Dual SGLT-1 and SGLT-2 inhibition improves left atrial dysfunction in HFpEF

Structural and functional adaptations of human cardiomyocytes in metabolic disease and heart failure

Heart failure (HF), obesity, and diabetes are associated with structural and functional changes that affect the heart at both the organ and cellular levels. Studying isolated adult single cardiomyocytes provides valuable mechanistic insights. However, isolating single cardiomyocytes from human tissue is particularly challenging. This study presents an optimized multiple-step digestion protocol to isolate viable cardiomyocytes from atrial and ventricular human tissue obtained perioperatively or through myocardial biopsies. Using this method and resource, we analyzed calcium-signaling during excitation-contraction coupling and structural features such as t-tubules and mitochondria using confocal microscopy in patients with or without HF, obesity, or diabetes. In a subset of patients undergoing open heart surgery, tissue samples and serum from the great cardiac vein were obtained either under control conditions or upon cardiac volume challenge (VC). We isolated viable cells and observed distinct structural differences between atrial and ventricular cardiomyocytes, including variations in t-tubular and cell size. In atrial cardiomyocytes, when comparing control with patients with HF, the t-tubular networks were unchanged. However, patients with obesity exhibited significantly more t-tubules associated with larger cell sizes. Furthermore, mitochondrial density appeared higher in patients with overweight and diabetes, suggesting that the metabolic status influences cardiomyocyte structure. Finally, when exposing isolated cardiomyocytes with VC serum from the respective patients, excitation-contraction coupling was markedly enhanced, indicating a distention-related alteration of the cardiac secretome with immediate effects on cardiomyocytes. In summary, an optimized protocol for isolating human cardiomyocytes confirmed structural features, identified disease-related changes, and allowed studying the dynamic impact of cardiac distention on secretome-related cardiomyocyte function.NEW & NOTEWORTHY This study presents a novel protocol for isolating human cardiomyocytes, uncovering atrial-ventricular structural differences, obesity-related increases in t-tubules and mitochondria, and metabolic influences on cell architecture. It highlights the dynamic effects of cardiac volume challenge on excitation-contraction coupling through secretome alterations. These advancements provide insights into how conditions like obesity and diabetes reshape cardiomyocyte structure and function, advancing our understanding of heart disease mechanisms.

Sotagliflozin provides additional benefits for high-fat diet-induced cardiac inflammatory injury by extra inhibiting P38MAPK and JNK

SGLT1/2 dual-target inhibitors have demonstrated significant benefits for diabetic patients, particularly those with cardiovascular complications. However, pharmacological mechanisms beyond SGLT1/2 inhibition remain incompletely understood. The current study investigated the effects of sotagliflozin, a representative SGLT1/2 inhibitor, on obesity-related cardiomyopathy and explored the underlying molecular mechanisms. A high-fat diet-induced obese mouse model was employed to evaluate cardiac function and biochemical parameters, complemented by transcriptomic analysis and network pharmacology to identify potential therapeutic targets. Results demonstrated that sotagliflozin effectively ameliorated hyperglycemia, hyperlipidemia, and hypertension in obese mice while significantly improving obesity-induced cardiac dysfunction through suppression of myocardial inflammatory responses. Transcriptomic analysis revealed enrichment of differentially expressed genes in the MAPK pathway, which was further corroborated by network pharmacology. Both in vivo and in vitro validation confirmed direct binding of sotagliflozin to P38MAPK and JNK, leading to significant inhibition of their activation induced by palmitic acid or high-fat diet. These findings suggest that the cardioprotective effects of sotagliflozin against obesity-related cardiomyopathy are mediated through multi-target inhibition of P38MAPK and JNK pathways. Targeting inflammatory signaling pathways while managing cardiovascular risk factors may represent a promising therapeutic strategy for obesity-associated cardiovascular diseases.

Mitochondrial Dysfunction in HFpEF: Potential Interventions Through Exercise

HFpEF is a prevalent and complex type of heart failure. The concurrent presence of conditions such as obesity, hypertension, hyperglycemia, and hyperlipidemia significantly increase the risk of developing HFpEF. Mitochondria, often referred to as the powerhouses of the cell, are crucial in maintaining cellular functions, including ATP production, intracellular Ca2+ regulation, reactive oxygen species generation and clearance, and the regulation of apoptosis. Exercise plays a vital role in preserving mitochondrial homeostasis, thereby protecting the cardiovascular system from acute stress, and is a fundamental component in maintaining cardiovascular health. In this study, we review the mitochondrial dysfunction underlying the development and progression of HFpEF. Given the pivotal role of exercise in modulating cardiovascular diseases, we particularly focus on exercise as a potential therapeutic strategy for improving mitochondrial function. Graphical abstract Note: This picture was created with BioRender.com.

Insights into the Roles of GLP-1, DPP-4, and SGLT2 at the Crossroads of Cardiovascular, Renal, and Metabolic Pathophysiology

In recent years, new drugs for the treatment of type 2 diabetes (T2D) have been proposed, including glucagon-like peptide 1 (GLP-1) agonists or sodium-glucose cotransporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors. Over time, some of these agents (in particular, GLP-1 agonists and SGLT2 inhibitors), which were initially developed for their glucose-lowering actions, have demonstrated significant beneficial pleiotropic effects, thus expanding their potential therapeutic applications. This review aims to discuss the mechanisms, pleiotropic effects, and therapeutic potential of GLP-1, DPP-4, and SGLT2, with a particular focus on their cardiorenal benefits beyond glycemic control.

Cardiovascular Outcomes in Patients with Complex Type 2 Diabetes Mellitus Treated with the Dual SGLT Inhibitor Sotagliflozin: A Meta-analysis

INTRODUCTION

Scientific publications have shown sodium-glucose co-transporter-2 (SGLT2) inhibitors to have several beneficial effects in patients with complex type 2 diabetes mellitus (T2DM). However, sodium-glucose co-transporter-1 (SGLT-1) inhibitor is still under investigation in clinical trials. Recently, a dual inhibitor of sodium-glucose co-transporter (SGLT1/2), sotagliflozin, has been approved for use in patients with T2DM. In this analysis, we aimed to systematically compare the cardiovascular outcomes in patients with complex T2DM who were treated with the newly approved dual (SGLT 1 and 2) inhibitor sotagliflozin.

METHODS

Electronic databases, including Embase, MEDLINE, http://www.

CLINICALTRIALS

gov , Web of Science, Google Scholar, the Cochrane database, and reference lists of relevant publications, were searched for publications comparing the novel SGLT1/2 inhibitor versus placebo for the treatment of patients with complex T2DM. The primary endpoint, including total number of deaths from cardiovascular causes, hospitalization for heart failure, and urgent visits for heart failure, death from cardiovascular causes, cardiac mortality, hospitalization for heart failure, non-fatal myocardial infarction, and total number of cardiac events, were considered as the endpoints in this analysis. The RevMan software version 5.4 was used to carry out the statistical analysis. Risk ratios (RR) with 95% confidence intervals (CI) were used to represent the data following analysis.

RESULTS

A total of 13,054 participants enrolled between 2017 and 2020 were included in this analysis, with 6734 participants assigned to sotagliflozin and 6320 assigned to placebo. The results of this analysis showed that the primary endpoint was significantly in favor of sotagliflozin with (RR: 0.73, 95% CI 0.67-0.80; P = 0.00001). Hospitalization for heart failure (RR: 0.67, 95% CI 0.60-0.75; P = 0.00001) and the total number of cardiac events (RR: 0.73, 95% CI 0.67-0.79; P = 0.00001) were also significantly lower with sotagliflozin when compared to placebo in these patients with complex T2DM. However, the risk for cardiovascular mortality and non-fatal myocardial infarction were not significantly different with (RR: 0.91, 95% CI 0.76-1.09; P = 0.31) and (RR: 0.92, 95% CI 0.27-3.12; P = 0.89), respectively.

CONCLUSIONS

Cardiovascular outcomes, including the total number of adverse cardiac events and hospitalization for heart failure, were significantly reduced with the newly approved SGLT1/2 inhibitor sotagliflozin apparently showing its cardiovascular efficacy in patients with complex T2DM. Future trials with larger sample sizes and a longer follow-up time could possibly confirm this hypothesis.

The role of SGLT1 in atrial fibrillation and its relationship with endothelial-mesenchymal transition

Atrial fibrillation (AF) is a prevalent arrhythmia closely associated with atrial fibrosis, posing significant challenges to cardiovascular health. Recent studies have identified the sodium-glucose co-transporter 1 (SGLT1) as a potential key player in the pathophysiology of heart diseases, particularly in the context of AF and atrial fibrosis. This review aims to synthesize current knowledge regarding the mechanisms by which SGLT1 influences the development of AF and atrial fibrosis, with a specific focus on its relationship with endothelial-mesenchymal transition (EMT). By analyzing the latest research findings, this paper discusses how SGLT1 may modulate structural and functional changes in the atria, thereby enhancing our understanding of the underlying mechanisms driving AF.

