Design and rationale of the EMPA-VISION trial: investigating the metabolic effects of empagliflozin in patients with heart failure

Most UK cardiovascular disease trial protocols feature criteria that exclude ethnic minority participants: a systematic review

OBJECTIVES

We systematically reviewed UK cardiovascular disease (CVD) randomized controlled trial (RCT) protocols to identify the proportion featuring eligibility criteria that may disproportionately exclude ethnic minority (EM) participants.

METHODS

We searched MEDLINE, Embase, and Cochrane Library databases, January 2014-June 2022, to identify UK CVD RCT protocols. We extracted nonclinical eligibility criteria from trial protocols and inductively categorized the trials by their language, consent, and broad (ambiguous) criteria. Findings are narratively reported.

RESULTS

Of the seventy included RCT protocols, most (87.1%; 61/70) mentioned consent within the eligibility criteria, with more than two-thirds (68.9%; 42/61) indicating a requirement for 'written' consent. Alternative consent pathways that can aid EM participation were absent. English language requirement was present in 22.9% (16/70) of the studies and 37.1% (26/70) featured broad criteria that are open to interpretation and subject to recruiter bias. Only 4.3% (3/70) protocols mentioned the provision of translation services.

CONCLUSION

Most UK CVD trial protocols feature eligibility criteria that potentially exclude EM groups. Trial eligibility criteria must be situated within a larger inclusive recruitment framework, where ethnicity is considered alongside other intersecting and disadvantaging identities.

Assessment of Cardiac Energy Metabolism, Function, and Physiology in Patients With Heart Failure Taking Empagliflozin: The Randomized, Controlled EMPA-VISION Trial

BACKGROUND

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have emerged as a paramount treatment for patients with heart failure (HF), irrespective of underlying reduced or preserved ejection fraction. However, a definite cardiac mechanism of action remains elusive. Derangements in myocardial energy metabolism are detectable in all HF phenotypes, and it was proposed that SGLT2i may improve energy production. The authors aimed to investigate whether treatment with empagliflozin leads to changes in myocardial energetics, serum metabolomics, and cardiorespiratory fitness.

METHODS

EMPA-VISION (Assessment of Cardiac Energy Metabolism, Function and Physiology in Patients With Heart Failure Taking Empagliflozin) is a prospective, randomized, double-blind, placebo-controlled, mechanistic trial that enrolled 72 symptomatic patients with chronic HF with reduced ejection fraction (HFrEF; n=36; left ventricular ejection fraction ≤40%; New York Heart Association class ≥II; NT-proBNP [N-terminal pro-B-type natriuretic peptide] ≥125 pg/mL) and HF with preserved ejection fraction (HFpEF; n=36; left ventricular ejection fraction ≥50%; New York Heart Association class ≥II; NT-proBNP ≥125 pg/mL). Patients were stratified into respective cohorts (HFrEF versus HFpEF) and randomly assigned to empagliflozin (10 mg; n=35: 17 HFrEF and 18 HFpEF) or placebo (n=37: 19 HFrEF and 18 HFpEF) once daily for 12 weeks. The primary end point was a change in the cardiac phosphocreatine:ATP ratio (PCr/ATP) from baseline to week 12, determined by phosphorus magnetic resonance spectroscopy at rest and during peak dobutamine stress (65% of age-maximum heart rate). Mass spectrometry on a targeted set of 19 metabolites was performed at baseline and after treatment. Other exploratory end points were investigated.

RESULTS

Empagliflozin treatment did not change cardiac energetics (ie, PCr/ATP) at rest in HFrEF (adjusted mean treatment difference [empagliflozin - placebo], -0.25 [95% CI, -0.58 to 0.09]; P=0.14) or HFpEF (adjusted mean treatment difference, -0.16 [95% CI, -0.60 to 0.29]; P=0.47]. Likewise, there were no changes in PCr/ATP during dobutamine stress in HFrEF (adjusted mean treatment difference, -0.13 [95% CI, -0.35 to 0.09]; P=0.23) or HFpEF (adjusted mean treatment difference, -0.22 [95% CI, -0.66 to 0.23]; P=0.32). No changes in serum metabolomics or levels of circulating ketone bodies were observed.

