Endothelial Dysfunction in Heart Failure With Preserved Ejection Fraction: What are the Experimental Proofs?

Association Between Endothelial Alterations, Cardiac Function, and Outcomes From Health to Heart Failure: Insight From the STANISLAS, MEDIA-DHF, and BIOSTAT-CHF Cohorts

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a multifaceted syndrome, likely stemming from comorbidity-induced inflammation resulting in endothelial dysfunction. Endothelial glycocalyx degradation's role in the development and prognosis of HFpEF remains largely unexplored. Our study aimed at exploring the association between glycocalyx degradation and diastolic dysfunction and determining whether glycocalyx degradation can predict clinical outcomes in patients with HFpEF.

METHODS

Perlecan and thrombomodulin concentrations were assessed in individuals deemed healthy (STANISLAS [Suivi Temporaire Annuel Non-Invasif de la Santé des Lorrains Assurés Sociaux (Annual Noninvasive Temporary Monitoring of the Health of Insured Lorrainers)] cohort, n=1705) and patients with HFpEF (MEDIA-DHF [Metabolic Road to Diastolic Heart Failure], n=460 and BIOSTAT-CHF [Biology Study to Tailored Treatment in Chronic Heart Failure], n=556) to evaluate endothelial glycocalyx degradation.

RESULTS

In patients with HFpEF, perlecan but not thrombomodulin was increased compared with controls (P<0.0001 versus P=0.73). In adjusted analysis, perlecan was associated with peak early mitral inflow velocity/peak early diastolic mitral annular velocity ratio and thrombomodulin with peak early diastolic mitral annular velocity in control individuals, whereas perlecan and thrombomodulin were associated with peak early mitral inflow velocity/peak early diastolic mitral annular velocity and left atrial volume index in patients with HFpEF (all P<0.03). Perlecan was significantly associated with cardiovascular hospitalization and death in the MEDIA-DHF (adjusted hazard ratio [HR] for highest tertile versus first tertile, 2.44 [95% CI, 1.11-5.34]; P=0.026) and BIOSTAT-CHF cohorts (adjusted HR, 2.12 [95% CI, 1.49-3.03]; P<0.0001). Thrombomodulin was associated with a worse outcome in BIOSTAT-CHF (P=0.004) but not in MEDIA-DHF.

CONCLUSIONS

Higher circulating levels of the endothelial glycocalyx degradation biomarkers like perlecan and, to a lesser extent, thrombomodulin are associated with features of diastolic dysfunction in population and HFpEF settings and predict poor outcome in patients with HFpEF. These results suggest that glycocalyx degradation may be an early step in the pathological processes leading to HFpEF and gain further prognostic value in later stages (ie, overt HFpEF).

REGISTRATION

URL: https://clinicaltrials.gov/; Unique identifiers: NCT01391442, https://clinicaltrials.gov/study/NCT01391442?cond=stanislas&rank=1; NCT02446327; URL: https://cordis.europa.eu; BIOSTAT-CHF ID: 242209.

Renal-Cardiac Crosstalk in the Pathogenesis and Progression of Heart Failure

Chronic kidney disease (CKD) represents a global health issue with a high socioeconomic impact. Beyond a progressive decline of kidney function, patients with CKD are at increased risk of cardiovascular diseases, including heart failure (HF) and sudden cardiac death. HF in CKD can manifest both as HF with reduced ejection fraction and HF with preserved ejection fraction, with the latter further increasing in relative importance in the more advanced stages of CKD. Typical cardiac remodeling characteristics in uremic cardiomyopathy include left ventricular hypertrophy, myocardial fibrosis, cardiac electrical dysregulation, capillary rarefaction, and microvascular dysfunction, which are triggered by increased cardiac preload, cardiac afterload, and preload and afterload-independent factors. The pathophysiological mechanisms underlying cardiac remodeling in CKD are multifactorial and include neurohormonal activation (with increased activation of the renin-angiotensin-aldosterone system, the sympathetic nervous system, and mineralocorticoid receptor signaling), cardiac steroid activation, mitochondrial dysfunction, inflammation, innate immune activation, and oxidative stress. Furthermore, disturbances in cardiac metabolism and calcium homeostasis, macrovascular and microvascular dysfunction, increased cellular profibrotic responses, the accumulation of uremic retention solutes, and mineral and bone disorders also contribute to cardiovascular disease and HF in CKD. Here, we review the current knowledge of HF in CKD, including the clinical characteristics and pathophysiological mechanisms revealed in animal studies. We also elaborate on the detrimental impact of comorbidities of CKD on HF using hypertension as an example and discuss the clinical characteristics of hypertensive heart disease and the genetic predisposition. Overall, this review aims to increase the understanding of HF in CKD to support future research and clinical translational approaches for improved diagnosis and therapy of this vulnerable patient population.

Endothelial cell metabolism in cardiovascular physiology and disease

Endothelial cells are multifunctional cells that form the inner layer of blood vessels and have a crucial role in vasoreactivity, angiogenesis, immunomodulation, nutrient uptake and coagulation. Endothelial cells have unique metabolism and are metabolically heterogeneous. The microenvironment and metabolism of endothelial cells contribute to endothelial cell heterogeneity and metabolic specialization. Endothelial cell dysfunction is an early event in the development of several cardiovascular diseases and has been shown, at least to some extent, to be driven by metabolic changes preceding the manifestation of clinical symptoms. Diabetes mellitus, hypertension, obesity and chronic kidney disease are all risk factors for cardiovascular disease. Changes in endothelial cell metabolism induced by these cardiometabolic stressors accelerate the accumulation of dysfunctional endothelial cells in tissues and the development of cardiovascular disease. In this Review, we discuss the diversity of metabolic programmes that control endothelial cell function in the cardiovascular system and how these metabolic programmes are perturbed in different cardiovascular diseases in a disease-specific manner. Finally, we discuss the potential and challenges of targeting endothelial cell metabolism for the treatment of cardiovascular diseases.