Redefining outcomes of ventricular arrhythmia for SGLT2 inhibitor medication in heart failure patients: a meta-analysis of randomized controlled trials

BACKGROUND

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have been shown to lower the risk of re-hospitalization and cardiovascular mortality among heart failure (HF) patients. Nevertheless, the impact of these agents on ventricular arrhythmias (VAs) has not been thoroughly investigated. To assess the beneficial impact of SGLT2 inhibitors on VAs in patients at various stages of HF, a systematic review and meta-analysis of randomized controlled trials involving SGLT2 inhibitors in this patient population was performed.

METHODS

A comprehensive search of the PubMed, Embase, Ovid, ProQuest, Scopus, and Cochrane databases was performed for clinical trials published up to November 21, 2024. The primary outcomes of interest were incidences of VAs and sudden cardiac death (SCD) between the groups receiving SGLT2 inhibitors and the control drugs. For the outcomes observed in the populations of the included trials and in specific subgroups, hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled and meta-analysed across the analyses.

RESULTS

A total of 23 randomized trials (22 placebo-controlled trials and 1 active-controlled trial) involving 74,380 patients (37,372 receiving SGLT2 inhibitors and 37,008 in the control group) were included. The analysed SGLT2 inhibitors included canagliflozin, dapagliflozin, empagliflozin, bexagliflozin, sotagliflozin, and ertugliflozin. The participants were non-advanced HF patients, including at-risk for HF, pre-HF, and symptomatic HF, with follow-up duration ranging from 12 to 296 weeks. Compared with the control, treatment with SGLT2 inhibitors was associated with significantly reduced risk of VAs (risk ratio (RR) 0.85, 95% confidence interval (CI) 0.74-0.98; P = 0.02) and SCD (RR 0.79, 95% CI 0.64-0.98; P = 0.03). Subgroup analyses indicated that longer follow-up (≥ 1 year) taking SGLT2 inhibitors can still reduce the risk of VAs (RR 0.79, 95% CI 0.65-0.96; P = 0.02) and SCD (RR 0.80, 95% CI 0.65-0.99; P = 0.04).

CONCLUSION

SGLT2 inhibitors have beneficial effects on lowering risks of VAs and SCD in patients with type 2 diabetes, cardiovascular diseases, heart failure with reduced ejection fraction (HFrEF), heart failure with preserved ejection fraction (HFpEF), and heart failure with mildly reduced ejection fraction (HFmrEF), with longer follow-up duration reinforcing these findings. However, future prospective trials are needed to verify the effects of SGLT2 inhibitors on VAs and SCD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (CRD42024601914).

Lack of renoprotective effects by long-term PCSK9 and SGLT2 inhibition using alirocumab and empagliflozin in obese ZSF1 rats

Chronic kidney disease (CKD) is associated with an increased risk of cardiovascular disease (CVD). Despite the entry of sodium glucose cotransporter 2 (SGLT2) inhibitors, CKD persists as a medical challenge. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition reduces low-density lipoprotein (LDL)-cholesterol, a major risk factor of CVD. Interestingly, studies indicate that PCSK9 inhibition decreases proteinuria in kidney disease, complementing the reduced CVD risk. This study aimed to validate obese ZSF1 rats as a model for the renoprotective effects of PCSK9 and SGLT2 inhibition using alirocumab and empagliflozin for 15 wk. Obese rats revealed a significant reduction in measured glomerular filtration rate (mGFR) and increased urine albumin/creatinine ratio (UACR) during follow-up compared with lean controls. Alirocumab treatment resulted in a decline in mGFR and increased UACR compared with vehicle-treated obese rats. Immunohistochemistry showed increased fibrosis and inflammation in kidney tissue from obese rats treated with empagliflozin or alirocumab, whereas hepatic cholesterol and triglyceride levels were lowered compared with vehicle-treated obese rats. Although alirocumab lowered circulating free cholesterol levels throughout the treatment period, certain cholesteryl esters were increased at the end of the study, resulting in no overall difference in total cholesterol levels in the alirocumab group. Correspondingly, only a trend toward increased hepatic LDL-receptor levels was observed. In conclusion, these findings suggest that alirocumab treatment aggravates kidney dysfunction in obese ZSF1 rats. Moreover, in contrast to the renoprotective properties of empagliflozin observed in patients with CKD, empagliflozin did not ameliorate kidney disease progression in the obese ZSF1 rat.NEW & NOTEWORTHY New treatments to slow kidney disease progression and reduce cardiovascular disease risk are needed for chronic kidney disease (CKD). We investigated the cholesterol-lowering PCSK9 inhibitor alirocumab as a new treatment for proteinuric CKD and the effect of SGLT2 inhibition using empagliflozin in obese ZSF1 rats. Regarding renoprotection, our findings were contradictory with previous preclinical studies and clinical data, suggesting that different pathophysiological mechanisms may apply to this rat model.

SGLT2 inhibitors for alleviating heart failure through non-hypoglycemic mechanisms

Sodium-glucose cotransporter-2 (SGLT2) inhibitors afford significant cardiovascular benefits to patients with diabetes mellitus and heart failure. Three large randomized clinical trials (EMPAREG-Outcomes, DECLARE-TIMI58, and DAPA-HF) have shown that SGLT2 inhibitors prevent cardiovascular events and reduce the risk of death and hospital admission resulting from heart failure. Patients without type 2 diabetes mellitus (T2DM) also experience a similar degree of cardiovascular benefit as those with T2DM do. SGLT2 inhibitors could improve cardiac function through potential non-hypoglycemic mechanisms, including the reduction of the circulatory volume load, regulation of energy metabolism, maintenance of ion homeostasis, alleviation of inflammation and oxidative stress, and direct inhibition of cardiac SGLT1 receptors and antimyocardial fibrosis. This article reviews the mechanism through which SGLT2 inhibitors prevent/alleviate heart failure through non-hypoglycemic pathways, to support their use for the treatment of heart failure in non-T2DM patients.

New Insights into the Role of SGLT-2 Inhibitors in the Prevention of Dementia

Diabetes mellitus (DM) is a chronic disease associated with numerous complications, including cardiovascular diseases, nephropathy, and neuropathy. Sodium-glucose cotransporter 2 (SGLT-2) inhibitors, a class of novel antidiabetic agents, have demonstrated promising therapeutic effects beyond glycemic control, with potential benefits extending to the cardiovascular and renal systems. Recently, research has increasingly focused on exploring the potential role of SGLT-2 inhibitors in preventing dementia. The aim of this review is to summarize the current research suggesting that SGLT-2 inhibitors, such as empagliflozin and dapagliflozin, may have neuroprotective effects that reduce dementia risk and improve cognitive function in type 2 diabetes patients. These benefits are likely due to better glycemic control, reduced oxidative stress, and less advanced glycation end-product (AGE) formation, all linked to neurodegeneration. Despite these promising findings, existing studies are limited by small sample sizes and short follow-up durations, which may not adequately capture long-term outcomes. To establish more robust evidence, larger-scale, long-term randomized controlled trials (RCTs) involving diverse populations are needed. These studies should involve diverse populations and focus on understanding the mechanisms behind the neuroprotective effects. Addressing these limitations will provide clearer guidelines for using SGLT-2 inhibitors in dementia prevention and management. This will help improve therapeutic strategies for cognitive health in diabetic patients.

Evaluation of the effect of empagliflozin on prevention of atrial fibrillation after coronary artery bypass grafting: a double-blind, randomized, placebo-controlled trial

This study is aimed at evaluating the effect of empagliflozin in preventing atrial fibrillation after coronary artery bypass grafting (CABG). Eighty-two patients who fulfilled the inclusion criteria were allocated to the empagliflozin group (n = 43) or placebo group (n = 39). In two groups, patients received empagliflozin or placebo tablets 3 days before surgery and on the first three postoperative days (for 6 days) in addition to the standard regimen during hospitalization. During the first 3 days after surgery, types of arrhythmias after cardiac surgery, including supraventricular arrhythmias, especially postoperative atrial fibrillation (POAF), ventricular arrhythmias, and heart blocks, were assessed by electrocardiogram monitoring. C-reactive protein (CRP) levels were evaluated pre-operatively and postoperative on the third day. The incidence of POAF in the treatment group was lower compared to the control group; however, this reduction was statistically non-significant (p = 0.09). The frequency of ventricular tachycardia was reduced significantly in the treatment group versus patients in the control (p = 0.02). Also, a significant reduction in the frequency of premature ventricular contractions (PVCs) was seen in the treatment group in comparison with the control group (p = 0.001). After the intervention, CRP levels were significantly less in the empagliflozin group compared to the control group in the third postoperative day (p = 0.04). The prophylactic use of empagliflozin effectively reduced the incidence of ventricular arrhythmia in patients undergoing CABG surgery.

