Endothelial function and dysfunction. Part I: Methodological issues for assessment in the different vascular beds: a statement by the Working Group on Endothelin and Endothelial Factors of the European Society of Hypertension

The impact of prediabetes and diabetes on endothelial function in a large population-based cohort

BACKGROUND

Diabetes and prediabetes are well-recognized risk factors for cardiovascular disease (CVD) and are marked by vascular endothelial dysfunction (ED). However, there is a scarcity of thorough population-based studies examining ED in individuals with diabetes/prediabetes free from manifest CVD. Here, we examined the association between ED assessed by reactive hyperaemia index (RHI) in the finger and diabetes/prediabetes in a large middle-aged population cohort.

METHODS

Within the Malmö Offspring Study, following the exclusion of participants <30 years and participants with prevalent CVD, 1384 participants had complete data on all covariates. The RHI was calculated using pulse amplitude tonometry. ED was defined as RHI < 1.67. Multivariable logistic and linear regression models were conducted to investigate associations between ED and RHI with diabetes and prediabetes.

RESULTS

The study population had a mean age of 53.6 ± 7.6 years (53% women). In study participants with manifest diabetes (n = 121) and prediabetes (n = 514), ED was present in 42% and 25% respectively, compared to 23% in those with normal glucometabolic status. In multivariable logistic regression analyses, prevalent diabetes was significantly associated with ED (OR 1.95; 95%CI 1.57-3.39; p = 0.002), as well as with lower RHI (β-coeff. -0.087; p = 0.002). However, prediabetes showed no association with neither ED nor RHI.

CONCLUSION

In a population free from CVD, vascular endothelial dysfunction was primarily associated with manifest diabetes, but not with prediabetes, implying that finger ED may develop when diabetes is established, rather than being an early sign of glucose intolerance. Further research is needed to explore whether addressing glucose intolerance could potentially delay or prevent vascular ED onset.

Endothelial dysfunction and cardiovascular diseases: The role of human induced pluripotent stem cells and tissue engineering

Cardiovascular disease (CVD) remains to be the leading cause of death globally today and therefore the need for the development of novel therapies has become increasingly important in the cardiovascular field. The mechanism(s) behind the pathophysiology of CVD have been laboriously investigated in both stem cell and bioengineering laboratories. Scientific breakthroughs have paved the way to better mimic cell types of interest in recent years, with the ability to generate any cell type from reprogrammed human pluripotent stem cells. Mimicking the native extracellular matrix using both organic and inorganic biomaterials has allowed full organs to be recapitulated in vitro. In this paper, we will review techniques from both stem cell biology and bioengineering which have been fruitfully combined and have fueled advances in the cardiovascular disease field. We will provide a brief introduction to CVD, reviewing some of the recent studies as related to the role of endothelial cells and endothelial cell dysfunction. Recent advances and the techniques widely used in both bioengineering and stem cell biology will be discussed, providing a broad overview of the collaboration between these two fields and their overall impact on tissue engineering in the cardiovascular devices and implications for treatment of cardiovascular disease.

The Positive Impact of Bariatric Surgery on Vascular Health

BACKGROUND

Obesity is one of the most prevalent medical conditions in the Western world. There are many risk factors associated with obesity, including cardiovascular and pulmonary risk. Vascular health is not studied in obese patients, and whether obesity has an adverse effect on vascular health in these patients remains unknown.

OBJECTIVE

The first objective is to find a correlation between vascular health and obesity and whether obesity can be classified as a risk factor for vascular health. The second objective is to see if weight loss leads to an improvement in vascular health in patients.

METHODS

The study was conducted with pre- and post-surgical methods at Baylor Scott & White (BSWH) Medical Center, Temple, Texas, USA. Ten patients were approached, consented, and prepared to obtain baseline values through WatchPAT and EndoPAT devices prior to their bariatric surgery. Values obtained include their initial weight, respiratory disturbance index, apnea-hypopnea index, oxygen desaturation index, and degree of endothelial dysfunction via the EndoPAT device. Post-surgery, these values were obtained again and compared using Wilcoxon non-parametric analyses with a level of significance at p < 0.05.

RESULTS

Our study results demonstrate a correlation between obesity and vascular health as endothelial dysfunction is widely seen. In our patients, after bariatric surgery, we saw a significant weight change (31.2% +11.2, p < 0.0001). There was a significant degree of endothelial function improvement after the weight loss (31.2% +34.7, p < 0.04).

CONCLUSION

Our results indicate that there is a correlation between obesity and vascular health, which also correlates with cardiovascular risk. There is a significant reduction in endothelial dysfunction after weight loss. We believe that obesity is a risk factor for vascular health outcomes.

Endothelial dysfunction and risk factors for atherosclerosis in psoriatic arthritis: overview and comparison with rheumatoid arthritis

Endothelial dysfunction (ED) is defined as an impairment in the vasodilatory, anti-thrombotic, and anti-inflammatory properties of the cells that make up the lining of blood vessels. ED is considered a key step in the development of atherosclerotic cardiovascular disease. The association between ED and systemic inflammatory diseases is well established. However, the prevalence and clinical significance of ED in psoriatic arthritis (PsA) have been investigated to a lesser extent. This review aims to explore the link between ED and PsA, including ED in macro- and microcirculation, as well as risk factors for its occurrence in PsA and its relationship with atherosclerosis in PsA. Furthermore, the ED in PsA was compared with that of rheumatoid arthritis (RA). Regarding ED in the microcirculation, the coronary flow reserve was found to be significantly reduced in individuals with PsA. The relationship between PsA and macrovascular ED is more pronounced, along with more advanced atherosclerosis detected in patients with PsA. These results are consistent with those obtained in RA studies. On the other hand, arterial stiffness and signs of vascular remodeling were found more frequently in RA than in PsA, with the potential role of efficient anti-TNF treatment in patients with PsA and psoriasis explaining this finding. The impact of ED on cardiovascular diseases and the burden of this risk caused independently by PsA have not yet been precisely established, however, this group of patients requires special attention with regard to cardiovascular events.

Effect of Coenzyme Q10 Supplementation on Vascular Endothelial Function: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

Coenzyme Q10 (CoQ10) has gained attention as a potential therapeutic agent for improving endothelial function. Several randomized clinical trials have investigated CoQ10 supplementation's effect on endothelial function. However, these studies have yielded conflicting results, therefore this systematic review and meta-analysis were conducted.

AIM

This systematic review and meta-analysis were conducted to assess the effects of CoQ10 supplementation on endothelial factors.

METHODS

A comprehensive search was done in numerous databases until July 19th, 2023. Quantitative data synthesis was performed using a random-effects model, with weight mean difference (WMD) and 95% confidence intervals (CI). Standard methods were used for the assessment of heterogeneity, meta-regression, sensitivity analysis, and publication bias.

RESULTS

12 studies comprising 489 subjects were included in the meta-analysis. The results demonstrated significant increases in Flow Mediated Dilation (FMD) after CoQ10 supplementation (WMD: 1.45; 95% CI: 0.55 to 2.36; p < 0.02), but there is no increase in Vascular cell adhesion protein (VCAM), and Intercellular adhesion molecule (ICAM) following Q10 supplementation (VCAM: SMD: - 0.34; 95% CI: - 0.74 to - 0.06; p < 0.10) (ICAM: SMD: - 0.18; 95% CI: - 0.82 to 0.46; p < 0.57). The sensitivity analysis showed that the effect size was robust in FMD and VCAM. In meta-regression, changes in FMD percent were associated with the dose of supplementation (slope: 0.01; 95% CI: 0.004 to 0.03; p = 0.006).

CONCLUSIONS

CoQ10 supplementation has a positive effect on FMD in a dose-dependent manner. Our findings show that CoQ10 has an effect on FMD after 8 weeks of consumption. Additional research is warranted to establish the relationship between CoQ10 supplementation and endothelial function.