Deciphering the molecular mechanisms of QLQX capsules in heart failure: A multi-omics perspective

PURPOSE

This study investigates the therapeutic mechanisms of Qiliqiangxin (QLQX) capsules in treating Heart Failure with Preserved Ejection Fraction (HFpEF). The study aims to understand how QLQX impacts cardiac function and underlying molecular pathways.

METHODS

HFpEF was induced in a rat model through unilateral nephrectomy, DOCA pellet implantation, and a high-salt diet. Cardiac function was assessed via M-mode imaging and Doppler flow measurements, focusing on key parameters like ejection fraction and diastolic function. A network pharmacology approach identified active QLQX components and potential targets, followed by comprehensive multi-omics analyses-including transcriptomics, proteomics, and metabolomics-to uncover the molecular mechanisms modulated by QLQX. Quantitative RT-PCR was employed to measure mRNA levels of key cardiac markers, providing further insights into QLQX's impact on cardiac remodeling.

RESULTS

QLQX treatment significantly improved cardiac function, with notable enhancements in ejection fraction and left ventricular diastolic function. Network pharmacology revealed 530 potential targets of QLQX, with 38 overlapping HFpEF targets. Key pathways identified include cGMP-PKG, adrenergic signaling, and calcium signaling. Transcriptomic analysis showed significant gene expression changes related to inflammation, energy metabolism, and myocardial remodeling, which were reversed by QLQX. Proteomic analysis identified 401 differentially expressed proteins, enriched in pathways such as cGMP-PKG and NF-κB signaling. Metabolomic profiling highlighted the role of lipid metabolism and adrenergic signaling in HFpEF, which were normalized by QLQX. In vivo validation confirmed the involvement of the cGMP-PKG pathway, with increased serum NO and cGMP levels, improved endothelial function, and reduced pro-fibrotic markers following QLQX treatment.

CONCLUSION

QLQX exerts multifaceted therapeutic effects on HFpEF by modulating gene expression, protein function, and metabolic pathways, particularly through the cGMP-PKG signaling pathway. These findings support QLQX as a promising therapeutic intervention for HFpEF, offering improvements in cardiac function and reversing pathological changes at multiple molecular levels.

Systemic aging fuels heart failure: Molecular mechanisms and therapeutic avenues

Systemic aging influences various physiological processes and contributes to structural and functional decline in cardiac tissue. These alterations include an increased incidence of left ventricular hypertrophy, a decline in left ventricular diastolic function, left atrial dilation, atrial fibrillation, myocardial fibrosis and cardiac amyloidosis, elevating susceptibility to chronic heart failure (HF) in the elderly. Age-related cardiac dysfunction stems from prolonged exposure to genomic, epigenetic, oxidative, autophagic, inflammatory and regenerative stresses, along with the accumulation of senescent cells. Concurrently, age-related structural and functional changes in the vascular system, attributed to endothelial dysfunction, arterial stiffness, impaired angiogenesis, oxidative stress and inflammation, impose additional strain on the heart. Dysregulated mechanosignalling and impaired nitric oxide signalling play critical roles in the age-related vascular dysfunction associated with HF. Metabolic aging drives intricate shifts in glucose and lipid metabolism, leading to insulin resistance, mitochondrial dysfunction and lipid accumulation within cardiomyocytes. These alterations contribute to cardiac hypertrophy, fibrosis and impaired contractility, ultimately propelling HF. Systemic low-grade chronic inflammation, in conjunction with the senescence-associated secretory phenotype, aggravates cardiac dysfunction with age by promoting immune cell infiltration into the myocardium, fostering HF. This is further exacerbated by age-related comorbidities like coronary artery disease (CAD), atherosclerosis, hypertension, obesity, diabetes and chronic kidney disease (CKD). CAD and atherosclerosis induce myocardial ischaemia and adverse remodelling, while hypertension contributes to cardiac hypertrophy and fibrosis. Obesity-associated insulin resistance, inflammation and dyslipidaemia create a profibrotic cardiac environment, whereas diabetes-related metabolic disturbances further impair cardiac function. CKD-related fluid overload, electrolyte imbalances and uraemic toxins exacerbate HF through systemic inflammation and neurohormonal renin-angiotensin-aldosterone system (RAAS) activation. Recognizing aging as a modifiable process has opened avenues to target systemic aging in HF through both lifestyle interventions and therapeutics. Exercise, known for its antioxidant effects, can partly reverse pathological cardiac remodelling in the elderly by countering processes linked to age-related chronic HF, such as mitochondrial dysfunction, inflammation, senescence and declining cardiomyocyte regeneration. Dietary interventions such as plant-based and ketogenic diets, caloric restriction and macronutrient supplementation are instrumental in maintaining energy balance, reducing adiposity and addressing micronutrient and macronutrient imbalances associated with age-related HF. Therapeutic advancements targeting systemic aging in HF are underway. Key approaches include senomorphics and senolytics to limit senescence, antioxidants targeting mitochondrial stress, anti-inflammatory drugs like interleukin (IL)-1β inhibitors, metabolic rejuvenators such as nicotinamide riboside, resveratrol and sirtuin (SIRT) activators and autophagy enhancers like metformin and sodium-glucose cotransporter 2 (SGLT2) inhibitors, all of which offer potential for preserving cardiac function and alleviating the age-related HF burden.