Metabolic remodelling in atrial fibrillation: manifestations, mechanisms and clinical implications

Atrial fibrillation (AF) is a continually growing health-care burden that often presents together with metabolic disorders, including diabetes mellitus and obesity. Current treatments often fall short of preventing AF and its adverse outcomes. Accumulating evidence suggests that metabolic disturbances can promote the development of AF through structural and electrophysiological remodelling, but the underlying mechanisms that predispose an individual to AF are aetiology-dependent, thus emphasizing the need for tailored therapeutic strategies to treat AF that target an individual's metabolic profile. AF itself can induce changes in glucose, lipid and ketone metabolism, mitochondrial function and myofibrillar energetics (as part of a process referred to as 'metabolic remodelling'), which can all contribute to atrial dysfunction. In this Review, we discuss our current understanding of AF in the setting of metabolic disorders, as well as changes in atrial metabolism that are relevant to the development of AF. We also describe the potential of available and emerging treatment strategies to target metabolic remodelling in the setting of AF and highlight key questions and challenges that need to be addressed to improve outcomes in these patients.

Potential Mechanisms of Epicardial Adipose Tissue Influencing Heart Failure with Preserved Ejection Fraction

Heart failure (HF) is the predominant terminal stage and the leading cause of mortality in cardiac disease. Heart failure with preserved ejection fraction (HFpEF) affects roughly 50% of HF patients globally. Due to the global aging population, the prevalence, morbidity, and mortality of HFpEF have gradually increased. Epicardial adipose tissue (EAT), as a key visceral adipose tissue around the heart, affects cardiac diastolic function and exercise reserve capacity. EAT closely adheres to the myocardium and can produce inflammatory factors, neurotransmitters, and other factors through autocrine or paracrine mechanisms, affecting the heart function by inflammatory response, cardiac metabolism and energy supply, cardiomyocyte structure and electrical activity, and pericardial vascular function. Currently, research on the mechanism and treatment methods of HFpEF is constantly improving. EAT may play a multi-level impact on the occurrence and development of HFpEF. This review also summarizes the potential impact of EAT on the heart in HFpEF combined with other metabolism-related diseases such as obesity or diabetes over other obesity-related measures, such as body mass index (BMI) or other adipose tissue. Above all, this review comprehensively summarizes the potential mechanisms by which EAT may affect HFpEF. The objective is to enhance our comprehension and management of HFpEF. Future research should delve into the mechanistic relationship between EAT and HFpEF, and investigate interventions aimed at EAT to improve the prognosis of patients with HFpEF.

Left Atrial Hemodynamics and Clinical Utility in Heart Failure

Comprehensive knowledge of the left atrium (LA) and its pathophysiology has emerged as an important clinical and research focus in the heart failure (HF) arena. Although studies on HF focusing on investigating left ventricular remodeling are numerous, those on atrial structural and functional changes have received comparatively less attention. Studies on LA remodeling have recently received increasing attention, and LA pressure (LAP) has become a novel target for advanced monitoring and is a potential therapeutic approach for treating HF. Various devices specifically designed for the direct measurement of LAP have been developed to optimize HF treatment by reducing LAP. This review focuses on LA hemodynamic monitoring and effective LAP decompression.

Recent Advances in Understanding the Molecular Mechanisms of SGLT2 Inhibitors in Atrial Remodeling

Atrial cardiomyopathy and remodeling play pivotal roles in the development of atrial fibrillation (AF) and heart failure (HF), involving complex changes in atrial structure and function. These changes facilitate the progression of AF and HF by creating a dynamic interplay between mechanical stress and electrical disturbances in the heart. Sodium-glucose cotransporter 2 inhibitors (SGLT2is), initially developed for the management of type 2 diabetes, have demonstrated promising cardiovascular benefits, being currently one of the cornerstone treatments in HF management. Despite recent data from randomized clinical trials indicating that SGLT2is may significantly influence atrial remodeling, their overall effectiveness in this context is still under debate. Given the emerging evidence, this review examines the molecular mechanisms through which SGLT2is exert their effects on atrial remodeling, aiming to clarify their potential benefits and limitations. By exploring these mechanisms, this review aims to provide insights into how SGLT2is can be integrated into strategies for preventing the progression of atrial remodeling and HF, as well as the development of AF.

Empagliflozin and left atrial function in patients with type 2 diabetes mellitus and coronary artery disease: insight from the EMPA-HEART CardioLink-6 randomized clinical trial

BACKGROUND

Sodium-glucose cotransporter-2 (SGLT2) inhibitors have demonstrated reduction in heart failure outcomes in patients with type 2 diabetes mellitus, although the exact mechanism of benefit remains unclear. Alteration in left atrial (LA) function due to chronic pressure or volume overload is a hallmark of heart failure.

OBJECTIVE

To evaluate the effect of the SGLT2 inhibitor empagliflozin on LA volume and function.

METHODS

90 patients with coronary artery disease and type 2 diabetes (T2DM) were randomized to empagliflozin (n = 44) or placebo (n = 46), and underwent cardiac magnetic resonance (CMR) imaging at baseline and after 6 months. The main outcome was change in LA volume; LA function, including active and passive components, was also measured by a blinded reader.

RESULTS

At baseline, there was no significant difference in LA volumes between the empagliflozin (indexed maximum LA volume 26.4 ± 8.4mL/m2, minimum LA volume 11.1 ± 5.7mL/m2) and placebo (indexed maximum LA volume 28.7 ± 8.2mL/m2, minimum LA volume 12.6 ± 5.0mL/m2) groups. After 6 months, changes in LA volumes did not differ with adjusted difference (empagliflozin minus placebo): 0.99 mL/m2 (95% CI: -1.7 to 3.7 mL/m2; p = 0.47) for indexed maximum LA volume, and 0.87 mL/m2 (95% CI: -0.9 to 2.6 mL/m2; p = 0.32) for indexed minimum LA volume. Changes in total LA emptying fraction were also similar, with between-group adjusted mean difference - 0.01 (95% CI: -0.05 to 0.03, p = 0.59).

CONCLUSION

SGLT2 inhibition with empagliflozin for 6 months did not have a significant impact on LA volume and function in patients with T2DM and coronary artery disease. (Effects of Empagliflozin on Cardiac Structure in Patients with Type 2 Diabetes [EMPA-HEART]; NCT02998970).

Exploring the bone marrow micro environment in thalassemia patients: potential therapeutic alternatives

Genetic mutations in the β-globin gene lead to a decrease or removal of the β-globin chain, causing the build-up of unstable alpha-hemoglobin. This condition is referred to as beta-thalassemia (BT). The present treatment strategies primarily target the correction of defective erythropoiesis, with a particular emphasis on gene therapy and hematopoietic stem cell transplantation. However, the presence of inefficient erythropoiesis in BT bone marrow (BM) is likely to disturb the previously functioning BM microenvironment. This includes accumulation of various macromolecules, damage to hematopoietic function, destruction of bone cell production and damage to osteoblast(OBs), and so on. In addition, the changes of BT BM microenvironment may have a certain correlation with the occurrence of hematological malignancies. Correction of the microenvironment can be achieved through treatments such as iron chelation, antioxidants, hypoglycemia, and biologics. Hence, This review describes damage in the BT BM microenvironment and some potential remedies.

Empagliflozin inhibits increased Na influx in atrial cardiomyocytes of patients with HFpEF

AIMS

Heart failure with preserved ejection fraction (HFpEF) causes substantial morbidity and mortality. Importantly, atrial remodelling and atrial fibrillation are frequently observed in HFpEF. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have recently been shown to improve clinical outcomes in HFpEF, and post-hoc analyses suggest atrial anti-arrhythmic effects. We tested if isolated human atrial cardiomyocytes from patients with HFpEF exhibit an increased Na influx, which is known to cause atrial arrhythmias, and if that is responsive to treatment with the SGTL2i empagliflozin.

