Empagliflozin Reduces Myocardial Extracellular Volume in Patients With Type 2 Diabetes and Coronary Artery Disease

Metabolism and bioenergetics in the pathophysiology of organ fibrosis

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

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Ventricular remodeling and hemodynamic changes in heart failure patients with non-ischemic dilated cardiomyopathy following dapagliflozin initiation

BACKGROUND

In heart failure with reduced ejection fraction (HFrEF), sodium-glucose co-transporter inhibitors (SGLT-2i) have persistently shown cardiovascular benefits through different trials. However, their impact on ventricular remodeling and cardiac hemodynamics has not been sufficiently studied. This study aimed to study how SGLT-2i initiation affects invasive hemodynamics and cardiac magnetic resonance imaging (CMR)-derived ventricular volumes, function, and fraction of the extracellular volume (ECV) in HFrEF patients with non-ischemic dilated cardiomyopathy (NIDCM).

RESULTS

In this study, 23 patients with HFrEF and a mean age of 42, including 82.6% males, all have NIDCM and underwent right heart catheterization and CMR at the initiation of dapagliflozin and at 6-month follow-up. The addition of dapagliflozin resulted in significant reductions in the following invasive hemodynamic parameters compared to baseline: left ventricular end-diastolic pressure (23.4 vs 19.7 mmHg, p = 0.003), mean pulmonary artery pressure (31.3 vs 27.7 mmHg, p = 0.03), and systemic vascular resistance (18 vs 15 Wood units, p = 0.047). Among the studied CMR-derived measurements, only the percentage of extracellular volume fraction was significantly less at follow-up (33.7 vs 32.16%, p = 0.001). Additionally, functional class showed significant improvement with a notable reduction of the NT-proBNP level and a considerable decrease in diuretic dose (median: 40 vs 80 mg, p = 0.01).

CONCLUSION

Adding dapagliflozin to patients with HFrEF due to NIDCM improved invasively measured hemodynamics and significantly reduced left ventricular extracellular volume fraction measured by CMR, with no significant change in ventricular volumes or ejection fraction.

Effect of empagliflozin on left ventricular volumes in type 2 diabetes or prediabetes heart failure patients with reduced ejection fraction

OBJECTIVE

Sodium-glucose cotransporter 2 (SGLT2) inhibitors, such as empagliflozin are antidiabetic drugs that have recently been reported to have cardio-protective action; however, their effect on cardiac structure and function in heart failure with reduced ejection fraction (HFrEF) has not yet been determined. This study evaluates the efficacy of empagliflozin on left ventricular (LV) volumes in type 2 diabetes or prediabetes patients with HFrEF.

METHODS

This randomised, double-blind, trial study was conducted on 104 patients with type 2 diabetes or prediabetes with HFrEF referred to Imam Khomeini and Golestan hospitals in Ahvaz, Iran. The patients were randomised to receive empagliflozin (10 mg once daily) in addition to standard treatments of HFrEF or receive only standard treatments (control group) for six months. During the six months of follow-up, changes in LV volumes, LVEF, hospitalisation for heart failure (HF) were evaluated.

RESULTS

Empagliflozin reduced LVEDVI and LVESVI by 10.0 and 8.0 mL/m2 (p < 0.0001). Furthermore, a significant increase in LVEF was observed in the empagliflozin group (p < 0.0001) without any significant change in the control group (p = 0.389). The hospitalisation rate was lower in the empagliflozin group than the control group (3.8% vs. 23.1%; p = 0.008).

CONCLUSIONS

Empagliflozin is effective in reducing LV volumes and hospitalisation rate in patients with type 2 diabetes and prediabetes and HFrEF. Therefore, treatment with empagliflozin for six months was associated with a significant reduction in adverse cardiovascular outcomes in these patients.

Targeting Interactions between Fibroblasts and Macrophages to Treat Cardiac Fibrosis

Excessive extracellular matrix (ECM) deposition is a defining feature of cardiac fibrosis. Most notably, it is characterized by a significant change in the concentration and volume fraction of collagen I, a disproportionate deposition of collagen subtypes, and a disturbed ECM network arrangement, which directly affect the systolic and diastolic functions of the heart. Immune cells that reside within or infiltrate the myocardium, including macrophages, play important roles in fibroblast activation and consequent ECM remodeling. Through both direct and indirect connections to fibroblasts, monocyte-derived macrophages and resident cardiac macrophages play complex, bidirectional, regulatory roles in cardiac fibrosis. In this review, we discuss emerging interactions between fibroblasts and macrophages in physiology and pathologic conditions, providing insights for future research aimed at targeting macrophages to combat cardiac fibrosis.

SGLT-2 inhibitors as novel treatments of multiple organ fibrosis

Fibrosis, a significant health issue linked to chronic inflammatory diseases, affects various organs and can lead to serious damage and loss of function. Despite the availability of some treatments, their limitations necessitate the development of new therapeutic options. Sodium-glucose cotransporter 2 inhibitors (SGLT2i), known for their glucose-lowering ability, have shown promise in offering protective effects against fibrosis in multiple organs through glucose-independent mechanisms. This review explores the anti-fibrotic potential of SGLT2i across different tissues, providing insights into their underlying mechanisms and highlighting recent research advancements. The evidence positions SGLT2i as a potential future treatments for fibrotic diseases.

Cardiovascular and Kidney Risks in Individuals With Type 2 Diabetes: Contemporary Understanding With Greater Emphasis on Excess Adiposity

In high-income countries, rates of atherosclerotic complications in type 2 diabetes have declined markedly over time due to better management of traditional risk factors including lipids, blood pressure, and glycemia levels. Population-wide reductions in smoking have also helped lower atherosclerotic complications and so reduce premature mortality in type 2 diabetes. However, as excess adiposity is a stronger driver for heart failure (HF), and obesity levels have remained largely unchanged, HF risks have not declined as much and may even be rising in the increasing number of people developing type 2 diabetes at younger ages. Excess weight is also an underrecognized risk factor for chronic kidney disease (CKD). Based on evidence from a range of sources, we explain how excess adiposity must be influencing most risks well before diabetes develops, particularly in younger-onset diabetes, which is linked to greater excess adiposity. We also review potential mechanisms linking excess adiposity to HF and CKD and speculate on how some of the responsible pathways-e.g., hemodynamic, cellular overnutrition, and inflammatory-could be favorably influenced by intentional weight loss (via lifestyle or drugs). On the basis of available evidence, we suggest that the cardiorenal outcome benefits seen with sodium-glucose cotransporter 2 inhibitors may partially derive from their interference of some of these same pathways. We also note that many other complications common in diabetes (e.g., hepatic, joint disease, perhaps mental health) are also variably linked to excess adiposity, the aggregated exposure to which has now increased in type 2 diabetes. All such observations suggest a greater need to tackle excess adiposity earlier in type 2 diabetes.

The cardiovascular changes underlying a low cardiac output with exercise in patients with type 2 diabetes mellitus

The significant morbidity and premature mortality of type 2 diabetes mellitus (T2DM) is largely associated with its cardiovascular consequences. Focus has long been on the arterial atheromatosis of DM giving rise to early stroke and myocardial infarctions, whereas less attention has been given to its non-ischemic cardiovascular consequences. Irrespective of ischemic changes, T2DM is associated with heart failure (HF) most commonly with preserved ejection fraction (HFpEF). Largely due to increasing population ages, hypertension, obesity and T2DM, HFpEF is becoming the most prevalent form of heart failure. Unfortunately, randomized controlled trials of HFpEF have largely been futile, and it now seems logical to address the important different phenotypes of HFpEF to understand their underlying pathophysiology. In the early phases, HFpEF is associated with a significantly impaired ability to increase cardiac output with exercise. The lowered cardiac output with exercise results from both cardiac and peripheral causes. T2DM is associated with left ventricular (LV) diastolic dysfunction based on LV hypertrophy with myocardial disperse fibrosis and significantly impaired ability for myocardial blood flow increments with exercise. T2DM is also associated with impaired ability for skeletal muscle vasodilation during exercise, and as is the case in the myocardium, such changes may be related to vascular rarefaction. The present review discusses the underlying phenotypical changes of the heart and peripheral vascular system and their importance for an adequate increase in cardiac output. Since many of the described cardiovascular changes with T2DM must be considered difficult to change if fully developed, it is suggested that patients with T2DM are early evaluated with respect to their cardiovascular compromise.

