Ipragliflozin Reduces Epicardial Fat Accumulation in Non-Obese Type 2 Diabetic Patients with Visceral Obesity: A Pilot Study

Ethnic disparities and its association between epicardial adipose tissue thickness and cardiometabolic parameters

Excessive deposit of epicardial adipose tissue (EAT) were recently shown to be positively correlated with cardiovascular disease (CVD). This study aims to investigate the thickness of EAT and its association with the components of metabolic syndrome among multi-ethnic Malaysians with and without acute coronary syndrome (ACS). A total of 213 patients were recruited, with the thickness of EAT were quantified non-invasively using standard two-dimensional echocardiography. EAT thickness among the Malaysian population was prompted by several demographic factors and medical comorbidities, particularly T2DM and dyslipidaemia. ACS patients have significantly thicker EAT compared to those without ACS (4.1 mm vs 3.7 mm, p = 0.035). Interestingly, among all the races, Chinese had the thickest EAT distribution (4.6 mm vs 3.8 mm), with age (p = 0.04 vs p < 0.001), and overall diastolic blood pressure (p = 0.028) was also found to be associated with EAT thickness. Further study is warranted to investigate its role as a cardiovascular risk marker among Malaysians with ACS.

Epicardial Adipose Tissue and Heart Failure, Friend or Foe?

Heart failure (HF) management guidelines recommend individualized assessments based on HF phenotypes. Adiposity is a known risk factor for HF. Recently, there has been an increased interest in organ-specific adiposity, specifically the role of the epicardial adipose tissue (EAT), in HF risk. EAT is easily assessable through various imaging modalities and is anatomically and functionally connected to the myocardium. In pathological conditions, EAT secretes inflammatory cytokines, releases excessive fatty acids, and increases mechanical load on the myocardium, resulting in myocardial remodeling. EAT plays a pathophysiological role in characterizing both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). In HFrEF, EAT volume is reduced, reflecting an impaired metabolic reservoir, whereas in HFpEF, the amount of EAT is associated with worse biomarker and hemodynamic profiles, indicating increased EAT activity. Studies have examined the possibility of therapeutically targeting EAT, and recent studies using sodium glucose cotransporter 2 inhibitors have shown potential in reducing EAT volume. However, further research is required to determine the clinical implications of reducing EAT activity in patients with HF.

Epicardial Adipose Tissue: A Precise Biomarker for Cardiovascular Risk, Metabolic Diseases, and Target for Therapeutic Interventions

Epicardial adipose tissue (EAT) is located between the heart muscle and visceral pericardium, where it has direct contact with coronary blood vessels. Elevated thickness of this tissue can induce local inflammation affecting the myocardium and the underlying coronary arteries, contributing to various cardiovascular diseases such as coronary artery disease, atrial fibrillation, or heart failure with preserved ejection fraction. Recent studies have identified EAT thickness as a simple and reliable biomarker for certain cardiovascular outcomes. Examples include the presence of atherosclerosis, incident cardiovascular disease (CVD) in individuals with type 2 diabetes mellitus (T2DM), and the prevalence of atrial fibrillation. Furthermore, EAT measurements can help to identify patients with a higher risk of developing metabolic syndrome. Since the EAT thickness can be easily measured using echocardiography, such examinations could serve as a useful and cost-effective preventive tool for assessing cardiovascular health. This review also summarizes therapeutical interventions aimed at reducing EAT. Reducing EAT thickness has been shown to be possible through pharmacological, surgical, or lifestyle-change interventions. Pharmaceutical therapies, including thiazolidinediones, glucagon-like peptide 1-receptor agonists, sodium-glucose cotransporter 2 inhibitors, dipeptidyl peptidase-4 inhibitors, and statins, have been shown to influence EAT thickness. Additionally, EAT thickness can also be managed more invasively through bariatric surgery, or noninvasively through lifestyle changes to diet and exercise routines.

Role of epicardial adipose tissue in diabetic cardiomyopathy through the lens of cardiovascular magnetic resonance imaging - a narrative review

Accumulating evidence suggests that ectopic/visceral adiposity may play a key role in the pathogenesis of nonischaemic cardiovascular diseases associated with type 2 diabetes. Epicardial adipose tissue (EAT) is a complex visceral fat depot, covering 80% of the cardiac surface with anatomical and functional contiguity to the myocardium and coronary arteries. EAT interacts with the biology of the underlying myocardium by secreting a wide range of adipokines. Magnetic resonance imaging (MRI) is the reference modality for structural and functional imaging of the heart. The technique is now also emerging as the reference imaging modality for EAT quantification. With this narrative review, we (a) surveyed contemporary clinical studies that utilized cardiovascular MRI to characterize EAT (studies published 2010-2023); (b) listed the clinical trials monitoring the response to treatment in EAT size as well as myocardial functional and structural parameters and (c) discussed the potential pathophysiological role of EAT in the development of diabetic cardiomyopathy. We concluded that increased EAT quantity and its inflammatory phenotype correlate with early signs of left ventricle dysfunction and may have a role in the pathogenesis of cardiac disease in diabetes with and without coronary artery disease.

The effect of sodium-glucose co-transporter-2 inhibitors on markers of subclinical atherosclerosis

BACKGROUND

Despite the widespread use of classical cholesterol-lowering drugs to mitigate the adverse impacts of dyslipidaemia on atherosclerosis, many patients still face a substantial residual risk of developing atherosclerotic cardiovascular disease (CVD). This risk is partially attributed to non-traditional pathophysiological pathways. Latest evidence suggests that sodium glucose co-transporter-2 (SGLT2) inhibitors are beneficial for patients suffering from type 2 diabetes mellitus (T2DM) or established CVD by reducing morbidity and mortality. However, the underlying mechanisms of this benefit have not been clearly elucidated. It has been hypothesized that one possible mechanism could be the attenuation of subclinical atherosclerosis (SA) progression.

AIM

The objective of this narrative review is to examine the present evidence concerning the impact of SGLT2 inhibitors on markers of SA.

RESULTS

The current evidence on the efficacy of SGLT2 on SA, endothelial function and arterial stiffness remains controversial. Findings from observational and randomized studies are quite heterogeneous; however, they converge that the antiatherosclerotic activity of SGLT2 inhibitors is not strong enough to be widely used for prevention of atherosclerosis progression in patients with or without T2DM.

CONCLUSIONS

Further research is needed to investigate the underlying mechanisms and the possible beneficial impact of SGLT2i on primary and secondary CVD prevention through attenuation of premature atherosclerosis progression.

Epicardial adipose tissue, metabolic disorders, and cardiovascular diseases: recent advances classified by research methodologies

Epicardial adipose tissue (EAT) is located between the myocardium and visceral pericardium. The unique anatomy and physiology of the EAT determines its great potential in locally influencing adjacent tissues such as the myocardium and coronary arteries. Classified by research methodologies, this study reviews the latest research progress on the role of EAT in cardiovascular diseases (CVDs), particularly in patients with metabolic disorders. Studies based on imaging techniques demonstrated that increased EAT amount in patients with metabolic disorders is associated with higher risk of CVDs and increased mortality. Then, in-depth profiling studies indicate that remodeled EAT may serve as a local mediator of the deleterious effects of cardiometabolic conditions and plays a crucial role in CVDs. Further, in vitro coculture studies provided preliminary evidence that the paracrine effect of remodeled EAT on adjacent cardiomyocytes can promote the occurrence and progression of CVDs. Considering the important role of EAT in CVDs, targeting EAT might be a potential strategy to reduce cardiovascular risks. Several interventions have been proved effective in reducing EAT amount. Our review provides valuable insights of the relationship between EAT, metabolic disorders, and CVDs, as well as an overview of the methodological constructs of EAT-related studies.