Analysis of the Model of Atherosclerosis Formation in Pig Hearts as a Result of Impaired Activity of DNA Repair Enzymes

Excessive consumption of food rich in saturated fatty acids and carbohydrates can lead to metabolic disturbances and cardiovascular disease. Hyperlipidemia is a significant risk factor for acute cardiac events due to its association with oxidative stress. This leads to arterial wall remodeling, including an increase in the thickness of the intima media complex (IMT), and endothelial dysfunction leading to plaque formation. The decreased nitric oxide synthesis and accumulation of lipids in the wall result in a reduction in the vasodilating potential of the vessel. This study aimed to establish a clear relationship between markers of endothelial dysfunction and the activity of repair enzymes in cardiac tissue from a pig model of early atherosclerosis. The study was conducted on 28 female Polish Landrace pigs, weighing 40 kg (approximately 3.5 months old), which were divided into three groups. The control group (n = 11) was fed a standard, commercial, balanced diet (BDG) for 12 months. The second group (n = 9) was fed an unbalanced, high-calorie Western-type diet (UDG). The third group (n = 8) was fed a Western-type diet for nine months and then switched to a standard, balanced diet (regression group, RG). Control examinations, including blood and urine sampling, were conducted every three months under identical conditions with food restriction for 12 h and water restriction for four hours before general anesthesia. The study analyzed markers of oxidative stress formed during lipid peroxidation processes, including etheno DNA adducts, ADMA, and NEFA. These markers play a crucial role in reactive oxygen species analysis in ischemia-reperfusion and atherosclerosis in mammalian tissue. Essential genes involved in oxidative-stress-induced DNA demethylation like OGG1 (8-oxoguanine DNA glycosylase), MPG (N-Methylpurine DNA Glycosylase), TDG (Thymine-DNA glycosylase), APEX (apurinic/apirymidinic endodeoxyribonuclease 1), PTGS2 (prostaglandin-endoperoxide synthase 2), and ALOX (Arachidonate Lipoxygenase) were measured using the Real-Time RT-PCR method. The data suggest that high oxidative stress, as indicated by TBARS levels, is associated with high levels of DNA repair enzymes and depends on the expression of genes involved in the repair pathway. In all analyzed groups of heart tissue homogenates, the highest enzyme activity and gene expression values were observed for the OGG1 protein recognizing the modified 8oxoG. Conclusion: With the long-term use of an unbalanced diet, the levels of all DNA repair genes are increased, especially (significantly) Apex, Alox, and Ptgs, which strongly supports the hypothesis that an unbalanced diet induces oxidative stress that deregulates DNA repair mechanisms and may contribute to genome instability and tissue damage.

Impaired brachial flow-mediated dilation may predict choroidal and retinal nerve fibre layer thickness changes in people with obesity

CLINICAL RELEVANCE

Choroidal thickness and peripapillary retinal nerve fibre layer (RNFL) changes are known to occur in obesity. Endothelial dysfunction and systemic atherosclerosis may play a role in the pathophysiology of these differences.

BACKGROUND

Flow-mediated dilation (FMD) is reduced in patients with endothelial dysfunction, and the ankle-brachial index is a surrogate marker for atherosclerosis. This study was conducted to examine the relationship between systemic vascular parameters (FMD, and ankle-brachial index), subfoveal choroidal thickness, and peripapillary RNFL thickness in obese individuals.

METHODS

This observational, cross-sectional study involved 108 total participants who were divided into two groups. One group consisted of 54 obese subjects who each had a body mass index of 30 kg/m2 or more. The other control group contained 54 participants who each had a body mass index of 25 kg/m2 or less but higher than 20 kg/m2 . For each participant, only one eye was examined in this study. Subfoveal choroidal thickness, RNFL thickness, ankle-brachial index, and ultrasound measurement of the brachial artery FMD were performed. FMD was categorised according to receiver operating characteristic analysis, and endothelial dysfunction was defined as an FMD ≤ 7.29%.

RESULTS

Subfoveal choroidal and RNFL thicknesses in the temporal quadrant were significantly lower in the obese group (p < 0.05). Lower mean values of subfoveal choroidal and RNFL thicknesses in the temporal and inferior quadrants were observed in subjects with an FMD ≤ 7.29% (p < 0.05). In people with obesity, FMD was positively correlated with subfoveal choroidal thickness (r = 0.322, p = 0.001), inferior RNFL thickness (r = 0.259, p = 0.007), and temporal RNFL thickness (r = 0.297, p = 0.002). However, the ankle-brachial index was not correlated with obesity.

CONCLUSIONS

Impaired FMD was associated with reduced subfoveal choroidal and RNFL thicknesses in the temporal and inferior quadrants of people with obesity.

Multiple exposures to low-dose ionizing radiation induced the initiation and progression of pro-atherosclerotic phenotypes in mice and vascular endothelial cell damage

OBJECTIVE

This study aimed to investigate the effects of low-dose radiation on the abdominal aorta of mice and vascular endothelial cells.

METHODS

Wild-type and tumor-bearing mice were exposed to 15 sessions of low-dose irradiation, resulting in cumulative radiation doses of 187.5, 375, and 750 mGy. The effect on the cardiovascular system was assessed. Immunohistochemistry analyzed protein expressions of PAPP-A, CD62, P65, and COX-2 in the abdominal aorta. Microarray technology, Gene Ontology analysis, and pathway enrichment analysis evaluated gene expression changes in endothelial cells exposed to 375 mGy X-ray. Cell viability was assessed using the Cell Counting Kit 8 assay. Immunofluorescence staining measured γ-H2AX levels, and real-time polymerase chain reaction quantified mRNA levels of interleukin-6 (IL-6), ICAM-1, and Cx43.

RESULTS

Hematoxylin and eosin staining revealed thickening of the inner membranes and irregular arrangement of smooth muscle cells in the media membrane at 375 and 750 mGy. Inflammation was observed in the inner membranes at 750 mGy, with a clear inflammatory response in the hearts of tumor-bearing mice. Immunohistochemistry indicated increased levels of PAPP-A, P65, and COX-2 post-irradiation. Microarray analysis showed 425 up-regulated and 235 down-regulated genes, associated with processes like endothelial cell-cell adhesion, IL-6, and NF-κB signaling. Cell Counting Kit 8 assay results indicated inhibited viability at 750 mGy in EA.hy926 cells. Immunofluorescence staining demonstrated a dose-dependent increase in γ-H2AX foci. Reverse transcription quantitative PCR results showed increased expression of IL6, ICAM-1, and Cx43 in EA.hy926 cells post 750 mGy X-ray exposure.

CONCLUSION

Repeated low-dose ionizing radiation exposures triggered the development of pro-atherosclerotic phenotypes in mice and damage to vascular endothelial cells.

Variations in metabolic enzymes cause differential changes of heparan sulfate and hyaluronan in high glucose treated cells on chip

Glycocalyx dysfunction is believed as the first step in diabetic vascular disease. However, few studies have systematically investigated the influence of HG on the glycocalyx as a whole and its major constituent glycans towards one type of cell. Furthermore, most studies utilized traditional two-dimensional (2D) cultures in vitro, which can't provide the necessary fluid environment for glycocalyx. Here, we utilized vascular glycocalyx on chips to evaluate the changes of glycocalyx and its constituent glycans in HG induced HUVECs. Fluorescence microscopy showed up-regulation of hyaluronan (HA) but down-regulation of heparan sulfate (HS). By analyzing the metabolic enzymes of both glycans, a decrease in the ratio of synthetic/degradative enzymes for HA and an increase in that for HS were demonstrated. Two substrates (UDP-GlcNAc, UDP-GlcA) for the synthesis of both glycans were increased according to omics analysis. Since they were firstly pumped into Golgi apparatus to synthesize HS, less substrates may be left for HA synthesis. Furthermore, the differential changes of HA and HS were confirmed in vessel slides from db/db mice. This study would deepen our understanding of impact of HG on glycocalyx formation and diabetic vascular disease.