Effect of proton pump inhibitor (lansoprazole) on adverse drug reactions and rational drug use in elderly patients with chronic heart failure

OBJECTIVE

To evaluate the efficacy and rationale of proton pump inhibitors (PPIs) for adverse drug reactions in elderly patients with heart failure (HF).

METHODS

From February 2019 to September 2021, 120 elderly patients with chronic heart failure (CHF) treated at Jintan First People's Hospital were enrolled as subjects. The patients were classified into a control group (n=60) and a research group (n=60). In addition to clopidogrel, the control group received cimetidine, while the research group received lansoprazole. Clinical efficacy, oxidative stress markers, echocardiographic indices, vascular endothelial function, cardiac function indicators, and adverse reactions were compared between the two groups. A cost-effectiveness analysis was also performed, and risk factors affecting patient efficacy were examined.

RESULTS

The clinical efficacy of the research group was remarkably superior to that of the control group (88.33% versus 63.33%, P<0.05). The combination of clopidogrel and cimetidine was identified as a risk factor affecting patient efficacy (P=0.003). Besides, the research group showed significant elevation in superoxide dismutase (SOD), glutathione peroxidase (GPx), left ventricular ejection fraction (LVEF), and nitric oxide (NO) after treatment, all higher compared to the control group (all P<0.05). Additionally, significant reductions in malondialdehyde (MDA), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic dimension (LVSD), endothelin-1 (ET-1), N-terminal pro-B-type natriuretic peptide (NT-proBNP), creatine kinase (CK), lactate dehydrogenase (LDH), and free fatty acids (FFA) were observed in the research group, all lower than the control group (P<0.05). The incidence of bradycardia, hypotension and electrolyte disturbances in the research group was remarkably lower (P<0.05). Additionally, the research group demonstrated greater cost-effectiveness compared to the control group.

CONCLUSION

The use of PPIs in elderly patients with HF not only improves efficacy but also enhances safety, making this drug treatment approach worth promoting.

Heart failure and microvascular dysfunction: an in-depth review of mechanisms, diagnostic strategies, and innovative therapies

Microvascular dysfunction (MVD) is increasingly recognized as a critical contributor to the pathogenesis of heart failure (HF), particularly in heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF). Coronary microvascular dysfunction (CMD) significantly impacts HFpEF by reducing coronary flow reserve and myocardial perfusion reserve, leading to adverse outcomes such as myocardial ischemia, diastolic dysfunction, and increased risk of major cardiovascular events, including atrial fibrillation. In HFrEF, microvascular impairment is linked to heightened oxidative stress, reduced nitric oxide production, and activation of the renin-angiotensin-aldosterone system, further driving disease progression and contributing to poor prognosis. Advancements in diagnostic techniques, such as positron emission tomography, cardiac magnetic resonance imaging, and biomarker analysis, improve our ability to assess CMD in heart failure patients, enabling earlier diagnosis and risk stratification. Emerging therapies, including sodium-glucose cotransporter-2 inhibitors, angiotensin receptor-neprilysin inhibitors, and endothelial-targeted interventions, enhance microvascular function and improve patient outcomes. The role of personalized medicine is becoming increasingly important, as individualized therapeutic approaches tailored to patient-specific microvascular abnormalities are essential for optimizing treatment effectiveness. This review underscores the pivotal role of MVD in HF. It highlights the urgent need for innovative therapeutic strategies and diagnostic tools to address this complex condition and improve clinical outcomes for HF patients.

Menopause, epicardial adiposity and preserved ejection fraction heart failure

Postmenopausal women are overrepresented in the preserved ejection heart failure population. Expansion of visceral and epicardial adipose tissue during the menopause transition leads to local and low-grade systemic inflammation that in turn contributes to left ventricular concentric remodeling, diastolic dysfunction and the development and progression of preserved ejection fraction. In contrast to visceral adipose tissue imaging, epicardial adipose tissue can be inexpensively imaged on low radiation coronary calcium score computerized tomography examination. The menopause transition provides a unique time frame to evaluate the contribution of epicardial adipose tissue expansion to the pathogenesis of preserved ejection heart failure.

Human induced pluripotent stem cell-derived cardiomyocytes to study inflammation-induced aberrant calcium transient

Heart failure with preserved ejection fraction (HFpEF) is commonly found in persons living with HIV (PLWH) even when antiretroviral therapy suppresses HIV viremia. However, studying this condition has been challenging because an appropriate animal model is not available. In this article, we studied calcium transient in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in culture to simulate the cardiomyocyte relaxation defect noted in PLWH and HFpEF and assess whether various drugs have an effect. We show that treatment of hiPSC-CMs with inflammatory cytokines (such as interferon-γ or TNF-α) impairs their Ca2+ uptake into sarcoplasmic reticulum and that SGLT2 inhibitors, clinically proven as effective for HFpEF, reverse this effect. Additionally, treatment with mitochondrial antioxidants (like mito-Tempo) and certain antiretrovirals resulted in the reversal of the effects of these cytokines on calcium transient. Finally, incubation of hiPSC-CMs with serum from HIV patients with and without diastolic dysfunction did not alter their Ca2+-decay time, indicating that the exposure to the serum of these patients is not sufficient to induce the decrease in Ca2+ uptake in vitro. Together, our results indicate that hiPSC-CMs can be used as a model to study molecular mechanisms of inflammation-mediated abnormal cardiomyocyte relaxation and screen for potential new interventions.