Cardiometabolic risk management: insights from a European Society of Cardiology Cardiovascular Round Table

Metabolic comorbidities are common in patients with cardiorenal disease; they can cause atherosclerotic cardiovascular disease (ASCVD), speed progression, and adversely affect prognosis. Common comorbidities are Type 2 diabetes mellitus (T2DM), obesity/overweight, chronic kidney disease (CKD), and chronic liver disease. The cardiovascular system, kidneys, and liver are linked to many of the same risk factors (e.g. dyslipidaemia, hypertension, tobacco use, diabetes, and central/truncal obesity), and shared metabolic and functional abnormalities lead to damage throughout these organs via overlapping pathophysiological pathways. The COVID-19 pandemic has further complicated the management of cardiometabolic diseases. Obesity, T2DM, CKD, and liver disease are associated with increased risk of poor outcomes of COVID-19 infection, and conversely, COVID-19 can lead to worsening of pre-existing ASCVD. The high rates of these comorbidities highlight the need to improve recognition and treatment of ASCVD in patients with obesity, insulin resistance or T2DM, chronic liver diseases, and CKD and equally, to improve recognition and treatment of these diseases in patients with ASCVD. Strategies to prevent and manage cardiometabolic diseases include lifestyle modification, pharmacotherapy, and surgery. There is a need for more programmes at the societal level to encourage a healthy diet and physical activity. Many pharmacotherapies offer mechanism-based approaches that can target multiple pathophysiological pathways across diseases. These include sodium-glucose cotransporter-2 inhibitors, glucagon-like peptide-1 receptor agonists, selective mineralocorticoid receptor antagonists, and combined glucose-dependent insulinotropic peptide/glucagon-like peptide-1 receptor agonist. Non-surgical and surgical weight loss strategies can improve cardiometabolic disorders in individuals living with obesity. New biomarkers under investigation may help in the early identification of individuals at risk and reveal new treatment targets.

SGLT2-Inhibitors on HFpEF Patients. Role of Ejection Fraction

Results from DELIVER trial and publication of EMPEROR-Preserved with sodium-glucose cotransporter 2 (SGLT2) inhibitors in patients with heart failure (HF) with ejection fraction (EF) > 40% represent a significant step forward in the treatment of HF with preserved EF (HFpEF). However, detailed analysis and attenuation of effect at higher EF levels have sparked some doubts about whether empagliflozin is effective across the entire spectrum of EF. HFpEF is no longer considered as one disease entity, but has been reconceptualized as a heterogenous group of phenotypes with derangements in multiple organ systems, driven by comorbidities. This heterogeneity suggests that it should not be considered as a single group in terms of treatment goals or clinical approach. Future research at the higher range of EF should ideally tailor investigations for unequivocally preserved EF (> 50%), consider the dynamic nature of EF over time, and use low-variability imaging techniques such as CMR. Furthermore, classifications based on pathophysiology and HF phenotypes beyond the EF construct will shape the design of future trials and help narrow down groups of patients who may respond to personalized treatment.

Reno- and cardioprotective molecular mechanisms of SGLT2 inhibitors beyond glycemic control: from bedside to bench

Large placebo-controlled clinical trials have shown that sodium-glucose cotransporter-2 inhibitors (SGLT2i) delay the deterioration of renal function and reduce cardiovascular events in a glucose-independent manner, thereby ultimately reducing mortality in patients with chronic kidney disease (CKD) and/or heart failure. These existing clinical data stimulated preclinical studies aiming to understand the observed clinical effects. In animal models, it was shown that the beneficial effect of SGLT2i on the tubuloglomerular feedback (TGF) improves glomerular pressure and reduces tubular workload by improving renal hemodynamics, which appears to be dependent on salt intake. High salt intake might blunt the SGLT2i effects on the TGF. Beyond the salt-dependent effects of SGLT2i on renal hemodynamics, SGLT2i inhibited several key aspects of macrophage-mediated renal inflammation and fibrosis, including inhibiting the differentiation of monocytes to macrophages, promoting the polarization of macrophages from a proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype, and suppressing the activation of inflammasomes and major proinflammatory factors. As macrophages are also important cells mediating atherosclerosis and myocardial remodeling after injury, the inhibitory effects of SGLT2i on macrophage differentiation and inflammatory responses may also play a role in stabilizing atherosclerotic plaques and ameliorating myocardial inflammation and fibrosis. Recent studies suggest that SGLT2i may also act directly on the Na+/H+ exchanger and Late-INa in cardiomyocytes thus reducing Na+ and Ca2+ overload-mediated myocardial damage. In addition, the renal-cardioprotective mechanisms of SGLT2i include systemic effects on the sympathetic nervous system, blood volume, salt excretion, and energy metabolism.

Generalizability of REDUCE-IT eligibility criteria in a large diabetes cardiovascular outcomes trial: A post hoc subgroup analysis of EMPA-REG outcome: Analysis of EMPA-REG OUTCOME using REDUCE-IT criteria

Objectives

REDUCE-IT showed that icosapent ethyl (IPE) improved cardiovascular (CV) outcomes in participants with established CV disease (CVD) or type 2 diabetes (T2D) and at least one additional risk factor plus mild-moderate hypertriglyceridemia and reasonably controlled low-density lipoprotein cholesterol (LDL-C). As the generalizability of REDUCE-IT has not been investigated in a T2D population with established CVD, this post hoc analysis investigated how many participants from EMPA-REG OUTCOME, which tested the effects of empagliflozin versus placebo on CV outcomes in participants with T2D and CVD, would have been eligible for IPE treatment, and whether CV outcomes differed based on eligibility for IPE treatment.

Methods

Participants from EMPA-REG OUTCOME were screened for inclusion using both REDUCE-IT-like criteria (baseline statin therapy, triglycerides 135-499 mg/dL and LDL-C 41-100 mg/dL) and slightly amended FDA indication criteria (triglycerides ≥150 mg/dL). Analyses were conducted to characterize the study population and CV outcomes in participants eligible for IPE versus those not eligible for IPE.

Results

Of the 7020 participants from EMPA-REG OUTCOME, 1810 (25.8%) fulfilled REDUCE-IT criteria and 3182 (45.3%) fulfilled FDA criteria for IPE treatment. Treatment effects of empagliflozin versus placebo on CV and kidney outcomes and mortality were consistent in participants meeting REDUCE-IT and FDA criteria and those who did not.

Conclusions

These results indicate that a sizable proportion of patients with diabetes and established CVD, such as those in EMPA-REG OUTCOME, may be eligible for IPE treatment to lower residual CV risk. Treatment benefit with empagliflozin was consistent, regardless of REDUCE-IT or FDA eligibility criteria.

Staphylococcus aureus and Pseudomonas aeruginosa infectious keratitis: key bacterial mechanisms that mediate pathogenesis and emerging therapeutics

Bacterial keratitis (bacterial infection of the cornea) is a major cause of vision loss worldwide. Given the rapid and aggressive nature of the disease, immediate broad-spectrum antibiotics are essential to adequately treat this disease. However, rising antibiotic resistance continues to accelerate, rendering many commonly used therapeutics increasingly ineffective. As such, there is a significant effort to understand the basic pathogenesis of common causative organisms implicated in keratitis in part, to fuel the development of novel therapies to treat this blinding disease. This review explores two common causes of bacterial keratitis, Staphylococcus aureus and Pseudomonas aeruginosa, with regards to the bacterial mediators of virulence as well as novel therapies on the horizon.

Targeting epicardial adipose tissue: A potential therapeutic strategy for heart failure with preserved ejection fraction with type 2 diabetes mellitus

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with various comorbidities, multiple cardiac and extracardiac pathophysiologic abnormalities, and diverse phenotypic presentations. Since HFpEF is a heterogeneous disease with different phenotypes, individualized treatment is required. HFpEF with type 2 diabetes mellitus (T2DM) represents a specific phenotype of HFpEF, with about 45%-50% of HFpEF patients suffering from T2DM. Systemic inflammation associated with dysregulated glucose metabolism is a critical pathological mechanism of HFpEF with T2DM, which is intimately related to the expansion and dysfunction (inflammation and hypermetabolic activity) of epicardial adipose tissue (EAT). EAT is well established as a very active endocrine organ that can regulate the pathophysiological processes of HFpEF with T2DM through the paracrine and endocrine mechanisms. Therefore, suppressing abnormal EAT expansion may be a promising therapeutic strategy for HFpEF with T2DM. Although there is no treatment specifically for EAT, lifestyle management, bariatric surgery, and some pharmaceutical interventions (anti-cytokine drugs, statins, proprotein convertase subtilisin/kexin type 9 inhibitors, metformin, glucagon-like peptide-1 receptor agonists, and especially sodium-glucose cotransporter-2 inhibitors) have been shown to attenuate the inflammatory response or expansion of EAT. Importantly, these treatments may be beneficial in improving the clinical symptoms or prognosis of patients with HFpEF. Accordingly, well-designed randomized controlled trials are needed to validate the efficacy of current therapies. In addition, more novel and effective therapies targeting EAT are needed in the future.