CONCLUSIONS

In patients with either HFrEF or HFpEF, treatment with 10 mg of empagliflozin once daily for 12 weeks did not improve cardiac energetics or change circulating serum metabolites associated with energy metabolism when compared with placebo. Based on our results, it is unlikely that enhancing cardiac energy metabolism mediates the beneficial effects of SGLT2i in HF.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03332212.

[Mechano-energetic defects in heart failure]

Heart failure is characterized by defects in excitation-contraction coupling, energetic deficit and oxidative stress. The energy for cardiac contraction and relaxation is provided in mitochondria, whose function is tightly regulated by excitation-contraction coupling in cardiac myocytes. In heart failure with reduced ejection fraction (HFrEF), alterations in the ion balance in cardiac myocytes impair mitochondrial Ca²⁺ uptake, which is required for activation of the Krebs cycle, causing an energetic deficit and oxidative stress in mitochondria. Recent clinical studies suggest that in heart failure with preserved ejection fraction (HFpEF), in stark contrast to HFrEF, hypercontractility often occurs as an attempt to compensate for a pathological increase in systemic and pulmonary vascular resistance. This hypercontractility increases cardiac energy and oxygen demands at rest and reduces the contractile, diastolic and coronary reserves, preventing an adequate increase in cardiac output during exercise. Moreover, increased contractility causes long-term maladaptive remodeling processes due to oxidative stress and redox-sensitive prohypertrophic signaling pathways. As overweight and diabetes, particularly in the interplay with hemodynamic stress, are important risk factors for the development of HFpEF, interventions targeting metabolism in particular could ameliorate the development and progression of HFpEF.

SGLT2 Inhibitor: an Emerging Pillar in Heart Failure Therapeutics?

Heart failure (HF) is a worldwide pandemic that affects at least 26 million people and is becoming more prevalent. Heart failure health expenditures are substantial and will considerably increase with population aging. Newer medications for treating type 2 diabetes include sodium-glucose cotransporter-2 inhibitors (SGLT2). Recent clinical studies and research have shown the efficacy of this class in treating heart failure by lowering the risk of cardiovascular events, hospitalization, and mortality. In addition, there is undeniable evidence that SGLT2 inhibitors have a beneficial effect on metabolic function, even though the mechanisms responsible for these drugs' practical consequences have not been completely elucidated. In this narrative review, we discuss the effects of SGLT2 inhibitors on the provision of cardiac energy by ketone bodies, pathological remodeling of the ventricle, arterial stiffness, and inflammation in patients with HF.

Gliflozins: From Antidiabetic Drugs to Cornerstone in Heart Failure Therapy-A Boost to Their Utilization and Multidisciplinary Approach in the Management of Heart Failure

Heart failure (HF) is a complex, multifactorial, progressive clinical condition affecting 64.3 million people worldwide, with a strong impact in terms of morbidity, mortality and public health costs. In the last 50 years, along with a better understanding of HF physiopathology and in agreement with the four main models of HF, many therapeutic options have been developed. Recently, the European Society of Cardiology (ESC) HF guidelines enthusiastically introduced inhibitors of the sodium-glucose cotransporter (SGLT2i) as first line therapy for HF with reduced ejection fraction (HFrEF) in order to reduce hospitalizations and mortality. Despite drugs developed as hypoglycemic agents, data from the EMPA-REG OUTCOME trial encouraged the evaluation of the possible cardiovascular effects, showing SGLT2i beneficial effects on loading conditions, neurohormonal axes, heart cells' biochemistry and vascular stiffness, determining an improvement of each HF model. We want to give a boost to their use by increasing the knowledge of SGLT2-I and understanding the probable mechanisms of this new class of drugs, highlighting strengths and weaknesses, and providing a brief comment on major trials that made Gliflozins a cornerstone in HF therapy. Finally, aspects that may hinder SGLT2-i widespread utilization among different types of specialists, despite the guidelines' indications, will be discussed.