Underlying mechanisms and cardioprotective effects of SGLT2i and GLP-1Ra: insights from cardiovascular magnetic resonance

Originally designed as anti-hyperglycemic drugs, Glucagon-Like Peptide-1 receptor agonists (GLP-1Ra) and Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have demonstrated protective cardiovascular effects, with significant impact on cardiovascular morbidity and mortality. Despite several mechanisms have been proposed, the exact pathophysiology behind these effects is not yet fully understood. Cardiovascular imaging is key for the evaluation of diabetic patients, with an established role from the identification of early subclinical changes to long-term follow up and prognostic assessment. Among the different imaging modalities, CMR may have a key-role being the gold standard for volumes and function assessment and having the unique ability to provide tissue characterization. Novel techniques are also implementing the possibility to evaluate cardiac metabolism through CMR and thereby further increasing the potential role of the modality in this context. Aim of this paper is to provide a comprehensive review of changes in CMR parameters and novel CMR techniques applied in both pre-clinical and clinical studies evaluating the effects of SGLT2i and GLP-1Ra, and their potential role in better understanding the underlying CV mechanisms of these drugs.

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

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

The SGLT2i Dapagliflozin Reduces RV Mass Independent of Changes in RV Pressure Induced by Pulmonary Artery Banding

BACKGROUND

Sodium glucose linked transporter 2 (SGLT2) inhibition not only reduces morbidity and mortality in patients with diagnosed heart failure but also prevents the development of heart failure hospitalization in those at risk. While studies to date have focused on the role of SGLT2 inhibition in left ventricular failure, whether this drug class is efficacious in the treatment and prevention of right heart failure has not been explored.

HYPOTHESIS

We hypothesized that SGLT2 inhibition would reduce the structural, functional, and molecular responses to pressure overload of the right ventricle.

METHODS

Thirteen-week-old Fischer F344 rats underwent pulmonary artery banding (PAB) or sham surgery prior to being randomized to receive either the SGLT2 inhibitor: dapagliflozin (0.5 mg/kg/day) or vehicle by oral gavage. After 6 weeks of treatment, animals underwent transthoracic echocardiography and invasive hemodynamic studies. Animals were then terminated, and their hearts harvested for structural and molecular analyses.

RESULTS

PAB induced features consistent with a compensatory response to increased right ventricular (RV) afterload with elevated mass, end systolic pressure, collagen content, and alteration in calcium handling protein expression (all p < 0.05 when compared to sham + vehicle). Dapagliflozin reduced RV mass, including both wet and dry weight as well as normalizing the protein expression of SERCA 2A, phospho-AMPK and LC3I/II ratio expression (all p < 0.05).

SIGNIFICANCE

Dapagliflozin reduces the structural, functional, and molecular manifestations of right ventricular pressure overload. Whether amelioration of these early changes in the RV may ultimately lead to a reduction in RV failure remains to be determined.

Two way workable microchanneled hydrogel suture to diagnose, treat and monitor the infarcted heart

During myocardial infarction, microcirculation disturbance in the ischemic area can cause necrosis and formation of fibrotic tissue, potentially leading to malignant arrhythmia and myocardial remodeling. Here, we report a microchanneled hydrogel suture for two-way signal communication, pumping drugs on demand, and cardiac repair. After myocardial infarction, our hydrogel suture monitors abnormal electrocardiogram through the mobile device and triggers nitric oxide on demand via the hydrogel sutures' microchannels, thereby inhibiting inflammation, promoting microvascular remodeling, and improving the left ventricular ejection fraction in rats and minipigs by more than 60% and 50%, respectively. This work proposes a suture for bidirectional communication that acts as a cardio-patch to repair myocardial infarction, that remotely monitors the heart, and can deliver drugs on demand.

Empagliflozin improves circulating vascular regenerative cell content in people without diabetes with risk factors for adverse cardiac remodeling

Sodium glucose-cotransporter 2 (SGLT2) inhibitors have been reported to reduce cardiovascular events and heart failure in people with and without diabetes. These medications have been shown to counter regenerative cell exhaustion in the context of prevalent diabetes. This study sought to determine if empagliflozin attenuates regenerative cell exhaustion in people without diabetes. Peripheral blood mononuclear cells were collected at the baseline and 6-mo visits from individuals randomized to receive empagliflozin (10 mg/day) or placebo who were participating in the EMPA-HEART 2 CardioLink-7 trial. Precursor cell phenotypes were characterized by flow cytometry for cell-surface markers combined with high aldehyde dehydrogenase activity to identify precursor cell subsets with progenitor (ALDHhi) versus mature effector (ALDHlow) cell attributes. Samples from individuals assigned to empagliflozin (n = 25) and placebo (n = 21) were analyzed. At baseline, overall frequencies of primitive progenitor cells (ALDHhiSSClow), monocyte (ALDHhiSSCmid), and granulocyte (ALDHhiSSChi) precursor cells in both groups were similar. At 6 mo, participants randomized to empagliflozin demonstrated increased ALDHhiSSClowCD133+CD34+ proangiogenic cells (P = 0.048), elevated ALDHhiSSCmidCD163+ regenerative monocyte precursors (P = 0.012), and decreased ALDHhiSSCmidCD86 + CD163- proinflammatory monocyte (P = 0.011) polarization compared with placebo. Empagliflozin promoted the recovery of multiple circulating provascular cell subsets in people without diabetes suggesting that the cardiovascular benefits of SGLT2 inhibitors may be attributed in part to the attenuation of vascular regenerative cell exhaustion that is independent of diabetes status.NEW & NOTEWORTHY Using an aldehyde dehydrogenase (ALDH) activity-based flow cytometry assay, we found that empagliflozin treatment for 6 mo was associated with parallel increases in circulating vascular regenerative ALDHhi-CD34/CD133-coexpressing progenitors and decreased proinflammatory ALDHhi-CD14/CD86-coexpressing monocyte precursors in individuals without diabetes but with cardiovascular risk factors. The rejuvenation of the vascular regenerative cell reservoir may represent a mechanism via which sodium glucose-cotransporter 2 (SGLT2) inhibitors limit maladaptive repair and delay the development and progression of cardiovascular diseases.

Changes in Cardiovascular and Renal Biomarkers Associated with SGLT2 Inhibitors Treatment in Patients with Type 2 Diabetes Mellitus

Type 2 diabetes mellitus is a major health problem worldwide with a steadily increasing prevalence reaching epidemic proportions. The major concern is the increased morbidity and mortality due to diabetic complications. Traditional but also nontraditional risk factors have been proposed to explain the pathogenesis of type 2 diabetes mellitus and its complications. Hyperglycemia has been considered an important risk factor, and the strict glycemic control can have a positive impact on microangiopathy but not macroangiopathy and its related morbidity and mortality. Thus, the therapeutic algorithm has shifted focus from a glucose-centered approach to a strategy that now emphasizes target-organ protection. Sodium-glucose transporter 2 inhibitors is an extremely important class of antidiabetic medications that, in addition to their glucose lowering effect, also exhibit cardio- and renoprotective effects. Various established and novel biomarkers have been described, reflecting kidney and cardiovascular function. In this review, we investigated the changes in established but also novel biomarkers of kidney, heart and vascular function associated with sodium-glucose transporter 2 inhibitors treatment in patients with type 2 diabetes mellitus.

Cardiac Fibrosis in heart failure: Focus on non-invasive diagnosis and emerging therapeutic strategies

Heart failure is a leading cause of mortality and hospitalization worldwide. Cardiac fibrosis, resulting from the excessive deposition of collagen fibers, is a common feature across the spectrum of conditions converging in heart failure. Eventually, either reparative or reactive in nature, in the long-term cardiac fibrosis contributes to heart failure development and progression and is associated with poor clinical outcomes. Despite this, specific cardiac antifibrotic therapies are lacking, making cardiac fibrosis an urgent unmet medical need. In this context, a better patient phenotyping is needed to characterize the heterogenous features of cardiac fibrosis to advance toward its personalized management. In this review, we will describe the different phenotypes associated with cardiac fibrosis in heart failure and we will focus on the potential usefulness of imaging techniques and circulating biomarkers for the non-invasive characterization and phenotyping of this condition and for tracking its clinical impact. We will also recapitulate the cardiac antifibrotic effects of existing heart failure and non-heart failure drugs and we will discuss potential strategies under preclinical development targeting the activation of cardiac fibroblasts at different levels, as well as targeting additional extracardiac processes.