Perivascular adipose tissue in vascular pathologies-a novel therapeutic target for atherosclerotic disease?

Most blood vessels are surrounded by adipose tissues known as perivascular adipose tissue (PVAT). Emerging experimental data have implicated the potential involvement of PVAT in the pathogenesis of cardiovascular disease: PVAT might be a source of inflammatory mediators under pathological conditions such as metabolic disorders, chronic inflammation, and aging, leading to vascular pathologies, while having vasculo-protective roles in a healthy state. PVAT has been also gaining attention in human disease conditions. Recent integrative omics approaches have greatly enhanced our understanding of the molecular mechanisms underlying the diverse functions of PVAT. This review summarizes recent progress in PVAT research and discusses the potential of PVAT as a target for the treatment of atherosclerosis.

Reducing Cardiac Steatosis: Interventions to Improve Diastolic Function - A Narrative Review

Heart failure is one of the main causes of morbidity and mortality around the globe. Heart failure with preserved ejection fraction is primarily caused by diastolic dysfunction. Adipose tissue deposition in the heart has been previously explained in the pathogenesis of diastolic dysfunction. In this article, we aim to discuss the potential interventions that can reduce the risk of diastolic dysfunction by reducing cardiac adipose tissue. A healthy diet with reduced dietary fat content can reduce visceral adiposity and improve diastolic function. Aerobic and resistance exercises also reduce visceral and epicardial fat and ameliorate diastolic dysfunction. Some medications, include metformin, glucagon-like peptide-1 analogues, dipeptidyl peptidase-4 inhibitors, thiazolidinediones, sodium-glucose co-transporter-2, inhibitors, statins, ACE-Is, and ARBs, have shown different degrees of effectiveness in improving cardiac steatosis and diastolic function. Bariatric surgery has also shown promising results in this field.

Ischemia with Nonobstructive Coronary Artery Disease and Atrial Cardiomyopathy-Two Sides of the Same Story?

Ischemia with nonobstructive coronary artery disease (INOCA) is increasingly recognized as a significant cause of angina, myocardial remodeling, and eventually heart failure (HF). Coronary microvascular dysfunction (CMD) is a major endotype of INOCA, and it is caused by structural and functional alterations of the coronary microcirculation. At the same time, atrial cardiomyopathy (ACM) defined by structural, functional, and electrical atrial remodeling has a major clinical impact due to its manifestations: atrial fibrillation (AF), atrial thrombosis, stroke, and HF symptoms. Both these pathologies share similar risk factors and have a high comorbidity burden. CMD causing INOCA and ACM frequently coexist. Thus, questions arise whether there is a potential link between these pathologies. Does CMD promote AF or the reverse? Which are the mechanisms that ultimately lead to CMD and ACM? Are both part of a systemic disease characterized by endothelial dysfunction? Lastly, which are the therapeutic strategies that can target endothelial dysfunction and improve the prognosis of patients with CMD and ACM? This review aims to address these questions by analyzing the existing body of evidence, offering further insight into the mechanisms of CMD and ACM, and discussing potential therapeutic strategies.

Efficacy of cardiometabolic drugs in reduction of epicardial adipose tissue: a systematic review and meta-analysis

BACKGROUND

Epicardial adipose tissue (EAT) plays an important role in cardiometabolic risk. EAT is a modifiable risk factor and could be a potential therapeutic target for drugs that already show cardiovascular benefits. The aim of this study is to evaluate the effect of cardiometabolic drugs on EAT reduction.

METHODS

A detailed search related to the effect on EAT reduction due to cardiometabolic drugs, such as glucagon-like peptide-1 receptor agonist (GLP-1 RA), sodium-glucose cotransporter-2 inhibitors (SGLT2-i), and statins was conducted according to PRISMA guidelines. Eighteen studies enrolling 1064 patients were included in the qualitative and quantitative analyses.

RESULTS

All three analyzed drug classes, in particular GLP-1 RA, show a significant effect on EAT reduction (GLP-1 RA standardize mean difference (SMD) = - 1.005; p < 0.001; SGLT2-i SMD = - 0.552; p < 0.001, and statin SMD = - 0.195; p < 0.001). The sensitivity analysis showed that cardiometabolic drugs strongly benefit EAT thickness reduction, measured by ultrasound (overall SMD of - 0.663; 95%CI - 0.79, - 0.52; p < 0.001). Meta-regression analysis revealed younger age and higher BMI as significant effect modifiers of the association between cardiometabolic drugs and EAT reduction for both composite effect and effect on EAT thickness, (age Z: 3.99; p < 0.001 and Z: 1.97; p = 0.001, respectively; BMI Z: - 4.40; p < 0.001 and Z: - 2.85; p = 0.004, respectively).

CONCLUSIONS

Cardiometabolic drugs show a significant beneficial effect on EAT reduction. GLP-1 RA was more effective than SGLT2-i, while statins had a rather mild effect. We believe that the most effective treatment with these drugs should target younger patients with high BMI.

Sodium-glucose Cotransporter 2 Inhibitors and Pathological Myocardial Hypertrophy

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

Sodium-glucose co-transporter-2 inhibitors and epicardial adiposity

Epicardial adipose tissue is a layer of adipocytes that physiologically surround the myocardium and play some physiologic roles in normal heart function. However, in pathologic conditions, the epicardial adipose tissue can present a potent cardiac risk factor that is capable of impairing heart function through several pathways, increasing the risk of dysrhythmia and creating an inflammatory milieu around the heart tissues. Sodium-glucose cotransporter 2 inhibitors (SGLT2is) are a relatively newly introduced class of antidiabetes drugs which effectively normalize blood glucose via overt glycosuria. Some recent reports suggest that these drugs are able to modulate epicardial adiposity and decrease the risk of cardiac complications in diabetic patients who are at higher risk of epicardial adiposity-dependent cardiac disorders. If proven to be true, these antidiabetic drugs can provide dual benefits as both hypoglycemic agents and as epicardial adiposity normalizing agents, thus providing cardiac benefits. In this study, we discuss the physiological and pathophysiological importance of epicardial adiposity and the potential positive effects of SGLT2is in the diabetic milieu.

Metformin and empagliflozin modulate monoamine oxidase-related oxidative stress and improve vascular function in human mammary arteries

Monoamine oxidases (MAOs), mitochondrial enzymes with two isoforms, A and B, have been recently recognized as significant contributors to oxidative stress in the cardiovascular system. The present study was purported to assess the effect of metformin and empagliflozin on MAO expression, oxidative stress and vascular reactivity in internal mammary arteries harvested from overweight patients with coronary heart disease subjected to bypass grafting. Vascular rings were prepared and acutely incubated (12 h) with high glucose (GLUC, 400 mg/dL) or angiotensin II (AII, 100 nM) and metformin (10 µM) and/or empagliflozin (10 µM) and used for the assessment of MAO expression (qRT-PCR and immune histochemistry), reactive oxygen species (ROS, confocal microscopy and spectrophotometry), and vasomotor function (myograph). Ex vivo stimulation with GLUC or AII increased both MAOs expression, ROS production and impaired relaxation to acetylcholine (ACh) of the vascular rings. All effects were alleviated by incubation with each antidiabetic drug; no cumulative effect was obtained when the drugs were applied together. In conclusion, MAO-A and B are upregulated in mammary arteries after acute stimulation with GLUC and AII. Endothelial dysfunction and oxidative stress were alleviated by either metformin or empagliflozin in both stimulated and non-stimulated vascular samples harvested from overweight cardiac patients.

A New Chapter in the Treatment of Patients with Heart Failure. The Role of Sodium-Glucose Co-transporter Type 2 Inhibitors

Heart failure (HF) remains one of the major social and medical public health problems worldwide. Despite new advances in the treatment of patients with HF, the prognosis is still poor. According to the European Cardiology Society guidelines for the diagnosis and treatment of acute and chronic heart failure (CHF) 2021, a new class of drugs related to hypoglycemic has been confirmed to be effective in influencing the survival of patients with heart failure with low ejection fraction (HFpEF), regardless of the presence of disorders of carbohydrate metabolism. We are talking about inhibitors of the sodium-glucose co-transporter type 2 (iSGLT-2) or gliflozins. The article presents the results of the latest large clinical trials on the effective use of SGLT-2 in patients with HF, not only with low, but also with intact ejection fraction (HFpEF), for which there is no evidence base at the present stage. The review article presents the results of experimental studies that explored the potential mechanisms of action of gliflozins with an emphasis on new ones that are of fundamental importance for patients with heart failure, and also describes controversial and little-studied issues. Currently, there is no therapy that improves outcomes in patients with acute heart failure. The article presents the results of small analyzes of the use of iSGLT-2 in this category of patients, which are the basis for the hypothesis of their potentially effective and safe use in the case of acute decompensation of CHF, however, the role of gliflozins in this category of patients requires further in-depth study.