The Emerging Role of Sodium-glucose Cotransporter 2 Inhibitors in Heart Failure

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively novel drug class that most cardiologists are becoming familiar with. By contrasting glucose reabsorption in the proximal convoluted tubule of the nephron, SGLT2 inhibition results in glycosuria with improved glycemic control. Although originally introduced as anti-diabetic medications, the cardiovascular effects of SGLT2i have progressively emerged, leading them to become one of the four pillars for the treatment of heart failure with reduced ejection fraction (HFrEF) according to the 2021 guidelines from the European Society of Cardiology. Also, two recent randomized trials have demonstrated SGLT2i as the first compounds with proven prognostic impact in heart failure with preserved ejection fraction (HFpEF), setting a milestone in the treatment for this condition. While the exact pathogenic mechanisms mediating the substantial reduction in cardiovascular death and heart failure (HF) hospitalizations are still controversial, there is growing clinical evidence on the efficacy and safety of SGLT2i in various subsets of patients with HF. As known, heart failure is a complex and heterogeneous clinical syndrome with a magnitude of phenotypes and a variety of underlying hemodynamic and physiological aspects which cannot be fully incorporated into the traditional left ventricular ejection fraction based classification adopted in clinical trials. The aim of this review is to provide an overview of the cardiovascular benefits and indications of SGLT2i across different HF patterns and to highlight current gaps in knowledge that should be addressed by future research.

Fabry Disease: Current and Novel Therapeutic Strategies. A Narrative Review

BACKGROUND

Fabry disease (FD) is an inherited lysosomal storage disorder, leading to multisystemic manifestations and causing significant morbidity and mortality.

OBJECTIVE

The aim of this narrative review is to present the current and novel therapeutic strategies in FD, including symptomatic and specific treatment options.

METHODS

A systematic literature search was conducted to identify relevant studies, including completed and ongoing randomized-controlled clinical trials (RCTs), prospective or retrospective cohort studies, case series and case reports that provided clinical data regarding FD treatment.

RESULTS

A multidisciplinary symptomatic treatment is recommended for FD patients, personalized according to disease manifestations and their severity. During the last two decades, FD-specific treatments, including two enzyme-replacement-therapies (agalsidase alfa and agalsidase beta) and chaperone treatment with migalastat have been approved for use and allowed for symptoms' stabilization or even disease burden reduction. More therapeutic agents are currently under investigation. Substrate reduction therapies, including lucerastat and venglustat, have shown promising results in RCTs and may be used either as monotherapy or as complementary therapy to established enzymereplacement- therapies. More stable enzyme-replacement-therapy molecules that are associated with less adverse events and lower likelihood of neutralizing antibodies formation have also been developed. Ex-vivo and in-vivo gene therapy is being tested in animal models and pilot human clinical trials, with preliminary results showing a favorable safety and efficacy profile.

CONCLUSION

The therapeutic landscape in FD appears to be actively expanding with more treatment options expected to become available in the near future, allowing for a more personalized approach in FD patients.

SGLT2 Inhibition in Heart Failure with Preserved Ejection Fraction - The New Frontier

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome with high morbidity and increasing socio-economic burden, compounded by the lack of effective treatment options available to treat this disease. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have previously been shown to improve cardiovascular and renal outcomes in patients with type 2 diabetes and patients with heart failure with reduced ejection fraction (HFrEF). Recent major clinical trials with SGLT2 inhibitors, both empagliflozin and dapagliflozin, have now demonstrated improved cardiovascular outcomes in patients with HFpEF and a significant reduction in heart failure hospitalization. Current evidence shows a potential for cardiovascular benefits with SGLT2 inhibition that is consistent across the spectrum of ejection fraction, age, New York Heart Association (NYHA) functional class, natriuretic peptide levels and diabetes status. Although the cardioprotective mechanisms behind SGLT2 inhibition remain unclear, ongoing clinical studies aim to clarify the role of SGLT2 inhibitors on biomarkers of cardiac metabolism, diastolic function and exercise capacity in HFpEF. This article analyzes current clinical evidence from randomized controlled trials and meta-analyses and explores the potential cardioprotective mechanisms of SGLT2 inhibitors, while also looking towards the future of SGLT2 inhibition in HFpEF.

