Endothelin in coronary endothelial dysfunction and early atherosclerosis in humans

Coronary and Systemic Vasodilator Responsiveness of Patients Receiving Conventional Intermittent or Nocturnal Hemodialysis

BACKGROUND

Nocturnal hemodialysis (nHD) restores the attenuated brachial artery vasodilator responsiveness of patients receiving conventional intermittent hemodialysis (iHD). Its impact on coronary vasodilatation is unknown.

METHODS

We evaluated 25 patients on hemodialysis who fulfilled transplant criteria: 15 on iHD (4-hour sessions, 3 d/wk) and 10 on nHD (≈40 h/wk over 8-10-hour sessions) plus 6 control participants. Following diagnostic angiography, left anterior descending (LAD) coronary flow reserve and mean luminal diameter were quantified at baseline and during sequential intracoronary administration of adenosine (infusion and bolus), nitroglycerin (bolus), acetylcholine (infusion), acetylcholine coinfused with vitamin C, and, finally, sublingual nitroglycerin.

RESULTS

Coronary flow reserve in those receiving nHD was augmented relative to iHD (3.28±0.26 versus 2.17±0.12 [mean±SEM]; P<0.03) but attenuated, relative to controls (4.80±0.63; P=0.011). Luminal dilatations induced by intracoronary adenosine and nitroglycerin were similar in nHD and controls but blunted in the iHD cohort (P<0.05 versus both). ACh elicited vasodilatation in controls but constriction in both dialysis groups (both P<0.05, versus control); vitamin C coinfusion had no effect. Sublingual nitroglycerin increased mid-left anterior descending diameter and reduced mean arterial pressure in controls (+15.2±2.68%; -16.00±1.60%) and in nHD recipients (+14.78±5.46%; -15.82±1.32%); iHD responses were markedly attenuated (+1.9±0.86%; -5.89±1.41%; P<0.05, all comparisons).

CONCLUSIONS

Coronary and systemic vasodilator responsiveness to both adenosine and nitroglycerin is augmented in patients receiving nHD relative to those receiving iHD, whereas vasoconstrictor responsiveness to acetylcholine does not differ. By improving coronary conduit and microvascular function, nHD may reduce the cardiovascular risk of patients on dialysis.

Coronary spasm and vasomotor dysfunction as a cause of MINOCA

Increasing evidence has shown that coronary spasm and vasomotor dysfunction may be the underlying cause in more than half of myocardial infarctions with non-obstructive coronary arteries (MINOCA) as well as an important cause of chronic chest pain in the outpatient setting. We review the contemporary understanding of coronary spasm and related vasomotor dysfunction of the coronary arteries, the pathophysiology and prognosis, and current and emerging approaches to diagnosis and evidence-based treatment.

Case report: Right coronary artery to left ventricular fistula complicated with coronary artery dilation presenting as persistent cardiogenic ischemic chest pain

We reported a patient with a fistula of the right coronary artery to the left ventricle, accompanied by dilation of the right coronary artery and persistent chest pain. This patient underwent surgical fistula closure surgery, but the fistula recurred. Persistent chest pain reappeared after encountering COVID-19 infection. We analyzed the mechanism of persistent myocardial ischemic chest pain caused by coronary artery fistula in this patient, the impact of surgery on the patient's disease, the possible mechanism of COVID-19 causing persistent ischemic chest pain in this patient, and the possible mechanism of metoprolol in alleviating myocardial ischemic chest pain in this patient.

The Role of Polymorphism in the Endothelial Homeostasis and Vitamin D Metabolism Genes in the Severity of Coronary Artery Disease

Coronary artery disease (CAD) remains one of the leading causes of cardiovascular morbidity and mortality worldwide. The maintenance of endothelial homeostasis and vitamin D metabolism play an important role in CAD pathogenesis. This study aimed to determine the association of endothelial homeostasis and vitamin D metabolism gene polymorphism with CAD severity. A total of 224 low-risk patients (SYNTAX score ≤ 31) and 36 high-risk patients (SYNTAX score > 31) were recruited for this study. The serum level of E-, L- and P-selectins; endothelin; eNOS; 25OH; and 1.25-dihydroxy vitamin D was measured using an enzyme-linked immunosorbent assay (ELISA). Polymorphic variants in SELE, SELP, SELPLG, END1, NOS3, VDR and GC were analyzed using a polymerase chain reaction (PCR). We found no differences in the serum levels of the studied markers between high- and low-risk patients. Three polymorphic variants associated with CAD severity were discovered: END1 rs3087459, END1 rs5370 and GC rs2298849 in the log-additive model. Moreover, we discovered a significantly decreased serum level of 1.25-dihydroxy vitamin D in high-risk CAD patients with the A/A-A/G genotypes of the rs2228570 polymorphism of the VDR gene, the A/A genotype of the rs7041 polymorphism of the GC gene and the A/A genotype of the rs2298849 polymorphism of the GC gene.

Endothelin-1 in Health and Disease

Discovered almost 40 years ago, the potent vasoconstrictor peptide endothelin-1 (ET-1) has a wide range of roles both physiologically and pathologically. In recent years, there has been a focus on the contribution of ET-1 to disease. This has led to the development of various ET receptor antagonists, some of which are approved for the treatment of pulmonary arterial hypertension, while clinical trials for other diseases have been numerous yet, for the most part, unsuccessful. However, given the vast physiological impact of ET-1, it is both surprising and disappointing that therapeutics targeting the ET-1 pathway remain limited. Strategies aimed at the pathways influencing the synthesis and release of ET-1 could provide new therapeutic avenues, yet research using cultured cells in vitro has had little follow up in intact ex vivo and in vivo preparations. This article summarises what is currently known about the synthesis, storage and release of ET-1 as well as the role of ET-1 in several diseases including cardiovascular diseases, COVID-19 and chronic pain. Unravelling the ET-1 pathway and identifying therapeutic targets has the potential to treat many diseases whether through disease prevention, slowing disease progression or reversing pathology.

Advances in the study of the vascular protective effects and molecular mechanisms of hawthorn (Crataegus anamesa Sarg.) extracts in cardiovascular diseases

Hawthorn belongs to the rose family and is a type of functional food. It contains various chemicals, including flavonoids, terpenoids, and organic acid compounds. This study aimed to review the vascular protective effects and molecular mechanisms of hawthorn and its extracts on cardiovascular diseases (CVDs). Hawthorn has a wide range of biological functions. Evidence suggests that the active components of HE reduce oxidative stress and inflammation, regulate lipid levels to prevent lipid accumulation, and inhibit free cholesterol accumulation in macrophages and foam cell formation. Additionally, hawthorn extract (HE) can protect vascular endothelial function, regulate endothelial dysfunction, and promote vascular endothelial relaxation. It has also been reported that the effective components of hawthorn can prevent age-related endothelial dysfunction, increase cellular calcium levels, cause antiplatelet aggregation, and promote antithrombosis. In clinical trials, HE has been proved to reduce the adverse effects of CVDs on blood lipids, blood pressure, left ventricular ejection fraction, heart rate, and exercise tolerance. Previous studies have pointed to the benefits of hawthorn and its extracts in treating atherosclerosis and other vascular diseases. Therefore, as both medicine and food, hawthorn can be used as a new drug source for treating cardiovascular diseases.

Microvascular Function, Inflammatory Status, and Oxidative Stress in Post-Bariatric Patients with Weight Regain

Weight loss after bariatric surgery in obesity improves vascular function and metabolic/inflammatory profiles and reduces cardiovascular mortality but there are limited data on the effects of weight regain on vascular health. We compared the metabolic/inflammatory profiles, oxidative status, and vascular function of post-bariatric patients with a high ratio of weight regain (RWR) vs. non-surgical controls. Thirty-two post-bariatric patients [Roux-en-Y gastric bypass; aged = 44 ± 8 years, BMI = 40.1 ± 7.7 kg/m², and RWR = 58.7 ± 24.3%] and thirty controls that were BMI-, age-, and gender-matched entered the study. We collected clinical data, metabolic/inflammatory/oxidative stress circulating biomarkers, and endothelial/microvascular reactivity through Venous occlusion plethysmography and Laser speckle contrast imaging. The bariatric group exhibited lower neck circumference, fasting glucose, and triglycerides than the non-surgical group, while HDL-cholesterol was higher in the bariatric group (p < 0.001). There was no significant difference between groups for endothelial/microvascular reactivities (p ≥ 0.06). Resistin, leptin, endothelin-1, soluble forms of intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1, tumor necrosis factor-α, and thiobarbituric acid reactive substances did not differ significantly between groups (p ≥ 0.09) either. The adiponectin level was higher in the bariatric compared to the non-surgical group, while interleukin-6 was lower in the bariatric group (p < 0.001). Despite the fact that endothelial/microvascular functions were not significantly different between groups, post-bariatric patients present partially preserved metabolic/inflammatory benefits even with high RWR.