Obesity-related glomerulopathy: Current approaches and future perspectives

Obesity-related glomerulopathy (ORG) is a silent comorbidity which is increasing in incidence as the obesity epidemic escalates. ORG is associated with serious health consequences including chronic kidney disease, end-stage renal disease (ESRD), and increased mortality. Although the pathogenic mechanisms involved in the development of ORG are not fully understood, glomerular hemodynamic changes, renin-angiotensin-aldosterone system (RAAS) overactivation, insulin-resistance, inflammation and ectopic lipid accumulation seem to play a major role. Despite albuminuria being commonly used for the non-invasive evaluation of ORG, promising biomarkers of early kidney injury that are emerging, as well as new approaches with proteomics and metabolomics, might permit an earlier diagnosis of this disease. In addition, the assessment of ectopic kidney fat by renal imaging could be a useful tool to detect and evaluate the progression of ORG. Weight loss interventions appear to be effective in ORG, although large-scale trials are needed. RAAS blockade has a renoprotective effect in patients with ORG, but even so, a significant proportion of patients with ORG will eventually progress to ESRD despite therapeutic efforts. It is noteworthy that certain antidiabetic agents such as sodium-glucose cotransporter 2 inhibitors (SGLT2i) or glucagon-like peptide-1 receptor agonists (GLP-1 RAs) could be useful in the treatment of ORG through different pleiotropic effects. In this article, we review current approaches and future perspectives in the care and treatment of ORG.

Epicardial adipose tissue in contemporary cardiology

Interest in epicardial adipose tissue (EAT) is growing rapidly, and research in this area appeals to a broad, multidisciplinary audience. EAT is unique in its anatomy and unobstructed proximity to the heart and has a transcriptome and secretome very different from that of other fat depots. EAT has physiological and pathological properties that vary depending on its location. It can be highly protective for the adjacent myocardium through dynamic brown fat-like thermogenic function and harmful via paracrine or vasocrine secretion of pro-inflammatory and profibrotic cytokines. EAT is a modifiable risk factor that can be assessed with traditional and novel imaging techniques. Coronary and left atrial EAT are involved in the pathogenesis of coronary artery disease and atrial fibrillation, respectively, and it also contributes to the development and progression of heart failure. In addition, EAT might have a role in coronavirus disease 2019 (COVID-19)-related cardiac syndrome. EAT is a reliable potential therapeutic target for drugs with cardiovascular benefits such as glucagon-like peptide 1 receptor agonists and sodium–glucose co-transporter 2 inhibitors. This Review provides a comprehensive and up-to-date overview of the role of EAT in cardiovascular disease and highlights the translational nature of EAT research and its applications in contemporary cardiology.

In this Review, Iacobellis provides a comprehensive overview of the role of epicardial adipose tissue (EAT) in cardiovascular disease, including coronary artery disease, heart failure and atrial fibrillation, discusses imaging techniques for EAT assessment and highlights the therapeutic potential of targeting EAT in cardiovascular disease.

Epicardial adipose tissue (EAT) has anatomical and functional interactions with the heart owing to the shared circulation and the absence of muscle fascia separating the two organs.

EAT can be clinically measured with cardiac imaging techniques that can help to predict and stratify cardiovascular risk.

Regional distribution of EAT is important because pericoronary EAT and left atrial EAT differently affect the risk of coronary artery diseases and atrial fibrillation, respectively.

EAT has a role in the development of several cardiovascular diseases through complex mechanisms, including gene expression profile, pro-inflammatory and profibrotic proteome, neuromodulation, and glucose and lipid metabolism.

EAT could be a potential therapeutic target for novel cardiometabolic medications that modulate adipose tissue such as glucagon-like peptide 1 receptor agonists and sodium–glucose co-transporter 2 inhibitors.

EAT might be a reservoir of severe acute respiratory syndrome coronavirus 2 and an amplifier of coronavirus disease 2019 (COVID-19)-related cardiac syndrome.

Cardiovascular risk reduction throughout GLP-1 receptor agonist and SGLT2 inhibitor modulation of epicardial fat

Epicardial adipose tissue is a novel cardiovascular risk factor. It plays a role in the progression of coronary artery disease, heart failure and atrial fibrillation. Given its rapid metabolism, clinical measurability, and modifiability, epicardial fat works well as therapeutic target of drugs modulating the adipose tissue. Epicardial fat responds to glucagon-like peptide 1 receptor agonists (GLP1A) and sodium glucose co-transporter 2 inhibitors (SGLT2i). GLP-1A and SGLT2i provide weight loss and cardiovascular protective effects beyond diabetes control, as recently demonstrated. The potential of modulating the epicardial fat morphology and genetic profile with targeted pharmacological agents can open new avenues in the pharmacotherapy of diabetes and obesity, with particular focus on cardiovascular risk reduction.

Role of Epicardial Adipose Tissue in Cardiovascular Diseases: A Review

Simple Summary

Cardiovascular diseases (CVDs) are the leading causes of death worldwide. Epicardial adipose tissue (EAT) is one of the most important risk factors for cardiovascular events and a promising new therapeutic target in CVDs. Here, we summarize the currently available evidence regarding the role of EAT in the development of CVDs, including coronary artery disease, heart failure and atrial fibrillation; compile data regarding the association between EAT’s function and the course of COVID-19; and present new potential therapeutic possibilities, aiming at modifying EAT’s function. The development of novel therapies specifically targeting EAT could revolutionize the prognosis in CVDs.

Abstract

Cardiovascular diseases (CVDs) are the leading causes of death worldwide. Epicardial adipose tissue (EAT) is defined as a fat depot localized between the myocardial surface and the visceral layer of the pericardium and is a type of visceral fat. EAT is one of the most important risk factors for atherosclerosis and cardiovascular events and a promising new therapeutic target in CVDs. In health conditions, EAT has a protective function, including protection against hypothermia or mechanical stress, providing myocardial energy supply from free fatty acid and release of adiponectin. In patients with obesity, metabolic syndrome, or diabetes mellitus, EAT becomes a deleterious tissue promoting the development of CVDs. Previously, we showed an adverse modulation of gene expression in pericoronary adipose tissue in patients with coronary artery disease (CAD). Here, we summarize the currently available evidence regarding the role of EAT in the development of CVDs, including CAD, heart failure, and atrial fibrillation. Due to the rapid development of the COVID-19 pandemic, we also discuss data regarding the association between EAT and the course of COVID-19. Finally, we present the potential therapeutic possibilities aiming at modifying EAT’s function. The development of novel therapies specifically targeting EAT could revolutionize the prognosis in CVDs.

Nonalcoholic Fatty Liver Disease: The Role of Visceral Adipose Tissue

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Dysregulated Epicardial Adipose Tissue as a Risk Factor and Potential Therapeutic Target of Heart Failure with Preserved Ejection Fraction in Diabetes

Cardiovascular (CV) disease and heart failure (HF) are the leading cause of mortality in type 2 diabetes (T2DM), a metabolic disease which represents a fast-growing health challenge worldwide. Specifically, T2DM induces a cluster of systemic metabolic and non-metabolic signaling which may promote myocardium derangements such as inflammation, fibrosis, and myocyte stiffness, which represent the hallmarks of heart failure with preserved ejection fraction (HFpEF). On the other hand, several observational studies have reported that patients with T2DM have an abnormally enlarged and biologically transformed epicardial adipose tissue (EAT) compared with non-diabetic controls. This expanded EAT not only causes a mechanical constriction of the diastolic filling but is also a source of pro-inflammatory mediators capable of causing inflammation, microcirculatory dysfunction and fibrosis of the underlying myocardium, thus impairing the relaxability of the left ventricle and increasing its filling pressure. In addition to representing a potential CV risk factor, emerging evidence shows that EAT may guide the therapeutic decision in diabetic patients as drugs such as metformin, glucagon-like peptide‑1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 inhibitors (SGLT2-Is), have been associated with attenuation of EAT enlargement.

