The impact of empagliflozin on cardiac physiology and fibrosis early after myocardial infarction in non-diabetic rats

Cardioprotection of Canagliflozin, Dapagliflozin, and Empagliflozin: Lessons from preclinical studies

Clinical and preclinical studies have elucidated the favorable effects of Inhibitors of Sodium-Glucose Cotransporter-2 (iSGLT2) in patients and animal models with type 2 diabetes. Notably, these inhibitors have shown significant benefits in reducing hospitalizations and mortality among patients with heart failure. However, despite their incorporation into clinical practice for indications beyond diabetes, the decision-making process regarding their use often lacks a systematic approach. The selection of iSGLT2 remains arbitrary, with only a limited number of studies simultaneously exploring the different classes of them. Currently, no unique guideline establishes their application in both clinical and basic research. This review delves into the prevalent use of iSGLT2 in animal models previously subjected to induced cardiac stress. We have compiled key findings related to cardioprotection across various animal models, encompassing diverse dosages and routes of administration. Beyond their established role in diabetes management, iSGLT2 has demonstrated utility as agents for safeguarding heart health and cardioprotection can be class-dependent among the iSGLT2. These findings may serve as valuable references for other researchers. Preclinical studies play a pivotal role in ensuring the safety of novel compounds or treatments for potential human use. By assessing side effects, toxicity, and optimal dosages, these studies offer a robust foundation for informed decisions, identifying interventions with the highest likelihood of success and minimal risk to patients. The insights gleaned from preclinical studies, which play a crucial role in highlighting areas of knowledge deficiency, can guide the exploration of novel mechanisms and strategies involving iSGLT2.

Empagliflozin ameliorates ventricular arrhythmias by inhibiting sympathetic remodeling via nerve growth factor/tyrosine kinase receptor A pathway inhibition

BACKGROUND AND AIMS

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) can ameliorate arrhythmias; however, the mechanisms underlying their antiarrhythmic effect remain unclear. Therefore, we aimed to test the hypothesis that the SGLT2i empagliflozin (EMPA) ameliorates ventricular arrhythmias caused by myocardial infarction (MI) by inhibiting sympathetic remodeling.

METHODS

Male nondiabetic Sprague-Dawley rats were divided into Sham ( n  = 10), MI ( n  = 13), low-EMPA (10 mg/kg/day; n  = 13), and high-EMPA (30 mg/kg/day; n  = 13) groups. Except for the Sham group, MI models were established by ligation of the left anterior descending coronary artery. After 4 weeks, the hearts were removed. Echocardiography, electrical stimulation, hematoxylin-eosin staining and Masson's staining, Western blotting, immunohistochemistry (IHC), and ELISA were performed.

RESULTS

Except for left ventricular posterior wall thickness (LVPWT), EMPA treatment significantly ameliorated the left ventricular anterior wall thickness (LVAWT), interventricular septum thickness (IVST), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), and left ventricular ejection fraction (LVEF) in MI rats; there was no statistical difference between the low-EMPA and high-EMPA groups. The threshold for ventricular fibrillation induction and myocardial fibrosis was significantly ameliorated in EMPA-treated rats, and there was no statistical difference between the high-EMPA and low-EMPA groups. EMPA decreased the expression of nerve growth factor (NGF), tyrosine kinase receptor A (TrkA), tyrosine hydroxylase, and growth-associated protein 43 (GAP43) in the left ventricular infarction margin myocardium of MI rats, especially in the high-EMPA group, with a statistically significant difference between the high-EMPA and low-EMPA groups. High-EMPA significantly decreased noradrenaline (NE) levels in the blood of MI rats; however, there was no statistical difference between the low-EMPA and MI groups.

CONCLUSION

EMPA ameliorated the occurrence of ventricular arrhythmias in MI rats, which may be related to a reduction in sympathetic activity, inhibition of the NGF/TrkA pathway, inhibition of sympathetic remodeling, and improvement in cardiac function and cardiac structural remodeling.

Metabolism and bioenergetics in the pathophysiology of organ fibrosis

Fibrosis is the tissue scarring characterized by excess deposition of extracellular matrix (ECM) proteins, mainly collagens. A fibrotic response can take place in any tissue of the body and is the result of an imbalanced reaction to inflammation and wound healing. Metabolism has emerged as a major driver of fibrotic diseases. While glycolytic shifts appear to be a key metabolic switch in activated stromal ECM-producing cells, several other cell types such as immune cells, whose functions are intricately connected to their metabolic characteristics, form a complex network of pro-fibrotic cellular crosstalk. This review purports to clarify shared and particular cellular responses and mechanisms across organs and etiologies. We discuss the impact of the cell-type specific metabolic reprogramming in fibrotic diseases in both experimental and human pathology settings, providing a rationale for new therapeutic interventions based on metabolism-targeted antifibrotic agents.

