area, capillary density, and fibrosis. Molecular analyses were also performed. To investigate the clinical relevance of this model, the oxidative-predominant, vastus lateralis muscle from patients with HFpEF was biopsied and examined for molecular changes in mitochondrial oxidative phosphorylation, vasculature, fibrosis, and inflammation.

Results

Histological analyses demonstrated a reduction in the abundance of oxidative fibers, type-2A fiber atrophy, decreased capillary density, and increased fibrotic area in the soleus muscle of HFpEF mice compared to Sham. Expression of targets of interest such as a reduction in mitochondrial oxidative-phosphorylation genes, increased VEGF-α and an elevated inflammatory response was also seen. The histological and molecular changes in HFpEF mice are consistent and comparable with changes seen in the oxidative-predominant SkM of patients with HFpEF.

Conclusion

The HFpEF SAUNA model recapitulates the SkM phenotypic switching seen in HFpEF patients. This model is suitable and relevant to study SkM phenotypic switching in HFpEF.

Endothelial Dysfunction in Heart Failure With Preserved Ejection Fraction: What are the Experimental Proofs?

Heart failure with preserved ejection fraction (HFpEF) has been recognized as the greatest single unmet need in cardiovascular medicine. Indeed, the morbi-mortality of HFpEF is high and as the population ages and the comorbidities increase, so considerably does the prevalence of HFpEF. However, HFpEF pathophysiology is still poorly understood and therapeutic targets are missing. An unifying, but untested, theory of the pathophysiology of HFpEF, proposed in 2013, suggests that cardiovascular risk factors lead to a systemic inflammation, which triggers endothelial cells (EC) and coronary microvascular dysfunction. This cardiac small vessel disease is proposed to be responsible for cardiac wall stiffening and diastolic dysfunction. This paradigm is based on the fact that microvascular dysfunction is highly prevalent in HFpEF patients. More specifically, HFpEF patients have been shown to have decreased cardiac microvascular density, systemic endothelial dysfunction and a lower mean coronary flow reserve. Importantly, impaired coronary microvascular function has been associated with the severity of HF. This review discusses evidence supporting the causal role of endothelial dysfunction in the pathophysiology of HFpEF in human and experimental models.

Pharmacological mechanisms of sodium-glucose co-transporter 2 inhibitors in heart failure with preserved ejection fraction

Background

More and more evidence indicates sodium-glucose co-transporter 2 inhibitors (SGLT2is) may display clinical benefits for heart failure with preserved ejection fraction (HFpEF). However, the mechanisms of the action remain unclear.

Methods

A systematic pharmacology-based strategy was applied for predicting the potential molecular mechanisms of SGLT2is in HFpEF. The potential targets of SGLT2is and HFpEF were contained from diverse databases. After networks were constructed, Metascape was applied to functional enrichment. Moreover, the key findings were validated through molecular docking.

Results

We obtained 487 SGLT2is related targets and 1505 HFpEF related targets. The networks showed the complex relationship of HFpEF-target-HFpEF. The results of functional enrichment analysis suggested that several biological processes, including muscle system process, inflammatory response, vasculature development, heart development, regulation of MAPK cascade, positive regulation of ion transport, negative regulation of cell population proliferation, cellular response to nitrogen compound, apoptotic signaling pathway, multicellular organismal homeostasis, response to oxidative stress, regulation of cell adhesion, positive regulation of cell death, response to growth factor, and cellular response to lipid, and signaling pathways, such as cardiomyopathy, cAMP signaling pathway, cytokine-cytokine receptor interaction, apoptosis, MAPK signaling pathway, HIF-1 signaling pathway, calcium signaling pathway, and NF-kappa B signaling pathway. Finally, we validated the interactions and combinations of SGLT2is and core targets.

Conclusion

SGLT2is play the potential role of anti-HFpEF through the direct or indirect synergy of multiple targets and pathways. Our study promotes the explanation of the molecular mechanisms of SGLT2is in HFpEF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02693-8.