Effects of empagliflozin on cardiac structure, function and biomarkers in patients with heart failure with preserved ejection fraction: study protocol for a randomised, placebo-controlled prospective trial

INTRODUCTION

Heart failure (HF) with preserved ejection fraction (HFpEF) has become the main type of HF worldwide. Although large randomised controlled studies have demonstrated the beneficial effects of sodium-glucose cotransporter 2 inhibitors among patients with HFpEF, the mechanisms remain unclear. Basic research suggests that empagliflozin inhibits myocardial fibrosis. Myocardial extracellular volume (ECV) can be calculated using cardiac MRI (CMRI), which can reflect the degree of diffuse myocardial fibrosis. Studies show that empagliflozin can reduce ECV and left ventricular mass (LVM) assessed by CMRI in patients with diabetes with coronary heart disease and patients without diabetes with HF with reduced ejection fraction. However, whether empagliflozin reduces ECV and LVM among patients with HFpEF is unclear. This study intends to use CMRI to evaluate ECV and LVM, combined with echocardiography and an assessment of related biomarkers, to determine whether empagliflozin can improve myocardial fibrosis and left ventricular remodelling in patients with HFpEF.

METHODS AND ANALYSIS

This report describes the study design of a prospective, multicentre, randomised, double-blind, placebo-controlled and parallel-group clinical study. A total of 180 participants with HFpEF aged 40-80 years old who meet the inclusion and exclusion criteria will be randomly divided into an empagliflozin treatment group or a placebo control group. The empagliflozin treatment group will receive 10 mg of empagliflozin per day for 6 months in addition to guideline-directed medical treatment, while the control group will receive placebo oral administration with guideline-directed medical therapy for 6 months. The primary outcomes are ECV and LVM changes measured by CMRI after 6 months of treatment.

ETHICS AND DISSEMINATION

The study design is approved by the ethical committee of Beijing Hospital (2022BJYYEC-070-02). The trial is registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn). The trial results will be published in peer-reviewed journals and conferences.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2200060862).

Influence and mechanism of sodium-glucose cotransporter-2 inhibitors on the cardiac function: study protocol for a prospective cohort study

Background

Acute myocardial infarction (AMI) poses a significant threat to cardiovascular diseases (CVDs), leading to a high risk of heart failure (HF) and cardiovascular death. Growing evidence has unveiled the potential of sodium-glucose cotransporter-2 (SGLT2) inhibitors to improve cardiovascular outcomes in patients with CVD regardless of diabetes, but there is limited evidence in AMI patients. Furthermore, it is controversial whether the effects can be ascribed to the amelioration of left ventricular (LV) function, which further complicates the understanding of their underlying mechanism.

Methods

This study is a prospective, phase IV, open-label, parallel group, single-center trial conducted in a large tertiary teaching hospital in China. A total of 120 patients with AMI and type 2 diabetes mellitus (T2DM) will be included. Those who received SGLT2 inhibitors are considered as the experimental group, and those taking other antidiabetic agents are considered as the control group. The primary outcome is change in LV end-systolic volume index (LVESVi) measured by cardiac magnetic resonance (CMR) imaging from baseline during 1-year follow-up period. Secondary outcomes include other LV parameters such as LV mass, LV volume, and LV ejection fraction (EF); quality of life and functional capacity such as Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OS) and EuroQol-5 dimension (EQ-5D); biomarkers associated with diagnostic parameters of AMI and possible mechanisms on cardiovascular protection, such as creatine kinase, troponin T (TnT) level, troponin I (TnI) level, soluble suppression of tumorigenicity-2 (sST2), galectin-3 (Gal-3), fibroblast growth factor 21 (FGF21), and microRNA (miRNA) level.

Discussion

This study aims to investigate whether SGLT2 inhibitors could improve LV function by measuring CMR, quality of life, and functional capacity in patients with AMI in real-world settings, providing evidence on the underlying mechanism of SGLT2 inhibitors on cardioprotection.

Clinical trial registration

https://www.chictr.org.cn/showproj.html?proj=173672, identifier ChiCTR2200065792.

Longitudinal Changes in the Myocardial T1 Relaxation Time, Extracellular Volume Fraction, and Left Ventricular Function in Asymptomatic Men

(1) Background: Longitudinal changes in myocardial T1 relaxation time are unknown. We aimed to assess the longitudinal changes in the left ventricular (LV) myocardial T1 relaxation time and LV function. (2) Methods: Fifty asymptomatic men (mean age, 52.0 years) who underwent 1.5 T cardiac magnetic resonance imaging twice at an interval of 54 ± 21 months were included in this study. The LV myocardial T1 times and extracellular volume fractions (ECVFs) were calculated using the MOLLI technique (before and 15 min after gadolinium contrast injection). The 10-year Atherosclerotic Cardiovascular Disease (ASCVD) risk score was calculated. (3) Results: No significant differences in the following parameters were noted between the initial and follow-up assessments: LV ejection fraction (65.0 ± 6.7% vs. 63.6 ± 6.3%, p = 0.12), LV mass/end-diastolic volume ratio (0.82 ± 0.12 vs. 0.80 ± 0.14, p = 0.16), native T1 relaxation time (982 ± 36 vs. 977 ± 37 ms, p = 0.46), and ECVF (24.97 ± 2.38% vs. 25.02 ± 2.41%, p = 0.89). The following parameters decreased significantly from the initial assessment to follow-up: stroke volume (87.2 ± 13.7 mL vs. 82.6 ± 15.3 mL, p = 0.01), cardiac output (5.79 ± 1.17 vs. 5.50 ± 1.04 L/min, p = 0.01), and LV mass index (110.16 ± 22.38 vs. 104.32 ± 18.26 g/m², p = 0.01). The 10-year ASCVD risk score also remained unchanged between the two timepoints (4.71 ± 0.19% vs. 5.16 ± 0.24%, p = 0.14). (4) Conclusion: Myocardial T1 values and ECVFs were stable over time in the same middle-aged men.

Diabetes medication following heart transplantation: a focus on novel cardioprotective therapies-a joint review from endocrinologists and cardiologists

There is accumulating evidence that novel glucose-lowering agents infer potent cardiovascular and renal benefits. Therefore, it is imperative to reassess the management of post-transplant diabetes mellitus and consider the role of newer agents. With improved transplant-related survival and high prevalence of post-transplant diabetes, management of long-term complications such as diabetes are increasingly important. There are limited guidelines to assist in choice of appropriate agents after solid organ transplantation. Traditional therapies including insulin and sulfonylureas may still have a role; however, other agents should be considered prior. The evidence of novel glucose-lowering agents in post-transplant care is limited, and most studies have focused on kidney transplant recipients. While there are some parallels between renal and cardiac transplant recipients, the potential cardiovascular benefits, particularly on cardiac fibrosis are unique to cardiac transplantation. The treatment of diabetes, with a focus on additional cardiac and renal benefits, needs to be brought to the forefront of post-transplant care with incorporation of recent evidence outside of transplantation. The role for novel glucose-lowering agents in cardiac transplant recipients will be explored, with a summary of available evidence.

Myocardial Revascularization in Patients With Ischemic Cardiomyopathy: For Whom and How

Background Myocardial revascularization has been advocated to improve myocardial function and prognosis in ischemic cardiomyopathy (ICM). We discuss the evidence for revascularization in patients with ICM and the role of ischemia and viability detection in guiding treatment. Methods and Results We searched for randomized controlled trials evaluating the prognostic impact of revascularization in ICM and the value of viability imaging for patient management. Out of 1397 publications, 4 randomized controlled trials were included, enrolling 2480 patients. Three trials (HEART [Heart Failure Revascularisation Trial], STICH [Surgical Treatment for Ischemic Heart Failure], and REVIVED [REVascularization for Ischemic VEntricular Dysfunction]-BCIS2) randomized patients to revascularization or optimal medical therapy. HEART was stopped prematurely without showing any significant difference between treatment strategies. STICH showed a 16% lower mortality with bypass surgery compared with optimal medical therapy at a median follow-up of 9.8 years. However, neither the presence/extent of left ventricle viability nor ischemia interacted with treatment outcomes. REVIVED-BCIS2 showed no difference in the primary end point between percutaneous revascularization or optimal medical therapy. PARR-2 (Positron Emission Tomography and Recovery Following Revascularization) randomized patients to imaging-guided revascularization versus standard care, with neutral results overall. Information regarding the consistency of patient management with viability testing results was available in ≈65% of patients (n=1623). No difference in survival was revealed according to adherence or no adherence to viability imaging. Conclusions In ICM, the largest randomized controlled trial, STICH, suggests that surgical revascularization improves patients' prognosis at long-term follow-up, whereas evidence supports no benefit of percutaneous coronary intervention. Data from randomized controlled trials do not support myocardial ischemia or viability testing for treatment guidance. We propose an algorithm for the workup of patients with ICM considering clinical presentation, imaging results, and surgical risk.