SGLT2 inhibitors: how do they affect the cardiac cells

The first sodium-glucose cotransporter-2 inhibitor (SGLT2I), canagliflozin, was approved by the U.S. Food and Drug Administration for the treatment of type 2 diabetes in 2013. Since then, other members of this drug class (such as dapagliflozin, empagliflozin, and ertugliflozin) have become widely used. Unlike classical antidiabetic agents, these drugs do not interfere with insulin secretion or action, but instead promote renal glucose excretion. Since their approval, many preclinical and clinical studies have been conducted to investigate the diverse effects of SGLT2Is. While originally introduced as antidiabetic agents, the SGLT2Is are now recognized as pillars in the treatment of heart failure and chronic kidney disease, in patients with or without diabetes. The beneficial cardiac effects of this class have been attributed to several mechanisms. Among these, SGLT2Is inhibit fibrosis, hypertrophy, apoptosis, inflammation, and oxidative stress. They regulate mitochondrial function and ion transport, and stimulate autophagy through several underlying mechanisms. This review details the potential effects of SGLT2Is on cardiac cells.

Assessment of the potential risks in SD rats gavaged with genetically modified yeast containing the cp4-epsps gene

Introduction

Despite the absence of definitive evidence indicating that the cp4-epsps gene and its resultant recombinant proteins have significant harmful effects on either human or animal health, the safety assessment of genetically modified (GM) crops expressing the CP4-EPSPS proteins has been controversial. This study endeavor was aimed at evaluating the potential risks posed by the CP4-EPSPS protein in transgenic crops, thereby contributing to the advancement of risk assessment methodologies in the context of genetically engineered crops.

Methods

To ascertain the appropriate daily dosages for oral gavage administration, the expression levels of the CP4-EPSPS protein in a recombinant yeast were quantified. Subsequently, physiological and biochemical analysis, metabolomics, and metagenomic analysis were conducted based on a 90-day Sprague-Dawley (SD) rats feeding experiment, respectively, thereby enhancing the depth and precision of our risk assessment framework.

Results

The results from the physiological and biochemical analysis, organ pathological, blood metabolism, gut microbiota, and correlation analysis of metabolites and gut microbiota revealed several biomarkers for further risk assessment. These biomarkers include clinical biochemical indexes such as total bilirubin (TBIL), direct bilirubin (DBIL), creatine kinase (CK), and lactate dehydrogenase (LDH); metabolites like Methionine, 2-Oxovaleric acid, and LysoPC (16:0); and gut microbiota including Blautia wexlerae, Holdemanella biformis, Dorea sp. CAG 317, Coriobacteriaceae and Erysipelotrichaceae.

Conclusion

In conclusion, the risk can be significantly reduced by directly consuming inactivated recombinant CP4-EPSPS. Therefore, in everyday life, the risk associated with consuming GM foods containing recombinant CP4-EPSPS is substantially reduced after heat treatment.

Targeting Nrf2/HO-1 and NF-κB/TNF-α signaling pathways with empagliflozin protects against atrial fibrillation-induced acute kidney injury in rats

A bidirectional relationship exists between atrial fibrillation (AF) and kidney function. Uncontrolled AF may lead to kidney injury, whereas renal dysfunction may contribute to AF initiation and maintenance. This study aimed to investigate the protective effect of the sodium glucose cotransporter-2 inhibitor empagliflozin (EMPA) on acute kidney injury (AKI) associated with AF induced by acetylcholine and calcium chloride (ACh/CaCl2) in rats and elucidate the potential underlying mechanism. Rats were randomly divided as follows: control (CTRL) group: administered vehicles only; AF group: intravenously injected 1 ml/kg of an ACh/CaCl2 mixture for seven days to induce AF; EMPA group: orally administered EMPA (30 mg/kg) for seven days; AF+EMPA10 and AF+EMPA30 groups: co-administered the induction mixture and EMPA (10 and 30 mg/kg, respectively) for seven days. Our results showed that EMPA (10 and 30 mg/kg) effectively maintained kidney function and demonstrated a significant antioxidant potential. EMPA also suppressed AF-induced renal tubulointerstitial injury and fibrotic changes concurrently with reducing renal levels of the pro-inflammatory cytokines tumour necrosis factor-α (TNF-α) and interleukin-6, as well as the pro-fibrotic marker transforming growth factor beta-1 and collagen type I. Mechanistically, EMPA boosted nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) renal tissue expression while repressing nuclear factor kappa B (NF-κB) activation. In addition, these beneficial effects of EMPA on kidneys were concurrent with its ability to effectively inhibit AF-related electrocardiographic changes, reduce incidence and duration of AF episodes, and markedly suppress serum B-type natriuretic peptide and C-reactive protein levels. In conclusion, EMPA protected against AKI associated with AF induced by ACh/CaCl2 in rats through simultaneous modulation of the Nrf2/HO-1 and the NF-κB/TNF-α signaling pathways, exerting antioxidant, anti-inflammatory, and anti-fibrotic effects.

Comprehensive proteomic characterization of urethral stricture disease in the Chinese population

Background

Male urethral stricture disease (USD) is predominantly characterized by scar formation. There are few effective therapeutic drugs, and comprehensive molecular characterizations of USD formation remain undefined.