Increased endothelin-1 levels in coronary artery disease with diabetes mellitus in an Indonesian population

Diabetes mellitus (DM) increases risk of coronary artery disease (CAD). Endothelin-1 (ET-1) is a potential biomarker of endothelial dysfunction. This study aimed to evaluate ET-1 level in CAD patients and its relationship with DM. The cross-sectional design included subjects with angiographically proven CAD and controls among Indonesian. DM was defined by medical history and anti-diabetics use. Serum ET-1 level was measured in both subject groups. We recruited 305 subjects, 183 CAD patients and 122 controls. CAD subjects had higher percentage of males, DM, hypertension, dyslipidemia, smoking, family history of cardiovascular disease, and obesity. ET-1 level was significantly higher in CAD than in controls (2.44 ± 1.49 pg/mL vs. 1.76 ± 0.83 pg/mL; p < 0.001). Increased ET-1 level was significantly associated with DM and dyslipidemia. The highest ET-1 level was observed in CAD with DM, followed by CAD non-DM (2.79 ± 1.63 pg/mL vs. 2.29 ± 1.40 pg/mL; p = 0.023). Among controls, ET-1 level was the lowest in non-DM subjects. Female CAD had higher proportion of DM; however, ET-1 level was similar to male CAD with DM. In conclusion, an increased ET-1 level was significantly associated with DM in patients with CAD. Further research should investigate the potential role of ET-1 receptor antagonists in the secondary prevention of CAD with DM.

Trans-myocardial Extraction of Endothelin-1 Correlates with Increased Microcirculatory Resistance following Percutaneous Coronary Intervention

Objective. Coronary microvascular dysfunction (CMD) can complicate successful percutaneous coronary intervention (PCI). The potent endogenous vasoconstrictor peptide Endothelin-1 (ET-1) may be an important mediator. To investigate the mechanism, we sought to define the peri-procedural trans-myocardial gradient (TMG-coronary sinus minus aortic root levels) of ET-1 and its precursor peptide – Big ET-1. We then assessed correlation with pressure-wire indices of CMD: coronary flow reserve (CFR) and index of microvascular resistance (IMR). Methods. Paired blood samples from the guide catheter and coronary sinus were collected before and after pressure-wire-guided PCI from patients with stable angina. Plasma was analysed using a specific enzyme-linked immunosorbent assay for quantification of ET-1 peptides and correlated with pressure-wire data. Non normally distributed continuous variables are presented as median [IQR]. Results. ET-1 and Big ET-1 increased post-PCI in the aorta (ET-1: 0.98 [0.76–1.26] pg/ml to 1.20 [1.03–1.67] pg/ml, $P<0.001$ and Big ET-1: 2.74 [1.78–2.50] pg/ml to 3.36 [2.33–3.97] pg/ml, $P<0.001$ ) and coronary sinus (ET-1: 1.00 [0.81–1.28] pg/ml to 1.09 [0.91–1.30] pg/ml, $P=0.03$ and Big ET-1: 2.89 [1.95–3.83] pg/ml to 3.56 [2.66–4.83] pg/ml, $P=0.01$ ). TMG of ET-1 shifted negatively compared with baseline following PCI reflecting significantly increased extraction (0.03 [−0.12–0.17] pg/ml pre-PCI versus −0.16 [−0.36–0.07] pg/ml post-PCI, $P=0.01$ ). Increased ET-1 trans-myocardial extraction correlated with higher IMR (Pearson’s r = 0.293, $P=0.02$ ) and increased hyperemic transit time (Pearson’s r = 0.333, $P<0.01$ ). In subgroup analysis, mean ET-1 trans-myocardial extraction was higher amongst patients with high IMR compared with low IMR (0.73 pg/ml, SD:0.78 versus 0.17 pg/ml, SD:0.42, $P=0.02$ ). There was additionally a numerical trend towards increased ET-1 trans-myocardial extraction in subgroups of patients with low CFR and in patients with Type 4a Myocardial Infarction, albeit not reaching statistical significance. Conclusions. Circulating ET-1 increases post-PCI and upregulated ET-1 trans-myocardial extraction contributes to increased microcirculatory resistance.

ET-1 as a Sex-Specific Mechanism Impacting Age-Related Changes in Vascular Function

Aging is a primary risk factor for cardiovascular disease (CVD), which is the leading cause of death in developed countries. Globally, the population of adults over the age of 60 is expected to double by the year 2050. CVD prevalence and mortality rates differ between men and women as they age in part due to sex-specific mechanisms impacting the biological processes of aging. Measures of vascular function offer key insights into cardiovascular health. Changes in vascular function precede changes in CVD prevalence rates in men and women and with aging. A key mechanism underlying these changes in vascular function is the endothelin (ET) system. Studies have demonstrated sex and sex hormone effects on endothelin-1 (ET-1), and its receptors ETA and ETB. However, with aging there is a dysregulation of this system resulting in an imbalance between vasodilation and vasoconstriction. Thus, ET-1 may play a role in the sex differences observed with vascular aging. While most research has been conducted in pre-clinical animal models, we describe more recent translational data in humans showing that the ET system is an important regulator of vascular dysfunction with aging and acts through sex-specific ET receptor mechanisms. In this review, we present translational evidence (cell, tissue, animal, and human) that the ET system is a key mechanism regulating sex-specific changes in vascular function with aging, along with therapeutic interventions to reduce ET-mediated vascular dysfunction associated with aging. More knowledge on the factors responsible for the sex differences with vascular aging allow for optimized therapeutic strategies to attenuate CVD risk in the expanding aging population.

Endothelin-1 is increased in the plasma of patients hospitalised with Covid-19

Virus induced endothelial dysregulation is a well-recognised feature of severe Covid-19 infection. Endothelin-1 (ET-1) is the most highly expressed peptide in endothelial cells and a potent vasoconstrictor, thus representing a potential therapeutic target. ET-1 plasma levels were measured in a cohort of 194 Covid-19 patients stratified according to the clinical severity of their illness. Hospitalised patients, including those who died and those developing acute myocardial or kidney injury, had significantly elevated ET-1 plasma levels during the acute phase of infection. The results support the hypothesis that endothelin receptor antagonists may provide clinical benefit for certain Covid-19 patients.

Curcumin improves the function of umbilical vein endothelial cells by inhibiting H2O2‑induced pyroptosis

Endothelial cell (EC) dysfunction is one of the initiating factors of atherosclerosis. EC dysfunction is primarily caused by oxidative damage and inflammation. As a classic non-specific antioxidant and anti-inflammatory drug, curcumin has been widely used in studies of lipid metabolism disorders. However, whether curcumin is able to alleviate H₂O₂-induced EC damage and its related mechanisms has remained to be elucidated. The present study confirmed the protective effects of curcumin on human umbilical vein endothelial cells (HUVECs). A HUVEC injury model was established using H₂O₂ and the optimal concentrations and time of curcumin to achieve therapeutic effects were explored. Curcumin was observed to inhibit H₂O₂-induced pyroptosis by inhibiting the activation of NOD-, LRR- and pyrin domain-containing protein 3. In addition, curcumin improved HUVEC function by restoring αvβ3 and reducing endothelin-1 expression. In conclusion, the results of the present study revealed the mechanism through which curcumin inhibits pyroptosis and indicated that curcumin may have a potential utility in treating diseases of EC dysfunction.

Preclinical atherosclerosis and cardiovascular events: Do we have a consensus about the role of preclinical atherosclerosis in the prediction of cardiovascular events?

Atherosclerosis has a long preclinical phase, and the risk of cardiovascular (CV) events may be high in asymptomatic subjects. Conventional risk factors provide information for the statistical probability of developing CV events, but they lack precision in asymptomatic subjects. This review aims to summarize the role of some widely publicized indicators of early atherosclerosis in predicting CV events. The earliest measurable indicator of the atherosclerotic process is endothelial dysfunction, measured by flow-mediated dilation (FMD) of the brachial artery. However, reduced FMD is a stronger predictor of future CV events in patients with existing CV disease than in apparently healthy persons. Alternatively, measurement of carotid artery intima-media thickness does not improve the predictive value of risk factor scores, while detection of asymptomatic atherosclerotic plaques in carotid or common femoral arteries by ultrasound indicates high CV risk. Coronary calcium is a robust and validated help in the estimation of vascular changes and risk, which may improve risk stratification beyond traditional risk factors with relatively low radiation exposure. Arterial stiffness of the aorta, measured as the carotid-femoral pulse wave velocity is an independent marker of CV risk at the population level, but it is not recommended as a routine procedure because of measurement difficulties. Low ankle-brachial index (ABI) indicates flow-limiting atherosclerosis in the lower limbs and indicates high CV risk, while normal ABI does not rule out advanced asymptomatic atherosclerosis. Novel circulating biomarkers are associated with the atherosclerotic process. However, because of limited specificity, their ability to improve risk classification at present remains low.