Diabetes Mellitus and Heart Failure: Epidemiology, Pathophysiologic Mechanisms, and the Role of SGLT2 Inhibitors

Diabetes mellitus (DM) and heart failure (HF) are frequently encountered afflictions that are linked by a common pathophysiologic background. According to landmark studies, those conditions frequently coexist, and this interaction represents a poor prognostic indicator. Based on mechanistic studies, HF can be propagated by multiple pathophysiologic pathways, such as inflammation, oxidative stress, endothelial dysfunction, fibrosis, cardiac autonomic neuropathy, and alterations in substrate utilization. In this regard, DM may augment myocardial inflammation, fibrosis, autonomic dysfunction, and lipotoxicity. As the interaction between DM and HF appears critical, the new cornerstone in DM and HF treatment, sodium-glucose cotransporter-2 inhibitors (SGLT2i), may be able to revert the pathophysiology of those conditions and lead to beneficial HF outcomes. In this review, we aim to highlight the deleterious pathophysiologic interaction between DM and HF, as well as demonstrate the beneficial role of SGLT2i in this field.

SGLT2 inhibitor therapy for transthyretin amyloid cardiomyopathy: early tolerance and clinical response to dapagliflozin

AIMS

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve clinical outcomes in heart failure patients with reduced and preserved left ventricular ejection fraction (LVEF), but have not yet been investigated in transthyretin amyloid cardiomyopathy (ATTR-CM). This study aimed to evaluate tolerability, clinical outcomes, and changes in NT-proBNP levels and glomerular filtration rate (GFR) in ATTR-CM patients treated with dapagliflozin.

METHODS AND RESULTS

Patients with stable, tafamidis-treated ATTR-CM were retrospectively evaluated at the initiation of dapagliflozin and 3 months thereafter. Tafamidis-treated ATTR-CM patients without SGLT2i served as a reference cohort. Overall, SLGT2i therapy was initiated in 34 patients. Seventeen patients with stable disease on tafamidis, who were subsequently started on dapagliflozin, were included in the analysis. Patients selected for SGLT2i presented with signs of advanced disease, evidenced by higher Gillmore disease stage (stage ≥2: 53% vs. 27.5%; P = 0.041), baseline median NT-proBNP [median (IQR) 2668 pg/mL (1314-3451) vs. 1424 (810-2059); P = 0.038] and loop diuretic demand (76.5% vs. 45% of patients; P = 0.044), and lower LVEF (46.6 ± 12.9 vs. 53.7 ± 8.7%; P = 0.019) and GFR (51.8 ± 16.5 vs. 68.5 ± 18.6 mL/min; P = 0.037) compared with the reference cohort. At 3-month follow-up, a numerical decrease in NT-proBNP levels was observed in 13/17 (76.5%) patients in the dapagliflozin (-190 pg/mL, IQR: -1,028-71, P = 0.557) and 27/40 (67.5%) of patients in the control cohort (-115 pg/mL, IQR: -357-105, P = 0.551). Other disease parameters remained stable and no adverse events occurred.

CONCLUSIONS

In tafamidis-treated ATTR-CM patients, initiation of dapagliflozin was well tolerated. The efficacy of SGLT2i therapy in patients with ATTR-CM needs to be studied in randomized controlled trials.

Empagliflozin and Left Ventricular Remodeling in People Without Diabetes: Primary Results of the EMPA-HEART 2 CardioLink-7 Randomized Clinical Trial

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors have been demonstrated to promote reverse cardiac remodeling in people with diabetes or heart failure. Although it has been theorized that sodium-glucose cotransporter 2 inhibitors might afford similar benefits in people without diabetes or prevalent heart failure, this has not been evaluated. We sought to determine whether sodium-glucose cotransporter 2 inhibition with empagliflozin leads to a decrease in left ventricular (LV) mass in people without type 2 diabetes or significant heart failure.

METHODS

Between April 2021 and January 2022, 169 individuals, 40 to 80 years of age, without diabetes but with risk factors for adverse cardiac remodeling were randomly assigned to empagliflozin (10 mg/d; n=85) or placebo (n=84) for 6 months. The primary outcome was the 6-month change in LV mass indexed (LVMi) to baseline body surface area as measured by cardiac magnetic resonance imaging. Other measures included 6-month changes in LV end-diastolic and LV end-systolic volumes indexed to baseline body surface area and LV ejection fraction.

RESULTS

Among the 169 participants (141 men [83%]; mean age, 59.3±10.5 years), baseline LVMi was 63.2±17.9 g/m² and 63.8±14.0 g/m² for the empagliflozin- and placebo-assigned groups, respectively. The difference (95% CI) in LVMi at 6 months in the empagliflozin group versus placebo group adjusted for baseline LVMi was -0.30 g/m² (-2.1 to 1.5 g/m²; P=0.74). Median baseline (interquartile range) NT-proBNP (N-terminal-pro B-type natriuretic peptide) was 51 pg/mL (20-105 pg/mL) and 55 pg/mL (21-132 pg/mL) for the empagliflozin- and placebo-assigned groups, respectively. The 6-month treatment effect of empagliflozin versus placebo (95% CI) on blood pressure and NT-proBNP (adjusted for baseline values) were -1.3 mm Hg (-5.2 to 2.6 mm Hg; P=0.52), 0.69 mm Hg (-1.9 to 3.3 mm Hg; P=0.60), and -6.1 pg/mL (-37.0 to 24.8 pg/mL; P=0.70) for systolic blood pressure, diastolic blood pressure, and NT-proBNP, respectively. No clinically meaningful between-group differences in LV volumes (diastolic and systolic indexed to baseline body surface area) or ejection fraction were observed. No difference in adverse events was noted between the groups.

CONCLUSIONS

Among people with neither diabetes nor significant heart failure but with risk factors for adverse cardiac remodeling, sodium-glucose cotransporter 2 inhibition with empagliflozin did not result in a meaningful reduction in LVMi after 6 months.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04461041.

The SGLT2 inhibitor empagliflozin reduces tissue sodium content in patients with chronic heart failure: results from a placebo-controlled randomised trial

INTRODUCTION

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have cardiovascular protective properties in addition to the metabolic effects and represent a cornerstone of treating patients with chronic heart failure (CHF). We hypothesised that empagliflozin reduces tissue sodium content in patients with CHF.

METHODS

In a double-blind, randomised (2:1), placebo-controlled, parallel-group, clinical trial, 74 patients with NYHA class II-III CHF and an ejection fraction of 49% or less received empagliflozin 10 mg once daily or placebo for 3 months. In each patient, tissue sodium content of the lower leg was assessed non-invasively by sodium-MRI (²³Na-MRI) at baseline, after 1 and 3 months of treatment.

RESULTS

After 1 and 3 months treatment with empagliflozin (n = 48), a significant decrease in skin sodium content was observed (1 month: 22.8 ± 6.1 vs. 21.6 ± 6.0 AU, p = 0.039; 3 months: 22.9 ± 6.1 vs. 21.6 ± 6.1 AU, p = 0.013), while there was no change in muscle sodium and muscle water content. In direct comparison, the change in skin sodium content between baseline and 3 months was - 1.3 ± 3.5 AU in the empagliflozin group versus 0.6 ± 3.5 AU in the placebo group (p for between-group difference = 0.022). No significant difference regarding change in muscle sodium and in muscle water content was observed after 3 months treatment between the two groups.

CONCLUSION

This trial showed a significant decrease in skin sodium content after 1 and 3 months of treatment with empagliflozin. The decrease in skin sodium content may reflect a decrease in subclinical micro-oedema or/and in non-osmotic bound tissue sodium, both reported to impair left ventricular function.

TRIAL REGISTRATION NUMBER

NCT03128528 ( http://www.

CLINICALTRIALS

gov ).

TRIAL REGISTRATION DATE

25th April 2017.