Promise of sodium-glucose co-transporter-2 inhibitors in heart failure with mildly reduced ejection fraction

Heart failure with mildly reduced ejection fraction (HFmrEF) is associated with comparable poor outcomes as other subtypes of heart failure and remains a medical unmet need due to the paucity of effective therapies. According to large cardiovascular (CV) outcome trials in patients with heart failure, sodium–glucose co‐transporter‐2 inhibitors (SGLT2is) reduce CV mortality and hospitalizations for heart failure in patients with heart failure across the spectrum of left ventricular ejection fraction (LVEF). There has been a lack of dedicated trials in HFmrEF. However, several large outcome trials in heart failure that enrolled patients with HFmrEF could provide a hint on the role of SGLT2is in this subgroup. This review focuses on CV effects of three major SGLT2is—dapagliflozin, empagliflozin, and sotagliflozin—in patients with HFmrEF. A narrative review of trials investigating the efficacy of each medication in treating heart failure with LVEF > 40% is provided with a focus on their LVEF subgroup analyses. The purpose of this review is to discuss the current state of evidence regarding the potential of SGLT2is in HFmrEF management. Current limited evidence suggests that SGLT2is might be a favourable treatment modality for patients with HFmrEF to reduce hospitalization for heart failure and CV mortality. This conclusion needs to be further supported by clear HFmrEF subgroup analysis of the existing trials. Further outcome trials involving sufficient patients with different subtypes of HFmrEF are needed to confirm and assess CV benefits of SGLT2is in HFmrEF. Possible mechanisms by which SGLT2is exert their cardioprotective effect are also described briefly.

Defining the Role of SGLT2 Inhibitors in Primary Care: Time to Think Differently

Disease burden in people with diabetes is mainly driven by long-term complications such as cardiovascular disease, heart failure and chronic kidney disease. This is a consequence of the interconnection between the cardiovascular, renal and metabolic systems, through a continuous chain of events referred to as 'the cardiorenal metabolic continuum'. Increasing evidence suggests that sodium-glucose cotransporter 2 inhibitors (SGLT2is) have beneficial effects across all stages of the cardiorenal metabolic continuum, reducing morbidity and mortality in a wide range of individuals, from those with diabetes and multiple risk factors to those with established heart failure and chronic kidney disease, regardless of the presence of diabetes. Despite this robust evidence base, the complexity of label indications and misconceptions concerning potential side effects have resulted in a lack of clear understanding in primary care regarding the implementation of SGLT2is in clinical practice. With this in mind, we provide an overview of the clinical and economic benefits of SGLT2is across the cardiorenal metabolic continuum together with practical considerations in order to help address some of these concerns and clearly define the role of SGLT2is in primary care as a holistic outcomes-driven treatment with the potential to reduce disease burden across the cardiorenal metabolic spectrum.

Canagliflozin Prevents Hyperglycemia-Associated Muscle Extracellular Matrix Accumulation and Improves the Adaptive Response to Aerobic Exercise

Chronic hyperglycemia is associated with low response to aerobic exercise training in rodent models and humans, including reduced aerobic exercise capacity and impaired oxidative remodeling in skeletal muscle. Here, we investigated whether glucose lowering with the sodium-glucose cotransporter 2 inhibitor (SGLT2i), canagliflozin (Cana; 30 mg/kg/day), could restore exercise training response in a model of hyperglycemia (low-dose streptozotocin [STZ]). Cana effectively prevented increased blood glucose in STZ-treated mice. After 6 weeks of voluntary wheel running, Cana-treated mice displayed improvements in aerobic exercise capacity, higher capillary density in striated muscle, and a more oxidative fiber-type in skeletal muscle. In contrast, these responses were blunted or absent in STZ-treated mice. Recent work implicates glucose-induced accumulation of skeletal muscle extracellular matrix (ECM) and hyperactivation of c-Jun N-terminal kinase (JNK)/SMAD2 mechanical signaling as potential mechanisms underlying poor exercise response. In line with this, muscle ECM accretion was prevented by Cana in STZ-treated mice. JNK/SMAD2 signaling with acute exercise was twofold higher in STZ compared with control but was normalized by Cana. In human participants, ECM accumulation was associated with increased JNK signaling, low VO2peak, and impaired metabolic health (oral glucose tolerance test-derived insulin sensitivity). These data demonstrate that hyperglycemia-associated impairments in exercise adaptation can be ameliorated by cotherapy with SGLT2i.