METHODS AND RESULTS

Cardiomyocytes were isolated from atrial biopsies of 124 patients (82 with HFpEF) undergoing elective cardiac surgery. Na influx was measured with the Na-dye Asante Natrium Green-2 AM (ANG-2). Compared to patients without heart failure (NF), Na influx was doubled in HFpEF patients (NF vs. HFpEF: 0.21 ± 0.02 vs. 0.38 ± 0.04 mmol/L/min (N = 7 vs. 18); P = 0.0078). Moreover, late INa (measured via whole-cell patch clamp) was significantly increased in HFpEF compared to NF. Western blot and HDAC4 pulldown assay indicated a significant increase in CaMKII expression, CaMKII autophosphorylation, CaMKII activity, and CaMKII-dependent NaV1.5 phosphorylation in HFpEF compared to NF, whereas NaV1.5 protein and mRNA abundance remained unchanged. Consistently, increased Na influx was significantly reduced by treatment not only with the CaMKII inhibitor autocamtide-2-related inhibitory peptide (AIP), late INa inhibitor tetrodotoxin (TTX) but also with sodium/hydrogen exchanger 1 (NHE1) inhibitor cariporide. Importantly, empagliflozin abolished both increased Na influx and late INa in HFpEF. Multivariate linear regression analysis, adjusting for important clinical confounders, revealed HFpEF to be an independent predictor for changes in Na handling in atrial cardiomyocytes.

CONCLUSION

We show for the first time increased Na influx in human atrial cardiomyocytes from HFpEF patients, partly due to increased late INa and enhanced NHE1-mediated Na influx. Empagliflozin inhibits Na influx and late INa, which could contribute to anti-arrhythmic effects in patients with HFpEF.

The Off-Target Cardioprotective Mechanisms of Sodium-Glucose Cotransporter 2 Inhibitors: An Overview

Sodium-glucose cotransporter 2 inhibitors (SGLT2i), a novel class of glucose-lowering drugs, have revolutionized the management of heart failure with reduced and preserved ejection fraction, regardless of the presence of diabetes, and are currently incorporated in the heart failure guidelines. While these drugs have consistently demonstrated their ability to decrease heart failure hospitalizations in several landmark clinical trials, their cardioprotective effects are far from having been completely elucidated. In the past decade, a growing body of experimental research has sought to address the molecular and cellular mechanisms of SGLT2i in order to provide a better understanding of the off-target acute and chronic cardiac benefits, beyond the on-target renal effect responsible for blood glucose reduction. The present narrative review addresses the direct cardioprotective effects of SGLT2i, delving into the off-target mechanisms of the drugs currently approved for heart failure therapy, and provides insights into future perspectives.

New Molecules in Type 2 Diabetes: Advancements, Challenges and Future Directions

Although good glycemic control in patients with type 2 diabetes (T2D) can prevent cardiovascular complications, many diabetic patients still have poor optimal control. A new class of antidiabetic drugs (e.g., glucagon-like peptide-1-GLP-1 receptor agonists, sodium-glucose co-transporters-SGLT2 inhibitors), in addition to the low hypoglycemic effect, exert multiple beneficial effects at a metabolic and cardiovascular level, through mechanisms other than antihyperglycemic agents. This review aims to discuss the effects of these new antidiabetic drugs, highlighting cardiovascular and metabolic benefits, through the description of their action mechanisms as well as available data by preclinical and clinical studies. Moreover, new innovative tools in the T2D field will be described which may help to advance towards a better targeted T2D personalized care in future.

Empagliflozin, a sodium-glucose cotransporter inhibitor enhancing mitochondrial action and cardioprotection in metabolic syndrome

Metabolic syndrome (MetS) has a large clinical population nowadays, usually due to excessive energy intake and lack of exercise. During MetS, excess nutrients stress the mitochondria, resulting in relative hypoxia in tissues and organs, even when blood supply is not interrupted or reduced, making mitochondrial dysfunction a central pathogenesis of cardiovascular disease in the MetS. Sodium-glucose cotransporter 2 inhibitors were designed as a hyperglycemic drug that acts on the renal tubules to block sugar reabsorption in primary urine. Recently they have been shown to have anti-inflammatory and other protective effects on cardiomyocytes in MetS, and have also been recommended in the latest heart failure guidelines as a routine therapy. Among these inhibitors, empagliflozin shows better clinical promise due to less influence from glomerular filtration rate. This review focuses on the mitochondrial mechanisms of empagliflozin, which underlie the anti-inflammatory and recover cellular functions in MetS cardiomyocytes, including stabilizing calcium concentration, mediating metabolic reprogramming, maintaining homeostasis of mitochondrial quantity and quality, stable mitochondrial DNA copy number, and repairing damaged mitochondrial DNA.

Sodium-glucose cotransporter 1 promotes the biofunctions of perivascular preadipocytes mediated by Akt/mTOR/p70S6K signaling pathway

The influence of SGLT-1 on perivascular preadipocytes (PVPACs) and vascular remodeling is not well understood. This study aimed to elucidate the role and mechanism of SGLT-1-mediated PVPACs bioactivity. PVPACs were cultured in vitro and applied ex vivo to the carotid arteries of mice using a lentivirus-based thermosensitive in situ gel (TISG). The groups were treated with Lv-SGLT1 (lentiviral vector, overexpression), Lv-siSGLT1 (RNA interference, knockdown), or specific signaling pathway inhibitors. Assays were conducted to assess changes in cell proliferation, apoptosis, glucose uptake, adipogenic differentiation, and vascular remodeling in the PVPACs. Protein expression was analyzed by Western blotting, immunocytochemistry, and/or immunohistochemistry. The methyl thiazolyl tetrazolium (MTT) assay and Hoechst 33342 staining indicated that SGLT-1 overexpression significantly promoted PVPACs proliferation and inhibited apoptosis in vitro. Conversely, SGLT-1 knockdown exerted the opposite effect. Oil Red O staining revealed that SGLT-1 overexpression facilitated adipogenic differentiation, while its inhibition mitigated these effects. 3H-labeled glucose uptake experiments demonstrated that SGLT-1 overexpression enhanced glucose uptake by PVPACs, whereas RNA interference-mediated SGLT-1 inhibition had no significant effect on glucose uptake. Moreover, RT-qPCR, Western blotting, and immunofluorescence analyses revealed that SGLT-1 overexpression upregulated FABP4 and VEGF-A levels and activated the Akt/mTOR/p70S6K signaling pathway, whereas SGLT-1 knockdown produced the opposite effects. In vivo studies corroborated these findings and indicated that SGLT-1 overexpression facilitated carotid artery remodeling. Our study demonstrates that SGLT-1 activation of the Akt/mTOR/p70S6K signaling pathway promotes PVPACs proliferation, adipogenesis, glucose uptake, glucolipid metabolism, and vascular remodeling.NEW & NOTEWORTHY SGLT-1 is expressed in PVPACs and can affect preadipocyte glucolipid metabolism and vascular remodeling. SGLT-1 promotes the biofunctions of PVPACs mediated by Akt/mTOR/p70S6K signaling pathway. Compared with caudal vein or intraperitoneal injection, the external application of lentivirus-based thermal gel around the carotid artery is an innovative attempt at vascular remodeling model, it may effectively avoid the transfection of lentiviral vector into the whole body of mice and the adverse effect on experimental results.

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.

Microvascular dysfunction in heart transplantation is associated with altered cardiomyocyte mitochondrial structure and unimpaired excitation-contraction coupling

INTRODUCTION

Microvascular dysfunction (MVD) is a hallmark feature of chronic graft dysfunction in patients that underwent orthotopic heart transplantation (OHT) and is the main contributor to impaired long-term graft survival. The aim of this study was to determine the effect of MVD on functional and structural properties of cardiomyocytes isolated from ventricular biopsies of OHT patients.

METHODS

We included 14 patients post-OHT, who had been transplanted for 8.1 years [5.0; 15.7 years]. Mean age was 49.6 ± 14.3 years; 64% were male. Coronary microvasculature was assessed using guidewire-based coronary flow reserve(CFR)/index of microvascular resistance (IMR) measurements. Ventricular myocardial biopsies were obtained and cardiomyocytes were isolated using enzymatic digestion. Cells were electrically stimulated and subcellular Ca2+ signalling as well as mitochondrial density were measured using confocal imaging.

RESULTS

MVD measured by IMR was present in 6 of 14 patients with a mean IMR of 53±10 vs. 12±2 in MVD vs. controls (CTRL), respectively. CFR did not differ between MVD and CTRL. Ca2+ transients during excitation-contraction coupling in isolated ventricular cardiomyocytes from a subset of patients showed unaltered amplitudes. In addition, Ca2+ release and Ca2+ removal were not significantly different between MVD and CTRL. However, mitochondrial density was significantly increased in MVD vs. CTRL (34±1 vs. 29±2%), indicating subcellular changes associated with MVD.

CONCLUSION

In-vivo ventricular microvascular dysfunction post OHT is associated with preserved excitation-contraction coupling in-vitro, potentially owing to compensatory changes on the mitochondrial level or due to the potentially reversible cause of the disease.