Effect of sodium-glucose cotransporter protein-2 inhibitors on left ventricular hypertrophy in patients with type 2 diabetes: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis was performed to compare the effect of sodium-glucose cotransporter protein-2 inhibitors (SGLT-2i) and placebo on left ventricular hypertrophy (LVH) in patients with type 2 diabetes.

METHOD

Randomized controlled trials (RCTs) comparing the LVH parameters of SGLT-2i to placebo in patients with type 2 diabetes were included. Our primary outcomes were the changes in left ventricular mass (LVM) and left ventricular mass index (LVMI) from baseline to the study endpoint. Secondary outcomes were the changes in left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and the ratio of early mitral inflow velocity to atrial inflow velocity (E/A). Summary odds ratios were estimated using a fixed-effect or random-effect model.

RESULTS

A total of 11 articles were included. Data were extracted from 11 original studies matching our inclusion criteria. In our meta-analysis, there were significant improvement in LVM (SMD -0.23, 95% CI -0.44 to -0.02, I ² = 22.6%, p = 0.034), LVMI (SMD -0.25, 95% CI -0.38 to -0.12, I ² = 0.0%, p = 0.000), LVEDV (SMD -0.19, 95% CI -0.36 to -0.01, I ² = 62.3%, p = 0.035), and LVESV (SMD -0.21, 95% CI -0.39 to -0.04, I ² = 32.9%, p = 0.017) in the SGLT-2i group compared with the placebo group. Furthermore, no significant differences were found in LVEF (SMD 0.13, 95% CI 0.00 to 0.26, I ² = 0.0%, p = 0.050) and E/A (SMD -0.01, 95% CI -0.22 to 0.20, I ² = 0%, p = 0.908) between the two groups.

CONCLUSIONS

This meta-analysis confirmed the beneficial effects of SGLT-2i on reversal of left ventricular remodeling. The LVH regression was more pronounced in studies of type 2 diabetes patients receiving SGLT-2i than placebo.

Targeting Epicardial Fat in Obesity and Diabetes Pharmacotherapy

Epicardial adipose tissue surrounds and infiltrates the heart. Epicardial fat displays unique anatomic, genetic, and biomolecular properties. People with obesity and in particular, those with abdominal obesity and associated type 2 diabetes mellitus, have an increased amount of epicardial adipose tissue (EAT). Epicardial fat works well as therapeutic target due to its fast-responding metabolism, organ fat specificity, and easy measurability. Epicardial fat responds to thiazolidinediones (TZD), glucagon-like peptide 1-receptor agonists (GLP1A), sodium-glucose cotransporter 2 inhibitors (SGLT2i), dipeptidyl peptidase-4 inhibitors (DPP4i), and statins. Modulating epicardial fat morphology and genetic profile with targeted pharmacological agents suggests novel strategies in the pharmacotherapy of diabetes and obesity.

Predictors of Epicardial Fat Volume Decrease after Dapagliflozin Treatment in Patients with Type 2 Diabetes

Background and Objectives: Dapagliflozin treatment proved to reduce the epicardial fat volume (EFV) in patients with type 2 diabetes (T2D). Despite the reduction in EFV being associated with improved diastolic function in patients with T2D, EVF is not routinely evaluated in T2D because it is costly and involves radiation exposure. This study aims to identify biomarkers that predict EFV reduction after dapagliflozin treatment in patients with T2D. Materials and Methods: In a prospective, observational, consecutive-case enrollment scenario, 52 patients with T2D were initiated on dapagliflozin 10 mg q.d. as part of the standard of care. At enrollment and after six months of dapagliflozin treatment, patients were evaluated using cardiac ultrasonography, native computer tomography, transient liver elastography, and metabolic lab tests. In addition, the atherogenic index of plasma (AIP), atherogenic coefficient (AC), triglyceride glucose index (TyG), cardiac risk ratio (CRR), and visceral abdominal index (VAI) were calculated. Results: Higher AIP (r = 0.28; p = 0.04), CRR (r = 0.28; p = 0.04), and TyG (r = 0.32; p = 0.01) are associated with more important reductions in the EFV. A lower conicity index (β = −0.29; p = 0.03), visceral fat volume at the 4th vertebrae (L4VFV) (β = −0.32; p = 0.02), left atrium volume (β = −3.08; p = 0.003), and right ventricle diameter (β = −2.13; p = 0.04) are associated with higher reductions in the EFV after six months of dapagliflozin treatment. A valid performance for predicting clinically relevant decreases in EFV after dapagliflozin treatment was observed for AIP (AUROC = 0.903; Youden = 0.732; p < 0.001), CRR (AUROC = 0.772; Youden = 0.595; p = 0.004), TyG (AUROC = 0.957; Youden = 0.904; p < 0.001), and VAI (AUROC = 0.898; Youden = 0.712; p < 0.001). Conclusion: Higher initial EFV values are associated with more important reductions in EFV in patients with T2D treated for six months with dapagliflozin. TyG values have the best prediction performances for EFV reduction, having the highest sum of sensitivity and specificity at the 0.904 threshold level. AIP, CRR, VAI, conicity index, L4VF, left atrium volume, and right ventricle volume are valid biomarkers for a decrease in EFV after dapagliflozin treatment in diabetes patients.

Effect of SGLT2-Inhibitors on Epicardial Adipose Tissue: A Meta-Analysis

(1) Sodium-glucose cotransporter-2 inhibitors (SGLT2-i) reduce adipose tissue and cardiovascular events in patients with type 2 diabetes (T2D). Accumulation of epicardial adipose tissue (EAT) is associated with increased cardio-metabolic risks and obstructive coronary disease events in patients with T2D. (2) We performed a systematic review and meta-analysis of SGLT2-i therapy on T2D patients, reporting data on changes in EAT after searching the PubMed/MEDLINE, Embase, Science Direct, Scopus, Google Scholar, and Cochrane databases. A random effects or fixed effects model meta-analysis was then applied. (3) Results: A total of three studies (n = 64 patients with SGLT2-i, n = 62 with standard therapy) were included in the final analysis. SGLT2 inhibitors reduced EAT (SMD: -0.82 (-1.49; -0.15); p < 0.0001). An exploratory analysis showed that HbA1c was significantly reduced with SGLT2-i use, while body mass index was not significantly reduced with this drug. (4) Conclusions: This meta-analysis suggests that the amount of EAT is significantly reduced in T2D patients with SGLT2-i treatment.

CARDIOVASCULAR EFFECTS OF NON-INSULIN GLUCOSE-LOWERING AGENTS: A COMPREHENSIVE REVIEW OF TRIAL EVIDENCE AND POTENTIAL CARDIOPROTECTIVE MECHANISMS

Type 2 diabetes mellitus (T2DM) is highly prevalent and associated with a 2-fold increased mortality, mostly explained by cardiovascular diseases. Trial evidence on older glucose-lowering agents such as metformin and sulfonylureas is limited in terms of cardiovascular efficacy. Since 2008, after rosiglitazone was observed to increase the risk of myocardial infarction and heart failure (HF), cardiovascular outcome trials (CVOT) have been required by regulators for licensing new glucose-lowering agents. In the following CVOTs, dipeptidyl peptidase 4 inhibitors (DPP4i) have been shown to be safe but not to improve morbidity/mortality, except for saxagliptin which increased the risk of HF. Several glucagon-like peptide-1 receptor agonists (GLP1-Ra) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been demonstrated to reduce the risk of cardiovascular morbidity and mortality. SGLT2i have shown a class effect for the reduction in risk of HF events in patients with T2DM, leading to trials testing their efficacy/safety in HF regardless of T2DM. In the DAPA-HF and the EMPEROR-Reduced trials dapagliflozin and empagliflozin, respectively, improved cardiovascular mortality/morbidity in patients with HF and reduced ejection fraction (HFrEF), with and without T2DM. Therefore, these drugs are now key part of HFrEF pharmacotherapy. In the SOLOIST-WHF, sotagliflozin reduced cardiovascular mortality/morbidity in patients with T2DM and a recent acute episode of HF regardless of EF. The DELIVER and the EMPEROR-Preserved are testing dapagliflozin and empagliflozin, respectively, in patients with HF with mildly reduced and preserved EF. A strong renal protective role of SGLT2i has also emerged in trials enrolling patients with and without T2DM.