Sodium-glucose co-transporter 2 inhibitors in heart failure with mildly reduced or preserved ejection fraction: an updated systematic review and meta-analysis

OBJECTIVES

Heart failure with mildly reduced ejection fraction (HFmrEF)  or  heart failure with preserved ejection fraction (HFpEF)  are associated with significant morbidity and mortality, as well as growing health and economic burden. Sodium-glucose co-transporter 2 (SGLT2) inhibitors are very promising for the outcome improvement of patients with HFpEF or HFmrEF. The meta-analysis was performed to investigate the effects of SGLT2 inhibitors in HFpEF or  HFmrEF, by pooling data from all clinically randomized controlled trials (RCTs) available to increase power to testify.

METHODS

Studies were searched in electronic databases from inception to November, 2022. We performed a meta-analysis to estimate the effect of SGLT2 inhibitors on clinical endpoints in patients with HFpEF or HFmrEF, using trial-level data with consistent endpoint definitions. The primary outcome was the composite of heart failure (HF) hospitalization or cardiovascular death. Hazard ratio (HR) was pooled with 95% confidence interval (CI) for dichotomous data. This study was registered with INPLASY 2022110095.

RESULTS

Six studies involving 15,989 participants were included into the final analysis. Pooled analyses revealed that SGLT2 inhibitors significantly reduced the composite of HF hospitalization or cardiovascular death [HR: 0.79 (0.72-0.85); I² = 0%; P < 0.00001] and HF hospitalizations [HR: 0.74 (0.67-0.82); I² = 0%; P < 0.00001]. This finding was seen in both HFmrEF trials [HR: 0.76 (0.67-0.87); I² = 49%; P < 0.0001] and HFpEF subgroup studies [HR: 0.70 (0.53-0.93); I² = 0%; P = 0.01]. The incidence of any serious adverse events [OR: 0.89 (0.83-0.96); I² = 0%; P = 0.002] was significantly lower in the SGLT2 inhibitor arm. No significant differences were observed between the two groups with regard to cardiovascular death and all-cause death.

CONCLUSIONS

This meta-analysis of patients with heart failure of left ventricular ejection fraction (LVEF) > 40% showed that SGLT2 inhibitors significantly reduce the risk of  the composite of cardiovascular death and hospitalization for heart failure, but not cardiovascular death and all-cause death. Nevertheless, given that SGLT2 inhibitors may reduce the risk of hospitalization for heart failure, they should be considered the fundamental treatment for all patients with HFpEF or  HFmrEF.

Myocardial Extracellular Volume Expansion in Type 2 Diabetes Is Associated With Ischemic Heart Disease, Autonomic Neuropathy, and Active Smoking

OBJECTIVE

Myocardial interstitial fibrosis expands the extracellular volume (ECV) and in patients with type 2 diabetes is implicated in development of heart failure. ECV can be determined with gadolinium contrast MRI. We investigated which known risk factors for cardiovascular disease were associated with increased ECV in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 296 patients with type 2 diabetes and 25 sex and age-matched control subjects were included in a cross-sectional MRI study. The influence of risk factors on ECV was investigated with multiple regression analysis.

RESULTS

Control subjects and patients with type 2 diabetes without complications had similar ECV (mean ± SD 27.4 ± 2.1% vs. 27.9 ± 2.6%, P = 0.4). Compared with patients without, ECV was significantly increased in patients with one or more complications (29.0 ± 3.3%, P = 0.02). Both in univariable analysis and after multivariable adjustment, ischemic heart disease, autonomic neuropathy, and active smoking were associated with increased levels of ECV. Active smoking exhibited the largest effect size (β = 2.0 percentage points, 95% CI 0.7-3.3). Former smokers ECV similar to that of never smokers. Albuminuria and systolic blood pressure were inversely associated with ECV in multivariable analysis, but after adjustment for medication suspected to affect ECV, the association with albuminuria was no longer significant (P = 0.1). Sodium-glucose cotransporter 2 inhibitor treatment was not significantly associated with reduced ECV (-0.8%, 95% CI -1.7 to 0.06, P = 0.067).

CONCLUSIONS

Patients with complications of diabetes have increased ECV, not seen in patients without complications. Ischemic heart disease, autonomic neuropathy, and active but not former smoking were highly associated with increased ECV.

Direct actions of dapagliflozin and interactions with LCZ696 and spironolactone on cardiac fibroblasts of patients with heart failure and reduced ejection fraction

AIMS

Inhibitors of SGLT2 (SGLT2i) have shown a positive impact in patients with chronic heart failure and reduced ejection fraction (HFrEF). Nonetheless, the direct effects of SGLT2i on cardiac cells and how their association with main drugs used for HFrEF affect the behaviour and signalling pathways of myocardial fibroblasts are still unknown. We aimed to determine the effects of dapagliflozin alone and in combination with sacubitril/valsartan (LCZ696) or spironolactone on the function of myocardial fibroblasts of patients with heart failure and reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Myocardial fibroblasts isolated from HFrEF patients (n = 5) were treated with dapagliflozin alone (1 nM-1 μM) or combined with LCZ696 (100 nM) or spironolactone (100 nM). The migratory rate was determined by wound-healing scratch assay. Expression of heart failure (HF) markers and signalling pathways activation were analysed with multiplexed protein array. Commercially available cardiac fibroblasts from healthy donors were used as Control (n = 4). Fibroblasts from HFrEF show higher migratory rate compared with control (P = 0.0036), and increased expression of HF markers [fold-change (Log2): COL1A1-1.3; IL-1b-1.9; IL-6-1.7; FN1-2.9 (P < 0.05)]. Dapagliflozin slowed the migration rate of HFrEF fibroblasts in a dose-dependent manner and markedly decreased the expression of IL-1β, IL-6, MMP3, MMP9, GAL3, and FN1. SGLT2i had no effect on control fibroblasts. These effects were associated with decreased phosphorylation of AKT/GSK3 and PYK2 kinases and the signal transducer and activator of transcription (STAT). A combination of dapagliflozin + LCZ696 further decreased fibroblast migration, although it did not have a significant effect on the regulation of signalling pathways and the expression of biomarkers induced by SGLT2 inhibition alone. In contrast, the combination of dapagliflozin + spironolactone did not change the migration rate of fibroblast but significantly altered SGLT2i responses on MMP9, GAL3, and IL-1b expression, in association with increased phosphorylation of the kinases AKT/GSK3 and ERK1/2.

CONCLUSIONS

SGLT2i, LCZ696, and spironolactone modulate the function of isolated myocardial fibroblasts from HFrEF patients through the activation of different signalling pathways. The combination of SGLT2i + LCZ696 shows an additive effect on migration, while spironolactone modifies the signalling pathways activated by SGLT2i and its beneficial effects of biomarkers of heart failure.

Aqueous Ethanolic Extract of Adiantum incisum Forssk. Protects against Type 2 Diabetes Mellitus via Attenuation of α-Amylase and Oxidative Stress

Purpose : This study was designed to investigate the antidiabetic effects of the aqueous ethanolic extract of Adiantum incisum Forssk. whole plant (AE-AI) in order to validate the folkloric claim. Methods : Streptozotocin (STZ) was used to induce type 2 diabetes mellitus (TII DM) in male Sprague-Dawley rats. STZ-induced diabetic rats were later treated orally with either AE-AI (125, 250, and 500 mg/kg) or glibenclamide for 35 days. Blood glucose levels were measured weekly and on day 35, animals were sacrificed, and blood samples and tissues were harvested for subsequent antioxidant and histopathological analyses. AE-AI was also analyzed in vitro for phytochemical, antioxidant, and α-amylase inhibitory assays. Results : The phytochemical screening of AE-AI confirmed the presence of essential bioactive compounds like cardiac glycosides, flavonoids, phenolic compounds, saponins, and fixed oils. AE-AI demonstrated abundant amounts of total phenolic and flavonoid contents and displayed prominent antioxidant activity as assessed via DPPH, phosphomolybdate, and nitric oxide scavenging assays. AE-AI treatment also showed α-amylase inhibitory activity comparable to acarbose. In addition, AE-AI treatment exhibited a wide margin of safety in rats and dose-dependently reduced STZ-induced blood glucose levels. Moreover, AE-AI increased the levels of GSH, SOD, catalase, and reduced MDA, and therefore prevented pathological effects of STZ on the kidney, liver, and pancreas. The blood glucose regulatory effect and antioxidant activity of AE-AI also aided in normalizing TII DM-mediated dyslipidemias. GC-MS analysis also demonstrated several potential antidiabetic phytoconstituents in AE-AI. Conclusion : These findings reveal that AE-AI possesses certain pharmacologically active compounds that can effectively treat STZ-induced TII DM owing to its antioxidant and α-amylase inhibitory potentials.