Dickkopf-Related Protein 1 (DKK-1) as a Possible Link between Bone Erosions and Increased Carotid Intima-Media Thickness in Psoriatic Arthritis: An Ultrasound Study

Psoriatic arthritis (PsA) is a heterogenous systemic inflammatory disorder that affects peripheral joints and skin, but also causes inflammation at entheseal sites, digits (dactylitis) and the axial skeleton. Despite considerable advances, our understanding of the pathogenesis and management of PsA is hampered by its complex clinical expression. We enrolled patients who met the ClASsification for Psoriatic Arthritis (CASPAR) criteria for PsA (n = 17), and healthy controls (n = 13). The lipid profile, C-reactive protein (CRP) and Dickkopf-related protein 1 (DKK-1) circulating levels were measured for all subjects. For the patients with PsA, (1) the erosive character of the articular disease was assessed by a musculoskeletal ultrasound and (2) the cardiovascular risk was evaluated using the Systematic Coronary Risk Evaluation (SCORE) chart and the ultrasound measurement of the carotid intima-media thickness. A higher titer of serum DKK-1 was associated with the presence of erosions (p < 0.005) and the cIMT correlated with DKK-1 levels in patients with PsA (r = 0.6356, p = 0.0061). Additionally, we observed a positive correlation between increased cIMT and CRP (r = 0.5186, p = 0.0329). Our results suggest that DKK-1 could be used as an early biomarker for the erosive character of the articular disease and for the assessment of the cardiovascular risk in PsA patients.

Impact of bariatric surgery on carotid intima-media thickness, flow-mediated dilation, and nitrite-mediated dilation: a systematic review and meta-analysis

Obesity is considered one of the independent risk factors for atherosclerosis and is strongly correlated with cardiovascular morbidity and mortality. Previous studies showed carotid intima-media thickness (CIMT), flow-mediated dilation (FMD), and nitrite-mediated dilatation (NMD) are reliable non-invasive markers of arterial damage and dysfunction. The aim of this study was to evaluate the effect of bariatric surgery on CIMT, FMD, and NMD markers in patients with obesity. A systematic search was performed in the PubMed, Embase, Scopus, and Web of Science databases until May 2022. All the English-published studies on the effect of bariatric surgery on CIMT, FMD, and NMD were included. A quantitative meta-analysis was performed, as well as subgroup analyses for the type of procedure and duration of follow-up. Meta-analysis of 41 studies with 1639 patients showed CIMT was significantly reduced by .11 mm after bariatric surgery (95% CI, -.14 to -.08; P < .001; mean follow-up = 10.8 mo). The pooled analysis of 23 studies with 1106 patients showed an increase of FMD by 4.57% after bariatric surgery (95% CI, 2.69-6.44; P < .001; mean follow-up = 11.5 mo). The results of a pooled analysis of 12 studies with 346 patients showed a significant increase of NMD by 2.46% after bariatric surgery (95% CI, .99-3.94; P < .001; mean follow-up = 11.4 mo). The random effect meta-regression demonstrated that baseline CIMT and FMD significantly affect the changes in CIMT and FMD. This meta-analysis showed bariatric surgery can improve CIMT, FMD, and NMD markers in patients with obesity. These improvements show the known effect of metabolic surgery in decreasing cardiovascular risk.

Small extracellular vesicles from pregnant women with maternal supraphysiological hypercholesterolemia impair endothelial cell function in vitro

Maternal physiological hypercholesterolemia (MPH, maternal total cholesterol (TC) levels at term of pregnancy ≤280 mg/dl) occurs to assure fetal development. Maternal supraphysiological hypercholesterolemia (MSPH, TC levels >280 mg/dl) is a pathological condition associated with maternal, placental, and fetal endothelial dysfunction and early neonatal atherosclerosis development. Small extracellular vesicles (sEVs) are delivered to the extracellular space by different cells, where they modulate cell functions by transporting active signaling molecules, including proteins and miRNA.

AIM

To determine whether sEVs from MSPH women could alter the function of endothelial cells (angiogenesis, endothelial activation and nitric oxide synthesis capacity).

METHODS

This study included 24 Chilean women (12 MPH and 12 MSPH). sEVs were isolated from maternal plasma and characterized by sEV markers (CD9, Alix and HSP70), nanoparticle tracking analysis, transmission electron microscopy, and protein and cholesterol content. The endothelial cell line HMEC-1 was used to determine the uptake of labeled sEVs and the effects of sEVs on cell viability, endothelial tube formation, endothelial cell activation, and endothelial nitric oxide expression and function.

RESULTS

In MSPH women, the plasma concentration of sEVs was increased compared to that in MPH women. MSPH-sEVs were highly taken up by HMEC-1 cells and reduced angiogenic capacity and the expression and activity of eNOS without changing cell viability or endothelial activation.

CONCLUSION

sEVs from MSPH women impair angiogenesis and nitric oxide synthesis in endothelial cells, which could contribute to MSPH-associated endothelial dysfunction.

Cocoa Consumption Decreases Oxidative Stress, Proinflammatory Mediators and Lipid Peroxidation in Healthy Subjects: A Randomized Placebo-Controlled Dose-Response Clinical Trial

INTRODUCTION

Cocoa flavonoids have been described to reduce the cardiovascular risk. Nevertheless, the involved mechanisms should be clarified and the dose-effect relation has never been evaluated.

AIM

To investigate the dose-dependent effects of cocoa flavonoids on markers of endothelial and platelet activation and oxidative stress.

METHODS

According to a randomized, double-blind, controlled, cross-over design, 20 healthy nonsmokers were assigned to receive either five treatments with daily intake of 10 g cocoa (0, 80, 200, 500 and 800 mg cocoa flavonoids/day) in five periods lasting 1 week each.

RESULTS

Compared with flavonoid-free cocoa control, cocoa reduced sICAM-1 mean values [from 1190.2 to 1123.0; 906.3; 741.7 and 625.6 pg/mL (p = 0.0198 and p = 0.0016, for 500 and 800 mg respectively], sCD40L mean values [from 218.8 to 210.2; 165.5; 134.5 and 128.4 pg/mL (p = 0.023 and p = 0.013, for 500 and 800 mg respectively] and 8-isoprostanes F2 mean values [from 4703.9 to 4670.7; 2000.1; 2098.4 and 2052.3 pg/mL (p = 0.025; p = 0.034 and p = 0.029, for 200, 500 and 800 mg respectively)].

CONCLUSIONS

In our study we observed that short-term cocoa consumption improved proinflammatory mediators, lipid peroxidation and oxidative stress with a significant effect for higher dosages of flavonoids. Our findings suggest cocoa might be a valid tool for dietary intervention in prevention of atherosclerosis.

Preeclampsia Affects Lipid Metabolism and HDL Function in Mothers and Their Offspring

Preeclampsia (PE) is linked to an overall increased cardiovascular risk for both the mother and child. Functional impairment of high-density lipoproteins (HDL) may contribute to the excess cardiovascular risk associated with PE. In this study, we investigated the effects of PE on maternal and neonatal lipid metabolism, and the parameters of HDL composition and function. The study cohort included 32 normotensive pregnant women, 18 women diagnosed with early-onset PE, and 14 women with late-onset PE. In mothers, early- and late-onset PE was associated with atherogenic dyslipidemia, characterized by high plasma triglycerides and low HDL-cholesterol levels. We observed a shift from large HDL to smaller HDL subclasses in early-onset PE, which was associated with an increased plasma antioxidant capacity in mothers. PE was further associated with markedly increased levels of HDL-associated apolipoprotein (apo) C-II in mothers, and linked to the triglyceride content of HDL. In neonates of early-onset PE, total cholesterol levels were increased, whereas HDL cholesterol efflux capacity was markedly reduced in neonates from late-onset PE. In conclusion, early- and late-onset PE profoundly affect maternal lipid metabolism, potentially contributing to disease manifestation and increased cardiovascular risk later in life. PE is also associated with changes in neonatal HDL composition and function, demonstrating that complications of pregnancy affect neonatal lipoprotein metabolism.

Effect of Carotid Body Denervation on Systemic Endothelial Function in a Diabetic Animal Model

Endothelial dysfunction is an essential intermediary for development of cardiovascular diseases associated with diabetes and hypertension (HT). The carotid body (CB) dysfunction contributes to dysmetabolic states, and the resection of carotid sinus nerve (CSN) prevents and reverts dysmetabolism and HT. Herein, we investigated if CSN denervation ameliorates systemic endothelial dysfunction in an animal model of type 2 diabetes mellitus (T2DM).We used Wistar male rats submitted to HFHSu diet during 25 weeks and the correspondent age-matched controls fed with a standard diet. CSN resection was performed in half of the groups after 14 weeks of diet. In vivo insulin sensitivity, glucose tolerance and blood pressure, ex vivo aortic artery contraction and relaxation and nitric oxide (NO) levels in plasma and aorta, aorta nitric oxide synthase (NOS) isoforms, and PGF2αR levels were evaluated.We demonstrated that, alongside to dysmetabolism and HT reversion, CSN resection restores endothelial function in the aorta and decreases the NO levels in plasma and aorta at the same time that restores normal levels of iNOS in aorta without changing eNOS or PGF2αR levels.These results suggest that the modulation of CB activity can be important for the treatment of HT and endothelial dysfunction related with T2DM.