Cellular interplay between cardiomyocytes and non-myocytes in diabetic cardiomyopathy

Patients with Type 2 diabetes mellitus (T2DM) frequently exhibit a distinctive cardiac phenotype known as diabetic cardiomyopathy. Cardiac complications associated with T2DM include cardiac inflammation, hypertrophy, fibrosis and diastolic dysfunction in the early stages of the disease, which can progress to systolic dysfunction and heart failure. Effective therapeutic options for diabetic cardiomyopathy are limited and often have conflicting results. The lack of effective treatments for diabetic cardiomyopathy is due in part, to our poor understanding of the disease development and progression, as well as a lack of robust and valid preclinical human models that can accurately recapitulate the pathophysiology of the human heart. In addition to cardiomyocytes, the heart contains a heterogeneous population of non-myocytes including fibroblasts, vascular cells, autonomic neurons and immune cells. These cardiac non-myocytes play important roles in cardiac homeostasis and disease, yet the effect of hyperglycaemia and hyperlipidaemia on these cell types are often overlooked in preclinical models of diabetic cardiomyopathy. The advent of human induced pluripotent stem cells provides a new paradigm in which to model diabetic cardiomyopathy as they can be differentiated into all cell types in the human heart. This review will discuss the roles of cardiac non-myocytes and their dynamic intercellular interactions in the pathogenesis of diabetic cardiomyopathy. We will also discuss the use of sodium-glucose cotransporter 2 inhibitors as a therapy for diabetic cardiomyopathy and their known impacts on non-myocytes. These developments will no doubt facilitate the discovery of novel treatment targets for preventing the onset and progression of diabetic cardiomyopathy.

An Overview of the Cardiorenal Protective Mechanisms of SGLT2 Inhibitors

Sodium-glucose co-transporter 2 (SGLT2) inhibitors block glucose reabsorption in the renal proximal tubule, an insulin-independent mechanism that plays a critical role in glycemic regulation in diabetes. In addition to their glucose-lowering effects, SGLT2 inhibitors prevent both renal damage and the onset of chronic kidney disease and cardiovascular events, in particular heart failure with both reduced and preserved ejection fraction. These unexpected benefits prompted changes in treatment guidelines and scientific interest in the underlying mechanisms. Aside from the target effects of SGLT2 inhibition, a wide spectrum of beneficial actions is described for the kidney and the heart, even though the cardiac tissue does not express SGLT2 channels. Correction of cardiorenal risk factors, metabolic adjustments ameliorating myocardial substrate utilization, and optimization of ventricular loading conditions through effects on diuresis, natriuresis, and vascular function appear to be the main underlying mechanisms for the observed cardiorenal protection. Additional clinical advantages associated with using SGLT2 inhibitors are antifibrotic effects due to correction of inflammation and oxidative stress, modulation of mitochondrial function, and autophagy. Much research is required to understand the numerous and complex pathways involved in SGLT2 inhibition. This review summarizes the current known mechanisms of SGLT2-mediated cardiorenal protection.

Emerging Horizons in Heart Failure with Preserved Ejection Fraction: The Role of SGLT2 Inhibitors

Heart failure with preserved ejection fraction (HFpEF) is a condition with increasing disease burden. Prevalence of HFpEF is increasing, reflecting an increasingly elderly and comorbid population, as well as reinforcing the need for more treatments for this disease. The pathophysiology of HFpEF is complex. Some inflammatory processes seen in HFpEF are shared with diabetes mellitus (DM) and there is an association seen between the two conditions. It is therefore no wonder that treatments for diabetes may have some effect on heart failure outcomes. Current treatment strategies in HFpEF are limited, with treatments focusing on symptom control rather than morbidity or mortality benefit. However, there are now promising results from the EMPEROR-Preserved study that show significantly reduced cardiovascular death or hospitalisation for heart failure (HHF) in patients taking empagliflozin, compared to those taking placebo. These results indicate a promising future for sodium-glucose co-transporter 2 (SGLT2) inhibitors in HFpEF. The ongoing DELIVER trial (investigating the use of dapagliflozin in HFpEF) is awaited but could provide further evidence of support for SGLT2 inhibitors in HFpEF. With hospital admissions for HFpEF increasing in the UK, the economic impact of treatments that reduce HHF is vast. The European Society of Cardiology (ESC) recently added SGLT2 inhibitors to their guidelines for treatment of heart failure with reduced ejection fraction (HFrEF) following DAPA-HF and EMPEROR-Reduced trials and we suggest that similar changes be made to guidelines to support the use of SGLT2 inhibitors in the management of HFpEF in upcoming months.