Mechanisms of SGLT2 Inhibitors in Heart Failure and Their Clinical Value

ABSTRACT

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are widely used to treat diabetes mellitus. Abundant evidence has shown that SGLT2 inhibitors can reduce hospitalization for heart failure (HF) in patients with or without diabetes. An increasing number of studies are being conducted on the mechanisms of action of SGLT2 inhibitors in HF. Our review summarizes a series of clinical trials on the cardioprotective effects of SGLT2 inhibitors in the treatment of HF. We have summarized several classical SGLT2 inhibitors in cardioprotection research, including empagliflozin, dapagliflozin, canagliflozin, ertugliflozin, and sotagliflozin. In addition, we provided a brief overview of the safety and benefits of SGLT2 inhibitors. Finally, we focused on the mechanisms of SGLT2 inhibitors in the treatment of HF, including ion-exchange regulation, volume regulation, ventricular remodeling, and cardiac energy metabolism. Exploring the mechanisms of SGLT2 inhibitors has provided insight into repurposing these diabetic drugs for the treatment of HF.

Glucose-Lowering and Metabolic Effects of SGLT2 Inhibitors

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have consistently demonstrated improved outcomes in patients with heart failure with or without type 2 diabetes; however, the mechanisms contributing to these benefits remain poorly understood. Although SGLT2 inhibitors do have glucose-lowering effects, it is unlikely that their cardiovascular benefits are solely due to improved glycemic control. This improved glycemia leads to consequent metabolic effects that could provide further explanation for their action. This review discusses the glucose-lowering and metabolic effects of SGLT2 inhibitors and how these might lead to improved cardiovascular outcomes in patients with heart failure.

Metabolomic Profiling of the Effects of Dapagliflozin in Heart Failure With Reduced Ejection Fraction: DEFINE-HF

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors are foundational therapy in patients with heart failure with reduced ejection fraction (HFrEF), but underlying mechanisms of benefit are not well defined. We sought to investigate the relationships between sodium-glucose cotransporter-2 inhibitor treatment, changes in metabolic pathways, and outcomes using targeted metabolomics.

METHODS

DEFINE-HF (Dapagliflozin Effects on Biomarkers, Symptoms and Functional Status in Patients With HF With Reduced Ejection Fraction) was a placebo-controlled trial of dapagliflozin in HFrEF. We performed targeted mass spectrometry profiling of 63 metabolites (45 acylcarnitines [markers of fatty acid oxidation], 15 amino acids, and 3 conventional metabolites) in plasma samples at randomization and 12 weeks. Using mixed models, we identified principal components analysis-defined metabolite clusters that changed differentially with treatment and examined the relationship between change in metabolite clusters and change in Kansas City Cardiomyopathy Questionnaire scores and NT-proBNP (N-terminal probrain natriuretic peptide). Models were adjusted for relevant clinical covariates and nominal P<0.05 with false discovery rate-adjusted P<0.10 was used to determine statistical significance.