CD39 in the development and progression of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating progressive disease characterised by pulmonary arterial vasoconstriction and vascular remodelling. Endothelial dysfunction has emerged as a contributing factor in the development of PAH. However, despite progress in the understanding of the pathophysiology of this disease, current therapies fail to impact upon long-term outcomes which remain poor in most patients. Recent observations have suggested the disturbances in the balance between ATP and adenosine may be integral to the vascular remodelling seen in PAH. CD39 is an enzyme important in regulating these nucleos(t)ides which may also provide a novel pathway to target for future therapies. This review summarises the role of adenosine signalling in the development and progression of PAH and highlights the therapeutic potential of CD39 for treatment of PAH.

The evaluation of constant coronary artery flow versus constant coronary perfusion pressure during normothermic ex situ heart perfusion

BACKGROUND

Evidence suggests that hearts that are perfused under ex-situ conditions lose normal coronary vasomotor tone and experience contractile failure over a few hours. We aimed to evaluate the effect of different coronary perfusion strategies during ex situ heart perfusion on cardiac function and coronary vascular tone.

METHODS

Porcine hearts (n = 6 each group) were perfused in working mode for 6 hours with either constant aortic diastolic pressure (40 mmHg) or constant coronary flow rate (500 mL/min). Functional and metabolic parameters, cytokine profiles, cardiac and vascular injury, coronary artery function and oxidative stress were compared between groups.

RESULTS

Constant coronary flow perfusion demonstrated better functional preservation and less edema formation (Cardiac index: flow control = 8.33 vs pressure control = 6.46 mL·min^-1·g^-1, p = 0.016; edema formation: 7.92% vs 19.80%, p < 0.0001). Pro-inflammatory cytokines, platelet activation as well as endothelial activation were lower in the flow control group. Similarly, less cardiac and endothelial injury was observed in the constant coronary flow group. Evaluation of coronary artery function showed there was loss of coronary autoregulation in both groups. Oxidative stress was induced in the coronary arteries and was relatively lower in the flow control group.

CONCLUSIONS

A strategy of controlled coronary flow during ex situ heart perfusion provides superior functional preservation and less edema formation, together with less myocardial damage, leukocyte, platelet, endothelial activation, and oxidative stress. There was loss of coronary autoregulation and decrease of coronary vascular resistance during ESHP irrespective of coronary flow control strategy. Inflammation and oxidative stress state in the coronary vasculature may play a role.

Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial

Long COVID, a condition characterized by symptom and/or sign persistence following an acute COVID-19 episode, is associated with reduced physical performance and endothelial dysfunction. Supplementation of l-arginine may improve endothelial and muscle function by stimulating nitric oxide synthesis. A single-blind randomized, placebo-controlled trial was conducted in adults aged between 20 and 60 years with persistent fatigue attending a post-acute COVID-19 outpatient clinic. Participants were randomized 1:1 to receive twice-daily orally either a combination of 1.66 g l-arginine plus 500 mg liposomal vitamin C or a placebo for 28 days. The primary outcome was the distance walked on the 6 min walk test. Secondary outcomes were handgrip strength, flow-mediated dilation, and fatigue persistence. Fifty participants were randomized to receive either l-arginine plus vitamin C or a placebo. Forty-six participants (median (interquartile range) age 51 (14), 30 [65%] women), 23 per group, received the intervention to which they were allocated and completed the study. At 28 days, l-arginine plus vitamin C increased the 6 min walk distance (+30 (40.5) m; placebo: +0 (75) m, p = 0.001) and induced a greater improvement in handgrip strength (+3.4 (7.5) kg) compared with the placebo (+1 (6.6) kg, p = 0.03). The flow-mediated dilation was greater in the active group than in the placebo (14.3% (7.3) vs. 9.4% (5.8), p = 0.03). At 28 days, fatigue was reported by two participants in the active group (8.7%) and 21 in the placebo group (80.1%; p < 0.0001). l-arginine plus vitamin C supplementation improved walking performance, muscle strength, endothelial function, and fatigue in adults with long COVID. This supplement may, therefore, be considered to restore physical performance and relieve persistent symptoms in this patient population.

Chemerin-Induced Down-Regulation of Placenta-Derived Exosomal miR-140-3p and miR-574-3p Promotes Umbilical Vein Endothelial Cells Proliferation, Migration, and Tube Formation in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) leads to poor pregnancy outcomes and fetoplacental endothelial dysfunction; however, the underlying mechanisms remain unknown. This study aimed to investigate the effect of placenta-derived exosomal miRNAs on fetoplacental endothelial dysfunction in GDM, as well as to further explore the role of chemerin to this end. Placenta-derived exosomal miR-140-3p and miR-574-3p expression (next-generation sequencing, quantitative real-time PCR), its interactions with cell function (Cell Counting Kit-8, Transwell, tube formation assay), chemerin interactions (Western blotting), and placental inflammation (immunofluorescence staining, enzyme-linked immunosorbent assay) were investigated. Placenta-derived exosomal miR-140-3p and miR-574-3p were downregulated in GDM. Additionally, miR-140-3p and miR-574-3p inhibited the proliferation, migration, and tube formation ability of umbilical vein endothelial cells by targeting vascular endothelial growth factor. Interestingly, miR-140-3p and miR-574-3p expression levels were negatively correlated with chemerin, which induced placental inflammation through the recruitment of macrophage cells and release of IL-18 and IL-1β. These findings indicate that chemerin reduces placenta-derived exosomal miR-140-3p and miR-574-3p levels by inducing placental inflammation, thereby promoting the proliferation, migration, and tube formation of umbilical vein endothelial cells in GDM, providing a novel perspective on the underlying pathogenesis and therapeutic targets for GDM and its offspring complications.

Hypertension in chronic kidney disease: What lies behind the scene

Hypertension is a frequent condition encountered during kidney disease development and a leading cause in its progression. Hallmark factors contributing to hypertension constitute a complexity of events that progress chronic kidney disease (CKD) into end-stage renal disease (ESRD). Multiple crosstalk mechanisms are involved in sustaining the inevitable high blood pressure (BP) state in CKD, and these play an important role in the pathogenesis of increased cardiovascular (CV) events associated with CKD. The present review discusses relevant contributory mechanisms underpinning the promotion of hypertension and their consequent eventuation to renal damage and CV disease. In particular, salt and volume expansion, sympathetic nervous system (SNS) hyperactivity, upregulated renin–angiotensin–aldosterone system (RAAS), oxidative stress, vascular remodeling, endothelial dysfunction, and a range of mediators and signaling molecules which are thought to play a role in this concert of events are emphasized. As the control of high BP via therapeutic interventions can represent the key strategy to not only reduce BP but also the CV burden in kidney disease, evidence for major strategic pathways that can alleviate the progression of hypertensive kidney disease are highlighted. This review provides a particular focus on the impact of RAAS antagonists, renal nerve denervation, baroreflex stimulation, and other modalities affecting BP in the context of CKD, to provide interesting perspectives on the management of hypertensive nephropathy and associated CV comorbidities.

Novel Method to Assess Endothelial Function via Monitoring of Perfusion Response to Local Heating by Imaging Photoplethysmography

Endothelial dysfunction is one of the most important markers of the risk of cardiovascular complications. This study is aimed to demonstrate the feasibility of imaging photoplethysmography to assess microcirculation response to local heating in order to develop a novel technology for assessing endothelial function. As a measure of vasodilation, we used the relative dynamics of the pulsatile component of the photoplethysmographic waveform, which was assessed in a large area of the outer surface of the middle third of the subject's forearm. The perfusion response was evaluated in six healthy volunteers during a test with local skin heating up to 40-42 °C and subsequent relaxation. The proposed method is featured by accurate control of the parameters affecting the microcirculation during the prolonged study. It was found that in response to local hyperthermia, a multiple increase in the pulsation component, which has a biphasic character, was observed. The amplitude of the first phase of the perfusion reaction depends on both the initial skin temperature and the difference between the basal and heating temperatures. The proposed method allows the assessment of a reproducible perfusion increase in response to hyperthermia developed due to humoral factors associated with the endothelium, thus allowing detection of its dysfunction.