Differential Pathophysiological Mechanisms in Heart Failure With a Reduced or Preserved Ejection Fraction in Diabetes

Diabetes promotes the development of both heart failure with a reduced ejection fraction and heart failure with a preserved ejection fraction through diverse mechanisms, which are likely mediated through hyperinsulinemia rather than hyperglycemia. Diabetes promotes nutrient surplus signaling (through Akt and mammalian target of rapamycin complex 1) and inhibits nutrient deprivation signaling (through sirtuin-1 and its downstream effectors); this suppresses autophagy and promotes endoplasmic reticulum and oxidative stress and mitochondrial dysfunction, thereby undermining the health of diabetic cardiomyocytes. The hyperinsulinemia of diabetes may also activate sodium-hydrogen exchangers in cardiomyocytes (leading to injury and loss) and in the proximal renal tubules (leading to sodium retention). Diabetes may cause epicardial adipose tissue expansion, and the resulting secretion of proinflammatory adipocytokines onto the adjoining myocardium can lead to coronary microcirculatory dysfunction and myocardial inflammation and fibrosis. Interestingly, sodium-glucose cotransporter 2 (SGLT2) inhibitors-the only class of antidiabetic medication that reduces serious heart failure events-may act to mitigate each of these mechanisms. SGLT2 inhibitors up-regulate sirtuin-1 and its downstream effectors and autophagic flux, thus explaining the actions of these drugs to reduce oxidative stress, normalize mitochondrial structure and function, and mute proinflammatory pathways in the stressed myocardium. Inhibition of SGLT2 may also lead to a reduction in the activity of sodium-hydrogen exchangers in the kidney (leading to diuresis) and in the heart (attenuating the development of cardiac hypertrophy and systolic dysfunction). Finally, SGLT2 inhibitors reduce the mass and mute the adverse biology of epicardial adipose tissue (and reduce the secretion of leptin), thus explaining the capacity of these drugs to mitigate myocardial inflammation, microcirculatory dysfunction, and fibrosis, and improve ventricular filling dynamics. The pathophysiological mechanisms by which SGLT2 inhibitors may benefit heart failure likely differ depending on ejection fraction, but each represents interference with distinct pathways by which hyperinsulinemia may adversely affect cardiac structure and function.

Implications of SGLT Inhibition on Redox Signalling in Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained (atrial) arrhythmia, a considerable global health burden and often associated with heart failure. Perturbations of redox signalling in cardiomyocytes provide a cellular substrate for the manifestation and maintenance of atrial arrhythmias. Several clinical trials have shown that treatment with sodium-glucose linked transporter inhibitors (SGLTi) improves mortality and hospitalisation in heart failure patients independent of the presence of diabetes. Post hoc analysis of the DECLARE-TIMI 58 trial showed a 19% reduction in AF in patients with diabetes mellitus (hazard ratio, 0.81 (95% confidence interval: 0.68-0.95), n = 17.160) upon treatment with SGLTi, regardless of pre-existing AF or heart failure and independent from blood pressure or renal function. Accordingly, ongoing experimental work suggests that SGLTi not only positively impact heart failure but also counteract cellular ROS production in cardiomyocytes, thereby potentially altering atrial remodelling and reducing AF burden. In this article, we review recent studies investigating the effect of SGLTi on cellular processes closely interlinked with redox balance and their potential effects on the onset and progression of AF. Despite promising insight into SGLTi effect on Ca²⁺ cycling, Na⁺ balance, inflammatory and fibrotic signalling, mitochondrial function and energy balance and their potential effect on AF, the data are not yet conclusive and the importance of individual pathways for human AF remains to be established. Lastly, an overview of clinical studies investigating SGLTi in the context of AF is provided.

Can We Decrease Epicardial and Pericardial Fat in Patients With Diabetes?

Diabetes mellitus (DM) is a chronic and complex metabolic disorder and also an important cause of cardiovascular (CV) disease (CVD). Patients with type 2 DM (T2DM) and obesity show a greater propensity for visceral fat deposition (and excessive fat deposits elsewhere) and the link between adiposity and CVD risk is greater for visceral than for subcutaneous (SC) adipose tissue (AT). There is growing evidence that epicardial AT (EAT) and pericardial AT (PAT) play a role in the development of DM-related atherosclerosis, atrial fibrillation (AF), myocardial dysfunction, and heart failure (HF). In this review, we will highlight the importance of PAT and EAT in patients with DM. We also consider therapeutic interventions that could have a beneficial effect in terms of reducing the amount of AT and thus CV risk. EAT is biologically active and a likely determinant of CV morbidity and mortality in patients with DM, given its anatomical characteristics and proinflammatory secretory pattern. Consequently, modification of EAT/PAT may become a therapeutic target to reduce the CV burden. In patients with DM, a low calorie diet, exercise, antidiabetics and statins may change the quantity of EAT, PAT or both, alter the secretory pattern of EAT, improve the metabolic profile, and reduce inflammation. However, well-designed studies are needed to clearly define CV benefits and a therapeutic approach to EAT/PAT in patients with DM.

Effects of intensive exercise combined with dapagliflozin on body composition in patients with type 2 diabetes: a randomized controlled trial

This study was aimed to evaluate the effects of intensive exercise in addition to the administration of sodium-glucose cotransporter 2 inhibitor dapagliflozin (DAPA) on body composition, including fat-free mass, in type 2 diabetes. We randomly assigned 146 patients to 24 weeks of treatment with intensive exercise, including resistance training, plus 5 mg (up to 10 mg) of DAPA daily (IT group) or DAPA alone (CT group). The primary endpoint was the difference in the change in fat-free mass from baseline to 24 weeks between the groups. The skeletal muscle mass index (SMI); metabolic profile, including HbA1c; and regional fat mass were also determined. ANCOVA was used for the group comparison, with least squares mean (LSM) differences and 95% confidence interval (CI). There was no significant difference in the change in fat-free mass (LSM difference -0.1 kg (95% CI: -0.5 to 0.4) and SMI (LSM difference -0.1 kg (95% CI: -0.2 to 0.1) between the groups. In contrast, the reduction of trunk fat mass was significantly higher in the IT group than in the CT group ((LSM difference -0.5 kg [95% CI -0.9 to -0.1]). Higher adherence to the resistance training tended to be associated with changes in HbA1c and high-sensitivity CRP levels. Our study suggests that intensive exercise do not prevent the reduction of fat-free mass after administration of SGLT2 inhibitors but can increase the reduction in abdominal fat, presumably leading to further improvements of hyperglycemia and chronic inflammation than DAPA alone in type 2 diabetes patients.

Effect of empagliflozin on ectopic fat stores and myocardial energetics in type 2 diabetes: the EMPACEF study

BACKGROUND

Empagliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor that has demonstrated cardiovascular and renal protection in patients with type 2 diabetes (T2D). We hypothesized that empaglifozin (EMPA) could modulate ectopic fat stores and myocardial energetics in high-fat-high-sucrose (HFHS) diet mice and in type 2 diabetics (T2D).

METHODS

C57BL/6 HFHS mice (n = 24) and T2D subjects (n = 56) were randomly assigned to 12 weeks of treatment with EMPA (30 mg/kg in mice, 10 mg/day in humans) or with placebo. A 4.7 T or 3 T MRI with 1H-MRS evaluation-myocardial fat (primary endpoint) and liver fat content (LFC)-were performed at baseline and at 12 weeks. In humans, standard cardiac MRI was coupled with myocardial energetics (PCr/ATP) measured with 31P-MRS. Subcutaneous (SAT) abdominal, visceral (VAT), epicardial and pancreatic fat were also evaluated. The primary efficacy endpoint was the change in epicardial fat volume between EMPA and placebo from baseline to 12 weeks. Secondary endpoints were the differences in PCr/ATP ratio, myocardial, liver and pancreatic fat content, SAT and VAT between groups at 12 weeks.