The interplay between sodium/glucose cotransporter type 2 and mitochondrial ionic environment

Mitochondrial volume is maintained through the permeability of the inner mitochondrial membrane by a specific aquaporin and the osmotic balance between the mitochondrial matrix and cellular cytoplasm. Various electrolytes, such as calcium and hydrogen ions, potassium, and sodium, as well as other osmotic substances, affect the swelling of mitochondria. Intracellular glucose levels may also affect mitochondrial swelling, although the relationship between mitochondrial ion homeostasis and intracellular glucose is poorly understood. This article reviews what is currently known about how the Sodium-Glucose transporter (SGLT) may impact mitochondrial sodium (Na+) homeostasis. SGLTs regulate intracellular glucose and sodium levels and, therefore, interfere with mitochondrial ion homeostasis because mitochondrial Na+ is closely linked to cytoplasmic calcium and sodium dynamics. Recently, a large amount of data has been available on the effects of SGLT2 inhibitors on mitochondria in different cell types, including renal proximal tubule cells, endothelial cells, mesangial cells, podocytes, neuronal cells, and cardiac cells. The current evidence suggests that SGLT inhibitors (SGLTi) may affect mitochondrial dynamics regarding intracellular Sodium and hydrogen ions. Although the regulation of mitochondrial ion channels by SGLTs is still in its infancy, the evidence accumulated thus far of the effect of SGLTi on mitochondrial functions certainly will foster further research in this direction.

Hepatoprotective and cardioprotective effects of empagliflozin in spontaneously hypertensive rats fed a high-fat diet

A combination of liver and heart dysfunction worsens the prognosis of human survival. The aim of this study was to investigate whether empagliflozin (a sodium-glucose transporter-2 inhibitor) has beneficial effects not only on cardiac and renal function but also on hepatic function. Adult (6-month-old) male spontaneously hypertensive rats (SHR) were fed a high-fat diet (60% fat) for four months to induce hepatic steatosis and mild heart failure. For the last two months, the rats were treated with empagliflozin (empa, 10 mg.kg-1.day-1 in the drinking water). Renal function and oral glucose tolerance test were analyzed in control (n=8), high-fat diet (SHR+HF, n=10), and empagliflozin-treated (SHR+HF+empa, n=9) SHR throughout the study. Metabolic parameters and echocardiography were evaluated at the end of the experiment. High-fat diet feeding increased body weight and visceral adiposity, liver triglyceride and cholesterol concentrations, and worsened glucose tolerance. Although the high-fat diet did not affect renal function, it significantly worsened cardiac function in a subset of SHR rats. Empagliflozin reduced body weight gain but not visceral fat deposition. It also improved glucose sensitivity and several metabolic parameters (plasma insulin, uric acid, and HDL cholesterol). In the liver, empagliflozin reduced ectopic lipid accumulation, lipoperoxidation, inflammation and pro-inflammatory HETEs, while increasing anti-inflammatory EETs. In addition, empagliflozin improved cardiac function (systolic, diastolic and pumping) independent of blood pressure. The results of our study suggest that hepatoprotection plays a decisive role in the beneficial effects of empagliflozin in preventing the progression of cardiac dysfunction induced by high-fat diet feeding.

Sotagliflozin versus dapagliflozin to improve outcome of patients with diabetes and worsening heart failure: a cost per outcome analysis

Background and aim

Dapagliflozin inhibits the sodium-glucose cotransporter protein 2 (SGLT-2), while sotagliflozin, belonging to a new class of dual-acting SGLT-1/SGLT-2 inhibitors, has garnered considerable attention due to its efficacy and safety. Both Dapagliflozin and sotagliflozin play a significant role in treating worsening heart failure in diabetes/nondiabetes patients with heart failure. Therefore, this article was to analyze and compare the cost per outcome of both drugs in preventing one event in patients diagnosed with diabetes-related heart failure.

Method

The Cost Needed to Treat (CNT) was employed to calculate the cost of preventing one event, and the Number Needed to Treat (NNT) represents the anticipated number of patients requiring the intervention treatment to prevent a single adverse event, or the anticipated number of patients needing multiple treatments to achieve a beneficial outcome. The efficacy and safety data were obtained from the results of two published clinical trials, DAPA-HF and SOLOIST-WHF. Due to the temporal difference in the drugs' releases, we temporarily analyzed the price of dapagliflozin to calculate the price of sotagliflozin within the same timeframe. The secondary analyses aimed to assess the stability of the CNT study and minimize differences between the results of the RCT control and trial groups, employing one-way sensitivity analyses.

Result

The final results revealed an annualized Number Needed to Treat (aNNT) of 4 (95% CI 3-7) for preventing one event with sotagliflozin, as opposed to 23 (95% CI 16-55) for dapagliflozin. We calculated dapagliflozin's cost per prevented event (CNT) to be $109,043 (95% CI $75,856-$260,755). The price of sotagliflozin was set below $27,260, providing a favorable advantage. Sensitivity analysis suggests that sotagliflozin may hold a cost advantage.

Conclusion

In this study, sotagliflozin was observed to exhibit a price advantage over dapagliflozin in preventing one events, cardiovascular mortality, or all-cause mortality in patients with diabetes.

Impairment of the adrenergic reserve associated with exercise intolerance in a murine model of heart failure with preserved ejection fraction

AIM

Exercise intolerance is the central symptom in patients with heart failure with preserved ejection fraction. In the present study, we investigated the adrenergic reserve both in vivo and in cardiomyocytes of a murine cardiometabolic HFpEF model.

METHODS

12-week-old male C57BL/6J mice were fed regular chow (control) or a high-fat diet and L-NAME (HFpEF) for 15 weeks. At 27 weeks, we performed (stress) echocardiography and exercise testing and measured the adrenergic reserve and its modulation by nitric oxide and reactive oxygen species in left ventricular cardiomyocytes.

RESULTS

HFpEF mice (preserved left ventricular ejection fraction, increased E/e', pulmonary congestion [wet lung weight/TL]) exhibited reduced exercise capacity and a reduction of stroke volume and cardiac output with adrenergic stress. In ventricular cardiomyocytes isolated from HFpEF mice, sarcomere shortening had a higher amplitude and faster relaxation compared to control animals. Increased shortening was caused by a shift of myofilament calcium sensitivity. With addition of isoproterenol, there were no differences in sarcomere function between HFpEF and control mice. This resulted in a reduced inotropic and lusitropic reserve in HFpEF cardiomyocytes. Preincubation with inhibitors of nitric oxide synthases or glutathione partially restored the adrenergic reserve in cardiomyocytes in HFpEF.

CONCLUSION

In this murine HFpEF model, the cardiac output reserve on adrenergic stimulation is impaired. In ventricular cardiomyocytes, we found a congruent loss of the adrenergic inotropic and lusitropic reserve. This was caused by increased contractility and faster relaxation at rest, partially mediated by nitro-oxidative signaling.

Harnessing the Synergy of SGLT2 Inhibitors and Continuous Ketone Monitoring (CKM) in Managing Heart Failure among Patients with Type 1 Diabetes

Heart failure (HF) management in type 1 diabetes (T1D) is particularly challenging due to its increased prevalence and the associated risks of hospitalization and mortality, driven by diabetic cardiomyopathy. Sodium-glucose cotransporter-2 inhibitors (SGLT2-is) offer a promising avenue for treating HF, specifically the preserved ejection fraction variant most common in T1D, but their utility is hampered by the risk of euglycemic diabetic ketoacidosis (DKA). This review investigates the potential of SGLT2-is in T1D HF management alongside emergent Continuous Ketone Monitoring (CKM) technology as a means to mitigate DKA risk through a comprehensive analysis of clinical trials, observational studies, and reviews. The evidence suggests that SGLT2-is significantly reduce HF hospitalization and enhance cardiovascular outcomes. However, their application in T1D patients remains limited due to DKA concerns. CKM technology emerges as a crucial tool in this context, offering real-time monitoring of ketone levels, which enables the safe incorporation of SGLT2-is into treatment regimes by allowing for early detection and intervention in the development of ketosis. The synergy between SGLT2-is and CKM has the potential to revolutionize HF treatment in T1D, promising improved patient safety, quality of life, and reduced HF-related morbidity and mortality. Future research should aim to employ clinical trials directly assessing this integrated approach, potentially guiding new management protocols for HF in T1D.

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.