Microvascular Dysfunction in Skeletal Muscle Precedes Myocardial Vascular Changes in Diabetic Cardiomyopathy: Sex-Dependent Differences

Aim

To uncover sex-related microvascular abnormalities that underlie the early presentation of reduced perfusion in leg skeletal muscle in a type II rat model of diabetic cardiomyopathy.

Methods and Results

Diabetes was induced using a non-obese, diet-based, low-dose streptozotocin model in adult female (18 diabetic, 9 control) and male rats (29 diabetic, 11 control). Time-course monitoring over 12 months following diabetes induction was performed using echocardiography, treadmill exercise, photoacoustic imaging, flow-mediated dilation (FMD), histopathology, and immunohistochemistry. Diabetic rats maintained normal weights. Hypertension appeared late in both diabetic males (7 months) and females (10 months), while only diabetic males had elevated cholesterol (7 months). On echocardiography, all diabetic animals maintained normal ejection fraction and exhibited diastolic dysfunction, mild systolic dysfunction, and a slightly enlarged left ventricle. Exercise tolerance declined progressively and early in males (4 months), later in females (8 months); FMD showed lower baseline femoral arterial flow but unchanged reactivity in both sexes (5 months); and photoacoustic imaging showed lower tissue oxygen saturation in the legs of diabetic males (4 months) and diabetic females (10 months). Myocardial perfusion was normal in both sexes. Histopathology at the final timepoint of Month 10 (males) and Month 12 (females) revealed that myocardial microvasculature was normal in both vessel density and structure, thus explaining normal perfusion on imaging. However, leg muscle microvasculature exhibited perivascular smooth muscle thickening around small arterioles in diabetic females and around large arterioles in diabetic males, explaining the depressed readings on photoacoustic and FMD. Histology also confirmed the absence of commonly reported HFpEF markers, including microvessel rarefaction, myocardial fibrosis, and left ventricular hypertrophy.

Conclusion

Exercise intolerance manifesting early in the progression of diabetic cardiomyopathy can be attributed to decreased perfusion to the leg skeletal muscle due to perivascular smooth muscle thickening around small arterioles in females and large arterioles in males. This microvascular abnormality was absent in the myocardium, where perfusion levels remained normal throughout the study. We conclude that although skeletal muscle microvascular dysfunction of the vasculature presents at different levels depending on sex, it consistently presents early in both sexes prior to overt cardiac changes such as rarefaction, fibrosis, or hypertrophy.

Radial Peripapillary Capillary Plexus Perfusion and Endothelial Dysfunction in Early Post-SARS-CoV-2 Infection

Background: Endothelial cells damage and thromboinflammation are considered key elements in the generation of organ impairment in patients with COVID-19 disease. The endothelial function is evaluated by measuring flow-mediated dilation (FMD). We aimed to analyze the association between FMD impairment and retinal vascular parameters in early post-COVID-19 patients. 00118-00199Tomography (OCT), OCT Angiography (OCTA) and slit lamp examination were performed. FMD ≤ 7% was considered as pathological. Our primary outcome was to assess potential differences in the radial peripapillary capillary plexus flow index (RPCP-FI) and RPCP density (RPCP-D) values between post-COVID-19 patients with and without FMD impairment. The associations of other retinal vascular parameters with FMD impairment were assessed as secondary endpoints. Results: FMD impairment was detected in 31 patients (37.8%). RPCP-FI (p = 0.047), age (p = 0.048) and prevalence of diabetes (p = 0.046) significantly differed in patients with FMD ≤ 7% in regression analysis. RPCP-FI was linearly correlated with FMD values (R = 0.244, p =0.027). SCT was found to be lower in patients with impaired FMD (p = 0.004), although this difference was only a trend in binary logistic regression output (p = 0.07). Conclusions: Early post-COVID-19 patients showed a higher prevalence of FMD impairment compared to the general population. Age, diabetes and RPCP-FI were independently correlated with the presence of endothelial impairment in the early post-infective period.

EPR spectroscopic evidence of iron-catalysed free radical formation in chronic mountain sickness: Dietary causes and vascular consequences

Chronic mountain sickness (CMS) is a high-altitude (HA) maladaptation syndrome characterised by elevated systemic oxidative-nitrosative stress (OXNOS) due to a free radical-mediated reduction in vascular nitric oxide (NO) bioavailability. To better define underlying mechanisms and vascular consequences, this study compared healthy male lowlanders (80 m, n = 10) against age/sex-matched highlanders born and bred in La Paz, Bolivia (3600 m) with (CMS+, n = 10) and without (CMS-, n = 10) CMS. Cephalic venous blood was assayed using electron paramagnetic resonance spectroscopy and reductive ozone-based chemiluminescence. Nutritional intake was assessed via dietary recall. Systemic vascular function and structure were assessed via flow-mediated dilatation, aortic pulse wave velocity and carotid intima-media thickness using duplex ultrasound and applanation tonometry. Basal systemic OXNOS was permanently elevated in highlanders (P = <0.001 vs. lowlanders) and further exaggerated in CMS+, reflected by increased hydroxyl radical spin adduct formation (P = <0.001 vs. CMS-) subsequent to liberation of free 'catalytic' iron consistent with a Fenton and/or nucleophilic addition mechanism(s). This was accompanied by elevated global protein carbonylation (P = 0.046 vs. CMS-) and corresponding reduction in plasma nitrite (P = <0.001 vs. lowlanders). Dietary intake of vitamins C and E, carotene, magnesium and retinol were lower in highlanders and especially deficient in CMS + due to reduced consumption of fruit and vegetables (P = <0.001 to 0.028 vs. lowlanders/CMS-). Systemic vascular function and structure were also impaired in highlanders (P = <0.001 to 0.040 vs. lowlanders) with more marked dysfunction observed in CMS+ (P = 0.035 to 0.043 vs. CMS-) in direct proportion to systemic OXNOS (r = -0.692 to 0.595, P = <0.001 to 0.045). Collectively, these findings suggest that lifelong exposure to iron-catalysed systemic OXNOS, compounded by a dietary deficiency of antioxidant micronutrients, likely contributes to the systemic vascular complications and increased morbidity/mortality in CMS+. TRIAL REGISTRY: ClinicalTrials.gov; No: NCT01182792; URL: www.clinicaltrials.gov.

Impaired Endothelial Function in Convalescent Phase of COVID-19: A 3 Month Follow Up Observational Prospective Study

Background: Endothelial dysfunction has a role in acute COVID-19, contributing to systemic inflammatory syndrome, acute respiratory distress syndrome, and vascular events. Evidence regarding COVID-19 middle- and long-term consequences on endothelium are still lacking. Our study aimed to evaluate if COVID-19 severity could significantly affect the endothelial function after three months from the acute phase. Methods: We assessed endothelial function in outpatients with previous COVID-19 three months after negative SARS-CoV-2 molecular test by measuring flow-mediated dilation (FMD) in patients categorized according to a four-variable COVID-19 severity scale (“home care”; “hospital, no oxygen”; “hospital, oxygen”; “hospital requiring high-flow nasal canula, non-invasive ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation”). FMD difference among COVID-19 severity categories was assessed with analysis of variance; we further clarified the relationship between FMD and previous COVID-19 severity with multivariate logistic models. Results: Among 658 consecutive COVID-19 subjects, we observed a significant linear trend of FMD reduction with the increase of the COVID-19 category (p < 0.0001). The presence of endothelial dysfunction was more frequent among hospitalized patients (78.3%) with respect to home-care patients (21.7%; p < 0.0001). COVID-19 severity was associated with increased endothelial dysfunction risk (OR: 1.354; 95% CI: 1.06−1.71; p = 0.011) at multivariate binary logistic analysis. FMD showed a significant direct correlation with PaO2 (p = 0.004), P/F ratio (p = 0.004), FEV1 (p = 0.008), and 6MWT (p = 0.0001). Conclusions: Hospitalized COVID-19 subjects showed an impaired endothelial function three months after the acute phase that correlated with pulmonary function impairment. Further studies are needed to evaluate if these subjects are at higher risk of developing pulmonary disease or future cardiovascular events.