Safety outcomes of SGLT2i in the heart failure trials: A systematic review and Meta-analysis

AIMS

Sodium-glucose co-transporter inhibitors (SGLT2i) are emerging as a new treatment for heart failure (HF) after demonstrating favorable clinical outcomes in several randomized controlled trials (RCTs). In this meta-analysis, we assessed the safety of SGLT2i in the trials that prespecified heart failure in their inclusion criteria.

MATERIALS AND METHODS

We searched the databases for RCTs comparing SGLT2i to placebo in heart failure patients. The primary outcome was the incidence of serious adverse events (SAEs). A sensitivity analysis according to the class of HF was also performed.

RESULTS

The incidence of SAEs was significantly lower in the SGLT2i group (OR, 0.85; 95% CI, 0.77-0.92; P, 0.0002) and SAEs remained significantly lower after performing the sensitivity analysis (OR, 0.82; 95% CI, 0.75-0.89; P, <0.00001). Genital infections, urinary tract infections (UTIs), and hypotension were significantly higher in the SGLT2i group.

CONCLUSIONS

SGLT2i remain a safe option for patients with HF with a lower incidence of SAEs. However, since they increase the risk of genital infection, UTIs and hypotension, the risks vs benefits in each patient should be weighed when making a prescribing decision.

The current role of sodium-glucose cotransporter 2 inhibitors in type 2 diabetes mellitus management

Type 2 diabetes mellitus (T2DM) is a chronic, complex metabolic disease characterized by chronic hyperglycemia causing from insufficient insulin signaling because of insulin resistance or defective insulin secretion, and may induce severe complications and premature death. Sodium-glucose cotransporter-2 (SGLT2) inhibitors are oral drugs used to reduce hyperglycemia in patients with T2DM, including empagliflozin, ertugliflozin, dapagliflozin and canagliflozin. The primary objective of this article is to examine the clinical benefit, safety, and tolerability of the four SGLT2 inhibitors approved by the US FDA. SGLT2 inhibitors increase urinary glucose excretion via inhibiting SGLT2 to decrease renal reabsorption of filtered glucose and reduce the renal threshold for glucose. Rather than stimulating insulin release, SGLT2 inhibitors improve β-cell function by improving glucotoxicity, as well as reduce insulin resistance and increase insulin sensitivity. Early clinical trials have confirmed the beneficial effects of SGLT2 in T2DM with acceptable safety and excellent tolerability. In recent years, SGLT2 inhibitors has been successively approved by the FDA to decrease cardiovascular death and decrease the risk of stroke and cardiac attack in T2DM adults who have been diagnosed with cardiovascular disease, treating heart failure (HF) with reduced ejection fraction and HF with preserved ejection fraction, and treat diabetic kidney disease (DKD), decrease the risk of hospitalization for HF in T2DM and DKD patients. SGLT2 inhibitors are expected to be an effective treatment for T2DM patients with non alcoholic fatty liver disease. SGLT2 inhibitors have a similar safety profile to placebo or other active control groups, with major adverse events such as Ketoacidosis or hypotension and genital or urinary tract infections.

Diabetes and Myocardial Fibrosis: A Systematic Review and Meta-Analysis

OBJECTIVES

This systematic review and meta-analysis investigated the association of diabetes and glycemic control with myocardial fibrosis (MF).

BACKGROUND

MF is associated with an increased risk of heart failure, coronary artery disease, arrhythmias, and death. Diabetes may influence the development of MF, but evidence is inconsistent.

METHODS

The authors searched EMBASE, Medline Ovid, Cochrane CENTRAL, Web of Science, and Google Scholar for observational and interventional studies investigating the association of diabetes, glycemic control, and antidiabetic medication with MF assessed by histology and cardiac magnetic resonance (ie, extracellular volume fraction [ECV%] and T₁ time).

RESULTS

A total of 32 studies (88% exclusively on type 2 diabetes) involving 5,053 participants were included in the systematic review. Meta-analyses showed that diabetes was associated with a higher degree of MF assessed by histological collagen volume fraction (n = 6 studies; mean difference: 5.80; 95% CI: 2.00-9.59) and ECV% (13 studies; mean difference: 2.09; 95% CI: 0.92-3.27), but not by native or postcontrast T₁ time. Higher glycosylated hemoglobin levels were associated with higher degrees of MF.

CONCLUSIONS

Diabetes is associated with higher degree of MF assessed by histology and ECV% but not by T₁ time. In patients with diabetes, worse glycemic control was associated with higher MF degrees. These findings mostly apply to type 2 diabetes and warrant further investigation into whether these associations are causal and which medications could attenuate MF in patients with diabetes.

KDM3A Inhibition Ameliorates Hyperglycemia-Mediated Myocardial Injury by Epigenetic Modulation of Nuclear Factor Kappa-B/P65

Objectives

Even after the glucose level returns to normal, hyperglycemia-induced cardiac dysfunction as well as reactive oxygen species (ROS) generation, inflammatory responses, and apoptosis continued deterioration, showing a long-lasting adverse effect on cardiac function and structure. We aimed to unveil the molecular and cellular mechanisms underlying hyperglycemia-induced persistent myocardial injury and cardiac dysfunction.

Methods and Results

Recently, the accumulated evidence indicated epigenetic regulation act as a determining factor in hyperglycemia-induced continuous cardiovascular dysfunction. As an important histone demethylase, the expression of lysine-specific demethylase 3A (KDM3A) was continually increased, accompanied by a sustained decline of H3K9me2 levels in diabetic myocardium even if received hypoglycemic therapy. Besides, by utilizing gain- and loss-of-functional approaches, we identified KDM3A as a novel regulator that accelerates hyperglycemia-mediated myocardial injury by promoting ROS generation, aggregating inflammatory reaction, and facilitating cell apoptosis in vitro and in vivo. The KDM3A inhibition could significantly ameliorate the adverse effect of hyperglycemia in both diabetes model and diabetic intensive glycemic control model. Mechanically, our data uncovered that KDM3A could promote the expression and transcriptional activity of nuclear factor kappa-B (NF-κB/P65), and the succedent rescue experiments further verified that KDM3A regulates hyperglycemia-induced myocardial injury in an NF-κB/P65 dependent manner.

Conclusion

This study revealed histone-modifying enzymes KDM3A drives persistent oxidative stress, inflammation, apoptosis, and subsequent myocardial injury in the diabetic heart by regulating the transcription of NF-κB/P65.

Sodium-Glucose Cotransporter 2 Inhibitors and Cardiac Remodeling

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have evident cardiovascular benefits in patients with type 2 diabetes with or at high risk for atherosclerotic cardiovascular disease, heart failure with reduced ejection fraction, heart failure with preserved ejection fraction (only empagliflozin and dapagliflozin have been investigated in this group so far), and chronic kidney disease. Prevention and reversal of adverse cardiac remodeling is one of the mechanisms by which SGLT2 inhibitors may exert cardiovascular benefits, especially heart failure-related outcomes. Cardiac remodeling encompasses molecular, cellular, and interstitial changes that result in favorable changes in the mass, geometry, size, and function of the heart. The pathophysiological mechanisms of adverse cardiac remodeling are related to increased apoptosis and necrosis, decreased autophagy, impairments of myocardial oxygen supply and demand, and altered energy metabolism. Herein, the accumulating evidence from animal and human studies is reviewed investigating the effects of SGLT2 inhibitors on these mechanisms of cardiac remodeling.