RESULTS

Among the 234 DEFINE-HF participants with targeted metabolomic data, the mean age was 62.0±11.1 years, 25% were women, 38% were Black, and mean ejection fraction was 27±8%. Dapagliflozin increased ketone-related and short-chain acylcarnitine as well as medium-chain acylcarnitine principal components analysis-defined metabolite clusters compared with placebo (nominal P=0.01, false discovery rate-adjusted P=0.08 for both clusters). However, ketosis (β-hydroxybutyrate levels >500 μmol/L) was achieved infrequently (3 [2.5%] in dapagliflozin arm versus 1 [0.9%] in placebo arm) and supraphysiologic levels were not observed. Increases in long-chain acylcarnitine, long-chain dicarboxylacylcarnitine, and aromatic amino acid metabolite clusters were associated with decreases in Kansas City Cardiomyopathy Questionnaire scores (ie, worse quality of life) and increases in NT-proBNP levels, without interaction by treatment group.

CONCLUSIONS

In this study of targeted metabolomics in a placebo-controlled trial of sodium-glucose cotransporter-2 inhibitors in HFrEF, we observed effects of dapagliflozin on key metabolic pathways, supporting a role for altered ketone and fatty acid biology with sodium-glucose cotransporter-2 inhibitors in patients with HFrEF. Only physiologic levels of ketosis were observed. In addition, we identified several metabolic biomarkers associated with adverse HFrEF outcomes.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02653482.

Effect of Sodium-Glucose Co-transporter Protein 2 Inhibitors on Arrhythmia in Heart Failure Patients With or Without Type 2 Diabetes: A Meta-Analysis of Randomized Controlled Trials

Aim

Arrhythmic events such as atrial fibrillation (AF) are tightly associated with an increased risk of heart failure (HF). Previous studies have shown inconsistent results regarding the association between sodium-glucose co-transporter 2 inhibitors (SGLT2i) and the risk of arrhythmia. The purpose of this study was to investigate the association of SGLT2i treatment with arrhythmia outcomes in clinical trials of patients with HF.

Methods

We searched Embase, PubMed, Web of Science, Medline, The Cochrane Library, and JAMA databases to identify appropriate randomized controlled trials (RCTs) of SGLT2i interventions. Endpoint outcomes included AF, atrial flutter (AFL), AF/AFL, ventricular fibrillation (VF), ventricular tachycardia (VT), VF/VT, and bradycardia. A random-effects model was used for the meta-analysis of all outcomes. The risk of bias and quality of evidence was assessed by using the Cochrane tool and assessment framework.

Results

Out of 1,725 citations, 9 trials were included in this study, with follow-up from 4 weeks to 52 weeks for 10,344 participants (mean age 68.27 years; 69.62% of participants were men). Compared with placebo, SGLT2i reduced the incidence of AF by 37% [ratio risk (RR) 0.63; 95% confidence interval (CI) 0.45–0.87; p < 0.05] and AF/AFL by 34% (RR 0.66; 95% CI 0.49–0.90; p < 0.05).

Conclusions

SGLT2i can reduce the risk of cardiac arrhythmias, particularly the AF. Our study provides strong evidence for recommending the use of SGLT2i in patients with HF.

Systematic Review Registration

PROSPERO, identifier: CRD42022296696.

Sodium-Glucose Cotransporter-2 Inhibitors Improve Heart Failure with Reduced Ejection Fraction Outcomes by Reducing Edema and Congestion

Pathological sodium-water retention or edema/congestion is a primary cause of heart failure (HF) decompensation, clinical symptoms, hospitalization, reduced quality of life, and premature mortality. Sodium-glucose cotransporter-2 inhibitors (SGLT-2i) based therapies reduce hospitalization due to HF, improve functional status, quality, and duration of life in patients with HF with reduced ejection fraction (HFrEF) independently of their glycemic status. The pathophysiologic mechanisms and molecular pathways responsible for the benefits of SGLT-2i in HFrEF remain inconclusive, but SGLT-2i may help HFrEF by normalizing salt-water homeostasis to prevent clinical edema/congestion. In HFrEF, edema and congestion are related to compromised cardiac function. Edema and congestion are further aggravated by renal and pulmonary abnormalities. Treatment of HFrEF patients with SGLT-2i enhances natriuresis/diuresis, improves cardiac function, and reduces natriuretic peptide plasma levels. In this review, we summarize current clinical research studies related to outcomes of SGLT-2i treatment in HFrEF with a specific focus on their contribution to relieving or preventing edema and congestion, slowing HF progression, and decreasing the rate of rehospitalization and cardiovascular mortality.