Endothelial cells and blood vessels are major targets for COVID-19-induced tissue injury and spreading to various organs

The coronavirus disease 2019 (COVID-19) infected so far over 250 million people and caused the death of over 5 million worldwide. Aging, diabetes, and cardiovascular diseases, conditions with preexisting impaired endothelial functions predispose to COVID-19. While respiratory epithelium is the main route of virus entry, the endothelial cells (ECs) lining pulmonary blood vessels are also an integral part of lung injury in COVID-19 patients. COVID-19 not only affects the lungs and respiratory system but also gastrointestinal (GI) tract, liver, pancreas, kidneys, heart, brain, and skin. Blood vessels are likely conduits for the virus dissemination to these distant organs. Importantly, ECs are also critical for vascular regeneration during injury/lesions healing and restoration of vascular network. The World Journal of Gastroenterology has published in last two years over 67 outstanding papers on COVID-19 infection with a focus on the GI tract, liver, pancreas, etc., however, the role of the endothelial and vascular components as major targets for COVID-19-induced tissue injury, spreading to various organs, and injury healing have not been sufficiently emphasized. In the present article, we focus on these subjects and on current treatments including the most recent oral drugs molnupiravir and paxlovid that show a dramatic, significant efficacy in controlling severe COVID-19 infection.

Relationship between endothelin and nitric oxide pathways in the onset and maintenance of hypertension in children and adolescents

The mechanisms that regulate blood pressure are numerous and complex; one mechanism that plays an important role in this scenario is represented by the balance between the vasoconstrictor effect of endothelin-1 and the vasodilator effect of nitric oxide. While there is agreement on the fact that increased endothelin-1 activity and decreased nitric oxide bioavailability are present in hypertensive adults, the situation is less clear in children and adolescents. Not all studies agree on the finding of an increase in plasma endothelin-1 levels in hypertensive children and adolescents; in addition, the picture is often confused by the concomitant presence of obesity, a condition that stimulates the production of endothelin-1. Furthermore, there is recent evidence that, in younger obese and hypertensive subjects, there is an overproduction of nitric oxide, rather than a reduction. This condition may change over time, causing endothelial dysfunction due to a reduced availability of nitric oxide in hypertensive adolescents. The purpose of this review is to address the main biochemical and pathophysiological aspects of endothelin and nitric oxide involvement in hypertension and to summarize the available scientific evidence on their role in the onset and maintenance of high blood pressure in children and adolescents.

Endothelial Dysfunction in Childhood Cancer Survivors: A Narrative Review

Assessment of endothelial dysfunction in cancer survivors may have a role in the early identification of non-communicable diseases and cardiovascular late effects. Oncological therapies may impair endothelial function. Therefore, in patients such as childhood cancer survivors who could benefit from early cardioprotective pharmacological interventions, it is essential to monitor endothelial function, even if the optimal methodology for investigating the multifaceted aspects of endothelial dysfunction is still under debate. Biochemical markers, as well as invasive and non-invasive tools with and without pharmacological stimuli have been studied. Human clinical studies that have examined lifestyle or cancer treatment protocols have yielded evidence showing the involvement of lipid and lipoprotein levels, glycemic control, blood pressure, adiposity, inflammation, and oxidative stress markers on the state of endothelial health and its role as an early indicator of cardiometabolic risk. However, with regards to pharmacological interventions, cautious interpretation of the result attained whilst monitoring the endothelial function is warranted due to methodological limitations and substantial heterogeneity of the results reported in the published studies. In this narrative review, an overview of evidence from human clinical trials examining the effects of cancer therapies on endothelial disease is provided together with a discussion of endothelial function assessment using the different non-invasive techniques available for researchers and clinicians, in recent years.

Ameliorative role of rolipram, PDE-4 inhibitor, against sodium arsenite-induced vascular dementia in rats

Arsenic exposure to the population leads to serious health problems like neurotoxicity, nephrotoxicity, and cardiovascular abnormality. In the present study, the work has been commenced to discover the prospect of rolipram a phosphodiestrase-4 (PDE-4) inhibitor against sodium arsenite (SA)-induced vascular endothelial dysfunction (EnDF) leading to dementia in rats. Wistar rats were treated with SA (5 mg/kg body weight/day orally) for 44 days for induction of vascular EnDF and dementia. Learning and memory were evaluated using Morris water maze (MWM) test. Vascular EnDF was evaluated using aortic ring preparation. Various biochemical parameters were also evaluated like brain oxidative stress (viz. reduced glutathione and thiobarbituric acid reactive substances level), serum nitrite/nitrate activity, acetylcholinesterase activity, and inflammatory markers (viz. neutrophil infiltration in brain and myeloperoxidase). SA-treated rats showed poor performance in water maze trials indicating attenuated memory and ability to learn with significant rise (p < 0.05) in brain acetylcholinesterase activity, brain oxidative stress, neutrophil count, and significant decrease (p < 0.05) in serum nitrite/nitrate levels and vascular endothelial functions. Rolipram (PDE-4 inhibitor) treatment (0.03 mg/kg and 0.06 mg/kg body weight, intraperitoneally daily for 14 days) significantly improved memory and learning abilities, and restored various biochemical parameters and EnDF. It is concluded that PDE-4 modulator may be considered the prospective target for the treatment of SA-induced vascular EnDF and related dementia.

Treatment with 2-methoxyestradiol increases endothelial nitric oxide synthase activity via scavenger receptor class BI in human umbilical vein endothelial cells

Concentrations of 2-methoxyestradiol (2ME2), a principal metabolite of estradiol, are significantly lower in women with severe preeclampsia. Nitric oxide (NO) released by endothelial nitric oxide synthase (eNOS) plays an important role in regulating cardiovascular homeostasis. Importantly, high-density lipoprotein (HDL) stimulates eNOS activity via endothelial human scavenger receptor class B type I (hSR-BI/CLA-1). Here, we aimed to determine the effect of 2ME2 on hSR-BI/CLA-1 expression in human umbilical vein endothelial cells (HUVECs). hSR-BI/CLA-1 expression was measured by real-time PCR, western blotting and reporter gene assays; eNOS activity was assessed by the measurement of eNOS phosphorylation. Both the mRNA and protein concentrations of hSR-BI/CLA-1 were significantly increased by 2ME2 in HUVECs. 2ME2 also dose-dependently increased the transcriptional activity of the hSR-BI/CLA-1 promoter. The effect of 2ME2 treatment on the promoter activity of hSR-BI/CLA-1 was abrogated by treatment with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase, as was the increase in HDL-induced eNOS activation. Notably, constitutively active Akt increased the activity of the hSR-BI/CLA-1 promoter, whereas dominant-negative Akt abolished the effect of 2ME2 treatment on hSR-BI/CLA-1 promoter activity. The nuclear Sp1 protein concentration was significantly increased by exposure to 2ME2 and Sp1 overexpression increased the promoter activity of the hSR-BI/CLA gene. Furthermore, knockdown of Sp1 inhibited the effect of 2ME2 treatment on hSR-BI/CLA-1 protein expression. These results indicate that 2ME2 treatment increases HDL-dependent eNOS phosphorylation by upregulating endothelial hSR-BI/CLA-1 expression, suggesting that 2ME2 has a potential therapeutic value in the treatment of preeclampsia.

Does endothelial dysfunction correlate with endocrinal abnormalities in patients with polycystic ovary syndrome?

To study and critically analyze the published evidence on correlation of hormonal abnormalities and endothelial dysfunction (ED) in polycystic ovary syndrome (PCOS) through a systematic review. The databases including MEDLINE, PubMed, Up-To-Date, and Science Direct were searched using Medical subject handling terms and free text term keywords such as endocrine abnormalities in PCOS, ED assessment in PCOS, ED in combination with insulin resistance (IR), hyperandrogenism (HA), increased free testosterone, free androgen index (FAI), gonadotrophin levels, luteinizing hormone (LH), prolactin, estrogen, adipocytokines to search trials, and observational studies published from January 1987 to September 2015. Authors of original studies were contacted for additional data when necessary. PCOS increases the risk of cardiovascular disease in women. ED, which is a reliable indicator of cardiovascular risk in general population, is seen in most (but not all) women with PCOS. IR, seen in 70% patients with PCOS, is associated with ED in these women, but patients can have normal endothelial function even in the presence of IR. Free testosterone and FAI are consistently associated with ED, but endothelial function can be normal despite HA. Estradiol (not estrone) appears to be protective against ED though estrone is the predominant estrogen produced in PCOS. Increased levels of adipocytokines (visfatin) are promising in predicting ED and cardiovascular risk. However, more studies are required focusing on direct correlation of levels of prolactin, LH, estrone, and visfatin with ED in PCOS.