New Insights in Early Detection of Anticancer Drug-Related Cardiotoxicity Using Perfusion and Metabolic Imaging

Cardio-oncology requires a good knowledge of the cardiotoxicity of anticancer drugs, their mechanisms, and their diagnosis for better management. Anthracyclines, anti-vascular endothelial growth factor (VEGF), alkylating agents, antimetabolites, anti-human epidermal growth factor receptor (HER), and receptor tyrosine kinase inhibitors (RTKi) are therapeutics whose cardiotoxicity involves several mechanisms at the cellular and subcellular levels. Current guidelines for anticancer drugs cardiotoxicity are essentially based on monitoring left ventricle ejection fraction (LVEF). However, knowledge of microvascular and metabolic dysfunction allows for better imaging assessment before overt LVEF impairment. Early detection of anticancer drug-related cardiotoxicity would therefore advance the prevention and patient care. In this review, we provide a comprehensive overview of the cardiotoxic effects of anticancer drugs and describe myocardial perfusion, metabolic, and mitochondrial function imaging approaches to detect them before over LVEF impairment.

Ischemia and no obstructive coronary arteries in patients with stable ischemic heart disease

A large proportion of patients with suspected obstructive coronary artery disease (CAD) is found to have ischemia with no obstructive coronary artery disease (INOCA). Based on current evidence, these patients are at increased risk of adverse cardiovascular events, even though they have no obstructive CAD. Importantly, INOCA is associated with recurrent clinical presentations with chest pain, impaired functional capacity, reduced health-related quality of life, and high healthcare costs. Underlying coronary microvascular dysfunction (CMD), through endothelium-dependent and independent mechanisms contribute to these adverse outcomes in INOCA. While non-invasive and invasive diagnostic testing has typically focused on identification of obstructive CAD in symptomatic patients, functional testing to detect coronary epicardial and microvascular dysfunction should be considered in those with INOCA who have persistent angina. Current diagnostic methods to clarify functional abnormalities and treatment strategies for epicardial and/or microvascular dysfunction in INOCA are reviewed.

Evaluation of efficacy and safety of improved transurethral plasma kinetic enucleation of the prostate in high-risk patients with benign prostatic hyperplasia and coronary artery disease

OBJECTIVE

This prospective study aimed to evaluate the safety of improved transurethral plasma kinetic enucleation of the prostate (iTUPKEP) in the perioperative period in high-risk patients with benign prostatic hyperplasia (BPH) and coronary artery disease.

METHODS

Patients with BPH underwent surgical treatment with transurethral vapour resection of the prostate (TUVP) or iTUPKEP. Serum endothelin-1, cardiac troponin-I, and high-sensitivity C-reactive protein concentrations were evaluated in the short term after surgery. The postvoid residual urine volume, maximum urinary flow rate, international prostate symptom score, and quality of life indicators were evaluated in the long term after surgery.

RESULTS

Endothelin-1 concentrations were lower in the iTUPKEP group than in the TUVP group at 1 and 2 days postoperatively. The iTUPKEP group had lower cardiac troponin-I and high-sensitivity C-reactive protein concentrations at all time points postoperatively. The postvoid residual urine volume, international prostate symptom score, and quality of life values were lower, but the maximum urinary flow rate was higher, in the iTUPKEP group than in the TUVP group.

CONCLUSIONS

The iTUPKEP procedure has a smaller effect on vascular endothelial function compared with TUVP. Therefore, iTUPKEP may reduce the incidence of postoperative cardiovascular adverse events in high-risk patients with BPH and coronary artery disease.

Machine learning aids clinical decision-making in patients presenting with angina and non-obstructive coronary artery disease

Aims

The current gold standard comprehensive assessment of coronary microvascular dysfunction (CMD) is through a limited-access invasive catheterization lab procedure. We aimed to develop a point-of-care tool to assist clinical guidance in patients presenting with chest pain and/or an abnormal cardiac functional stress test and with non-obstructive coronary artery disease (NOCAD).

Methods and results

This study included 1893 NOCAD patients (<50% angiographic stenosis) who underwent CMD evaluation as well as an electrocardiogram (ECG) up to 1-year prior. Endothelial-independent CMD was defined by coronary flow reserve (CFR) ≤2.5 in response to intracoronary adenosine. Endothelial-dependent CMD was defined by a maximal percent increase in coronary blood flow (%ΔCBF) ≤50% in response to intracoronary acetylcholine infusion. We trained algorithms to distinguish between the following outcomes: CFR ≤2.5, %ΔCBF ≤50, and the combination of both. Two classes of algorithms were trained, one depending on ECG waveforms as input, and another using tabular clinical data. Mean age was 51 ± 12 years and 66% were females (n = 1257). Area under the curve values ranged from 0.49 to 0.67 for all the outcomes. The best performance in our analysis was for the outcome CFR ≤2.5 with clinical variables. Area under the curve and accuracy were 0.67% and 60%. When decreasing the threshold of positivity, sensitivity and negative predictive value increased to 92% and 90%, respectively, while specificity and positive predictive value decreased to 25% and 29%, respectively.

Conclusion

An artificial intelligence-enabled algorithm may be able to assist clinical guidance by ruling out CMD in patients presenting with chest pain and/or an abnormal functional stress test. This algorithm needs to be prospectively validated in different cohorts.

The Causal Relationship between Endothelin-1 and Hypertension: Focusing on Endothelial Dysfunction, Arterial Stiffness, Vascular Remodeling, and Blood Pressure Regulation

Hypertension (HTN) is one of the most prevalent diseases worldwide and is among the most important risk factors for cardiovascular and cerebrovascular complications. It is currently thought to be the result of disturbances in a number of neural, renal, hormonal, and vascular mechanisms regulating blood pressure (BP), so crucial importance is given to the imbalance of a number of vasoactive factors produced by the endothelium. Decreased nitric oxide production and increased production of endothelin-1 (ET-1) in the vascular wall may promote oxidative stress and low-grade inflammation, with the development of endothelial dysfunction (ED) and increased vasoconstrictor activity. Increased ET-1 production can contribute to arterial aging and the development of atherosclerotic changes, which are associated with increased arterial stiffness and manifestation of isolated systolic HTN. In addition, ET-1 is involved in the complex regulation of BP through synergistic interactions with angiotensin II, regulates the production of catecholamines and sympathetic activity, affects renal hemodynamics and water–salt balance, and regulates baroreceptor activity and myocardial contractility. This review focuses on the relationship between ET-1 and HTN and in particular on the key role of ET-1 in the pathogenesis of ED, arterial structural changes, and impaired vascular regulation of BP. The information presented includes basic concepts on the role of ET-1 in the pathogenesis of HTN without going into detailed analyses, which allows it to be used by a wide range of specialists. Also, the main pathological processes and mechanisms are richly illustrated for better understanding.

Untangling the pathophysiologic link between coronary microvascular dysfunction and heart failure with preserved ejection fraction

Coronary microvascular disease (CMD), characterized by impaired coronary flow reserve (CFR), is a common finding in patients with stable angina. Impaired CFR, in the absence of obstructive coronary artery disease, is also present in up to 75% of patients with heart failure with preserved ejection fraction (HFpEF). Heart failure with preserved ejection fraction is a heterogeneous syndrome comprising distinct endotypes and it has been hypothesized that CMD lies at the centre of the pathogenesis of one such entity: the CMD–HFpEF endotype. This article provides a contemporary review of the pathophysiology underlying CMD, with a focus on the mechanistic link between CMD and HFpEF. We discuss the central role played by subendocardial ischaemia and impaired lusitropy in the development of CMD–HFpEF, as well as the clinical and research implications of the CMD–HFpEF mechanistic link. Future prospective follow-up studies detailing outcomes in patients with CMD and HFpEF are much needed to enhance our understanding of the pathological processes driving these conditions, which may lead to the development of physiology-stratified therapy to improve the quality of life and prognosis in these patients.