Methods

The proteomic profiling of twelve scar tissues and five matched normal adjacent tissues (NATs). Proteomic analysis methods were applied to explore the molecular characterizations of USD formation, including uncovering mechanistic pathways and providing novel biomarkers for scar formation.

Results

Comparative proteomic analysis showed that the extracellular matrix (ECM) and complement cascade signaling were predominant in scar tissues. COL11A1 and CD248 significantly contributed to the accumulation of ECM components. Our study presented diverse molecular mechanisms of scar formation across different ages and suggested the potential effects of PXK in Age 1 (<45) patients. Furthermore, immune infiltration studies indicated the therapeutic potential of inhibiting the complement system (C4A, C4B) in Age 2 (≥45) patients, providing a potential clinical strategy for USD.

Conclusion

This study illustrated the pathogenesis of USD formation and the diverse characteristics of USD patients with different ages, enhancing our understanding of the disease's pathogenesis and providing a valuable resource for USD treatment.

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.

Unraveling the Cardiac Matrix: From Diabetes to Heart Failure, Exploring Pathways and Potential Medications

Myocardial infarction (MI) often leads to heart failure (HF) through acute or chronic maladaptive remodeling processes. This establishes coronary artery disease (CAD) and HF as significant contributors to cardiovascular illness and death. Therefore, treatment strategies for patients with CAD primarily focus on preventing MI and lessening the impact of HF after an MI event. Myocardial fibrosis, characterized by abnormal extracellular matrix (ECM) deposition, is central to cardiac remodeling. Understanding these processes is key to identifying new treatment targets. Recent studies highlight SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1-RAs) as favorable options in managing type 2 diabetes due to their low hypoglycemic risk and cardiovascular benefits. This review explores inflammation's role in cardiac fibrosis and evaluates emerging anti-diabetic medications' effectiveness, such as SGLT2i, GLP1-RAs, and dipeptidyl peptidase-4 inhibitors (DPP4i), in preventing fibrosis in patients with diabetes post-acute MI. Recent studies were analyzed to identify effective medications in reducing fibrosis risk in these patients. By addressing these areas, we can advance our understanding of the potential benefits of anti-diabetic medications in reducing cardiac fibrosis post-MI and improve patient outcomes in individuals with diabetes at risk of HF.

Protective Mechanisms of SGLTi in Ischemic Heart Disease

Ischemic heart disease (IHD) is a common clinical cardiovascular disease with high morbidity and mortality. Sodium glucose cotransporter protein inhibitor (SGLTi) is a novel hypoglycemic drug. To date, both clinical trials and animal experiments have shown that SGLTi play a protective role in IHD, including myocardial infarction (MI) and ischemia/reperfusion (I/R). The protective effects may be involved in mechanisms of energy metabolic conversion, anti-inflammation, anti-fibrosis, ionic homeostasis improvement, immune cell development, angiogenesis and functional regulation, gut microbiota regulation, and epicardial lipids. Thus, this review summarizes the above mechanisms and aims to provide theoretical evidence for therapeutic strategies for IHD.

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.

Role and molecular mechanisms of SGLT2 inhibitors in pathological cardiac remodeling (Review)

Cardiovascular diseases are caused by pathological cardiac remodeling, which involves fibrosis, inflammation and cell dysfunction. This includes autophagy, apoptosis, oxidative stress, mitochondrial dysfunction, changes in energy metabolism, angiogenesis and dysregulation of signaling pathways. These changes in heart structure and/or function ultimately result in heart failure. In an effort to prevent this, multiple cardiovascular outcome trials have demonstrated the cardiac benefits of sodium‑glucose cotransporter type 2 inhibitors (SGLT2is), hypoglycemic drugs initially designed to treat type 2 diabetes mellitus. SGLT2is include empagliflozin and dapagliflozin, which are listed as guideline drugs in the 2021 European Guidelines for Heart Failure and the 2022 American Heart Association/American College of Cardiology/Heart Failure Society of America Guidelines for Heart Failure Management. In recent years, multiple studies using animal models have explored the mechanisms by which SGLT2is prevent cardiac remodeling. This article reviews the role of SGLT2is in cardiac remodeling induced by different etiologies to provide a guideline for further evaluation of the mechanisms underlying the inhibition of pathological cardiac remodeling by SGLT2is, as well as the development of novel drug targets.

Systemic and organ-specific anti-inflammatory effects of sodium-glucose cotransporter-2 inhibitors

Inflammation plays an essential role and is a common feature in the pathogenesis of many chronic diseases. The exact mechanisms through which sodium-glucose cotransporter-2 (SGLT2) inhibitors achieve their much-acclaimed clinical benefits largely remain unknown. In this review, we detail the systemic and tissue- or organ-specific anti-inflammatory effects of SGLT2 inhibitors using evidence from animal and human studies. We discuss the potential pathways through which SGLT2 inhibitors exert their anti-inflammatory effects, including oxidative stress, mitochondrial, and inflammasome pathways. Finally, we highlight the need for further investigation of the extent of the contribution of the anti-inflammatory effects of SGLT2 inhibition to improvements in cardiometabolic and renal outcomes in clinical studies.