Guideline directed medical therapy induced nephrotoxicity in HFrEF patients; an insight to its mechanism

Guideline Directed Medical Therapy (GDMT) has been the standard pharmacotherapy for the treatment of Heart Failure patients with reduced Ejection Fraction (HFrEF) recommended by the European Society of Cardiology (ESC). However, patients on GDMT are likely to possess nephrotoxicity as an adverse effect. We utilized multiple system biology tools like ADVER-Pred, gene enrichment analysis, molecular docking, molecular dynamic simulations, and MMPBSA analysis to predict a possible molecular mechanism of how selected combinations of GDMT may cause nephrotoxicity. As per the ACC/AHA/ESC guidelines, we categorized the drugs as category 1 including β-blockers (BB), angiotensin receptor blockers (ARB), and sodium-glucose cotransporter-2 inhibitors (SGLT2I), category 2 includes BB's, SGLT2I, and angiotensin receptor-neprilysin inhibitors (ARNI), and category 3 includes BB's, SGLT2I, and angiotensin-converting enzyme (ACE) inhibitors. Enrichment analysis predicted category 2 drugs to possess the highest number of proteins to be involved in the development of nephrotoxicity i.e. 79.41%. The targets HBA1, CBR1, ATG5, and SLC6A3 were the top hub genes with an edge count of 7 followed by GPX1 with an edge count of 6. Molecular docking studies revealed candesartan-SLC6A3 to possess the highest binding affinity of -10.2 kcal/mol. In addition, simulation studies displayed empagliflozin-CBR1 to possess the highest stability followed by candesartan-ATG5. A combination of β-blockers, ARBs, and SGLT2I are predicted to likely possess nephrotoxicity which may be due to the modulation of HBA1, CBR1, ATG5, and GPX1. In conclusion, candesartan and empagliflozin are most likely to cause nephrotoxicity via the modulation of HBA1, CBR1, ATG5, and GPX1.

SGLT2 inhibitors: Beyond glycemic control

Multiple randomized controlled trials have extensively examined the therapeutic effectiveness of sodium-glucose cotransporter 2 (SGLT2) inhibitors, ushering in a transformative approach to treating individuals with type 2 diabetes mellitus (DM). Notably, emerging reports have drawn attention to the potential positive impacts of SGLT2 inhibitors in nondiabetic patients. In an effort to delve into this phenomenon, a comprehensive systematic literature review spanning PubMed (NLM), Medline (Ovid), and Cochrane Library, covering publications from 2000 to 2024 was undertaken. This systematic review encompassed twenty-six randomized control trials (RCTs) involving 35,317 participants. The findings unveiled a multifaceted role for SGLT2 inhibitors, showcasing their ability to enhance metabolic control and yield cardioprotective effects through a reduction in cardiovascular death (CVD) and hospitalization related to heart failure (HF). Additionally, a renalprotective effect was observed, evidenced by a slowdown in chronic kidney disease (CKD) progression and a decrease in albuminuria. Importantly, these benefits were coupled with an acceptable safety profile. The literature also points to various biological plausibility and underlying mechanistic pathways, offering insights into the association between SGLT2 inhibitors and these positive outcomes in nondiabetic individuals. Current research trends indicate a continual exploration of additional role for SGLT2 inhibitors in. Nevertheless, further research is imperative to fully elucidate the mechanisms and long-term outcomes associated with the nondiabetic use of SGLT2 inhibitors.

Chapter 2: Clinical and Mechanistic Potential of Sodium-Glucose Co-Transporter 2 (SGLT2) Inhibitors in Heart Failure with Preserved Ejection Fraction

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have emerged as an important approach for the treatment of heart failure in patients with or without diabetes. Although the precise mechanisms underpinning their clinical impact remain incompletely resolved, mechanistic studies and insights from major clinical trials have demonstrated the impact of SGLT2 inhibitors on numerous cardio-renal-metabolic pathways of relevance to heart failure with preserved ejection fraction (HFpEF), which, in the contemporary era, constitutes approximately half of all patients with heart failure. Despite rates of morbidity and mortality that are commensurate with those of heart failure with reduced ejection fraction, disease-modifying therapies have comparatively been severely lacking. As such, HFpEF remains among the greatest unmet needs in cardiovascular medicine. Within the past decade, HFpEF has been established as a highly integrated disorder, involving not only the cardiovascular system, but also the lungs, kidneys, skeletal muscle, and adipose tissue. Given their multisystem impact, SGLT2i offer unique promise in addressing the complex pathophysiology of HFpEF, and in recent randomized controlled trials, were shown to significantly reduce heart failure events and cardiovascular death in patients with HFpEF. Herein, we discuss several proposed mechanisms of clinical benefit of SGLT2i in HFpEF.

Acute antiarrhythmic effects of SGLT2 inhibitors-dapagliflozin lowers the excitability of atrial cardiomyocytes

In recent years, SGLT2 inhibitors have become an integral part of heart failure therapy, and several mechanisms contributing to cardiorenal protection have been identified. In this study, we place special emphasis on the atria and investigate acute electrophysiological effects of dapagliflozin to assess the antiarrhythmic potential of SGLT2 inhibitors. Direct electrophysiological effects of dapagliflozin were investigated in patch clamp experiments on isolated atrial cardiomyocytes. Acute treatment with elevated-dose dapagliflozin caused a significant reduction of the action potential inducibility, the amplitude and maximum upstroke velocity. The inhibitory effects were reproduced in human induced pluripotent stem cell-derived cardiomyocytes, and were more pronounced in atrial compared to ventricular cells. Hypothesizing that dapagliflozin directly affects the depolarization phase of atrial action potentials, we examined fast inward sodium currents in human atrial cardiomyocytes and found a significant decrease of peak sodium current densities by dapagliflozin, accompanied by a moderate inhibition of the transient outward potassium current. Translating these findings into a porcine large animal model, acute elevated-dose dapagliflozin treatment caused an atrial-dominant reduction of myocardial conduction velocity in vivo. This could be utilized for both, acute cardioversion of paroxysmal atrial fibrillation episodes and rhythm control of persistent atrial fibrillation. In this study, we show that dapagliflozin alters the excitability of atrial cardiomyocytes by direct inhibition of peak sodium currents. In vivo, dapagliflozin exerts antiarrhythmic effects, revealing a potential new additional role of SGLT2 inhibitors in the treatment of atrial arrhythmias.

Aging and atrial fibrillation: A vicious circle

Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia observed in clinical practice. Its prevalence increases dramatically with advancing age. This review article discusses the recent advances in studies investigating the relationship between aging and AF and the possible underlying mechanisms.

Animal models of heart failure with preserved ejection fraction (HFpEF): from metabolic pathobiology to drug discovery

Heart failure (HF) with preserved ejection fraction (HFpEF) is currently a preeminent challenge for cardiovascular medicine. It has a poor prognosis, increasing mortality, and is escalating in prevalence worldwide. Despite accounting for over 50% of all HF patients, the mechanistic underpinnings driving HFpEF are poorly understood, thus impeding the discovery and development of mechanism-based therapies. HFpEF is a disease syndrome driven by diverse comorbidities, including hypertension, diabetes and obesity, pulmonary hypertension, aging, and atrial fibrillation. There is a lack of high-fidelity animal models that faithfully recapitulate the HFpEF phenotype, owing primarily to the disease heterogeneity, which has hampered our understanding of the complex pathophysiology of HFpEF. This review provides an updated overview of the currently available animal models of HFpEF and discusses their characteristics from the perspective of energy metabolism. Interventional strategies for efficiently utilizing energy substrates in preclinical HFpEF models are also discussed.

Interatrial Shunt Devices

Elevated left atrial pressure during exercise is a hallmark of heart failure (HF) and is associated with adverse left atrial remodeling and poor outcomes. To decompress the pressure-overloaded left atrium in patients with HF, several device-based approaches have been developed to create a permanent, pressure-dependent, left-to-right interatrial shunt. Such approaches are currently in various stages of investigations in both HF with reduced ejection fraction (EF) and HF with preserved EF. This review discusses the evolution of the concept of left atrial decompression and summarizes the current landscape of device-based approaches used for left atrial decompression.

Cardiac radiotherapy transiently alters left ventricular electrical properties and induces cardiomyocyte-specific ventricular substrate changes in heart failure

AIMS

Ongoing clinical trials investigate the therapeutic value of stereotactic cardiac radioablation (cRA) in heart failure patients with ventricular tachycardia. Animal data indicate an effect on local cardiac conduction properties. However, the exact mechanism of cRA in patients remains elusive. Aim of the current study was to investigate in vivo and in vitro myocardial properties in heart failure and ventricular tachycardia upon cRA.