Endothelial Dysfunction and Its Clinical Implications

Endothelial dysfunction (ED) plays a substantial role in the pathogenesis of atherosclerosis and some other vascular diseases. ED has been demonstrated in patients with hypercholesterolemia, diabetes, smoking, hypertension, and in patients with atherosclerotic disease. Besides classical risk factors, ED is affected by chronic inflammatory diseases and acute infections, particularly viral diseases. Causes of ED include oxidative stress, inflammation, and shear stress, which decrease the bioavailability of nitric oxide. Markers of ED have been sought, particularly circulating markers. Using these tests, it is possible to evaluate the response to harmful effects of risk factors and the effects of treatment on vessel wall function. Endothelial dysfunction is significantly and directly correlated with the occurrence of cardiac events and the risk of cardiac events increase as ED worsens. Because endothelial function plays a central role in atherogenesis it became a therapeutic target. Endothelial dysfunction is reversible and its improvement may be achieved by elimination of risk factors, inhibitors of endothelium-derived contracting factors (angiotensin-converting enzyme), smoking cessation, lipid-lowering drugs, diet, and physical exercise. By reversing ED, it is possible to restore vascular function.

Recurrent versus new-onset depressive symptoms: Relationships with biomarkers of cardiovascular health following acute coronary syndrome

OBJECTIVE

New-onset depressive symptoms commonly arise among persons without a history of major depressive disorder (MDD) in the setting of acute medical illness. Although depressive symptoms in general are associated with alterations in prognostic biomarkers following acute coronary syndrome (ACS), the nature of specifically new-onset depressive symptoms is less well-characterized. It is unclear whether such symptoms neurobiologically resemble recurrent symptoms of MDD or instead represent a distinct condition. In this exploratory analysis, we aimed to examine the effects of prior MDD history on the relationships between post-ACS depressive symptoms and cardiovascular biomarkers.

METHODS

One-hundred sixty-four participants attended study visits 2 weeks and 6 months after ACS to complete self-report measures and provide biomarker samples. MDD history was identified by a psychiatrist through systematic electronic medical record review. Generalized estimating equations were performed to examine the moderating effects of MDD history on concurrent relationships between depressive symptoms and several biomarkers (endothelin-1, soluble intercellular adhesion molecule-1, high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-alpha).

RESULTS

Twenty percent (n = 33) of participants had a history of MDD. Depressive symptoms were more strongly associated with levels of endothelin-1 in patients with prior MDD compared to those without (B = 0.024, 95% CI [0.005, 0.043], p = .012), adjusting for age, sex, medical factors, and anxiety. MDD history did not moderate relationships between depressive symptoms and other biomarkers.

CONCLUSION

Recurrent post-ACS depressive symptoms are more strongly associated with elevated endothelin-1 levels than new-onset symptoms. Further work is needed to clarify the mechanism and clinical implications of this relationship.

Genetic dysregulation of endothelin-1 is implicated in coronary microvascular dysfunction

AIMS

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide linked to vascular diseases through a common intronic gene enhancer [(rs9349379-G allele), chromosome 6 (PHACTR1/EDN1)]. We performed a multimodality investigation into the role of ET-1 and this gene variant in the pathogenesis of coronary microvascular dysfunction (CMD) in patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (CAD).

METHODS AND RESULTS

Three hundred and ninety-one patients with angina were enrolled. Of these, 206 (53%) with obstructive CAD were excluded leaving 185 (47%) eligible. One hundred and nine (72%) of 151 subjects who underwent invasive testing had objective evidence of CMD (COVADIS criteria). rs9349379-G allele frequency was greater than in contemporary reference genome bank control subjects [allele frequency 46% (129/280 alleles) vs. 39% (5551/14380); P = 0.013]. The G allele was associated with higher plasma serum ET-1 [least squares mean 1.59 pg/mL vs. 1.28 pg/mL; 95% confidence interval (CI) 0.10-0.53; P = 0.005]. Patients with rs9349379-G allele had over double the odds of CMD [odds ratio (OR) 2.33, 95% CI 1.10-4.96; P = 0.027]. Multimodality non-invasive testing confirmed the G allele was associated with linked impairments in myocardial perfusion on stress cardiac magnetic resonance imaging at 1.5 T (N = 107; GG 56%, AG 43%, AA 31%, P = 0.042) and exercise testing (N = 87; -3.0 units in Duke Exercise Treadmill Score; -5.8 to -0.1; P = 0.045). Endothelin-1 related vascular mechanisms were assessed ex vivo using wire myography with endothelin A receptor (ETA) antagonists including zibotentan. Subjects with rs9349379-G allele had preserved peripheral small vessel reactivity to ET-1 with high affinity of ETA antagonists. Zibotentan reversed ET-1-induced vasoconstriction independently of G allele status.

CONCLUSION

We identify a novel genetic risk locus for CMD. These findings implicate ET-1 dysregulation and support the possibility of precision medicine using genetics to target oral ETA antagonist therapy in patients with microvascular angina.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03193294.

Phytosterols Supplementation Reduces Endothelin-1 Plasma Concentration in Moderately Hypercholesterolemic Individuals Independently of Their Cholesterol-Lowering Properties

Experimental and clinical studies have demonstrated the effect of phytosterols (PS) on reducing plasma levels of cholesterol and LDL-c, but the effects of plant sterols beyond cholesterol-lowering are still questionable. Since inflammation and endothelial dysfunction are involved in the pathogenesis of atherosclerosis, this study aims to evaluate the effect of PS on biomarkers involved in atherosclerosis progression and whether these effects are independent of alterations in plasma LDL-c levels. Thirty-eight moderately hypercholesterolemic volunteers (58 ± 12 years; LDL-c ≥ 130 mg/dL) were randomly assigned to consume 400 mL/day of soy milk or soy milk + PS (1.6 g/day) for 4 weeks in a double-blind, placebo-controlled, cross-over study. Blood samples were collected and lipid profiles and biomarkers for inflammation and endothelial dysfunction determined. The results showed that PS treatment reduced endothelin-1 plasma concentration by 11% (p = 0.02) independently of variations in plasma levels of LDL-c. No alterations were observed regarding fibrinogen, IL-6, hs-CRP, SAA, TNFα, or VCAM-1 between placebo and PS-treated groups. Furthermore, PS reduced total plasma cholesterol concentration (−5,5%, p < 0.001), LDL-c (−6.4%, p < 0.05), triglycerides (−8.3%, p < 0.05), and apo B (−5.3%, p < 0.05), without changing HDL-c concentration (p > 0.05). Therefore, PS supplementation effectively lowers endothelin-1 independently of the reductions in plasma levels of LDL-c, contributing to the comprehension of the effect of plant sterols on endothelial function and prevention of cardiovascular diseases.

Endothelin-1-induced endothelial microvesicles impair endothelial cell function

The aim of this study was to determine the effects of endothelin-1 (ET-1)-generated endothelial microvesicles (EMVs) on endothelial cell inflammation, apoptosis, and endothelial nitric oxide synthase (eNOS). Human umbilical vein endothelial cells (HUVECs) were treated with ET-1 for 24 h. EMVs released into the supernatant from cells treated with ET-1 or vehicle were isolated and quantified. EMV release was higher (P < 0.05) in cells treated with ET-1 compared with control (95 ± 15 vs. 54 ± 5 EMV/µL). Fresh HUVECs were then treated with either ET-1, ET-1-induced EMVs, or control EMVs for 24 h. ET-1-generated EMVs induced significantly higher release of IL-6 (181.0 ± 16.0 vs. 132.1 ± 8.1 pg/mL) and IL-8 (303.4 ± 37.4 vs. 211.8 ± 10.0 pg/mL), as well as greater total NF-κB p65 (76.0 ± 7.6 vs. 57.1 ± 2.1 AU) and active NF-κB p65 (Ser-536) (11.6 ± 0.9 vs. 6.8 ± 1.0 AU) expression than control EMVs. There were no significant differences in expression of caspase-9 (230.1 ± 24.3 vs. 243.6 ± 22.3 AU), caspase-3 (271.9 ± 22.7 vs. 265.1 ± 30.5 AU), and active caspase-3 (4.4 ± 0.4 vs. 4.3 ± 0.1 AU) in cells treated with ET-1-EMVs versus control EMVs. Total eNOS (108.4 ± 11.4 vs. 158.8 ± 1.6 AU) and activated eNOS (4.7 ± 0.5 vs. 9.6 ± 1.4 AU) were significantly lower in endothelial cells treated with ET-1-generated EMVs compared with control EMVs. The effects of ET-1-generated EMVs on cellular markers and mediators of endothelial inflammation, as well as eNOS function, was comparable to the effects of ET-1. In summary, ET-1 induces an EMV phenotype that adversely affects endothelial cell function. ET-1-generated EMVs may contribute to the atherogenic effect of ET-1.NEW & NOTEWORTHY Endothelin-1 (ET-1) is a potent vasoconstrictor peptide released by the endothelium that contributes to the regulation of vascular tone. Overexpression of ET-1 has been implicated in the etiology of atherosclerotic vascular disease. Endothelial cell-derived microvesicles (EMVs) play a pivotal role in vascular health and disease. Their functional phenotype is largely dictated by the stimulus for release. EMVs released in response to various pathological conditions have been shown to elicit deleterious vascular effects. In the present study, we determined, in vitro, the effect of ET-1 on EMV release from endothelial cells and the effects of ET-1-generated EMVs on endothelial cell inflammation, apoptosis, and endothelial nitric oxide synthase (eNOS). ET-1 induced a marked increase in EMV release. ET-1-generated EMVs significantly increased endothelial cell inflammation and reduced eNOS protein expression and activation. Moreover, the endothelial effects of ET-1-derived EMVs were similar to the direct effects of ET-1. ET-1-generated EMVs may contribute to the proatherogenic profile of ET-1.