Carotid elasticity is impaired in stage 1 hypertensive patients with well-controlled blood pressure levels

Whether impaired arterial elasticity in stage 1 hypertension can be brought back to normal by antihypertensive treatment is unknown. Aim of this study was to evaluate the impact of long-term well-controlled blood pressure (BP) on carotid artery elasticity and endothelial function in stage 1 hypertensive patients. We studied 40 middle-age hypertensives (mean age 49.7 years) whose BP had been kept at target by pharmacological treatment and/or lifestyle modifications for a mean of 7.5 years. Carotid compliance coefficient (CC) and distensibility coefficient (DC) were measured by B-mode ultrasound system. Measurement of carotid intima-media thickness (IMT) was performed in each carotid artery segment, bilaterally. Endothelial function was evaluated by post-occlusion flow mediated dilation (FMD). Forty normotensive subjects matched for age and sex served as controls. In the hypertensive subjects, BP levels were well controlled throughout the study period (mean office BP 133.7 ± 9.0/81.27 ± 7.0 mmHg). However, compared to controls, significantly higher office BP levels and waist circumference were present. Compared to normotensives, carotid elasticity (DC 24.5 ± 9.0 vs 37.0 ± 8.5 10^-3/kPa, and CC 0.92 ± 0.34 vs 1.28 ± 0.36 mm²/kPa, p < 0.0005 for both) as well as endothelial function (FMD 5.7 ± 2.4% vs 9.2 ± 2.9%, p < 0.0005) were significantly impaired in hypertensives. In a logistic regression, hypertensive patients had increased risk of impaired carotid vascular stiffness (odds ratio, 95% CI: 13.04 (2.27-74.96), p = 0.004). Despite the "pseudo-normalization" of BP levels, hypertensive patients with long-term well-controlled BP according to current standards exhibited increased local arterial stiffness and endothelial dysfunction suggesting that lower BP targets should be sought.

The Effect of Septoplasty on Endothelial Function in Patients With Marked Nasal Septal Deviation

BACKGROUND

It is known that nasal septal deviation (NSD) has negative effects on the cardiovascular system, but the possible pathophysiological mechanisms of these effects still need to be explained. The aim of this study was to investigate the endothelial dysfunction (ED) caused by NSD and the effects of septoplasty on it.

METHODS

The study included 40 patients between the ages of 18 to 50 years with a marked NSD indication for septoplasty and 40 healthy age-and gender-matched individuals. Nasal obstruction symptom evaluation scale was used to evaluate the severity of nasal obstruction and the effectiveness of septoplasty. All participants underwent detailed cardiac examination and ultrasonographic measurement of flow-mediated dilatation (FMD). The same cardiac evaluations and nasal obstruction symptom evaluation scale assessments were repeated in the patient group at the postoperative 3rd month.

RESULTS

The mean FMD value in the control group was significantly higher than preoperative FMD in the patient group (9.1 ± 2.9 versus 7.6 ± 2.4, P = 0.024). In the patient group, preoperative and postoperative FMD values were measured as 7.6 ± 2.4 and 9.0 ± 2.7, respectively, and there was a significant difference between them (P = 0.032). There was no significant difference in FMD values between the control group and postoperative patient group (P = 0.925).

CONCLUSIONS

This study shows that NSD can cause ED, which is a precursor of atherosclerosis, and that successful septoplasty can improve ED.

High total cholesterol and triglycerides levels increase arginases metabolism, impairing nitric oxide signaling and worsening fetoplacental endothelial dysfunction in gestational diabetes mellitus pregnancies

During human pregnancy, maternal physiological dyslipidemia (MPD) supports fetal development. However, some women develop maternal supraphysiological dyslipidemia (MSPD: increased total cholesterol (TC) and triglycerides (TG) levels). MSPD is present in normal and pregnancies with gestational diabetes mellitus (GDM). Both pathologies associate with fetoplacental endothelial dysfunction, producing alterations in nitric oxide (NO)-L-arginine/arginase metabolism. Nevertheless, the effect of MSPD on GDM, and how this synergy alters fetoplacental endothelial function is unknown, which is the aim of this study. 123 women at term of pregnancy were classified as MPD (n=40), MSPD (n=35), GDM with normal lipids (GDM- MPD, n=23) and with increased lipids (GDM-MSPD, n=25). TC ≥291 mg/dL and TG ≥275 mg/dL were considered as MSPD. Endothelial NO synthase (eNOS), human cationic amino acid transporter 1 (hCat1), and arginase II protein abundance and activity, were assayed in umbilical vein endothelial cells. In MSPD and MSPD-GDM, TC and TG increased respect to MPD and MPD-GDM. eNOS activity was reduced in MSPD and MSPD-GDM, but increased in MPD-GDM compared with MPD. No changes were observed in eNOS protein. However, decreased tetrahydrobiopterin levels were observed in all groups compared with MPD. Increased hCat1 protein and L-arginine transport were observed in both GDM groups compared with MPD. However, the transport was higher in GDM-MSPD compared to GDM-MPD. Higher Arginase II protein and activity were observed in MSPD-GDM compared with MPD. Thus, MSPD in GDM pregnancies alters fetal endothelial function associated with NO metabolism.

Effects of Anti-Inflammatory Treatment and Surgical Intervention on Endothelial Glycocalyx, Peripheral and Coronary Microcirculatory Function and Myocardial Deformation in Inflammatory Bowel Disease Patients: A Two-Arms Two-Stage Clinical Trial

Sixty inflammatory bowel disease (IBD) patients (45 Crohn disease and 15 ulcerative colitis, 40 ± 13 years, 53% male) were examined at baseline and 4 months after intervention (surgical (35 patients) or anti-TNFa treatment (25 patients)). IBD severity, using Mayo score, Harvey–Bradshaw Index (HBI) and biomarkers, was correlated with cardiovascular markers. At baseline, the disease severity, the white blood cells (WBC) values and the reducing power (RP) were significantly correlated with the aortic pulse wave velocity (PWV) (r = 0.4, r = 0.44 and r = 0.48, p < 0.05) and the lateral mitral E’ velocity (r = 0.35, p < 0.05 and r = 0.3, p < 0.05). Four months after intervention, there was a reduction of WBC (1962.8/mm³ ± 0.425/mm³, p < 0.001), C-reactive protein (CRP) (8.1 mg/L ± 1.7 mg/L, p < 0.001), malondialdehyde (MDA) (0.81 nmol/mg ± 0.37, p < 0.05) and glycocalyx perfused boundary region (PBR 5-25) (0.24 μm ± 0.05 μm, p < 0.01). Moreover, the brachial flow mediated dilatation (FMD), the coronary flow reserve (CFR) and the left ventricle global longitudinal strain (LV GLS) were significantly improved for both groups (4.5% ± 0.9%, 0.55 ± 0.08, 1.4% ± 0.35%, p < 0.01), while a more significant improvement of PWV/GLS was noticed in the anti-TNFa group. IBD severity is associated with vascular endothelial, cardiac diastolic, and coronary microcirculatory dysfunction. The systemic inflammatory inhibition and the local surgical intervention lead to significant improvement in endothelial function, coronary microcirculation and myocardial deformation.