Growing role of SGLT2i in heart failure: evidence from clinical trials

INTRODUCTION

: There is an unmet need for therapies that improve overall mortality and morbidity for patients with preserved ejection fraction, who comprise roughly half of all heart failure (HF) cases. The growing role of sodium-glucose cotransporter-2 inhibitors (SGLT2is) in cardiovascular outcomes provide a paradigm shift in the treatment of HF.

AREAS COVERED

: This review article provides a general overview of the growing role of SGLT2is and summarizes the mechanism of action, side effects, and contraindications for the treatment of HF. We also discuss recent clinical trials measuring the effects of different SGLT2is as possible treatment options for HF with reduced ejection fraction and HF with mid-range and preserved EF. We conducted a review of all the randomized, controlled studies with SGLT2is in patients with known heart failure with and without type-2 diabetes (T2DM). We performed a literature search in PubMed, Google Scholar, the Web of Science, and the Cochrane Library while screening results by the use of titles and abstracts.

EXPERT OPINION

: The promising pathophysiological profile of SGLT2i and their role in cardioprotective effects demonstrate an invaluable discovery in the management of patients with HF irrespective of their diabetes status.

Empagliflozin Treatment Is Associated With Improvements in Cardiac Energetics and Function and Reductions in Myocardial Cellular Volume in Patients With Type 2 Diabetes

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of major adverse cardiovascular (CV) events and hospitalization for heart failure (HF) in patients with type 2 diabetes (T2D). Using CV MRI (CMR) and 31P-MRS in a longitudinal cohort study, we aimed to investigate the effects of the selective SGLT2 inhibitor empagliflozin on myocardial energetics and cellular volume, function, and perfusion. Eighteen patients with T2D underwent CMR and 31P-MRS scans before and after 12 weeks' empagliflozin treatment. Plasma N-terminal prohormone B-type natriuretic peptide (NT-proBNP) levels were measured. Ten volunteers with normal glycemic control underwent an identical scan protocol at a single visit. Empagliflozin treatment was associated with significant improvements in phosphocreatine-to-ATP ratio (1.52 to 1.76, P = 0.009). This was accompanied by a 7% absolute increase in the mean left ventricular ejection fraction (P = 0.001), 3% absolute increase in the mean global longitudinal strain (P = 0.01), 8 mL/m2 absolute reduction in the mean myocardial cell volume (P = 0.04), and 61% relative reduction in the mean NT-proBNP (P = 0.05) from baseline measurements. No significant change in myocardial blood flow or diastolic strain was detected. Empagliflozin thus ameliorates the "cardiac energy-deficient" state, regresses adverse myocardial cellular remodeling, and improves cardiac function, offering therapeutic opportunities to prevent or modulate HF in T2D.

Vascular and metabolic effects of SGLT2i and GLP-1 in heart failure patients

Alterations of endothelial function, inflammatory activation, and nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway are involved in the pathophysiology of heart failure. Metabolic alterations have been studied in the myocardium of heart failure (HF) patients; alterations in ketone body and amino acid/protein metabolism have been described in patients affected by HF, as well as mitochondrial dysfunction and other modified metabolic signaling. However, their possible contributions toward cardiac function impairment in HF patients are not completely known. Recently, sodium-glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) have emerged as a new class of drugs designed to treat patients with type 2 diabetes (T2D), but have also been shown to be protective against HF-related events and CV mortality. To date, the protective cardiovascular effects of these drugs in patients with and without T2D are not completely understood and several mechanisms have been proposed. In this review, we discuss on vascular and metabolic effects of SGLT2i and GLP-1 in HF patients.