RESULTS

In mice fed HFHS, EMPA significantly improved glucose tolerance and increased blood ketone bodies (KB) and β-hydroxybutyrate levels (p < 0.05) compared to placebo. Mice fed HFHS had increased myocardial and liver fat content compared to standard diet mice. EMPA significantly attenuated liver fat content by 55%, (p < 0.001) but had no effect on myocardial fat. In the human study, all the 56 patients had normal LV function with mean LVEF = 63.4 ± 7.9%. Compared to placebo, T2D patients treated with EMPA significantly lost weight (- 2.6 kg [- 1.2; - 3.7]) and improved their HbA1c by 0.88 ± 0.74%. Hematocrit and EPO levels were significantly increased in the EMPA group compared to placebo (p < 0.0001, p = 0.041). EMPA significantly increased glycosuria and plasma KB levels compared to placebo (p < 0.0001, p = 0.012, respectively), and significantly reduced liver fat content (- 27 ± 23 vs. - 2 ± 24%, p = 0.0005) and visceral fat (- 7.8% [- 15.3; - 5.6] vs. - 0.1% [- 1.1;6.5], p = 0.043), but had no effect on myocardial or epicardial fat. At 12 weeks, no significant change was observed in the myocardial PCr/ATP (p = 0.57 between groups).

CONCLUSIONS

EMPA effectively reduced liver fat in mice and humans without changing epicardial, myocardial fat or myocardial energetics, rebutting the thrifty substrate hypothesis for cardiovascular protection of SGLT2 inhibitors. Trial registration NCT, NCT03118336. Registered 18 April 2017, https://clinicaltrials.gov/ct2/show/NCT03118336.

Cardiac Adiposity and Arrhythmias: The Role of Imaging

Increased cardiac fat depots are metabolically active tissues that have a pronounced pro-inflammatory nature. Increasing evidence supports a potential role of cardiac adiposity as a determinant of the substrate of atrial fibrillation and ventricular arrhythmias. The underlying mechanism appears to be multifactorial with local inflammation, fibrosis, adipocyte infiltration, electrical remodeling, autonomic nervous system modulation, oxidative stress and gene expression playing interrelating roles. Current imaging modalities, such as echocardiography, computed tomography and cardiac magnetic resonance, have provided valuable insight into the relationship between cardiac adiposity and arrhythmogenesis, in order to better understand the pathophysiology and improve risk prediction of the patients, over the presence of obesity and traditional risk factors. However, at present, given the insufficient data for the additive value of imaging biomarkers on commonly used risk algorithms, the use of different screening modalities currently is indicated for personalized risk stratification and prognostication in this setting.

Mechanisms and Perspectives of Sodium-Glucose Co-transporter 2 Inhibitors in Heart Failure

Heart failure (HF) is a common complication or late-stage manifestation of various heart diseases. Numerous risk factors and underlying causes may contribute to the occurrence and progression of HF. The pathophysiological mechanisms of HF are very complicated. Despite accumulating advances in treatment for HF during recent decades, it remains an intractable clinical syndrome with poor outcomes, significantly reducing the quality of life and expectancy of patients, and imposing a heavy economic burden on society and families. Although initially classified as antidiabetic agents, sodium-glucose co-transporter 2 (SGLT2) inhibitors have demonstrated reduced the prevalence of hospitalization for HF, cardiovascular death, and all-cause death in several large-scale randomized controlled clinical trials. These beneficial effects of SGLT-2 inhibitors can be attributed to multiple hemodynamic, inflammatory and metabolic mechanisms, not only reducing the serum glucose level. SGLT2 inhibitors have been used increasingly in treatment for patients with HF with reduced ejection fraction due to their surprising performance in improving the prognosis. In addition, their roles and mechanisms in patients with HF with preserved ejection fraction or acute HF have also attracted attention. In this review article, we discuss the possible mechanisms and applications of SGLT2 inhibitors in HF.

A prospective randomized study comparing effects of empagliflozin to sitagliptin on cardiac fat accumulation, cardiac function, and cardiac metabolism in patients with early-stage type 2 diabetes: the ASSET study

Background

While the cardioprotective benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors have been established in patients with cardiovascular disease (CVD), their advantages over other anti-diabetic drugs at earlier stages remain unclear. We compared the cardioprotective effects of empagliflozin, an SGLT2 inhibitor, with those of sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, focusing on cardiac fat accumulation, cardiac function, and cardiac metabolism in patients with early-stage type 2 diabetes mellitus (T2DM) without CVD complications.

Methods

This was a prospective, randomized, open-label, blinded-endpoint, parallel-group trial that enrolled 44 Japanese patients with T2DM. The patients were randomized for 12-week administration of empagliflozin or sitagliptin. Pericardial fat accumulation and myocardial triglyceride content were evaluated by magnetic resonance imaging and proton magnetic resonance spectroscopy, respectively. Echocardiography, ¹²³I-β-methyl-iodophenyl pentadecanoic acid myocardial scintigraphy, and laboratory tests were performed at baseline and after the 12-week treatment period.

Results

The patients were middle-aged (50.3 ± 10.7 years, mean ± standard deviation) and overweight (body mass index 29.3 ± 4.9 kg/m²). They had a short diabetes duration (3.5 ± 3.2 years), HbA1c levels of 7.1 ± 0.8%, and preserved cardiac function (ejection fraction 73.8 ± 5.0%) with no vascular complications, except for one baseline case each of diabetic nephropathy and peripheral arterial disease. After the 12-week treatment, no differences from baseline were observed between the two groups regarding changes in pericardial, epicardial, and paracardial fat content; myocardial triglyceride content; cardiac function and mass; and cardiac fatty acid metabolism. However, considering cardiometabolic biomarkers, high-density lipoprotein cholesterol and ketone bodies, including β-hydroxybutyric acid, were significantly increased, whereas uric acid, plasma glucose, plasma insulin, and homeostasis model assessment of insulin resistance were significantly lower in the empagliflozin group than in the sitagliptin group (p < 0.05).

Conclusions

Although the effects on cardiac fat and function were not statistically different between the two groups, empagliflozin exhibited superior effects on cardiometabolic biomarkers, such as uric acid, high-density lipoprotein cholesterol, ketone bodies, and insulin sensitivity. Therefore, when considering the primary preventive strategies for CVD, early supplementation with SGLT2 inhibitors may be more beneficial than DPP-4 inhibitors, even in patients with early-stage T2DM without current CVD complications.

Clinical Trial Registration: UMIN000026340; registered on February 28, 2017. https://upload.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000030257

Does SGLT2 Inhibition Affect Sympathetic Nerve Activity in Type 2 Diabetes?

SGLT2 inhibitors increase renal glucose excretion and thus decrease both fasting and postprandial plasma glucose levels. The effects of SGLT2 inhibition outweigh those on glycemic control and are also associated with the induction of hemodynamic changes that improve cardiovascular and renal function in people with type 2 diabetes. The exact mechanisms have not yet been completely clarified. This review is focused on the potential relationship between SGLT2 inhibition and sympathetic nerve activity. There is accumulating evidence for a suppressive effect of SGLT2 inhibitors on the sympathetic nerve tone, which might be a putative mechanism for cardiovascular protection in subjects with type 2 diabetes.

Targeting epicardial adipose tissue with exercise, diet, bariatric surgery or pharmaceutical interventions: A systematic review and meta-analysis

Epicardial adipose tissue (EAT) and pericardial adipose tissue (PAT) are metabolically active fat depots implicated in cardiovascular disease, and EAT has potential as a novel cardiac risk factor, suitable as a target for interventions. The objective of this systematic review and meta-analysis was to investigate the evidence whether EAT and PAT volume can be reduced by weight-loss interventions (exercise, diet, bariatric surgery or pharmaceutical interventions). A systematic literature search identified 34 studies that were included in the qualitative synthesis (exercise, n = 10, diet, n = 5, bariatric surgery, n = 9 and pharmaceutical interventions, n = 10). Of the 34 studies, 10 reported sufficient data to be included in the meta-analysis. The meta-analysis was only conducted for changes in EAT volume, since only few controlled studies reported changes in PAT (n = 3) or total cardiac adipose tissue volume (n = 1). A significant pooled effect size (ES) for reduction in EAT volume was observed following weight-loss interventions as compared with control interventions (ES = -0.89, 95% CI: -1.23 to -0.55, P < 0.001). When comparing the effect of exercise training versus control on EAT volume reduction, there was a significant pooled ES favouring exercise training (ES: -1.11, 95% CI: -1.57 to -0.65, P < 0.001). Similarly, the ES of pharmaceutical versus control interventions on EAT volume reduction was significant, favouring pharmaceutical interventions (ES: -0.79, 95% CI: -1.37 to -0.21, P < 0.0072). In conclusion, this systematic review and meta-analysis provides evidence that exercise, diet, bariatric surgery and pharmaceutical interventions can reduce cardiac adipose tissue volume.