Impact of Sex in the Incidence of Heart Failure in Patients with Chronic Coronary Syndrome

PURPOSE OF REVIEW

This review examines the available evidence concerning the incidence of heart failure in patients with chronic coronary syndrome, with a focus on gender differences.

RECENT FINDINGS

The incidence of heart failure in the context of chronic coronary syndrome presents conflicting data. Most of the available information stems from studies involving stable patients' post-acute coronary syndrome, revealing a wide range of incidence rates, from less than 3% to over 20%, observed over 5 years of follow-up. Regarding the gender differences in heart failure incidence, there is no consensus about whether women exhibit a higher incidence, particularly in the presence of evidence of obstructive coronary artery disease. However, in cases where obstructive coronary artery disease is absent, women may face a more unfavourable prognosis due to a higher prevalence of microvascular disease and heart failure with preserved ventricular function. The different profile of ischaemic heart disease in women difficult to establish differences in prognosis independently associated with female sex. Targeted investigations are essential to discern the incidence of heart failure in chronic coronary syndrome and explore potential gender-specific associations.

Is endothelin targeting finally ready for prime time?

The endothelin family of peptides has long been recognized as a physiological regulator of diverse biological functions and mechanistically involved in various disease states, encompassing, among others, the cardiovascular system, the kidney, and the nervous system. Pharmacological blockade of the endothelin system, however, has encountered strong obstacles in its entry into the clinical mainstream, having obtained only a few proven indications until recently. This translational gap has been attributable predominantly to the relevant side effects associated with endothelin receptor antagonism (ERA), particularly fluid retention. Of recent, however, an expanding understanding of the pathophysiological processes involving endothelin, in conjunction with the development of new antagonists of endothelin receptors or adjustment of their doses, has driven a flourish of new clinical trials. The favorable results of some of them have extended the proven indications for ET targeting to a variety of clinical conditions, including resistant arterial hypertension and glomerulopathies. In addition, on the ground of strong preclinical evidence, other studies are ongoing to test the potential benefits of ERA in combination with other treatments, such as sodium-glucose co-transporter 2 inhibition in fluid retentive states or anti-cancer therapies in solid tumors. Furthermore, antibodies providing long-term blockade of endothelin receptors are under testing to overcome the short half-life of most small molecule endothelin antagonists. These efforts may yet bring new life to the translation of endothelin targeting strategies in clinical practice.

Preclinical systolic dysfunction relating to ankle-brachial index among high-risk PAD population with preserved left ventricular ejection fraction

Peripheral artery disease (PAD) shares common clinical risk factors, for example, endothelial dysfunction, with preserved ejection fraction (LVEF) heart failure (HFpEF). Whether PAD is associated with preclinical systolic dysfunction and higher HF risk among individuals presenting preserved LVEF remains uncertain. We retrospectively included outpatients with at least one known or established cardiovascular (CV) risk factor with LVEF ≥ 50%. Patients were categorized into high risk and low risk of developing PAD (PAD vs Non-PAD) by ankle-brachial index (ABI) (≤ 0.90 or > 1.4) and further stratified based on their history of HFpEF (HFpEF vs. Non-HFpEF), resulting in the formation of four distinct strata. Preclinical systolic dysfunction was defined using dedicated speckle-tracking algorithm. A total of 2130 consecutive patients were enrolled in the study, with a median follow-up of 4.4 years. The analysis revealed a higher prevalence of high risk of developing PAD in patients with HFpEF compared to those without HFpEF (25.1% vs. 9.4%). Both high risk of developing PAD and HFpEF were independently associated with preclinical systolic dysfunction (global longitudinal strain, GLS ≥ - 18%) (odds ratio, OR: 1.38; 95% confidence interval, CI: 1.03-1.86). In comparison to patients at low risk of developing PAD without HFpEF (Non-PAD/Non-HFpEF group), those categorized as having a high risk of developing PAD with HFpEF (PAD/HFpEF group) exhibited the most impaired GLS and a heightened susceptibility to heart failure hospitalization (hazard ratio, HR: 6.51; 95% CI: 4.43-9.55), a twofold increased risk of all-cause mortality (HR: 2.01; 95% CI: 1.17-3.38), cardiovascular mortality (HR: 2.44; 95% CI: 1.08-5.51), and non-cardiovascular mortality (HR: 1.78; 95% CI: 0.82-3.84). A high risk of developing PAD was strongly linked to impaired preclinical systolic function and an increased likelihood for subsequent hospitalization for HF, all-cause mortality, CV mortality and non-CV mortality. There is a clear need for preventive strategies aimed at reducing hospitalizations for HF and mortality in this high-risk population.

Leucine Supplementation Prevents the Development of Skeletal Muscle Dysfunction in a Rat Model of HFpEF

Heart failure with preserved ejection fraction (HFpEF) is associated with exercise intolerance due to alterations in the skeletal muscle (SKM). Leucine supplementation is known to alter the anabolic/catabolic balance and to improve mitochondrial function. Thus, we investigated the effect of leucine supplementation in both a primary and a secondary prevention approach on SKM function and factors modulating muscle function in an established HFpEF rat model. Female ZSF1 obese rats were randomized to an untreated, a primary prevention, and a secondary prevention group. For primary prevention, leucine supplementation was started before the onset of HFpEF (8 weeks of age) and for secondary prevention, leucine supplementation was started after the onset of HFpEF (20 weeks of age). SKM function was assessed at an age of 32 weeks, and SKM tissue was collected for the assessment of mitochondrial function and histological and molecular analyses. Leucine supplementation prevented the development of SKM dysfunction whereas it could not reverse it. In the primary prevention group, mitochondrial function improved and higher expressions of mitofilin, Mfn-2, Fis1, and miCK were evident in SKM. The expression of UCP3 was reduced whereas the mitochondrial content and markers for catabolism (MuRF1, MAFBx), muscle cross-sectional area, and SKM mass did not change. Our data show that leucine supplementation prevented the development of skeletal muscle dysfunction in a rat model of HFpEF, which may be mediated by improving mitochondrial function through modulating energy transfer.