Design and rationale of the EMPA-VISION trial: investigating the metabolic effects of empagliflozin in patients with heart failure

Aims

Despite substantial improvements over the last three decades, heart failure (HF) remains associated with a poor prognosis. The sodium‐glucose co‐transporter‐2 inhibitor empagliflozin demonstrated significant reductions of HF hospitalization in patients with HF independent of the presence or absence of type 2 diabetes mellitus in the EMPEROR‐Reduced trial and cardiovascular mortality in the EMPA‐REG OUTCOME trial. To further elucidate the mechanisms behind these positive outcomes, this study aims to determine the effects of empagliflozin treatment on cardiac energy metabolism and physiology using magnetic resonance spectroscopy (MRS) and cardiovascular magnetic resonance (CMR).

Methods and results

The EMPA‐VISION trial is a double‐blind, randomized, placebo‐controlled, mechanistic study. A maximum of 86 patients with HF with reduced ejection fraction (n = 43, Cohort A) or preserved ejection fraction (n = 43, Cohort B), with or without type 2 diabetes mellitus, will be enrolled. Participants will be randomized 1:1 to receive either 10 mg of empagliflozin or placebo for 12 weeks. Eligible patients will undergo cardiovascular magnetic resonance, resting and dobutamine stress MRS, echocardiograms, cardiopulmonary exercise tests, serum metabolomics, and quality of life questionnaires at baseline and after 12 weeks. The primary endpoint will be the change in resting phosphocreatine‐to‐adenosine triphosphate ratio, as measured by ³¹Phosphorus‐MRS.

Conclusions

EMPA‐VISION is the first clinical trial assessing the effects of empagliflozin treatment on cardiac energy metabolism in human subjects in vivo. The results will shed light on the mechanistic action of empagliflozin in patients with HF and help to explain the results of the safety and efficacy outcome trials (EMPEROR‐Reduced and EMPEROR‐Preserved).

[Empagliflozin alleviates cardiac microvascular ischemia/reperfusion injury by maintaining myocardial mitochondrial homeostasis]

OBJECTIVE

To evaluate the effect of empagliflozin (EMPA) in mitigating microvascular and endothelial damage induced by myocardial ischemia-reperfusion (I/R) injury.

METHODS

Fifteen male C57BL/6J mice were randomized into shamoperated group, I/R group and I/R+EMPA group, and in the latter two groups, myocardial I/R injury was induced by ligating the left anterior descending coronary artery followed by reperfusion for 2 h. EMPA treatment was administered at the daily dose of 10 mg/kg for 7 days. After the treatment, the changes in myocardial microvascular structure of the mice were observed under electron microscopy. In the cell experiment, cultured human coronary artery endothelial cells (HCAECs) were treated with 10 μmol/L EMPA before exposure to hypoxia for 45 min followed normoxic culture for 2 h. Western blotting and immunofluorescence assay were performed to observe fibrin accumulation and endothelial cell protein expressions in the myocardial tissues of the mice and in HCAECs, and RT-qPCR was used to detect the expressions of pro-inflammatory cytokines.

RESULTS

Electron microscopy revealed significant myocardial microvascular wall thickening and lumen narrowing in mice with myocardial I/R injury. Fibrin accumulation and ICAM1 expression in the microvessels were more pronounced in I/R group than in the sham-operated and I/R + EMPA groups (P < 0.05). EMPA treatment obviously alleviated microvascular occlusion and microthrombus formation induced by I/R injury. At the cellular level, the protein levels of p-eNOS, Fak, and Src kinases in hypoxic exposure group were significantly lower than those in the control and EMPA treatment groups (P < 0.05). Hypoxic exposure significantly reduced mitochondrial DNA replication and transcription and lowered the expression levels of Cox-Ⅰ and Cox-Ⅱ in HCAECs, and these changes were obviously improved by EMPA treatment (P < 0.05).

CONCLUSION

EMPA can alleviate myocardial I/R injury by maintaining mitochondrial homeostasis to protect the microvascular system.