Gliflozins in the Treatment of Non-diabetic Experimental Cardiovascular Diseases

A new class of antidiabetic drugs - gliflozins (inhibitors of sodium glucose cotransporter-2; SGLT-2i) stimulate glucose and sodium excretion, thereby contributing to improved glycemic control, weight loss and blood pressure reduction in diabetic patients. Large clinical trials in patients with type 2 diabetes treated with empagliflozin, canagliflozin or dapagliflozin have demonstrated their excellent efficacy in improving many cardiovascular outcomes, including the reduction of death from cardiovascular diseases, non-fatal myocardial infarction or stroke, and hospitalization for heart failure. Moreover, the beneficial effects of SGLT-2i were also demonstrated in the decrease in proteinuria, which leads to a lower risk of progression to end-stage renal disease and thus a delay in initiation of the renal replacement therapy. Unexpectedly, their cardioprotective and renoprotective effects have been demonstrated not only in patients with diabetes but also in those without diabetes. Recently, much effort has been focused on patients with heart failure (either with reduced or preserved ejection fraction) or liver disease. Experimental studies have highlighted pleiotropic effects of SGLT-2 inhibitors beyond their natriuretic and glycosuric effects, including reduction of fibrosis, inflammation, reactive oxygen species, and others. Our results in experimental non-diabetic models of hypertension, chronic kidney disease and heart failure are partially consistent with these findings. This raises the question of whether the same mechanisms are at work in diabetic and non-diabetic conditions, and which mechanisms are responsible for the beneficial effects of gliflozins under non-diabetic conditions. Are these effects cardio-renal, metabolic, or others? This review will focus on the effects of gliflozins under different pathophysiological conditions, namely in hypertension, chronic kidney disease, and heart failure, which have been evaluated in non-diabetic rat models of these diseases. Key words: SGLT-2 inhibitor, hypertension, chronic kidney disease, heart failure, liver disease, rat.

Empagliflozin and pirfenidone confer renoprotection through suppression of glycogen synthase kinase-3β and promotion of tubular regeneration in rats with induced metabolic syndrome

Metabolic syndrome (MetS) is largely coupled with chronic kidney disease (CKD). Glycogen synthase kinase-3β (GSK-3β) pathway drives tubular injury in animal models of acute kidney injury; but its contribution in CKD is still elusive. This study investigated the effect empagliflozin and/or pirfenidone against MetS-induced kidney dysfunction, and to clarify additional underpinning mechanisms particularly the GSK-3β signaling pathway. Adult male rats received 10%w/v fructose in drinking water for 20 weeks to develop MetS, then treated with either drug vehicle, empagliflozin (30 mg/kg/day) and/or pirfenidone (100 mg/kg/day) via oral gavage for subsequent 4 weeks, concurrently with the high dietary fructose. Age-matched rats receiving normal drinking water were used as controls. After 24 weeks, blood and kidneys were harvested for subsequent analyses. Rats with MetS showed signs of kidney dysfunction, structural changes and interstitial fibrosis. Activation of GSK-3β, decreased cyclinD1 expression and enhanced apoptotic signaling were found in kidneys of MetS rats. There was abundant alpha-smooth muscle actin (α-SMA) expression along with up-regulation of TGF-β1/Smad3 in kidneys of MetS rats. These derangements were almost alleviated by empagliflozin or pirfenidone, with evidence that the combined therapy was more effective than either individual drug. This study emphasizes a novel mechanism underpinning the beneficial effects of empagliflozin and pirfenidone on kidney dysfunction associated with MetS through targeting GSK-3β signaling which can mediate the regenerative capacity, anti-apoptotic effects and anti-fibrotic properties of such drugs. These findings recommend the possibility of using empagliflozin and pirfenidone as promising therapies for management of CKD in patients with MetS.

Current experimental and early investigational agents for cardiac fibrosis: where are we at?

INTRODUCTION

Myocardial fibrosis (MF) is induced by factors activating pro-fibrotic pathways such as acute and prolonged inflammation, myocardial ischemic events, hypertension, aging process, and genetically-linked cardiomyopathies. Dynamics and characteristics of myocardial fibrosis development are very different. The broad range of myocardial fibrosis presentations suggests the presence of multiple potential targets.

AREA COVERED

Heart failure treatment involves medications primarily aimed at counteracting neurohormonal activation. While these drugs have demonstrated efficacy against MF, not all specifically target inflammation or fibrosis progression with some exceptions such as RAAS inhibitors. Consequently, new therapies are being developed to address this issue. This article is aimed to describe anti-fibrotic drugs currently employed in clinical practice and emerging agents that target specific pathways, supported by evidence from both preclinical and clinical studies.

EXPERT OPINION

Despite various preclinical findings suggesting the potential utility of new drugs and molecules for treating cardiac fibrosis in animal models, there is a notable scarcity of clinical trials investigating these effects. However, the pathology of damage and repair in the heart muscle involves a complex network of interconnected inflammatory pathways and various types of immune cells. Our comprehension of the positive and negative roles played by specific immune cells and cytokines is an emerging area of research.