Coronary Artery Spasm: The Interplay Between Endothelial Dysfunction and Vascular Smooth Muscle Cell Hyperreactivity

Patients with angina pectoris, the cardinal symptom of myocardial ischaemia, yet without significant flow-limiting epicardial artery stenosis represent a diagnostic and therapeutic challenge. Coronary artery spasm (CAS) is an established cause for anginal chest pain in patients with angiographically unobstructed coronary arteries. CAS may occur at the epicardial level and/or in the microvasculature. Although the underlying pathophysiological mechanisms of CAS are still largely unclear, endothelial dysfunction and vascular smooth muscle cell (VSMC) hyperreactivity seem to be involved as major players, although their contribution to induce CAS is still seen as controversial. This article will look at the role and possible mechanistic interplay between an impaired endothelial and VSMC function in the pathogenesis of CAS.

Knockdown of Long Noncoding RNA (lncRNA) AK094457 Relieved Angiotensin II Induced Vascular Endothelial Cell Injury

Background

Hypertension could induce many serious diseases, including damage to vascular endothelial cells. As a non-coding RNA, long noncoding RNA (lncRNA) has received much attention in scientific research and has a regulating efficacy on many critical life activities in human body. The level of lncRNA AK094457 is thought to be elevated in hypertensive rats. However, there is no research indicating the relationship between the level of lncRNA AK094457 and vascular endothelial injury.

Material/Methods

In our study, we used lentiviral to knockdown lncRNA AK094457, and the human umbilical vein endothelial cells (HUVECs) were stimulated by the Ang II to imitate the vascular endothelial cell damage caused by hypertension. The Cell Counting Kit-8 assays were used to detect the cells viability. Western blotting was performed to detect the endothelial nitric oxide synthase (eNOS), p-eNOS and endothelin-1 (ET-1). After that the production of the NO was monitored. At last, the reactive oxygen species (ROS) levels and apoptosis rates were detected in this study.

Results

According to the results, we found that knockdown lncRNA AK094457 could alleviate the decrease of vascular endothelial cell viability induced by angiotensin II (Ang II). The knockdown of lncRNA AK094457 also relieved the downregulation of eNOS and p-eNOS, and the decreasing of NO release. At the same time, the knockdown of lncRNA inhibited the levels of Ang II-induced proinflammatory cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-1, and IL-6) and cell adhesion molecules (vascular cell adhesion molecule 1 [VCAM-1], intercellular adhesion molecule 1 [ICAM-1], and monocyte chemoattractant protein-1 [MCP-1]). The levels of ROS and apoptosis rates also decreased after the knockdown of lncRNA AK094457.

Conclusions

All these results indicated that lncRNA AK094457 could promote Ang II-induced vascular endothelial cell injury. On the contrary, knockdown of lncRNA AK094457 could alleviate this damage.

Quality of life of patients with central serous chorioretinopathy - a major cause of vision threat among middle-aged individuals

INTRODUCTION

The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was designed to measure the vision-related quality of life (QoL). We aimed to assess the effect of disease duration, disease type (i.e., acute vs. chronic and unilateral vs. bilateral), and selected sociodemographic data on the QoL of patients with central serous chorioretinopathy (CSC).

MATERIAL AND METHODS

The study included 79 patients diagnosed with CSC. The QoL was assessed using the NEI VFQ-25. The statistical analysis was performed using IBM SPSS Statistics 24.

RESULTS

A significant positive correlation was found between deterioration in peripheral vision as assessed by the NEI VFQ-25 and duration of CSC (r = -0.22, p = 0.046). Compared with women, men obtained higher scores on the scales assessing general health, mental health, ocular pain and role limitations (p = 0.018, p = 0.027, p = 0.009 and p = 0.007, respectively). Patients with acute CSC reported higher levels of social functioning as compared with those with chronic CSC (p = 0.04). There were no differences in any of the scales between patients with unilateral and bilateral CSC. Elderly patients obtained lower scores on 9 of the 12 analyzed scales, as compared with younger patients (p < 0.05).

CONCLUSIONS

Patients with CSC do not assess their QoL in negative terms, which may be related to the fact that the disease presents with transient symptoms. However, the QoL deteriorated with longer disease duration. Men with CSC have better vision-related QoL than women.

Peripheral Vasoconstriction During Mental Stress and Adverse Cardiovascular Outcomes in Patients With Coronary Artery Disease

RATIONALE

Excessive vasoconstriction in response to mental stress may be a potential mechanism by which acute psychological stress leads to adverse cardiac events.

OBJECTIVES

We investigated whether excessive digital vasoconstriction during acute mental stress predicts adverse cardiovascular outcomes among patients with coronary artery disease.

METHODS AND RESULTS

Five hundred forty-nine patients with stable coronary artery disease (age 63±9, 76% male, 29% black) underwent mental stress testing with a standardized public speaking stressor and followed prospectively for cardiovascular end points. Digital pulse wave amplitude was continuously measured using peripheral artery tonometry (PAT, Itamar Inc). Stress/rest PAT ratio (sPAT) of pulse wave amplitude during mental stress/baseline was calculated and dichotomized by the median value into low and high sPAT ratio groups. Upon 3-year follow-up, Fine and Gray's subdistribution hazard ratios were used to examine the association between sPAT ratio and the composite end point of cardiovascular death, myocardial infarction, revascularization, and hospitalization for heart failure. The median sPAT ratio was 0.68 (interquartile range, 0.48-0.88), indicating 32% vasoconstriction with mental stress. Men were more likely to have low sPAT ratio than women (odds ratio, 1.79; P=0.007) while those on β-blockers were less likely to have low sPAT ratio (odds ratio, 0.52; P=0.003). After adjusting for demographic and cardiovascular risk factors, medications, and rate-pressure product change during mental stress, those with low sPAT ratio were at significantly higher risk of adverse outcomes (subdistribution hazard ratio, 1.77 [95% CI, 1.12-2.80]).

CONCLUSIONS

Greater peripheral vasoconstriction with mental stress, denoted by a low sPAT ratio, is associated with a higher risk of adverse cardiovascular outcomes in patients with coronary artery disease.

The association of endothelin-1 gene polymorphism and its plasma levels with hypertension and coronary atherosclerosis

INTRODUCTION

Endothelin-1 (ET-1) is the most potent among all vasoconstrictors, and its association with cardiovascular diseases has been reported before. Our aim was to investigate the association of ET-1 plasma level and its gene polymorphisms (rs5370 and rs10478694) with hypertension and coronary atherosclerosis (CA).

MATERIAL AND METHODS

This study was carried out on 128 women and 132 men, who were divided into 4 groups: hypertensive without atherosclerosis (H+A-); hypertensive with atherosclerosis (H+A+); non-hypertensive with atherosclerosis (H-A+); and non-hypertensive without atherosclerosis (control group). Endothelin-1 plasma levels were measured by ELISA, and gene polymorphisms were detected by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) methods. Coronary artery diseases (CAD) were then defined based on angiography data.

RESULTS

The ET-1 plasma level was significantly higher in the H+A+ group in comparison with the other groups, especially H+A-. Comparing people with CA and those without it, the highest frequency level of the T allele of rs5370 was found in people with CA. Significantly higher frequencies of the 3A allele were detected in hypertensive patients in comparison with non-hypertensive individuals, when analyzing rs10478694.