New Insights into Endothelial Dysfunction in Cardiometabolic Diseases: Potential Mechanisms and Clinical Implications

The endothelium is a monocellular layer covering the inner surface of blood vessels. It maintains vascular homeostasis regulating vascular tone and permeability and exerts anti-inflammatory, antioxidant, anti-proliferative, and anti-thrombotic functions. When the endothelium is exposed to detrimental stimuli including hyperglycemia, hyperlipidemia, and neurohormonal imbalance, different biological pathways are activated leading to oxidative stress, endothelial dysfunction, increased secretion of adipokines, cytokines, endothelin-1, and fibroblast growth factor, and reduced nitric oxide production, leading eventually to a loss of integrity. Endothelial dysfunction has emerged as a hallmark of dysmetabolic vascular impairment and contributes to detrimental effects on cardiac metabolism and diastolic dysfunction, and to the development of cardiovascular diseases including heart failure. Different biomarkers of endothelial dysfunction have been proposed to predict cardiovascular diseases in order to identify microvascular and macrovascular damage and the development of atherosclerosis, particularly in metabolic disorders. Endothelial dysfunction also plays an important role in the development of severe COVID-19 and cardiovascular complications in dysmetabolic patients after SARS-CoV-2 infection. In this review, we will discuss the biological mechanisms involved in endothelial dysregulation in the context of cardiometabolic diseases as well as the available and promising biomarkers of endothelial dysfunction in clinical practice.

Assessing Cardiac Contractility From Single Molecules to Whole Hearts

Fundamentally, the heart needs to generate sufficient force and power output to dynamically meet the needs of the body. Cardiomyocytes contain specialized structures referred to as sarcomeres that power and regulate contraction. Disruption of sarcomeric function or regulation impairs contractility and leads to cardiomyopathies and heart failure. Basic, translational, and clinical studies have adapted numerous methods to assess cardiac contraction in a variety of pathophysiological contexts. These tools measure aspects of cardiac contraction at different scales ranging from single molecules to whole organisms. Moreover, these studies have revealed new pathogenic mechanisms of heart disease leading to the development of novel therapies targeting contractility. In this review, the authors explore the breadth of tools available for studying cardiac contractile function across scales, discuss their strengths and limitations, highlight new insights into cardiac physiology and pathophysiology, and describe how these insights can be harnessed for therapeutic candidate development and translational.

Isolation of circulating endothelial cells provides tool to determine endothelial cell senescence in blood samples

Circulating endothelial cells (CEC) are arising as biomarkers for vascular diseases. However, whether they can be utilized as markers of endothelial cell (EC) senescence in vivo remains unknown. Here, we present a protocol to isolate circulating endothelial cells for a characterization of their senescent signature. Further, we characterize different models of EC senescence induction in vitro and show similar patterns of senescence being upregulated in CECs of aged patients as compared to young volunteers. Replication-(ageing), etoposide-(DNA damage) and angiotensin II-(ROS) induced senescence models showed the expected cell morphology and proliferation-reduction effects. Expression of senescence-associated secretory phenotype markers was specifically upregulated in replication-induced EC senescence. All models showed reduced telomere lengths and induction of the INK4a/ARF locus. Additional p14ARF-p21 pathway activation was observed in replication- and etoposide-induced EC senescence. Next, we established a combined magnetic activated- and fluorescence activated cell sorting (MACS-FACS) based protocol for CEC isolation. Interestingly, CECs isolated from aged volunteers showed similar senescence marker patterns as replication- and etoposide-induced senescence models. Here, we provide first proof of senescence in human blood derived circulating endothelial cells. These results hint towards an exciting future of using CECs as mirror cells for in vivo endothelial cell senescence, of particular interest in the context of endothelial dysfunction and cardiovascular diseases.

Myocardial Metabolic Reprogramming in HFpEF

Heart failure (HF) caused by structural or functional cardiac abnormalities is a significant cause of morbidity and mortality worldwide. While HF with reduced ejection fraction (HErEF) is well understood, more than half of patients have HF with preserved ejection fraction (HFpEF). Currently, the treatment for HFpEF primarily focuses on symptom alleviation, lacking specific drugs. The stressed heart undergoes metabolic switches in substrate preference, which is a compensatory process involved in cardiac pathological remodeling. Although metabolic reprogramming in HF has gained attention in recent years, its role in HFpEF still requires further elucidation. In this review, we present a summary of cardiac mitochondrial dysfunction and cardiac metabolic reprogramming in HFpEF. Additionally, we emphasize potential therapeutic approaches that target metabolic reprogramming for the treatment of HFpEF.

Thrombosis in the Coronary Microvasculature Impairs Cardiac Relaxation and Induces Diastolic Dysfunction

BACKGROUND

Heart failure with preserved ejection fraction is proposed to be caused by endothelial dysfunction in cardiac microvessels. Our goal was to identify molecular and cellular mechanisms underlying the development of cardiac microvessel disease and diastolic dysfunction in the setting of type 2 diabetes.

METHODS

We used Leprdb/db (leptin receptor-deficient) female mice as a model of type 2 diabetes and heart failure with preserved ejection fraction and identified Hhipl1 (hedgehog interacting protein-like 1), which encodes for a decoy receptor for HH (hedgehog) ligands as a gene upregulated in the cardiac vascular fraction of diseased mice.