Empagliflozin protects against isoprenaline-induced fibrosis in rat heart through modulation of TGF-β/SMAD pathway

AIM

Cardiac fibrosis is characterized by excessive accumulation of fibrous tissue, particularly collagens, in the myocardium. Accumulated fibrous tissue renders myocardium stiffer and reduces its contractility. Empagliflozin is an oral hypoglycemic agent with extra-diabetic functional profile toward maintaining cardiac functions. The present study aimed to examine protective effect of empagliflozin against an in-vivo model of cardiac fibrosis induced by isoprenaline and targeting TGF-β/SMAD signaling as a possible pathway responsible for such effect.

MAIN METHODS

Sixty animals were divided into six groups; the first was normal, and the second was treated with isoprenaline only (5 mg/kg/day I.P.) as a control. The third received pirfenidone (500 mg/kg/day P.O.), and the remaining groups received graded doses (5, 10, 20 mg/kg respectively) of empagliflozin for 14 days before fibrosis induction by isoprenaline (5 mg/kg/day) for 30 days.

KEY FINDINGS

Isoprenaline increased cardiac enzymes, and cardiac tissues revealed elevated concentrations of transforming growth factor β (TGF-β1), monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor α (TNF-α), and c-jun N-terminal kinase (JNK) proteins. Expression of nuclear factor kappa B (NF-κB), alpha smooth muscle actin (α-SMA), collagens, suppressor of mothers against decapentaplegic (SMADs), connective tissue growth factor (CTGF), and fibronectin was upregulated. Empagliflozin improved the histological picture of heart tissue in comparison to fibrosis developed in controls, and protected against fibrosis through significant modulation of all mentioned parameters' concentrations and expressions.

SIGNIFICANCE

Empagliflozin demonstrated a promising protective approach against biological model of cardiac fibrosis through an anti-fibrotic effect through targeting TGF-β signaling pathways.

Safety and Efficacy of Early SGLT2 Inhibitors Initiation in Diabetic Patients Following Acute Myocardial Infarction, a Retrospective Study

INTRODUCTION

Sodium-glucose cotransporter- 2 (SGLT2) inhibitors have become a cornerstone in heart failure (HF), Type 2 diabetes mellitus (T2DM), and cardiovascular disease (CVD) management. In the current retrospective study, we aimed to assess efficacy and safety of SGLT2 inhibitors early following acute myocardial infarction (AMI).

METHODS

Patients with T2DM hospitalized for AMI in 2017-2020 were divided according to SGLT2 inhibitors therapy status on discharge (with vs without therapy). Primary outcome was defined as a composite of hospitalizations for HF, recurrent AMI, and cerebrovascular accident (CVA). Secondary outcomes included hospitalizations for any cause, total cumulative number of hospitalizations, and all-cause mortality.

RESULTS

A total of 69 patients (mean age 59.2 ± 8.2 years) with AMI discharged with SGLT2 inhibitors were compared to 253 patients (mean age 62.5 ± 9.8) with no SGLT2 inhibitors. During the first year post-AMI, 4 (5.8%) patients in the treatment group and 16 (6.3%) in the control group were hospitalized for CV events (p = 1.0). Patients in the SGLT2 inhibitors group had lower rates of hospitalization for any cause (31.9% vs 47.8%, P = 0.02), with no change in mortality (0% vs 3.6%, P = 0.21). After multivariate regression analysis, only female gender was associated with increased risk for readmission, mainly due to urinary tract infections. No events of diabetic ketoacidosis (DKA) or limb amputation were reported.

CONCLUSIONS

We found that early initiation of SGLT2 inhibitors in T2DM patients following AMI is safe and decreases the risk of hospitalization for any cause.

Effects of empagliflozin on right ventricular adaptation to pressure overload

Background

Right ventricular (RV) failure is the prime cause of death in patients with pulmonary arterial hypertension. Novel treatment strategies that protect the RV are needed. Empagliflozin, a sodium-glucose co-transporter-2 inhibitor, shows cardioprotective effects on the left ventricle in clinical and preclinical studies, but its direct effects on RV remain elusive. We investigated the effects of empagliflozin on RV dysfunction induced by pulmonary trunk banding (PTB).

Methods

Male Wistar rats (116 ± 10 g) were randomized to PTB or sham surgery. One week after surgery, PTB animals received empagliflozin mixed into the chow (300 mg empagliflozin/kg chow; PTB-empa, n = 10) or standard chow (PTB-control, n = 10). Sham rats (Sham, n = 6) received standard chow. After five weeks, RV function was evaluated by echocardiography, cardiac MRI, and invasive pressure-volume measurements.

Results

PTB caused RV failure evident by decreased cardiac output compared with sham. PTB-empa rats had a 49% increase in water intake compared with PTB-control yet no differences in hematocrit or blood glucose. Treatment with empagliflozin decreased RV end-systolic pressures without any changes in RV cardiac output or ventricular-arterial coupling (Ees/Ea). The decrease in RV end-systolic pressure was complemented by a slight reduction in RV cross sectional area as a sign of reduced hypertrophy. Load-independent measures of RV systolic and diastolic function were not affected in PTB-empa rats compared with PTB-control.