CONCLUSIONS

Endothelin-1 plasma level shows a direct association with the risk of CA development. The T allele of rs5370 can be regarded as a risk factor for CA development. The 3A allele of rs10478694 can be associated with the risk of hypertension; therefore, it can be concluded that ET-1 and its gene polymorphisms play an important role in CA development and hypertension observed in the south-eastern populations of Iran.

Strong Relationship Between Vascular Function in the Coronary and Brachial Arteries

Early detection of coronary artery dysfunction is of paramount cardiovascular clinical importance, but a noninvasive assessment is lacking. Indeed, the brachial artery flow-mediated dilation test only weakly correlated with acetylcholine-induced coronary artery function ( r=0.36). However, brachial artery flow-mediated dilation methodologies have, over time, substantially improved. This study sought to determine if updates to this technique have improved the relationship with coronary artery function and the noninvasive indication of coronary artery dysfunction. Coronary artery and brachial artery function were assessed in 28 patients referred for cardiac catheterization (61±11 years). Coronary artery function was determined by the change in artery diameter with a 1.82 μg/min intracoronary acetylcholine infusion. Based on the change in vessel diameter, patients were characterized as having dysfunctional coronary arteries (>5% vasoconstriction) or relatively functional coronary arteries (<5% vasoconstriction). Brachial artery function was determined by flow-mediated dilation, adhering to current guidelines. The acetylcholine-induced change in vessel diameter was smaller in patients with dysfunctional compared with relatively functional coronary arteries (-11.8±4.6% versus 5.8±9.8%, P<0.001). Consistent with this, brachial artery flow-mediated dilation was attenuated in patients with dysfunctional compared with relatively functional coronaries (2.9±1.9% versus 6.2±4.2%, P=0.007). Brachial artery flow-mediated dilation was strongly correlated with the acetylcholine-induced change in coronary artery diameter ( r=0.77, P<0.0001) and was a strong indicator of coronary artery dysfunction (receiver operator characteristic=78%). The current data support that updates to the brachial artery flow-mediated dilation technique have strengthened the relationship with coronary artery function, which may now provide a clinically meaningful indication of coronary artery dysfunction.

Association between circulating big endothelin-1 and noncalcified or mixed coronary atherosclerotic plaques

Background

Noncalcified plaques (NCPs) and mixed plaques (MPs) are considered as the high-risk coronary plaques. Endothelin-1 (ET-1) is a vasoactive peptide and shows a high expression in vulnerable plaque. The aim of this study is to investigate the relationship between the bigET-1, the precursor of ET-1, and NCPs/MPs in a Chinese population.

Methods and results

A total of 513 patients with chest pain and suspected coronary artery disease were collected and divided into three groups with no plaques, calcified plaques, or NCPs/MPs according to the characteristics of all the plaques. It demonstrated that NCPs/MPs were associated with elevated bigET-1 (P < 0.001). Moreover, the proportion of NCPs/MPs was significantly increased from 43.3% in bigET-1 tertile 1 to 61.0% in tertile 3 group (P = 0.001). Multiple logistic regression analysis further showed that bigET-1 was an independent predictor for the presence of NCPs/MPs (odds ratio = 1.858; 95% confidence interval: 1.017–3.394; P = 0.044).

Conclusion

The bigET-1 could be an independent predictor for the presence of NCPs/MPs.

Noncalcified plaques (NCPs) and mixed plaques (MPs) are considered as the high risk coronary plaques. Endothelin- 1(ET-1) is a vasoactive peptide and shows a high expression in vulnerable plaque. However, the relationship between circulating ET-1 and NCPs/MPs is still an unanswered question. In the present study, we found that NCPs and MPs were associated with elevated plasma bigET-1, the precursor of ET-1. The patients with NCPs and MPs had significantly elevated bigET-1, compared to those without coronary plaque or those have calcified plaques. Multiple logistic regression analysis further showed that bigET-1 was an independent predictor for the presence of NCPs/MPs. The finding highlights the potential value of this assay in predicting the characteristics of plaques in patients with suspected or known coronary artery disease.

Plasma endothelin-1 and adrenomedullin are associated with coronary artery function and cardiovascular outcomes in humans

BACKGROUND

Endothelin-1 (ET-1) is a vasoconstrictor associated with cardiovascular disease, whereas adrenomedullin (ADM) is a vasorelaxant with cardioprotective properties. We sought to determine the relationship between plasma ET-1 and ADM with coronary circulatory function and long-term major adverse cardiovascular events (MACE).

METHODS

Thirty-two patients undergoing coronary angiography for chest pain were recruited. Baseline plasma ET-1 and ADM levels were measured. The index of microcirculatory resistance (IMR), coronary flow mediated dilatation (cFMD) and coronary flow reserve (CFR) were measured in a non-obstructed coronary artery. Patients were assessed for MACE over a median period of 8.8 years.

RESULTS

Plasma ET-1 levels correlated with IMR (r = 0.57; p < 0.01) and ADM levels correlated with CFR (r = 0.50; p = 0.04) and cFMD (r = 0.62; p = 0.01). After adjustment for age, gender and cardiovascular risk factors, the association between ADM and cFMD (β = 0.79; p < 0.01) and between ET-1 and IMR (β = 5.7; p = 0.01) remained significant. IMR was higher, although not statistically significant, in patients with long-term MACE (17.9 ± 5.3 vs. 13.1 ± 6.0 units; p = 0.14). In patients free of MACE, cFMD (9.3 ± 7.6 vs. 2.8 ± 5.0%; p = 0.01) and plasma ADM levels (7.6 ± 5.3 vs. 4.0 ± 1.9 pmol/L; p = 0.07) were higher.

CONCLUSIONS

Plasma ET-1 and ADM were associated with measures of coronary microvascular and coronary conduit vessel function, respectively. Increased cFMD and elevated plasma ADM were associated with a cardioprotective effect.

Coronary microvascular dysfunction is associated with poor glycemic control amongst female diabetics with chest pain and non-obstructive coronary artery disease

Background

Patients with type 2 diabetes mellitus are at an increased risk of adverse cardiovascular events compared to those without diabetes. The timing, relative to disease onset, and degree of glycemic control that reduces the risk of adverse cardiovascular events remains uncertain. Coronary microvascular dysfunction is prevalent in patients with type 2 diabetes mellitus and is linked to adverse cardiovascular events. We assessed the association between endothelial-dependent and endothelial-independent coronary microvascular dysfunction and glycemic control in patients presenting with chest pain and nonobstructive coronary disease at angiography.

Methods

Patients presenting with chest pain and found to have non-obstructive CAD (stenosis < 40%) at angiography underwent an invasive assessment of endothelial-independent and endothelial –dependent microvascular function. Endothelial-independent microvascular function was assessed by comparing the coronary flow velocity, measured using a Doppler guidewire, in response to intracoronary infusion of adenosine to calculate the coronary flow reserve ratio in response to adenosine (CFRAdn Ratio). A CFRAdn Ratio ≤ 2.5 was considered abnormal. Endothelial-dependent microvascular function was assessed by measuring the percent change in coronary blood flow in response to intracoronary infusions of acetylcholine (%ΔCBFAch), and microvascular endothelial dysfunction defined as a %ΔCBFAch of ≤ 50%. Patients were classified by normal versus abnormal CFRAdn Ratio and %ΔCBFAch. Measurements of HbA1c and fasting serum glucose were obtained prior to catheterization and compared between groups.

Results

Between 1993 and 2012, 1469 patients (mean age 50.4 years, 35% male) underwent coronary angiography and invasive testing for coronary microvascular dysfunction, of which 129 (8.8%) had type 2 diabetes. Fifty-one (39.5%) had an abnormal %ΔCBFAch and 49 (38.0%) had an abnormal CFRAdn Ratio. Conventional cardiovascular risk factors and cardiovascular or diabetic medication use did not vary significantly between groups. Females with an abnormal CFRAdn Ratio or abnormal %ΔCBFAch had a significantly higher HbA1c compared to patients with a normal CFRAdn Ratio or %ΔCBFAch respectively: HbA1c % (standard deviation) 7.4 (2.1) vs. 6.5 (1.1), p = 0.035 and 7.3 (1.9) vs. 6.4 (1.2), p = 0.022, respectively. Female patients with an abnormal CFRAdn Ratio had significantly higher fasting serum glucose concentrations compared to those with a normal CFRAdn Ratio: fasting serum glucose mg/dL (standard deviation) 144.4 (55.6) vs. 121.9 (28.1), p = 0.035. This was not observed in men. Amongst female diabetics, a higher HbA1c was significantly associated with any coronary microvascular dysfunction both in a univariate and multivariate analysis: odds ratio (95% confidence interval) 1.69 (1.01–2.86) p = 0.049; and a fasting serum glucose > 140 mg/dL was significantly associated with an abnormal CFRAdn Ratio, 4.28 (1.43–12.81).