RESULTS

We then used Dhh (desert HH)-deficient mice to investigate the functional consequences of impaired HH signaling in the adult heart. We found that Dhh-deficient mice displayed increased end-diastolic pressure while left ventricular ejection fraction was comparable to that of control mice. This phenotype was associated with a reduced exercise tolerance in the treadmill test, suggesting that Dhh-deficient mice do present heart failure. At molecular and cellular levels, impaired cardiac relaxation in DhhECKO mice was associated with a significantly decreased PLN (phospholamban) phosphorylation on Thr17 (threonine 17) and an alteration of sarcomeric shortening ex vivo. Besides, as expected, Dhh-deficient mice exhibited phenotypic changes in their cardiac microvessels including a prominent prothrombotic phenotype. Importantly, aspirin therapy prevented the occurrence of both diastolic dysfunction and exercise intolerance in these mice. To confirm the critical role of thrombosis in the pathophysiology of diastolic dysfunction, we verified Leprdb/db also displays increased cardiac microvessel thrombosis. Moreover, consistently, with Dhh-deficient mice, we found that aspirin treatment decreased end-diastolic pressure and improved exercise tolerance in Leprdb/db mice.

CONCLUSIONS

Altogether, these results demonstrate that microvessel thrombosis may participate in the pathophysiology of heart failure with preserved ejection fraction.

Coronary Microvascular Dysfunction and Hypertension: A Bond More Important than We Think

Coronary microvascular dysfunction (CMD) is a clinical entity linked with various risk factors that significantly affect cardiac morbidity and mortality. Hypertension, one of the most important, causes both functional and structural alterations in the microvasculature, promoting the occurrence and progression of microvascular angina. Endothelial dysfunction and capillary rarefaction play the most significant role in the development of CMD among patients with hypertension. CMD is also related to several hypertension-induced morphological and functional changes in the myocardium in the subclinical and early clinical stages, including left ventricular hypertrophy, interstitial myocardial fibrosis, and diastolic dysfunction. This indicates the fact that CMD, especially if associated with hypertension, is a subclinical marker of end-organ damage and heart failure, particularly that with preserved ejection fraction. This is why it is important to search for microvascular angina in every patient with hypertension and chest pain not associated with obstructive coronary artery disease. Several highly sensitive and specific non-invasive and invasive diagnostic modalities have been developed to evaluate the presence and severity of CMD and also to investigate and guide the treatment of additional complications that can affect further prognosis. This comprehensive review provides insight into the main pathophysiological mechanisms of CMD in hypertensive patients, offering an integrated diagnostic approach as well as an overview of currently available therapeutical modalities.

Heart Failure, Female Sex, and Atrial Fibrillation Are the Main Drivers of Human Atrial Cardiomyopathy: Results From the CATCH ME Consortium

BACKGROUND

Atrial cardiomyopathy (atCM) is an emerging prognostic factor in cardiovascular disease. Fibrotic remodeling, cardiomyocyte hypertrophy, and capillary density are hallmarks of atCM. The contribution of etiological factors and atrial fibrillation (AF) to the development of differential atCM phenotypes has not been quantified. This study aimed to evaluate the association between histological features of atCM and the clinical phenotype.

METHODS AND RESULTS

We examined left atrial (LA, n=95) and right atrial (RA, n=76) appendages from a European cohort of patients undergoing cardiac surgery. Quantification of histological atCM features was performed following wheat germ agglutinin/CD31/vimentin staining. The contributions of AF, heart failure, sex, and age to histological characteristics were determined with multiple linear regression models. Persistent AF was associated with increased endomysial fibrosis (LA: +1.13±0.47 μm, P=0.038; RA: +0.94±0.38 μm, P=0.041), whereas total extracellular matrix content was not. Men had larger cardiomyocytes (LA: +1.92±0.72 μm, P<0.001), while women had more endomysial fibrosis (LA: +0.99±0.56 μm, P=0.003). Patients with heart failure showed more endomysial fibrosis (LA: +1.85±0.48 μm, P<0.001) and extracellular matrix content (LA: +3.07±1.29%, P=0.016), and a higher capillary density (LA: +0.13±0.06, P=0.007) and size (LA: +0.46±0.22 μm, P=0.044). Fuzzy k-means clustering of histological features identified 2 subtypes of atCM: 1 characterized by enhanced endomysial fibrosis (LA: +3.17 μm, P<0.001; RA: +2.86 μm, P<0.001), extracellular matrix content (LA: +3.53%, P<0.001; RA: +6.40%, P<0.001) and fibroblast density (LA: +4.38%, P<0.001), and 1 characterized by cardiomyocyte hypertrophy (LA: +1.16 μm, P=0.008; RA: +2.58 μm, P<0.001). Patients with fibrotic atCM were more frequently female (LA: odds ratio [OR], 1.33, P=0.002; RA: OR, 1.54, P=0.004), with persistent AF (LA: OR, 1.22, P=0.036) or heart failure (LA: OR, 1.62, P<0.001). Hypertrophic features were more common in men (LA: OR=1.33, P=0.002; RA: OR, 1.54, P=0.004).

CONCLUSIONS

Fibrotic atCM is associated with female sex, persistent AF, and heart failure, while hypertrophic features are more common in men.

Endothelial cell dysfunction in cardiac disease: driver or consequence?