Conclusion

Empagliflozin treatment reduced RV end-systolic pressure in RV failure induced by pressure overload. Further studies are needed to elucidate whether this simply relates to a diuretic effect and/or additional independent beneficial RV effects.

Multi-parameter cardiac magnetic resonance imaging detects anthracycline-induced cardiotoxicity in rabbits model

Background

Cardiac magnetic resonance (CMR) quantitative T1 and T2 mapping offers a non-invasive means to evaluate early cardiotoxicity changes. This study aimed to pinpoint the earliest CMR indicators of myocardial injury in Anthracycline-induced cardiotoxicity (AIC) and to elucidate the connections between these CMR indicators and associated pathological indicators.

Methods

A total of 34 rabbits were administered doxorubicin at a dosage of 1 mg/kg/weekly. The study incorporated six 3T CMR scan time points: baseline, and at intervals of four, six, eight, twelve, and sixteen weeks. Cine, T1 and T2 mapping sequences assessed the left ventricular ejection fraction (LVEF), native T1, extracellular volume fraction (ECV), and T2 values. Following each time point, three rabbits were sacrificed for histological analysis involving Hematoxylin and eosin (H&E), Masson, TUNEL, and microvascular density (MVD) stains. Spearman correlations and linear mixed model analysis served in the statistical analysis.

Results

Diverse degrees of alternation were recorded in LVEF, native T1, T2, and ECV over time. LVEF declined to 49.0 ± 2.6 % at 12 weeks from the baseline of 53.4 ± 3.2 %, p < 0.001. Native T1 values increase from the baseline (1396.5 ± 79.2 ms) until 8 weeks (1498.8 ± 95.4 ms, p < 0.001). T2 values increased from the baseline (36.6 ± 3.3 ms) within 4 weeks of initiation (37.5 ± 3.4, p = 0.02) and remained elevated through 16 weeks (42.8 ± 0.3, p < 0.01). ECV was elevated at 8 weeks (33.9 ± 3.8 %, p = 0.005) compared to the baseline (30.2 ± 2.5 %). By week 12, myocardial edema and increased CVF were apparent (p = 0.04 and = 0.001, respectively). The area under ROC curve for positive CMR presence and the gold standards were 0.87 (T2-ROC, 4 weeks) and 0.92 (LVEF&BNP-ROC, 12 weeks).

Conclusion

T1 and T2 mapping are effective tools for cardiotoxicity detection and monitoring. The prolongation of T2 value emerged as the most consistent and early-onset indicator.

SGLT2 Inhibitors in Aging-Related Cardiovascular Disease: A Review of Potential Mechanisms

Population aging combined with higher susceptibility to cardiovascular diseases in older adults is increasing the incidence of conditions such as atherosclerosis, myocardial infarction, heart failure, myocardial hypertrophy, myocardial fibrosis, arrhythmia, and hypertension. sodium-glucose cotransporter 2 inhibitors (SGLT2i) were originally developed as a novel oral drug for patients with type 2 diabetes mellitus. Unexpectedly, recent studies have shown that, beyond their effect on hyperglycemia, SGLT2i also have a variety of beneficial effects on cardiovascular disease. Experimental models of cardiovascular disease have shown that SGLT2i ameliorate the process of aging-related cardiovascular disease by inhibiting inflammation, reducing oxidative stress, and reversing endothelial dysfunction. In this review, we discuss the role of SGLT2i in aging-related cardiovascular disease and propose the use of SGLT2i to prevent and treat these conditions in older adults.

Pathophysiological basis of the cardiological benefits of SGLT-2 inhibitors: a narrative review

In recent years, GLP-1 receptor agonists (GLP-1RA), and SGLT-2 inhibitors (SGLT-2i) have become available, which have become valuable additions to therapy for type 2 diabetes as they are associated with low risk for hypoglycemia and cardiovascular benefits. Indeed, SGLT-2i have emerged as a promising class of agents to treat heart failure (HF). By inhibiting SGLT-2, these agents lead to excretion of glucose in urine with subsequent lowering of plasma glucose, although it is becoming clear that the observed benefits in HF cannot be explained by glucose-lowering alone. In fact, multiple mechanisms have been proposed to explain the cardiovascular and renal benefits of SGLT-2i, including hemodynamic, anti-inflammatory, anti-fibrotic, antioxidant, and metabolic effects. Herein, we review the available evidence on the pathophysiology of the cardiological benefits of SGLT-2i. In diabetic heart disease, in both clinical and animal models, the effect of SGLT-2i have been shown to improve diastolic function, which is even more evident in HF with preserved ejection fraction. The probable pathogenic mechanisms likely involve damage from free radicals, apoptosis, and inflammation, and therefore fibrosis, many of which have been shown to be improved by SGLT-2i. While the effects on systolic function in models of diabetic heart disease and HF with preserved ejection fraction is limited and contrasting, it is a key element in patients with HF and reduced ejection fraction both with and without diabetes. The significant improvement in systolic function appears to lead to subsequent structural remodeling of the heart with a reduction in left ventricle volume and a consequent reduction in pulmonary pressure. While the effects on cardiac metabolism and inflammation appear to be consolidated, greater efforts are still warranted to further define the entity to which these mechanisms contribute to the cardiovascular benefits of SGLT-2i.