METHODS AND RESULTS

High-density 3D electroanatomic mapping in sinus rhythm was performed in a patient with a left ventricular assist device and repeated ventricular tachycardia episodes upon several catheter-based endocardial radio-frequency ablation attempts. Subsequent to electroanatomic mapping and cRA of the left ventricular septum, two additional high-density electroanatomic maps were obtained at 2- and 4-month post-cRA. Myocardial tissue samples were collected from the left ventricular septum during 4-month post-cRA from the irradiated and borderzone regions. In addition, we performed molecular biology and mitochondrial density measurements of tissue and isolated cardiomyocytes. Local voltage was altered in the irradiated region of the left ventricular septum during follow-up. No change of local voltage was observed in the control (i.e. borderzone) region upon irradiation. Interestingly, local activation time was significantly shortened upon irradiation (2-month post-cRA), a process that was reversible (4-month post-cRA). Molecular biology unveiled an increased expression of voltage-dependent sodium channels in the irradiated region as compared with the borderzone, while Connexin43 and transforming growth factor beta were unchanged (4-month post-cRA). Moreover, mitochondrial density was decreased in the irradiated region as compared with the borderzone.

CONCLUSION

Our study supports the notion of transiently altered cardiac conduction potentially related to structural and functional cellular changes as an underlying mechanism of cRA in patients with ventricular tachycardia.

Effect of Metabolic Dysfunction-Associated Fatty Liver Disease on Left Ventricular Deformation and Atrioventricular Coupling in Patients With Metabolic Syndrome Assessed by MRI

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) was recently recognized as an important risk factor for cardiovascular diseases.

PURPOSE

To examine the effect of MAFLD on cardiac function in metabolic syndrome by MRI.

STUDY TYPE

Retrospective.

POPULATION

One hundred seventy-nine patients with metabolic syndrome (MetS), 101 with MAFLD (MAFLD [+]) and 78 without (MAFLD [-]). Eighty-one adults without any of the components of MetS or cardiac abnormalities were included as control group.

FIELD STRENGTH/SEQUENCE

3.0 T; balanced steady-state free precession sequence.

ASSESSMENT

Left atrial (LA) strain was assessed during three phases: reservoir strain (LA-RS), conduit strain (LA-CS), and booster strain (LA-BS). Left ventricular (LV) global longitudinal (LV-GLS) strain was also derived. The left atrioventricular coupling index (LACI) was calculated as the ratio of LA end-diastolic volume (LA-EDV) and LV-EDV.

STATISTICAL TESTS

Student's t test or Mann-Whitney U test; One-way analysis of variance. A P value <0.05 was considered statistically significant.

RESULTS

Among MetS patients, individuals with MAFLD had significantly lower magnitude LV-GLS (-11.6% ± 3.3% vs. -13.8% ± 2.7%) than those without MAFLD. For LA strains, LA-RS (36.9% ± 13.7% vs. 42.9% ± 13.5%) and LA-CS (20.0% ± 10.6% vs. 24.1% ± 9.2%) were also significantly reduced in MAFLD (+) compared to MAFLD (-). The LACIs (17.2% [12.9-21.2] % vs. 15.8% [12.2-19.7] %) were significantly higher in patients with MAFLD compared to those without MAFLD. After adjustment for other clinical factors, MAFLD was found to be independently correlated with LV-GLS (β = -0.270) and LACI (β = 0.260).

DATA CONCLUSION

MAFLD had an unfavorable effect on LV myocardial strain in MetS. Moreover, LA strain and atrioventricular coupling were further impaired in patients with concomitant MAFLD compared to those without MAFLD. Last, MAFLD was independently associated with subclinical LV dysfunction and atrioventricular coupling after adjustment for other clinical factors.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: 3.

Sodium-glucose cotransporter type 2 inhibitors and cardiac arrhythmias

The introduction of sodium-glucose cotransporter 2 (SGLT2) inhibitors as a new and effective class of therapeutic agents for type 2 diabetes (T2D) preventing the reabsorption of glucose in the kidneys and thus facilitating glucose excretion in the urine, but also as agents with cardiovascular benefits, particularly in patients with heart failure (HF), regardless of the diabetic status, has ushered in a new era in treating patients with T2D and/or HF. In addition, data have recently emerged indicating an antiarrhythmic effect of the SGLT2 inhibitors in patients with and without diabetes. Prospective studies, randomized controlled trials and meta-analyses have provided robust evidence for a protective and beneficial effect of these agents against atrial fibrillation, ventricular arrhythmias and sudden cardiac death. The antiarrhythmic mechanisms involved include reverse atrial and ventricular remodeling, amelioration of mitochondrial function, reduction of hypoglycemic episodes with their attendant arrhythmogenic effects, attenuated sympathetic nervous system activity, regulation of sodium and calcium homeostasis, and suppression of prolonged ventricular repolarization. These new data on antiarrhythmic actions of SGLT2 inhibitors are herein reviewed, potential mechanisms involved are discussed and pictorially illustrated, and treatment results on specific arrhythmias are described and tabulated.

Association of Sodium-Glucose Cotransporter 2 Inhibitors (SGLT2i) with Cardiac Arrhythmias: A Systematic Review and Meta-Analysis of Cardiovascular Outcome Trials

Background

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a class of widely used hypoglycemic agents for the treatment of type 2 diabetes mellitus (T2DM). In addition to lowering blood glucose, SGLT2i protects the heart and kidney, significantly reduces cardiovascular events, and delays the progression of heart failure and chronic kidney disease. However, previous studies have not exhaustively discussed the association between SGLT2i and the risk of developing cardiac arrhythmias. The purpose of this study is to assess the association of SGLT2i with cardiac arrhythmias in patients with T2DM and without T2DM in cardiovascular outcome trials (CVOTs).

Methods

We performed a meta-analysis and systematic review of CVOTs that compared SGLT2i with placebo. MEDLINE, Web of Science, The Cochrane Library and Embase were systematically searched from inception to December 2022. We included CVOTs reporting cardiovascular or renal outcomes with a follow-up duration of at least 6 months.

Results

A total of 12 CVOTs with 77,470 participants were included in this meta-analysis (42,016 SGLT2i vs 35,454 control), including patients with T2DM, heart failure (HF), or chronic kidney disease (CKD). Follow-up duration ranged from 9 months to 5.65 years. Medications included empagliflozin, canagliflozin, dapagliflozin and ertugliflozin. SGLT2i were associated with a lower risk of tachycardia (risk ratio (RR) 0.86; 95% confidence interval (CI) 0.79-0.95), supraventricular tachycardia (SVT; RR 0.84; 95% CI 0.75-0.94), atrial fibrillation (AF; RR 0.86; 95% CI 0.75-0.97) and atrial flutter (AFL; RR 0.75; 95% CI 0.57-0.99) in patients with T2DM, HF and CKD. SGLT2i could also reduce the risk of cardiac arrest in CKD patients (RR 0.50; 95% CI 0.26-0.95). Besides, SGLT2i therapy was not associated with a lower risk of ventricular arrhythmia and bradycardia.

Conclusions

SGLT2i therapy is associated with significantly reduced the risk of tachycardia, SVT, AF, and AFL in patients with T2DM, HF, and CKD. In addition, SGLT2i could also reduce the risk of cardiac arrest in CKD patients. Further researches are needed to fully elucidate the antiarrhythmic mechanism of SGLT2i.

New therapeutic directions in type II diabetes and its complications: mitochondrial dynamics

As important organelles of energetic and metabolism, changes in the dynamic state of mitochondria affect the homeostasis of cellular metabolism. Mitochondrial dynamics include mitochondrial fusion and mitochondrial fission. The former is coordinated by mitofusin-1 (Mfn1), mitofusin-2 (Mfn2), and optic atrophy 1 (Opa1), and the latter is mediated by dynamin related protein 1 (Drp1), mitochondrial fission 1 (Fis1) and mitochondrial fission factor (MFF). Mitochondrial fusion and fission are generally in dynamic balance and this balance is important to preserve the proper mitochondrial morphology, function and distribution. Diabetic conditions lead to disturbances in mitochondrial dynamics, which in return causes a series of abnormalities in metabolism, including decreased bioenergy production, excessive production of reactive oxygen species (ROS), defective mitophagy and apoptosis, which are ultimately closely linked to multiple chronic complications of diabetes. Multiple researches have shown that the incidence of diabetic complications is connected with increased mitochondrial fission, for example, there is an excessive mitochondrial fission and impaired mitochondrial fusion in diabetic cardiomyocytes, and that the development of cardiac dysfunction induced by diabetes can be attenuated by inhibiting mitochondrial fission. Therefore, targeting the restoration of mitochondrial dynamics would be a promising therapeutic target within type II diabetes (T2D) and its complications. The molecular approaches to mitochondrial dynamics, their impairment in the context of T2D and its complications, and pharmacological approaches targeting mitochondrial dynamics are discussed in this review and promise benefits for the therapy of T2D and its comorbidities.