The vascular endothelium is a multifunctional cellular system which directly influences blood components and cells within the vessel wall in a given tissue. Importantly, this cellular interface undergoes critical phenotypic changes in response to various biochemical and hemodynamic stimuli, driving several developmental and pathophysiological processes. Multiple studies have indicated a central role of the endothelium in the initiation, progression, and clinical outcomes of cardiac disease. In this review we synthesize the current understanding of endothelial function and dysfunction as mediators of the cardiomyocyte phenotype in the setting of distinct cardiac pathologies; outline existing in vivo and in vitro models where key features of endothelial cell dysfunction can be recapitulated; and discuss future directions for development of endothelium-targeted therapeutics for cardiac diseases with limited existing treatment options.

Deciphering the Dilemma: Anticoagulation for Heart Failure With Preserved Ejection Fraction (HFpEF)

Impairment in ventricular relaxation and preserved left ventricular ejection fraction are the two main features of heart failure with preserved ejection fraction (HFpEF) a difficult clinical condition. Therapeutic choices for HFpEF patients are still scarce despite its rising frequency and negative effects on morbidity and mortality, necessitating creative methods to enhance results. The increased thromboembolic risk seen in these individuals raises questions about the relevance of anticoagulation in the therapy of HFpEF. Although anticoagulation has been shown to be beneficial in heart failure with decreased ejection fraction (HFrEF) and other high-risk cardiovascular disorders, its efficacy and safety in HFpEF present a challenging therapeutic challenge. Anticoagulants have been the subject of clinical trials in HFpEF, but the results have been conflicting, giving clinicians only a little information with which to make decisions. The decision-making process is made more difficult by worries about potential bleeding hazards, particularly in susceptible elderly HFpEF patients with other comorbidities. The link between heart failure and anticoagulant medication in HFpEF is thoroughly analyzed in this narrative review. In HFpEF, cardiac fibrosis and endothelial dysfunction create a prothrombotic milieu, as is highlighted in this passage. Also covered are recent developments in innovative biomarker research and cutting-edge imaging techniques, which may provide ways to spot HFpEF patients who might benefit from anticoagulation. This therapeutic conundrum may be resolved by using precision medicine strategies based on risk classification and individualized therapy choices. This review emphasizes the need for more research to establish the best use of anticoagulation in HFpEF within the framework of personalized therapy and shared decision-making. To successfully manage thromboembolic risk and reduce bleeding consequences in HFpEF patients, it is essential to perform well-designed clinical studies and advance our understanding of the pathophysiology of HFpEF. These developments may ultimately improve the prognosis and quality of life for people who suffer from this difficult and mysterious ailment.

A network medicine approach to study comorbidities in heart failure with preserved ejection fraction

BACKGROUND

Comorbidities are expected to impact the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF). However, comorbidity profiles are usually reduced to a few comorbid disorders. Systems medicine approaches can model phenome-wide comorbidity profiles to improve our understanding of HFpEF and infer associated genetic profiles.

METHODS

We retrospectively explored 569 comorbidities in 29,047 HF patients, including 8062 HFpEF and 6585 HF with reduced ejection fraction (HFrEF) patients from a German university hospital. We assessed differences in comorbidity profiles between HF subtypes via multiple correspondence analysis. Then, we used machine learning classifiers to identify distinctive comorbidity profiles of HFpEF and HFrEF patients. Moreover, we built a comorbidity network (HFnet) to identify the main disease clusters that summarized the phenome-wide comorbidity. Lastly, we predicted novel gene candidates for HFpEF by linking the HFnet to a multilayer gene network, integrating multiple databases. To corroborate HFpEF candidate genes, we collected transcriptomic data in a murine HFpEF model. We compared predicted genes with the murine disease signature as well as with the literature.

RESULTS

We found a high degree of variance between the comorbidity profiles of HFpEF and HFrEF, while each was more similar to HFmrEF. The comorbidities present in HFpEF patients were more diverse than those in HFrEF and included neoplastic, osteologic and rheumatoid disorders. Disease communities in the HFnet captured important comorbidity concepts of HF patients which could be assigned to HF subtypes, age groups, and sex. Based on the HFpEF comorbidity profile, we predicted and recovered gene candidates, including genes involved in fibrosis (COL3A1, LOX, SMAD9, PTHL), hypertrophy (GATA5, MYH7), oxidative stress (NOS1, GSST1, XDH), and endoplasmic reticulum stress (ATF6). Finally, predicted genes were significantly overrepresented in the murine transcriptomic disease signature providing additional plausibility for their relevance.

CONCLUSIONS

We applied systems medicine concepts to analyze comorbidity profiles in a HF patient cohort. We were able to identify disease clusters that helped to characterize HF patients. We derived a distinct comorbidity profile for HFpEF, which was leveraged to suggest novel candidate genes via network propagation. The identification of distinctive comorbidity profiles and candidate genes from routine clinical data provides insights that may be leveraged to improve diagnosis and identify treatment targets for HFpEF patients.

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

Obesity, Preserved Ejection Fraction Heart Failure, and Left Ventricular Remodeling

Owing to the overwhelming obesity epidemic, preserved ejection fraction heart failure commonly ensues in patients with severe obesity and the obese phenotype of preserved ejection fraction heart failure is now commonplace in clinical practice. Severe obesity and preserved ejection fraction heart failure share congruent cardiovascular, immune, and renal derangements that make it difficult to ascertain whether the obese phenotype of preserved ejection fraction heart failure is the convergence of two highly prevalent conditions or severe obesity enables the development and progression of the syndrome of preserved ejection fraction heart failure. Nevertheless, the obese phenotype of preserved ejection fraction heart failure provides a unique opportunity to assess whether sustained and sizeable loss of excess body weight via metabolic bariatric surgery reverses the concentric left ventricular remodeling that patients with preserved ejection fraction heart failure commonly display.