Diastolic function: modeling left ventricular untwisting as a damped harmonic oscillator

Objective.We developed a method using cardiovascular magnetic resonance imaging to model the untwisting of the left ventricle (LV) as a damped torsional harmonic oscillator to estimate shear modulus (intrinsic myocardial stiffness) and frictional damping, then applied this method to evaluate the torsional stiffness of patients with resistant hypertension (RHTN) compared to a control group.Approach.The angular displacement of the LV during diastole was measured. Myocardial shear modulus and damping constant were determined by solving a system of equations modeling the diastolic untwisting as a damped, unforced harmonic oscillator, in 100 subjects with RHTN and 36 control subjects.Main Results.Though overall torsional stiffness was increased in RHTN (41.7 (27.1-60.7) versus 29.6 (17.3-35.7) kdyn*cm;p = 0.001), myocardial shear modulus was not different between RHTN and control subjects (0.34 (0.23-0.50) versus 0.33 (0.22-0.46) kPa;p= 0.758). RHTN demonstrated an increase in overall diastolic frictional damping (6.13 ± 3.77 versus 3.35 ± 1.70 kdyn*cm*s;p< 0.001), but no difference in damping when corrected for the overlap factor (74.3 ± 25.9 versus 68.0 ± 24.0 dyn*s/cm3;p = 0.201). There was an increase in the polar moment (geometric component of stiffness; 11.47 ± 6.95 versus 7.58 ± 3.28 cm4;p<0.001).Significance.We have developed a phenomenological method, estimating the intrinsic stiffness and relaxation properties of the LV based on restorative diastolic untwisting. This model finds increased overall stiffness in RHTN and points to hypertrophy, rather than tissue- level changes, as the major factor leading to increased stiffness.

Sodium Glucose Cotransporter-2 Inhibitors: Spotlight on Favorable Effects on Clinical Outcomes beyond Diabetes

Sodium glucose transporter type 2 (SGLT2) molecules are found in proximal tubules of the kidney, and perhaps in the brain or intestine, but rarely in any other tissue. However, their inhibitors, intended to improve diabetes compensation, have many more beneficial effects. They improve kidney and cardiovascular outcomes and decrease mortality. These benefits are not limited to diabetics but were also found in non-diabetic individuals. The pathophysiological pathways underlying the treatment success have been investigated in both clinical and experimental studies. There have been numerous excellent reviews, but these were mostly restricted to limited aspects of the knowledge. The aim of this review is to summarize the known experimental and clinical evidence of SGLT2 inhibitors' effects on individual organs (kidney, heart, liver, etc.), as well as the systemic changes that lead to an improvement in clinical outcomes.

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.

Empagliflozin reduces diffuse myocardial fibrosis by extracellular volume mapping: A meta-analysis of clinical studies

OBJECTIVE

The aim of the study was to evaluate the effect of empagliflozin on diffuse myocardial fibrosis by cardiac magnetic resonance (CMR) T1 mapping.

RESEARCH METHODS AND PROCEDURES

Databases including PubMed, Cochrane library, Embase, and Sinomed for clinical studies of empagliflozin on myocardial fibrosis were searched. Two authors extracted the data and evaluated study quality independently. Weighted mean difference (WMD) and 95% confidence intervals (CI) were used for continuous variables. Review Manager 5.3 was used to performed the analysis.

RESULTS

Six studies were included in this meta-analysis. One of the six studies was assessed as poor quality by the assessment of methodological quality; however, the remaining five studies were considered good. The WMD value of △extracellular volume (ECV) was merged by the fixed-effect model, and the pooled effect size was -1.48 (95% CI -1.76 to -1.21, P < 0.00001), which means in favor of empagliflozin. Heterogeneity analysis did not find any heterogeneity (chi² = 0.39, P = 0.82, I ² = 0%). In addition, empagliflozin had a tendency to reduce ECV compared to treatment before with no statistical significance (WMD = -0.29, 95% CI -1.26 to 0.67, P = 0.55; heterozygosity test, chi² = 2.66, P = 0.45, I ² = 0%). The WMD value of △native T1 was also merged by the fixed-effect model, but the pooled effect size showed neither statistical difference between empagliflozin and placebo treatment (WMD = -5.40, 95% CI -21.63 to 10.83, P = 0.51) nor heterogeneity (chi² = 0.05, P = 0.83, I ² = 0%).

CONCLUSIONS

Empagliflozin has cardiovascular benefits by reducing diffuse myocardial fibrosis. ECV could act as a non-invasive imaging tool to assess diffuse myocardial fibrosis and monitor disease progression.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=324804, identifier: CRD42022324804.

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.

Sodium Glucose Cotransporter Type 2 Inhibitors Improve Cardiorenal Outcome of Patients With Coronary Artery Disease: A Meta-Analysis

OBJECTIVE

Sodium glucose cotransporter type 2 inhibitors (SGLT-2i) are beneficial for cardiorenal outcomes in patients with type 2 diabetes mellitus (T2DM), heart failure (HF) or chronic kidney disease (CKD). However, whether or not the patients with coronary artery disease (CAD) have prognostic benefit from SGLT-2i treatment has not been fully studied. The purpose of this meta-analysis is to determine the prognostic benefit of SGLT-2i administration in CAD patients.

METHODS

We searched the PubMed, Embase and Cochrane Library from inception until October 15, 2021. We included randomized controlled trials (RCTs) reporting the effect of SGLT-2i on major adverse cardiovascular event (MACE), hospitalization for heart failure (HHF), cardiovascular (CV) death and cardiorenal parameters in CAD patients. Hazard ratio (HR) with 95% confidence interval (CI) and mean difference (MD) from trials were meta-analyzed using fixed-effects models.

RESULTS

Nine trials enrolling 15,301 patients with CAD were included in the analyses. Overall, SGLT2i were associated with a reduced risk of MACE (HR: 0.84; 95% CI 0.74-0.95; I² = 0%), HHF (HR: 0.69; 95% CI 0.58-0.83; I² = 0%) and a composite of CV death or HHF (HR: 0.78; 95% CI 0.71-0.86; I² = 37%) in CAD patients. Compared with control group, estimated glomerular filtration rate (eGFR) level decreased less in SGLT-2i group (mean difference [MD] = -3.60, 95% CI, -5.90 to -1.30, p = 0.002; I² = 0%).

CONCLUSIONS

SGLT-2i can improve cardiorenal outcomes in CAD patients. Further RCTs and real world studies are need to investigate the effect of SGLT2i on CAD patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021258237.

Sex Differences in Type 2 Diabetes Mellitus-Related Left Ventricular Remodeling: A Cardiovascular Magnetic Resonance Study

BACKGROUND

The purpose of this study was to evaluate the sex differences in myocardial structure, tissue characteristics, and myocardial function in type 2 diabetes mellitus (T2DM) patients.

METHODS

A total of 62 T2DM patients and 40 controls were prospectively recruited for the study. All the participants were scanned using cardiovascular magnetic resonance (CMR) cine and underwent native and postcontrast T1 mapping to obtain left ventricular (LV) structure, function, and tissue characteristics. The differences between the control and T2DM patients were compared in males and females, respectively.

RESULTS

For myocardial structure, T2DM was associated with a larger ratio of myocardial mass to end-diastolic volume (MVR, T2DM: 0.87 ± 0.20 vs. controls: 0.73 ± 0.14, p = 0.008) and thicker wall thickness (WT, T2DM: 6.5 ± 1.1 mm vs. controls: 5.6 ± 1.0 mm, p = 0.002) in females. For tissue characteristics, T2DM was associated with a similar T1 value, elevated extracellular volume fraction (ECV, T2DM: 27.8 ± 3.6% vs. controls: 25.1 ± 2.5%, p = 0.002), and increased extracellular matrix volume index (ECMVi, T2DM: 15.8 ± 3.8 ml/m² vs. controls: 13.4 ± 2.7 ml/m², p = 0.008) in males. For myocardial function, in male, compared with control, T2DM was associated with decreased peak longitudinal diastolic strain rate (PLDSR, T2DM: 0.97 ± 0.19 1/s vs. control: 1.13 ± 0.29 1/s, p = 0.030).

CONCLUSIONS

There might be sex differences in myocardial remodeling induced by T2DM, including LV structural concentric remodeling in female patients and extracellular matrix remodeling and subclinical diastolic dysfunction in male patients.

Effects of sodium-glucose cotransporter-2 inhibitors on cardiac structural and electrical remodeling: from myocardial cytology to cardiodiabetology

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have changed the clinical landscape of diabetes mellitus (DM) therapy through their favourable effects on cardiovascular outcomes. Notably, the use of SGLT2i has been linked to cardiovascular benefits regardless of DM status, while their pleiotropic actions remain to be fully elucidated. What we do know is that SGLT2i exert beneficial effects even at the level of the myocardial cell, and that these are linked to an improvement in the energy substrate, resulting in less inflammation and fibrosis. SGLT2i ameliorate myocardial extracellular matrix remodeling, cardiomyocyte stiffness and concentric hypertrophy, achieving beneficial remodeling of the left ventricle with significant implications for the pathogenesis and outcome of heart failure. Most studies show a significant improvement in markers of diastolic dysfunction along with a reduction in left ventricular hypertrophy. In addition to these effects there is electrophysiological remodeling, which explains initial data suggesting that SGLT2i have an antiarrhythmic action against both atrial and ventricular arrhythmias. However, future studies need to clarify not only the exact mechanisms of this beneficial functional, structural, and electrophysiological cardiac remodeling, but also its magnitude, and to determine whether this is a class or a drug effect.