Conclusion

Poor glycemic control is associated with coronary microvascular dysfunction amongst female diabetics presenting with chest pain and non-obstructive CAD. These findings highlight the importance of sex specific risk stratification models and treatment strategies when managing cardiovascular risk amongst diabetics. Further studies are required to identify additional risk prevention tools and therapies targeting microvascular dysfunction as an integrated index of cardiovascular risk.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0833-1) contains supplementary material, which is available to authorized users.

Coronary endothelial function testing may improve long-term quality of life in subjects with microvascular coronary endothelial dysfunction

Aim

Angina pectoris in the absence of obstructive coronary artery disease (CAD) is common and is associated with poor quality of life (QOL). Coronary microvascular endothelial dysfunction is associated with myocardial ischaemia and is a common cause of angina. We hypothesise that evaluation of coronary endothelial function, its diagnosis and treatment will favourably impact QOL in patients with angina symptoms and non-obstructive CAD.

Methods and results

Follow-up was done on 457 patients with chest pain and non-obstructive coronary arteries who had undergone coronary vascular reactivity evaluation by administration of intracoronary acetylcholine at the time of diagnostic study. After a mean follow-up of 8.4±4.7 years, QOL was assessed by administration of the SF-36 QOL survey. Patients diagnosed and treated for microvascular endothelial dysfunction had a higher (better) overall mental composite score (44.8 vs 40.9, p=0.036) and mental health score (44.2 vs 40.7, p=0.047), and a trend towards higher vitality scores (39.1 vs 35.9, p=0.053) and role emotional scores (43.6 vs 40.4, p=0.073), compared with patients with normal endothelial function.

Conclusion

Among patients with chest pain and normal coronaries, diagnosis and treatment of coronary microvascular endothelial dysfunction in those with angina pectoris and non-obstructive CAD are associated with better QOL compared with patients with normal endothelial function.

Systemic microvascular dysfunction in microvascular and vasospastic angina

Aims

Coronary microvascular dysfunction and/or vasospasm are potential causes of ischaemia in patients with no obstructive coronary artery disease (INOCA). We tested the hypothesis that these patients also have functional abnormalities in peripheral small arteries.

Methods and results

Patients were prospectively enrolled and categorised as having microvascular angina (MVA), vasospastic angina (VSA) or normal control based on invasive coronary artery function tests incorporating probes of endothelial and endothelial-independent function (acetylcholine and adenosine). Gluteal biopsies of subcutaneous fat were performed in 81 subjects (62 years, 69% female, 59 MVA, 11 VSA, and 11 controls). Resistance arteries were dissected enabling study using wire myography. Maximum relaxation to ACh (endothelial function) was reduced in MVA vs. controls [median 77.6 vs. 98.7%; 95% confidence interval (CI) of difference 2.3-38%; P = 0.0047]. Endothelium-independent relaxation [sodium nitroprusside (SNP)] was similar between all groups. The maximum contractile response to endothelin-1 (ET-1) was greater in MVA (median 121%) vs. controls (100%; 95% CI of median difference 4.7-45%, P = 0.015). Response to the thromboxane agonist, U46619, was also greater in MVA (143%) vs. controls (109%; 95% CI of difference 13-57%, P = 0.003). Patients with VSA had similar abnormal patterns of peripheral vascular reactivity including reduced maximum relaxation to ACh (median 79.0% vs. 98.7%; P = 0.03) and increased response to constrictor agonists including ET-1 (median 125% vs. 100%; P = 0.02). In all groups, resistance arteries were ≈50-fold more sensitive to the constrictor effects of ET-1 compared with U46619.

Conclusions

Systemic microvascular abnormalities are common in patients with MVA and VSA. These mechanisms may involve ET-1 and were characterized by endothelial dysfunction and enhanced vasoconstriction.

Clinical trial registration

ClinicalTrials.gov registration is NCT03193294.

Rationale and design of the British Heart Foundation (BHF) Coronary Microvascular Angina (CorMicA) stratified medicine clinical trial

Background

Coronary angiography is performed to assess for obstructive coronary artery disease (CAD), but “nonobstructive CAD” is a common finding. Microvascular or vasospastic angina may be relevant, but routine confirmatory testing is not evidence based and thus rarely performed.

Aim

The aim was to assess the effect of stratified medicine guided by coronary function testing on the diagnosis, treatment, and well-being of patients with angina and nonobstructive CAD.

Design

The BHF CorMicA trial is a prospective, multicenter, randomized, blinded, sham-controlled trial of stratified medicine (NCT03193294). All-comers referred for elective coronary angiography for investigation of suspected CAD will be screened. Following informed consent, eligible patients with angina and nonobstructive CAD will be randomized 1:1 immediately in the catheter laboratory to either coronary artery function–guided diagnosis and treatment (intervention group) or not (control group). Coronary function will be assessed using a pressure-temperature–sensitive guidewire and adenosine followed by pharmacological testing with intracoronary acetylcholine. Patients will be stratified into endotypes with linked therapy. The primary outcome is change in Seattle Angina Questionnaire score at 6 months. Secondary outcomes include safety, feasibility, diagnostic utility (impact on diagnosis and diagnostic certainty), and clinical utility (impact on treatment and investigations). Health status is a key secondary outcome assessed according to the following domains: quality of life, treatment satisfaction, illness perception, physical activity, and anxiety-depression score. Patients with obstructive disease who are not randomized will form a registry group who will be followed up as a comparator for secondary outcomes including health status. Health and economic outcomes will be evaluated in the longer term using electronic health record linkage.

Value

CorMicA is a proof-of-concept clinical trial of a disruptive stratified intervention with potential benefits to patients and health care providers.

The Value of Big Endothelin-1 in the Assessment of the Severity of Coronary Artery Calcification

Progression of coronary artery calcification (CAC) was significantly associated with all-cause mortality, and high coronary artery calcium score (CACS) portends a particularly high risk of cardiovascular events. But how often one should rescan is still an unanswered question. Preliminary screening by testing circulating biomarker may be an alternative before repeat computed tomography (CT) scan. The aim of this study was to investigate the value of big endothelin-1 (bigET-1), the precursor of endothelin-1 (ET-1), in predicting the severity of CAC. A total of 428 consecutively patients who performed coronary computed tomography angiography (CCTA) due to chest pain in Fuwai Hospital were included in the study. The clinical characteristics, CACS, and laboratory data were collected, and plasma bigET-1 was detected by enzyme-linked immunosorbent assay (ELISA). The bigET-1 was positively correlated with the CACS (r = .232, P < .001), and the prevalence of CACS >400 increased significantly in the highest bigET-1 tertile than the lowest tertile. Multivariate analysis showed that bigET-1was the independent predictor of the presence of CACS >400 (odds ratio [OR] = 1.721, 95% confidence interval [CI], 1.002-2.956, P = .049). The receiver operating characteristic (ROC) curve analysis showed that the optimal cutoff value of bigET-1 for predicting CACS >400 was 0.38 pmol/L, with a sensitivity of 59% and specificity of 68% (area under curve [AUC] = 0.65, 95% CI, 0.58-0.72, P < .001). The present study demonstrated that the circulating bigET-1 was valuable in the assessment of the severity of CAC.

Role of Activin A in the Pathogenesis of Endothelial Cell Dysfunction in Preeclampsia

This chapter describes the methodologies which may be used in evaluating in vitro endothelial cell dysfunction in preeclampsia.

High-sensitivity C-reactive protein is an independent marker of abnormal coronary vasoreactivity in patients with non-obstructive coronary artery disease

BACKGROUND

Coronary endothelial dysfunction (CED) is an early stage of atherosclerosis and is associated with adverse cardiovascular events. Inflammation may play a role in the development of endothelial dysfunction. To date no study has evaluated the relationship between C-reactive protein and CED. We aimed to determine if C-reactive protein is associated with CED.