The Impact of Pharmacotherapy for Heart Failure on Oxidative Stress-Role of New Drugs, Flozins

Heart failure (HF) is a multifactorial clinical syndrome involving many complex processes. The causes may be related to abnormal heart structure and/or function. Changes in the renin-angiotensin-aldosterone system, the sympathetic nervous system, and the natriuretic peptide system are important in the pathophysiology of HF. Dysregulation or overexpression of these processes leads to changes in cardiac preload and afterload, changes in the vascular system, peripheral vascular dysfunction and remodeling, and endothelial dysfunction. One of the important factors responsible for the development of heart failure at the cellular level is oxidative stress. This condition leads to deleterious cellular effects as increased levels of free radicals gradually disrupt the state of equilibrium, and, as a consequence, the internal antioxidant defense system is damaged. This review focuses on pharmacotherapy for chronic heart failure with regard to oxidation-reduction metabolism, with special attention paid to the latest group of drugs, SGLT2 inhibitors-an integral part of HF treatment. These drugs have been shown to have beneficial effects by protecting the antioxidant system at the cellular level.

SGLT1: A Potential Drug Target for Cardiovascular Disease

SGLT1 and SGLT2 are the two main members of the sodium-glucose cotransporters (SGLTs), which are mainly responsible for glucose reabsorption in the body. In recent years, many large clinical trials have shown that SGLT2 inhibitors have cardiovascular protection for diabetic and non-diabetic patients independent of lowering blood glucose. However, SGLT2 was barely detected in the hearts of humans and animals, while SGLT1 was highly expressed in myocardium. As SGLT2 inhibitors also have a moderate inhibitory effect on SGLT1, the cardiovascular protection of SGLT2 inhibitors may be due to SGLT1 inhibition. SGLT1 expression is associated with pathological processes such as cardiac oxidative stress, inflammation, fibrosis, and cell apoptosis, as well as mitochondrial dysfunction. The purpose of this review is to summarize the protective effects of SGLT1 inhibition on hearts in various cell types, including cardiomyocytes, endothelial cells, and fibroblasts in preclinical studies, and to highlight the underlying molecular mechanisms of protection against cardiovascular diseases. Selective SGLT1 inhibitors could be considered a class of drugs for cardiac-specific therapy in the future.

TRPM2 Mediates Hepatic Ischemia-Reperfusion Injury via Ca2+-Induced Mitochondrial Lipid Peroxidation through Increasing ALOX12 Expression

Hepatic ischemia-reperfusion (IR) injury is a serious clinical problem that complicates liver resection and transplantation. Despite recent advances in understanding of the pathophysiology of hepatic IR injury, effective interventions and therapeutics are still lacking. Here, we examined the role of transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable, non-selective cation channel, in mediating hepatic IR injury. Our data showed that TRPM2 deficiency attenuated IR-induced liver dysfunction, inflammation, and cell death in mice. Moreover, RNA sequencing analysis indicated that TRPM2-induced IR injury occurs via ferroptosis-related pathways. Consistently, as a ferroptosis inducer, (1S,3R)-RSL3 treatment induced mitochondrial dysfunction in hepatocytes and a TRPM2 inhibitor suppressed this. Interestingly, TRPM2-mediated calcium influx caused mitochondrial calcium accumulation via the mitochondrial Ca2+-selective uniporter and increased the expression level of arachidonate 12-lipoxygenase (ALOX12), which results in mitochondrial lipid peroxidation during hepatic IR injury. Furthermore, hepatic IR injury-induced ferroptosis was obviously relieved by a TRPM2 inhibitor or calcium depletion, both in vitro and in vivo. Collectively, these findings demonstrate a crucial role for TRPM2-mediated ferroptosis in hepatic IR injury via increased Ca2+-induced ALOX12 expression, indicating that pharmacological inhibition of TRPM2 may provide an effective therapeutic strategy for hepatic IR injury-related diseases, such as during liver resection and transplantation.

Canagliflozin protects diabetic cardiomyopathy by mitigating fibrosis and preserving the myocardial integrity with improved mitochondrial function

Sodium-glucose transport protein 2 (SGLT-2) inhibitors are approved antidiabetic drugs with a beneficial effect on reducing major adverse cardiac events and heart failure hospitalization. Among them, canagliflozin has the least selectivity toward SGLT-2 over the SGLT-1 isoform. Canagliflozin can inhibit SGLT-1 at therapeutic levels; however, the underlying molecular mechanism is not understood. This study aimed to evaluate the effect of canagliflozin on SGLT1 expression in an animal model of diabetic cardiomyopathy (DCM) and its associated effects. In vivo studies were carried out in the most clinically relevant high-fat diet and streptozotocin-induced type-2 diabetes model of diabetic cardiomyopathy, and in vitro studies were performed using cultured rat cardiomyocytes stimulated with high glucose and palmitic acid. DCM was induced in male Wistar rats for 8 weeks with or without 10 mg/kg canagliflozin treatment. At the end of the study, systemic and molecular characteristics were measured using immunofluorescence, quantitative RT‒PCR, immunoblotting, histology, and FACS analysis. SGLT-1 expression was upregulated in DCM hearts and was associated with fibrosis, apoptosis, and hypertrophy. Canagliflozin treatment attenuated these changes. The histological evaluation showed improved myocardial structure, and in vitro results revealed improved mitochondrial quality and biogenesis after canagliflozin treatment. In conclusion, canagliflozin protects the DCM heart by inhibiting myocardial SGLT-1 and associated hypertrophy, fibrosis, and apoptosis. Thus, developing novel pharmacological inhibitors targeting SGLT-1 could be a better strategy for treating DCM and associated cardiovascular complications.

Cardiac metabolism in HFpEF: from fuel to signalling

Heart failure (HF) is marked by distinctive changes in myocardial uptake and utilization of energy substrates. Among the different types of HF, HF with preserved ejection fraction (HFpEF) is a highly prevalent, complex, and heterogeneous condition for which metabolic derangements seem to dictate disease progression. Changes in intermediate metabolism in cardiometabolic HFpEF-among the most prevalent forms of HFpEF-have a large impact both on energy provision and on a number of signalling pathways in the heart. This dual, metabolic vs. signalling, role is played in particular by long-chain fatty acids (LCFAs) and short-chain carbon sources [namely, short-chain fatty acids (SCFAs) and ketone bodies (KBs)]. LCFAs are key fuels for the heart, but their excess can be harmful, as in the case of toxic accumulation of lipid by-products (i.e. lipotoxicity). SCFAs and KBs have been proposed as a potential major, alternative source of energy in HFpEF. At the same time, both LCFAs and short-chain carbon sources are substrate for protein post-translational modifications and other forms of direct and indirect signalling of pivotal importance in HFpEF pathogenesis. An in-depth molecular understanding of the biological functions of energy substrates and their signalling role will be instrumental in the development of novel therapeutic approaches to HFpEF. Here, we summarize the current evidence on changes in energy metabolism in HFpEF, discuss the signalling role of intermediate metabolites through, at least in part, their fate as substrates for post-translational modifications, and highlight clinical and translational challenges around metabolic therapy in HFpEF.

Benefits of the Non-Steroidal Mineralocorticoid Receptor Antagonist Finerenone in Metabolic Syndrome-Related Heart Failure with Preserved Ejection Fraction

The mineralocorticoid receptor (MR) plays an important role in the development of chronic kidney disease (CKD) and associated cardiovascular complications. Antagonizing the overactivation of the MR with MR antagonists (MRA) is a therapeutic option, but their use in patients with CKD is limited due to the associated risk of hyperkalemia. Finerenone is a non-steroidal MRA associated with an improved benefit-risk profile in comparison to steroidal MRAs. In this study, we decided to test whether finerenone improves renal and cardiac function in male hypertensive and diabetic ZSF1 rats as an established preclinical HFpEF model. Finerenone was administered at 10 mg/kg/day for 12 weeks. Cardiac function/hemodynamics were assessed in vivo. ZSF1 rats showed classical signs of CKD with increased BUN, UACR, hypertrophy, and fibrosis of the kidney together with characteristic signs of HFpEF including cardiac fibrosis, diastolic dysfunction, and decreased cardiac perfusion. Finerenone treatment did not impact kidney function but reduced renal hypertrophy and cardiac fibrosis. Interestingly, finerenone ameliorated diastolic dysfunction and cardiac perfusion in ZSF1 rats. In summary, we show for the first time that non-steroidal MR antagonism by finerenone attenuates cardiac diastolic dysfunction and improves cardiac perfusion in a preclinical HFpEF model. These cardiac benefits were found to be largely independent of renal benefits.