Diabetes and SGLT2-iss inhibitors in patients with heart failure with preserved or mid-range left ventricular ejection fractions

Diabetic patients frequently develop heart failure with preserved (HFpEF) or mid-range (HFmEF) cardiac ejection fractions. This condition may be secondary to diabetic cardiomyopathy or one of several relevant comorbidities, mainly hypertension. Several mechanisms link diabetes to HFpEF or HFmEF. Among these, non-enzymatic glycation of interstitial proteins, lipotoxicity, and endothelial dysfunction may promote structural damage and ultimate lead to heart failure. Findings from several large-scale trials indicated that treatment with sodium/glucose cotransporter 2 inhibitors (SGLT2-iss) resulted in significant improvements in cardiovascular outcomes in diabetic patients with high cardiovascular risk. However, there is currently some evidence that suggests a clinical advantage of using SGLT2-iss specifically in cases of HFpEF or HFmEF. Preclinical and clinical studies revealed that SGLT2-iss treatment results in a reduction in left ventricular mass and improved diastolic function. While some of the beneficial effects of SGLT2-iss have already been characterized (e.g., increased natriuresis and diuresis as well as reduced blood pressure, plasma volume, and arterial stiffness, and nephron-protective activities), there is increasing evidence suggesting that SGLT2-iss may have direct actions on the heart. These findings include SGLT2-iss-mediated reductions in the expression of hypertrophic foetal genes and diastolic myofilaments stiffness, increases in global phosphorylation of myofilament regulatory proteins (in HFpEF), inhibition of cardiac late sodium channel current and Na⁺/H⁺ exchanger activity, metabolic shifts, and effects on calcium cycling. Preliminary data from previously published studies suggest that SGLT2-iss could be useful for the treatment of HFpEF and HFmEF. Several large ongoing trials, including DELIVER AND EMPEROR -preserved have been designed to evalute the efficacy of SGLT2-iss in improving clinical outcomes in patients diagnosed with HFpEF. The goal of this manuscript is to review the use of SGLT2-iss inhibitors for HFpEF or HFmEF associated with diabetes.

Reverse remodelling in diabetic cardiomyopathy: the role of extracellular matrix

Diabetic patients are prone to suffer from cardiovascular disease, specifically from ischemic heart disease and diabetic cardiomyopathy, which have a huge impact on morbidity and mortality worldwide. Cardiac fibrosis due to alteration of the extracellular matrix (ECM) remodelling is often observed in diabetes and myocardial fibrosis is an important part of cardiac remodeling that leads to heart failure and death. At single-cell level, the ECM govern, metabolism, motility, orientation and proliferation. However, in pathological condition such as diabetes, changes in ECM lead to fibrosis and subsequently cardiac stiffness and cardiomyocytes dysfunction. Anti-diabetic drugs, particularly sodium-glucose cotransporter-2 (SGLT2) inhibitors have anti-fibrotic effects, and may promote ECM reverse remodelling. In this mini-review, the mechanisms and the role of ECM remodelling and reverse remodelling as a potential therapeutic targets for diabetic cardiomyopathy are discussed.

Effect of empagliflozin on myocardial structure and function in patients with type 2 diabetes at high cardiovascular risk: the SIMPLE randomized clinical trial

To investigate the effects of 13 weeks treatment with empagliflozin in patients with high-risk type-2 diabetes mellitus on echocardiographic measures of left ventricular (LV) structure and function compared to placebo. A total of 91 patients were randomized to treatment with empagliflozin (25 mg/day, n = 45) or matching placebo (n = 45) for 13 weeks. Left ventricular (LV) mass, volumes and geometry as well as measures of LV systolic and diastolic function were measured using echocardiography at baseline and follow up. Mean LV mass index (LVMi) was reduced by - 11.5 g/m² (95% CI - 56.4; 33.4, p = 0.03) with empagliflozin compared to - 1.4 g/m² (95% CI - 36.5; 33.8, p = 0.63) for placebo. The proportion of patients with LV hypertrophy was reduced by 16.3% (p = 0.04) in the empagliflozin group compared to 1.1% in the placebo group (p = 1.00). The proportion of patients with left atrial volume index > 34 mL/m² was reduced by 20.0% (p = 0.02) with empagliflozin compared to 9.5% for placebo (p = 0.45) and the E/e' ratio decreased (∆-0.8 (1.9) vs. ∆0.5 (2.0), p < 0.01). 13 weeks empagliflozin treatment in patients with type-2 diabetes at high CV risk significantly reduced LV mass, improved LV geometry and improved diastolic function compared to placebo.

Impact of empagliflozin on right ventricular parameters and function among patients with type 2 diabetes

Background

Sodium-glucose cotransporter 2 (SGLT2) inhibition reduces cardiovascular events in type 2 diabetes (T2DM) and is associated with a reduction in left ventricular (LV) mass index. However, the impact on right ventricular (RV) remodeling is unknown. Accordingly, the objective of this study was to assess the impact of SGLT2 inhibition on RV parameters and function in T2DM and coronary artery disease (CAD).

Methods

In EMPA-HEART CardioLink-6, 97 patients with T2DM and CAD were randomly assigned to empagliflozin 10 mg (n = 49) once daily or placebo (n = 48). Cardiac magnetic resonance imaging was performed at baseline and after 6 months. RV mass index (RVMi), RV end-diastolic and end-systolic volume index (RVEDVi, RVESVi) and RV ejection fraction (RVEF) were assessed in blinded fashion.

Results

At baseline, mean RVMi (± SD) (11.8 ± 2.4 g/m²), RVEF (53.5 ± 4.8%), RVEDVi (64.3 ± 13.2 mL/m²) and RVESVi (29.9 ± 6.9 mL/m²) were within normal limits and were similar between the empagliflozin and placebo groups. Over 6 months, there were no significant differences in RVMi (− 0.11 g/m², [95% CI − 0.81 to 0.60], p = 0.76), RVEF (0.54%, [95% CI − 1.4 to 2.4], p = 0.58), RVEDVi (− 1.2 mL/m², [95% CI − 4.1 to 1.7], p = 0.41) and RVESVi (− 0.81 mL/m², [95% CI − 2.5 to 0.90], p = 0.35) in the empaglifozin group as compared with the placebo group. In both groups, there was no significant correlation between RVMi and LVMi changes from baseline to 6 months.

Conclusions

In this post-hoc analysis, SGLT2 inhibition with empagliflozin had no impact on RVMi and RV volumes in patients with T2DM and CAD. The potentially differential effect of empagliflozin on the LV and RV warrants further investigation.

Clinical Trial Registration: URL: https://www.clinicaltrials.gov/ct2/show/NCT02998970?cond=NCT02998970&draw=2&rank=1. Unique identifier: NCT02998970.

Fibrosis of the diabetic heart: Clinical significance, molecular mechanisms, and therapeutic opportunities

In patients with diabetes, myocardial fibrosis may contribute to the pathogenesis of heart failure and arrhythmogenesis, increasing ventricular stiffness and delaying conduction. Diabetic myocardial fibrosis involves effects of hyperglycemia, lipotoxicity and insulin resistance on cardiac fibroblasts, directly resulting in increased matrix secretion, and activation of paracrine signaling in cardiomyocytes, immune and vascular cells, that release fibroblast-activating mediators. Neurohumoral pathways, cytokines, growth factors, oxidative stress, advanced glycation end-products (AGEs), and matricellular proteins have been implicated in diabetic fibrosis; however, the molecular links between the metabolic perturbations and activation of a fibrogenic program remain poorly understood. Although existing therapies using glucose- and lipid-lowering agents and neurohumoral inhibition may act in part by attenuating myocardial collagen deposition, specific therapies targeting the fibrotic response are lacking. This review manuscript discusses the clinical significance, molecular mechanisms and cell biology of diabetic cardiac fibrosis and proposes therapeutic targets that may attenuate the fibrotic response, preventing heart failure progression.