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.

New insights into the molecular mechanisms of SGLT2 inhibitors on ventricular remodeling

Ventricular remodeling is a pathological process of ventricular response to continuous stimuli such as pressure overload, ischemia or ischemia-reperfusion, which can lead to the change of cardiac structure and function structure, which is central to the pathophysiology of heart failure (HF) and is an established prognostic factor in patients with HF. Sodium glucose cotransporter 2 inhibitors (SGLT2i) get a new hypoglycemic drug that inhibit sodium glucose coconspirator on renal tubular epithelial cells. Recently, clinical trials increasingly and animal experiments increasingly have shown that SGLT2 inhibitors have been largely applied in the fields of cardiovascular diseases, forinstance heart failure, myocardial ischemia-reperfusion injury, myocardial infarction, atrial fibrillation, metabolic diseases such as obesity, diabetes cardiomyopathy and other diseases play a cardiovascular protective role in addition to hypoglycemic. These diseases are association with ventricular remodeling. Inhibiting ventricular remodeling can improve the readmission rate and mortality of patients with heart failure. So far, clinical trials and animal experiments demonstrate that the protective effect of SGLT2 inhibitors in the cardiovascular field is bound to inhibit ventricular remodeling. Therefore, this review briefly investigates the molecular mechanisms of SGLT2 inhibitors on ameliorating ventricular remodeling, and further explore the mechanisms of cardiovascular protection of SGLT2 inhibitors, in order to establish strategies for ventricular remodeling to prevent the progress of heart failure.

Post-myocardial infarction fibrosis: Pathophysiology, examination, and intervention

Cardiac fibrosis plays an indispensable role in cardiac tissue homeostasis and repair after myocardial infarction (MI). The cardiac fibroblast-to-myofibroblast differentiation and extracellular matrix collagen deposition are the hallmarks of cardiac fibrosis, which are modulated by multiple signaling pathways and various types of cells in time-dependent manners. Our understanding of the development of cardiac fibrosis after MI has evolved in basic and clinical researches, and the regulation of fibrotic remodeling may facilitate novel diagnostic and therapeutic strategies, and finally improve outcomes. Here, we aim to elaborate pathophysiology, examination and intervention of cardiac fibrosis after MI.

Cytokine storm: behind the scenes of the collateral circulation after acute myocardial infarction

At least 17 million people die from acute myocardial infarction (AMI) every year, ranking it first among causes of death of human beings, and its incidence is gradually increasing. Typical characteristics of AMI include acute onset and poor prognosis. At present, there is no satisfactory treatment, but development of coronary collateral circulation (CCC) can be key to improving prognosis. Recent research indicates that the levels of cytokines, including those related to promoting inflammatory responses and angiogenesis, increase after the onset of AMI. In the early phase of AMI, cytokines play a vital role in inducing development of collateral circulation. However, when myocardial infarction is decompensated, cytokine secretion increases greatly, which may induce a cytokine storm and worsen prognosis. Cytokines can regulate the activation of a variety of signal pathways and form a complex network, which may promote or inhibit the establishment of collateral circulation. We searched for published articles in PubMed and Google Scholar, employing the keyword "acute myocardial infarction", "coronary collateral circulation" and "cytokine storm", to clarify the relationship between AMI and a cytokine storm, and how a cytokine storm affects the growth of collateral circulation after AMI, so as to explore treatment methods based on cytokine agents or inhibitors used to improve prognosis of AMI.

Empagliflozin for Patients with Heart Failure and Type 2 Diabetes Mellitus: Clinical Evidence in Comparison with Other Sodium-Glucose Co-transporter-2 Inhibitors and Potential Mechanism

Heart failure remains a leading cause of morbidity and mortality globally and has been recognized as a common complication of diabetes, especially type 2 diabetes mellitus. Heart failure occurs in diabetic patients even in the absence of hypertension, coronary heart disease, or valvular heart disease, and is, therefore, a major cardiovascular complication in this vulnerable population. Given the continued rise in the prevalence of type 2 diabetes mellitus worldwide, the burden of heart failure on the healthcare system will continue to increase. Recent evidence demonstrates that empagliflozin, a sodium-glucose co-transporter-2 inhibitor, brings clinical benefit to patients with established heart failure and type 2 diabetes mellitus. Herein, we critically reviewed the clinical evidence of empagliflozin for patients with heart failure and type 2 diabetes mellitus with the comparison with other sodium-glucose co-transporter-2 inhibitors and potential mechanism to provide the optimal and evidence-based management for patients with established heart failure and type 2 diabetes mellitus with the goal to be conducive to the mechanism exploration of empagliflozin to advance a more comprehensive understanding of empagliflozin.