Endothelial Cell Dysfunction and Increased Cardiovascular Risk in Patients With Chronic Kidney Disease

The endothelium is considered to be the gatekeeper of the vessel wall, maintaining and regulating vascular integrity. In patients with chronic kidney disease, protective endothelial cell functions are impaired due to the proinflammatory, prothrombotic and uremic environment caused by the decline in kidney function, adding to the increase in cardiovascular complications in this vulnerable patient population. In this review, we discuss endothelial cell functioning in healthy conditions and the contribution of endothelial cell dysfunction to cardiovascular disease. Further, we summarize the phenotypic changes of the endothelium in chronic kidney disease patients and the relation of endothelial cell dysfunction to cardiovascular risk in chronic kidney disease. We also review the mechanisms that underlie endothelial changes in chronic kidney disease and consider potential pharmacological interventions that can ameliorate endothelial health.

Molecular Mechanisms and Therapeutic Implications of Endothelial Dysfunction in Patients with Heart Failure

Heart failure is a complex medical syndrome that is attributed to a number of risk factors; nevertheless, its clinical presentation is quite similar among the different etiologies. Heart failure displays a rapidly increasing prevalence due to the aging of the population and the success of medical treatment and devices. The pathophysiology of heart failure comprises several mechanisms, such as activation of neurohormonal systems, oxidative stress, dysfunctional calcium handling, impaired energy utilization, mitochondrial dysfunction, and inflammation, which are also implicated in the development of endothelial dysfunction. Heart failure with reduced ejection fraction is usually the result of myocardial loss, which progressively ends in myocardial remodeling. On the other hand, heart failure with preserved ejection fraction is common in patients with comorbidities such as diabetes mellitus, obesity, and hypertension, which trigger the creation of a micro-environment of chronic, ongoing inflammation. Interestingly, endothelial dysfunction of both peripheral vessels and coronary epicardial vessels and microcirculation is a common characteristic of both categories of heart failure and has been associated with worse cardiovascular outcomes. Indeed, exercise training and several heart failure drug categories display favorable effects against endothelial dysfunction apart from their established direct myocardial benefit.

The Sodium-Glucose Co-Transporter 2 (SGLT2) Inhibitor Empagliflozin Reverses Hyperglycemia-Induced Monocyte and Endothelial Dysfunction Primarily through Glucose Transport-Independent but Redox-Dependent Mechanisms

PURPOSE

Hyperglycaemia-induced oxidative stress and inflammation contribute to vascular cell dysfunction and subsequent cardiovascular events in T2DM. Selective sodium-glucose co-transporter-2 (SGLT-2) inhibitor empagliflozin significantly improves cardiovascular mortality in T2DM patients (EMPA-REG trial). Since SGLT-2 is known to be expressed on cells other than the kidney cells, we investigated the potential ability of empagliflozin to regulate glucose transport and alleviate hyperglycaemia-induced dysfunction of these cells.

METHODS

Primary human monocytes were isolated from the peripheral blood of T2DM patients and healthy individuals. Primary human umbilical vein endothelial cells (HUVECs) and primary human coronary artery endothelial cells (HCAECs), and fetoplacental endothelial cells (HPECs) were used as the EC model cells. Cells were exposed to hyperglycaemic conditions in vitro in 40 ng/mL or 100 ng/mL empagliflozin. The expression levels of the relevant molecules were analysed by RT-qPCR and confirmed by FACS. Glucose uptake assays were carried out with a fluorescent derivative of glucose, 2-NBDG. Reactive oxygen species (ROS) accumulation was measured using the H₂DFFDA method. Monocyte and endothelial cell chemotaxis were measured using modified Boyden chamber assays.

RESULTS

Both primary human monocytes and endothelial cells express SGLT-2. Hyperglycaemic conditions did not significantly alter the SGLT-2 levels in monocytes and ECs in vitro or in T2DM conditions. Glucose uptake assays carried out in the presence of GLUT inhibitors revealed that SGLT-2 inhibition very mildly, but not significantly, suppressed glucose uptake by monocytes and endothelial cells. However, we detected the significant suppression of hyperglycaemia-induced ROS accumulation in monocytes and ECs when empagliflozin was used to inhibit SGLT-2 function. Hyperglycaemic monocytes and endothelial cells readily exhibited impaired chemotaxis behaviour. The co-treatment with empagliflozin reversed the PlGF-1 resistance phenotype of hyperglycaemic monocytes. Similarly, the blunted VEGF-A responses of hyperglycaemic ECs were also restored by empagliflozin, which could be attributed to the restoration of the VEGFR-2 receptor levels on the EC surface. The induction of oxidative stress completely recapitulated most of the aberrant phenotypes exhibited by hyperglycaemic monocytes and endothelial cells, and a general antioxidant N-acetyl-L-cysteine (NAC) was able to mimic the effects of empagliflozin.

CONCLUSIONS

This study provides data indicating the beneficial role of empagliflozin in reversing hyperglycaemia-induced vascular cell dysfunction. Even though both monocytes and endothelial cells express functional SGLT-2, SGLT-2 is not the primary glucose transporter in these cells. Therefore, it seems likely that empagliflozin does not directly prevent hyperglycaemia-mediated enhanced glucotoxicity in these cells by inhibiting glucose uptake. We identified the reduction of oxidative stress by empagliflozin as a primary reason for the improved function of monocytes and endothelial cells in hyperglycaemic conditions. In conclusion, empagliflozin reverses vascular cell dysfunction independent of glucose transport but could partially contribute to its beneficial cardiovascular effects.