Roles of Epicardial Adipose Tissue in the Pathogenesis of Coronary Atherosclerosis - An Update on Recent Findings

Adipose tissue serves not only as an energy store or a mechanical cushion, but also as an endocrine organ. Recent evidence revealed that perivascular adipose tissue is involved in vascular homeostasis and pathophysiology of adjacent arteries by producing various adipokines. Epicardial adipose tissue (EAT) is located between the surface of the heart and the visceral layer of the pericardium and surrounds the coronary arteries. Many clinical studies suggest that an increase in EAT volume is associated with coronary artery disease. It has been reported that exercise and some antidiabetic drugs can reduce EAT volume. In this review, we outline recent findings on the roles of EAT in the pathogenesis of coronary atherosclerosis.

Inflammation and adiposity: new frontiers in atrial fibrillation

The aetiology of atrial fibrillation (AF) remains poorly understood, despite its growing prevalence and associated morbidity, mortality, and healthcare costs. Obesity is implicated in myriad different disease processes and is now recognized a major risk factor in the pathogenesis of AF. Moreover, the role of distinct adipose tissue depots is a matter of intense scientific interest with the depot directly surrounding the heart—epicardial adipose tissue (EAT) appearing to have the greatest correlation with AF presence and severity. Similarly, inflammation is implicated in the pathophysiology of AF with EAT thought to act as a local depot of inflammatory mediators. These can easily diffuse into atrial tissue with the potential to alter its structural and electrical properties. Various meta-analyses have indicated that EAT size is an independent risk factor for AF with adipose tissue expansion being inevitably associated with a local inflammatory process. Here, we first briefly review adipose tissue anatomy and physiology then move on to the epidemiological data correlating EAT, inflammation, and AF. We focus particularly on discussing the mechanistic basis of how EAT inflammation may precipitate and maintain AF. Finally, we review how EAT can be utilized to help in the clinical management of AF patients and discuss future avenues for research.

Renal physiology of glucose handling and therapeutic implications

The rationale for using sodium-glucose cotransporter 2 (SGLT2) inhibitors in patients with type 2 diabetes (T2D) has evolved over the last decade. Due to the effects on glucosuria and body weight loss, SGLT2 inhibitors were originally approved for glycemic control in T2D. Since glucosuria is attenuated in chronic kidney disease (CKD) Stages 3–5, initial regulatory approval for SGLT2 inhibitor use was limited to patients with T2D and preserved estimated glomerular filtration rate. Over time, however, it has become increasingly apparent that these therapies have a variety of important pharmacodynamic and clinical effects beyond glycemic lowering, including antihypertensive and antialbuminuric properties, and the ability to reduce glomerular hypertension. Importantly, these sodium-related effects are preserved across CKD stages, despite attenuated glycemic effects, which are lost at CKD Stage 4. With the completion of cardiovascular (CV) outcome safety trials—EMPA-REG OUTCOME, CANVAS Program and DECLARE TIMI-58—in addition to reductions in CV events, SGLT2 inhibition consistently reduces hard renal endpoints. Importantly, these CV and renal effects are independent of glycemic control. Subsequent data from the recent CREDENCE trial—the first dedicated renal protection trial with SGLT-2 inhibition—demonstrated renal and CV benefits in albuminuric T2D patients, pivotal results that have expanded the clinical importance of these therapies. Ongoing trials will ultimately determine whether SGLT2 inhibition will have a role in renal protection in other clinical settings, including nondiabetic CKD and type 1 diabetes.

Epicardial Adipose Tissue as a New Target of Therapeutic Interventions

There is evidence of a correlation between epicardial adipose tissue and the presence and severity of coronary heart disease, the development of hypertrophy, impaired diastolic and systolic function of the left ventricle, enlargement, fibrosis and electrophysiological remodeling of the atria, the occurrence and severity of supraventricular arrhythmias. There is also a lot of evidence of the influence of both non-drug methods and drugs on the severity and functional activity of epicardial adipose tissue, which can be considered as a potentially modifiable factor of cardiovascular risk, the various therapeutic interventions target and a criterion for their effectiveness. Its unique characteristics suggest the advisability of pharmacological strategies aimed at regulating the expression of genes encoding the secretion of adipocytokines and adipocyte function, and a dynamic assessment of the severity of epicardial fat during therapy can be a tool to evaluate its effectiveness in various cardiovascular diseases.

Targeting perivascular and epicardial adipose tissue inflammation: therapeutic opportunities for cardiovascular disease

Major shifts in human lifestyle and dietary habits toward sedentary behavior and refined food intake triggered steep increase in the incidence of metabolic disorders including obesity and Type 2 diabetes. Patients with metabolic disease are at a high risk of cardiovascular complications ranging from microvascular dysfunction to cardiometabolic syndromes including heart failure. Despite significant advances in the standards of care for obese and diabetic patients, current therapeutic approaches are not always successful in averting the accompanying cardiovascular deterioration. There is a strong relationship between adipose inflammation seen in metabolic disorders and detrimental changes in cardiovascular structure and function. The particular importance of epicardial and perivascular adipose pools emerged as main modulators of the physiology or pathology of heart and blood vessels. Here, we review the peculiarities of these two fat depots in terms of their origin, function, and pathological changes during metabolic deterioration. We highlight the rationale for pharmacological targeting of the perivascular and epicardial adipose tissue or associated signaling pathways as potential disease modifying approaches in cardiometabolic syndromes.

SGLT2 inhibitors: mechanisms of cardiovascular benefit beyond glycaemic control

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are effective antidiabetic therapies in patients with type 2 diabetes mellitus and are associated with improved glycaemic control as well as with reductions in body mass and blood pressure. In large cardiovascular outcome trials in patients with diabetes, SGLT2 inhibitors improve cardiovascular and renal outcomes, including hospitalization for heart failure, with this benefit extending to patients without diabetes who have heart failure with reduced ejection fraction. The possible mechanisms of benefit are being extensively investigated because they are unlikely to be related to improved glycaemic control. Early natriuresis with a reduction in plasma volume, a consequent rise in haematocrit, improved vascular function, a reduction in blood pressure and changes in tissue sodium handling are all likely to have a role. Additional mechanisms of SGLT2 inhibitors that might be beneficial include a reduction in adipose tissue-mediated inflammation and pro-inflammatory cytokine production, a shift towards ketone bodies as the metabolic substrate for the heart and kidneys, reduced oxidative stress, lowered serum uric acid level, reduced glomerular hyperfiltration and albuminuria, and suppression of advanced glycation end-product signalling. Further outcome trials and mechanistic studies, including in patients with heart failure with preserved ejection fraction or non-diabetic kidney disease, might identify other possible mechanisms of benefit of SGLT2-inhibitor therapy.

Effects of Dapagliflozin on Epicardial Fat Thickness in Patients with Type 2 Diabetes and Obesity

OBJECTIVE

Epicardial adipose tissue (EAT) thickness is a marker of visceral fat and an emerging therapeutic target. Dapagliflozin, a selective sodium-glucose cotransporter 2 inhibitor, improves glucose control and induces moderate weight loss in patients with type 2 diabetes mellitus. Dapagliflozin has recently been shown to reduce cardiovascular risk. Nevertheless, whether dapagliflozin could reduce EAT thickness is unknown.

METHODS

This hypothesis was tested in a 24-week, randomized, double-blind, placebo-controlled clinical trial in 100 patients with type 2 diabetes mellitus with BMI ≥ 27 kg/m² and a hemoglobin A1c level ≤ 8% on metformin monotherapy. Individuals were randomly assigned to 2 groups to receive additional dapagliflozin up to 10 mg once daily or to remain on metformin up to 1,000 mg twice daily. Ultrasound-measured EAT thickness was measured at baseline, 12 weeks, and 24 weeks.

RESULTS

In the dapagliflozin group, EAT decreased by 20% from baseline to 24 weeks, by 15% after 12 weeks, and by 7% between 12 and 24 weeks, respectively (P < 0.01 for all), whereas in the metformin group, there was a significant but smaller EAT reduction. There was no statistically significant correlation between EAT and body weight changes.

CONCLUSIONS

Dapagliflozin causes a rapid and significant EAT reduction that could be independent of weight loss.