Anti-Arrhythmic Effects of Sodium-Glucose Co-Transporter 2 Inhibitors

Arrhythmias are clinically prevalent with a high mortality rate. They impose a huge economic burden, thereby substantially affecting the quality of life. Sodium-glucose co-transporter 2 inhibitor (SGLT2i) is a new type of hypoglycemic drug, which can regulate blood glucose level safely and effectively. Additionally, it reduces the occurrence and progression of heart failure and cardiovascular events significantly. Recently, studies have found that SGLT2i can alleviate the occurrence and progression of cardiac arrhythmias; however, the exact mechanism remains unclear. In this review, we aimed to discuss and summarize new literature on different modes in which SGLT2i ameliorates the occurrence and development of cardiac arrhythmias.

Empagliflozin attenuates cardiac microvascular ischemia/reperfusion through activating the AMPKα1/ULK1/FUNDC1/mitophagy pathway

Mitophagy preserves microvascular structure and function during myocardial ischemia/reperfusion (I/R) injury. Empagliflozin, an anti-diabetes drug, may also protect mitochondria. We explored whether empagliflozin could reduce cardiac microvascular I/R injury by enhancing mitophagy. In mice, I/R injury induced luminal stenosis, microvessel wall damage, erythrocyte accumulation and perfusion defects in the myocardial microcirculation. Additionally, I/R triggered endothelial hyperpermeability and myocardial neutrophil infiltration, which upregulated adhesive factors and endothelin-1 but downregulated vascular endothelial cadherin and endothelial nitric oxide synthase in heart tissue. In vitro, I/R impaired the endothelial barrier function and integrity of cardiac microvascular endothelial cells (CMECs), while empagliflozin preserved CMEC homeostasis and thus maintained cardiac microvascular structure and function. I/R activated mitochondrial fission, oxidative stress and apoptotic signaling in CMECs, whereas empagliflozin normalized mitochondrial fission and fusion, neutralized supraphysiologic reactive oxygen species concentrations and suppressed mitochondrial apoptosis. Empagliflozin exerted these protective effects by activating FUNDC1-dependent mitophagy through the AMPKα1/ULK1 pathway. Both in vitro and in vivo, genetic ablation of AMPKα1 or FUNDC1 abolished the beneficial effects of empagliflozin on the myocardial microvasculature and CMECs. Taken together, the preservation of mitochondrial function through an activation of the AMPKα1/ULK1/FUNDC1/mitophagy pathway is the working mechanism of empagliflozin in attenuating cardiac microvascular I/R injury.

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Empagliflozin reduces I/R-induced microvascular damage.

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Empagliflozin suppresses I/R-induced endothelial cell damage.

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Empagliflozin activates FUNDC1-dependent mitophagy through the AMPKα1/ULK1 pathway.

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Ablation of FUNDC1 or AMPKα1 abolishes the protective effects of empagliflozin against I/R-induced microvascular damage.

Antifibrotic effects of low dose SGLT2 Inhibition with empagliflozin in comparison to Ang II receptor blockade with telmisartan in 5/6 nephrectomised rats on high salt diet

To date, the lowest protective SGLT2 inhibitor dose is unknown. We initially performed a dose-response pilot study in normal rats. Based on the results of this pilot study we compared the cardio-renal effects of the SGLT-2 inhibitor empagliflozin, with placebo or telmisartan in rats with 5/6 nephrectomy (5/6 Nx) on a high salt diet (HSD). The experimental set up was as follows: Sham operation (Sham) with normal diet and placebo; 5/6 Nx with 2% HSD and placebo; 5/6 Nx with HSD and empagliflozin (0.6 mg/kg/day, bid); 5/6 Nx with HSD and telmisartan (5 mg/kg/day, qd). Empagliflozin treatment increased urinary glucose excretion, in parallel to empagliflozin plasma levels, in a dose-dependent manner starting at doses of 1 mg/kg in the pilot study. 5/6Nx rats on HSD treated with this low empagliflozin dose showed significantly reduced cardiac (-34.85%; P < 0.05) and renal (-33.68%; P < 0.05) fibrosis in comparison to 5/6Nx rats on HSD treated with placebo. These effects were comparable to the effects observed when implementing the standard dose (5 mg/kg/day) of telmisartan (cardiac fibrosis: -36.37%; P < 0.01; renal fibrosis; -43.96%; P < 0.01). RNA-sequencing followed by confirmatory qRT-PCR revealed that both telmisartan and empagliflozin exert their cardiac effects on genes involved in vascular cell stability and cardiac iron homeostasis, whereas in the kidneys expression of genes involved in endothelial function and oxidative stress were differentially expressed. Urinary adenosine excretion, a surrogate marker of the tubuloglomerular feedback (TGF) mechanism, was not affected. In conclusion, the antifibrotic properties of low dose empagliflozin were comparable to a standard dose of telmisartan. The underlying pathways appear to be TGF independent.