METHODS

In 1016 patients (mean age 50.7±12.3 years, 34% male) presenting to the catheterization laboratory with chest pain and non-obstructive coronary artery disease, coronary vasoreactivity was assessed by measuring the percent change in coronary blood flow (%ΔCBF) and coronary artery diameter (%ΔCAD) in response to intracoronary acetylcholine. Plasma high sensitivity C-reactive protein (hs-CRP) was measured and patients were divided into 2 groups: hs-CRP≤3.0 mg/L (low-intermediate cardiovascular risk n=169) and 3 mg/L<hs-CRP≤10 mg/L (high cardiovascular risk n=847).

RESULTS

Patients with a high risk hs-CRP had a significantly lower %ΔCBF and %ΔCAD in response to acetylcholine vs low risk hs-CRP (43.8±6.1 vs 65.8±4.5, P=.004 and -17.2±1.5 vs -13.1±0.8, P=.02 respectively). Low risk hs-CRP was associated with significantly higher %ΔCBF and %ΔCAD vs high risk hs-CRP (27.1±11.0, P=.01 and 4.5±1.9, P=.02 respectively). CED was associated with significantly higher hs-CRP levels and high risk hs-CRP was independently associated with abnormal coronary vasoreactivity, OR 1.82 (95% CI 1.25-2.69).

CONCLUSIONS

Hs-CRP is independently associated with and a strong predictor of abnormal coronary vasoreactivity in patients with non-obstructive coronary artery disease.

Plasma levels of endothelin-1 and renal function among young and healthy adults

Background:

Endothelin-1 (ET-1), a vasoconstrictive and pro-inflammatory peptide, is associated with several cardiovascular risk factors and outcomes. We aimed to investigate the association of plasma ET-1 levels and renal function among young and healthy adults.

Methods:

Individuals aged 25–41 years were enrolled in a population-based cohort study. Main exclusion criteria were established kidney disease, cardiovascular diseases, diabetes mellitus and a body mass index>35 kg/m2. Fasting venous plasma samples were used to measure creatinine, cystatin C and ET-1. The estimated glomerular filtration rate (eGFR) was calculated using the creatinine based chronic kidney disease epidemiology collaboration (CKD-EPI) formula. Multivariable regression models were constructed to assess interrelationships of plasma ET-1 with parameters of renal function.

Results:

Median age of the 2139 participants was 37 years, 47% males. Median creatinine and eGFR were 67 μmol/L and 112 mL/min/1.73 m2, respectively. Using quartile one as the reference group, the β-coefficients (95% confidence intervals [CIs]) for eGFR were 0.06 (− 1.22 to 1.35),−0.66 (− 1.95 to 0.62) and−1.70 (− 3.01 to−0.39) for quartiles 2–4 (p-for-trend=0.0056), respectively and β-coefficients (95% CIs) for cystatin C were 0.002 (− 0.01 to 0.02), 0.02 (0.003–0.03) and 0.03 (0.01–0.04) for quartiles 2–4 (p-for-trend<0.0001), respectively. Using ET-1 as a continuous variable, the β-coefficient (95% CI) for eGFR per 1-unit increase was−1.82 (− 3.19 to−0.44, p=0.0095) and 0.02 (0.01–0.04, p=0.0003) for cystatin C. Similar results were found between creatinine and ET-1 levels.

Conclusions:

ET-1 levels are strongly associated with parameters of renal function among young and healthy adults, suggesting an important role of ET-1 and endothelial function in the regulation of kidney function.

Correlation Between Flow-Mediated Dilatation of the Brachial Artery and Serum Endothelial Biomarkers in the Evaluation of Acute Endothelial Injury After Cardiopulmonary Bypass

OBJECTIVES

The purpose of this study was to investigate the correlation between flow-mediated dilatation of the brachial artery and serum endothelial biomarkers and to discuss the feasibility of sonographic evaluation of acute endothelial injury during cardiopulmonary bypass (CPB) surgery.

METHODS

Sonography was applied to determine the percentage of change in the brachial artery size during flow-mediated dilatation. Meanwhile, the plasma concentrations of endothelial-derived biomarkers, such as endothelin 1, nitric oxide, and von Willebrand factor, were measured to monitor the changes in endothelial function. We analyzed the correlation between flow-mediated dilatation and biomarkers during the perioperative period of CPB in 27 patients.

RESULTS

All of the biomarkers changed dramatically, especially during the CPB period. There was a negative correlation between flow-mediated dilatation and von Willebrand factor (P = .001; R = -0.31).

CONCLUSIONS

A CPB event has a substantial impact on endothelial function, and sonographic assessment of the percentage of change in the brachial artery size during flow-mediated dilatation allows early detection of acute endothelial function injury in cardiac surgery.

Coronary endothelial function testing provides superior discrimination compared with standard clinical risk scoring in prediction of cardiovascular events

BACKGROUND

Endothelial dysfunction is regarded as the early stage of atherosclerosis and is associated with cardiovascular (CV) events. This study was designed to determine whether assessment of coronary endothelial function (CEF) is safe and can reclassify risk in patients with early coronary artery disease beyond the Framingham risk score (FRS).

METHODS AND RESULTS

CEF was evaluated using intracoronary acetylcholine in 470 patients who presented with chest pain and nonobstructive coronary artery disease. CV events were assessed after a median follow-up of 9.7 years. The association between CEF and CV events was examined, and the net reclassification improvement index (NRI) was used to compare the incremental contribution of CEF when added to FRS.The mean age was 53 years, and 68% of the patients were women with a median FRS of 8. Complications (coronary dissection) occurred in three (0.6%) and CV events in 61 (13%) patients. In univariate analysis, microvascular CEF [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.72-0.97, P=0.032] and epicardial CEF (HR 0.73, 95% CI 0.59-0.90, P=0.01) were found to be significant predictors of CV events, whereas FRS was not (HR 1.05, 95% CI 0.85-1.26, P=0.61). When added to FRS, microvascular CEF correctly reclassified 11.3% of patients [NRI 0.11 (95% CI 0.019-0.21)], epicardial CEF correctly reclassified 12.1% of patients [NRI 0.12 (95% CI -0.02 to 0.26)], and the combined microvascular and epicardial CEF correctly reclassified 22.8% of patients [NRI 0.23 (95% CI 0.08-0.37)].

CONCLUSION

CEF testing is safe and adds value to the FRS, with superior discrimination and risk stratification compared with FRS alone in patients presenting with chest pain or suspected ischemia.

Endothelial dysfunction and vascular disease - a 30th anniversary update

The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H₂ O₂ ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive G_i (e.g. responses to α₂ -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive G_q (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H₂ O₂ ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.

Role of endothelin in microvascular dysfunction following percutaneous coronary intervention for non-ST elevation acute coronary syndromes: a single-centre randomised controlled trial

OBJECTIVES

Percutaneous coronary intervention (PCI) for acute coronary syndromes frequently fails to restore myocardial perfusion despite establishing epicardial vessel patency. Endothelin-1 (ET-1) is a potent vasoconstrictor, and its expression is increased in atherosclerosis and after PCI. In this study, we aim to define the role of endothelin in regulating coronary microvascular blood flow and myocardial perfusion following PCI in patients with non-ST elevation acute coronary syndromes (NSTACS), by assessing whether adjunctive therapy with a selective endothelin A (ETA) receptor antagonist acutely improves postprocedural coronary microvascular blood flow.

METHODS

In a randomised, double-blinded, placebo-controlled trial, 23 NSTACS patients were enrolled to receive an intracoronary infusion of placebo (n=11) or BQ-123 (n=12) immediately before PCI. Post-PCI coronary microvascular blood flow and myocardial perfusion were assessed by measuring Doppler-derived average peak velocity (APV), and cardiac biomarker levels were quantified.

RESULTS

Compared with the placebo group, APV was significantly higher in the drug group immediately after PCI (30 (20, 37) vs 19 (9, 26) cm/s; p=0.03). Hyperaemic APV, measured post-adenosine administration, was higher in the BQ-123 group, but the difference did not achieve statistical significance (56 (48, 72) vs 46 (34, 64) cm/s; p=0.090). Maximum coronary flow reserve postprocedure was not different between the two groups (2.1 (1.6, 2.3) vs 2.5 (1.8, 3.0)). Per cent change in creatine kinase isoenzyme MB from the time of PCI to 8 and 16 hours post-PCI was significantly lower in the drug group compared with the placebo group (-17 (-26, -10) vs 26 (-15, 134); p=0.02 and -17 (-38, 14) vs 107 (2, 446); p=0.007, respectively).

CONCLUSIONS

Endothelin is a mediator of microvascular dysfunction during PCI in NSTACS, and adjunctive selective ETA antagonist may augment myocardial perfusion during PCI.

TRIAL REGISTRATION NUMBER

NCT00586820; Results.