Vascular endothelial damage in COPD: current functional assessment methods and future perspectives

Introduction: Cardiovascular disease is a major cause of death in chronic obstructive pulmonary disease (COPD), but the relationship between these two entities is not fully understood; smoking, inflammation, arterial stiffness and endothelial dysfunction are significant determinants. Endothelial dysfunction is not only associated with cardiovascular disease, but also with COPD severity.Areas covered: Several functional methods have been developed to evaluate endothelial function in healthy and diseased individuals; from the invasive angiography of epicardial coronary arteries and Venous-Occlusion-Plethysmography, to more modern, noninvasive approaches such as Flow-Mediated-Dilatation, Peripheral-Arterial-Tonometry and Near-Infrared-Spectroscopy, all these methods have boosted clinical research in this field. In this context, this narrative review, which included articles published in PubMed and Scopus up to 25-November-2020, summarizes available functional methods for endothelial damage assessment in COPD and discusses existing evidence on their associations with comorbidities and outcomes in this population.Expert opinion: Accumulated evidence suggests that endothelial dysfunction occurs in early stages of CΟPD and worsens with pulmonary obstruction severity and during acute exacerbations. Novel methods evaluating endothelial function offer a detailed, real-time assessment of different parameters related to vascular function and should be increasingly used to shed more light on the role of endothelial damage on cardiovascular and COPD progression.

Coronary heart disease risk: Low-density lipoprotein and beyond

Coronary heart disease (CHD) is the leading cause of morbidity and mortality world-wide and has been characterized as a chronic immunoinflammatory, fibroproliferative disease fueled by lipids. Great advances have been made in elucidating the complex mechanistic interactions among risk factors associated with CHD, yielding abundant success towards preventive measures and the development of pharmaceuticals to prevent and treat CHD via attenuation of lipoprotein-mediated risk. However, significant residual risk remains. Several potentially modifiable CHD risk factors ostensibly contributing to this residual risk have since come to the fore, including systemic inflammation, diabetes mellitus, high-density lipoprotein, plasma triglycerides (TG) and remnant lipoproteins (RLP), lipoprotein(a) (Lp[a]), and vascular endothelial dysfunction (ED). Herein, we summarize the body of evidence implicating each of these risk factors in residual CHD risk.

High-sodium diet does not worsen endothelial function in female patients with postural tachycardia syndrome

PURPOSE

Postural tachycardia syndrome (POTS), a syndrome characterized by orthostatic symptoms and a heart rate increase of at least 30 beats per minute in the absence of hypotension upon standing, is often accompanied by increased sympathetic activity and low blood volume. A common non-pharmacologic recommendation for patients with POTS is a high-sodium (HS) diet with the goal of bolstering circulating blood volume. The objective of this study is to assess the effects of 6 days of a HS diet on endothelial function in POTS.

METHODS

A total of 14 patients with POTS and 13 age-matched healthy controls, all females, were studied following 6 days on a low-sodium (LS) diet (10 mEq/day) and 6 days on a HS diet (300 mEq/day) in a crossover design. We measured endothelial function following reactive hyperemia in the brachial artery using flow-mediated dilation (FMD), leg blood flow (LBF) using strain gauge plethysmography in the calf, and reactive hyperemic index (RHI) in the microcirculation of the hand using pulsatile arterial tonometry.

RESULTS

On the LS diet, FMD% did not differ between patients with POTS and the healthy controls although peak brachial artery diameter was lower for the patient group. RHI was higher for the patient group than for the controls, but there were no differences in post-ischemic LBF increase. On the HS diet, there were no between-group differences in FMD%, LBF increase, or RHI.

CONCLUSION

In summary, a HS diet for 6 days did not induce endothelial dysfunction. This non-pharmacologic treatment used for patients with POTS does not negatively affect endothelial function when used for a sub-acute duration.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01550315; March 9, 2012.

Effects of lipoproteins on endothelial cells and macrophages function and its possible implications on fetal adverse outcomes associated to maternal hypercholesterolemia during pregnancy

Hypercholesterolemia is one of the main risk factors associated with atherosclerosis and cardiovascular disease, the leading cause of death worldwide. During pregnancy, maternal hypercholesterolemia develops, and it can occur in a physiological (MPH) or supraphysiological (MSPH) manner, where MSPH is associated with endothelial dysfunction and early atherosclerotic lesions in the fetoplacental vasculature. In the pathogenesis of atherosclerosis, endothelial activation and endothelial dysfunction, characterized by an imbalance in the bioavailability of nitric oxide, contribute to the early stages of this disease. Macrophages conversion to foam cells, cholesterol efflux from these cells and its differentiation into a pro- or anti-inflammatory phenotype are also important processes that contribute to atherosclerosis. In adults it has been reported that native and modified HDL and LDL play an important role in endothelial and macrophage function. In this review it is proposed that fetal lipoproteins could be also relevant factors involved in the detrimental vascular effects described in MSPH. Changes in the composition and function of neonatal lipoproteins compared to adults has been reported and, although in MSPH pregnancies the fetal lipid profile does not differ from MPH, differences in the lipidomic profiles of umbilical venous blood have been reported, which could have implications in the vascular function. In this review we summarize the available information regarding the effects of lipoproteins on endothelial and macrophage function, emphasizing its possible implications on fetal adverse outcomes associated to maternal hypercholesterolemia during pregnancy.

Chemotherapy-induced acute vascular injury involves intracellular generation of ROS via activation of the acid sphingomyelinase pathway

Several categories of chemotherapy confer substantial risk for late-term vascular morbidity and mortality. In the present study, we aimed to investigate the mechanism of acute chemotherapy-induced vascular injury in normal tissues. Specifically, we looked at activation of the acid sphingomyelinase (ASMase)/ceramide pathway, which leads to generation of reactive oxygen species (ROS) and induction of oxidative stress that may result in vascular injury. In particular, we focused on two distinct drugs, doxorubicin (DOX) and cisplatin (CIS) and their effects on normal endothelial cells. In vitro, DOX resulted in increased ASMase activity, intra-cellular ROS production and induction of apoptosis. CIS treatment generated significantly reduced effects in endothelial cells. In-vivo, murine femoral arterial blood flow was measured in real-time, during and after DOX or CIS administration, using fluorescence optical imaging system. While DOX caused constriction of small vessels and disintegration of large vessels' wall, CIS induced minor vascular changes in arterial blood flow, correlating with the in vitro findings. These results demonstrate that DOX induces acute vascular injury by increased ROS production, via activation of ASMase/ceramide pathway, while CIS increases ROS production and its immediate extracellular translocation, without causing detectable acute vascular injury. Our findings may potentially lead to the development of new strategies to prevent long-term cardiovascular morbidity in cancer survivors.

Effects of nifedipine on endothelial function, assessed by flow-mediated vasodilatation in pregnant patients

OBJECTIVES

To evaluate the endothelial function, through flow-mediated vasodilation parameters from brachial artery test in women receiving nifedipine for acute tocolysis with threatened preterm delivery.

METHODS

In a prospective study in a university-affiliated hospital, each participant served as herself control. We evaluated various parameters of endothelial function in 22 patients between 27 and 33 weeks of gestation with a diagnosis of threatened preterm delivery (TPTD) before and after 48 h of nifedipine treatment. Each patient received 80 mg nifedipine per day. The assessment tool was Brachial artery reactivity test (BART). Primary outcome was flow mediated vasodilation (FMD).

RESULTS

The average participant's age was 27 ± 4.5 years, median gestational age of 28.5 weeks, BMI, kg/m² (mean ± SD) 28.4 ± 3.3. Systolic blood pressure (mmHg) and diastolic blood pressure (mmHg) decreased from 108 ± 6 to 104 ± 5, p < .001 and from 66 ± 4 to 63 ± 4, p < .001, respectively. FMD (%) significantly decrease from 10.8 ± 6.1 to 7.2 ± 4.7, p = .03 prior to and after nifedipine treatment. The basal brachial artery diameter (mm) at rest was (3.19 ± 0.38 versus 3.39 ± 0.49, p = .28) before versus after nifedipine. The largest brachial artery diameter (mm) was (3.54 ± 0.35 versus 3.58 ± 0.44, p = .76) before versus after nifedipine.

CONCLUSIONS

Our results suggest unfavorable changes in FMD probably as a result of nifedipine used for acute tocolysis. Future prospective studies should try to evaluate the safety of acute and maintenance tocolytic therapy with nifedipine on endothelial function in pregnant women.

Carfilzomib-induced endothelial dysfunction, recovery of proteasome activity, and prediction of cardiovascular complications: a prospective study

Carfilzomib (CFZ) improves survival in relapsed/refractory multiple myeloma but is associated with cardiovascular adverse events (CVAEs). We prospectively investigated the effect of CFZ on endothelial function and associations with CVAEs. Forty-eight patients treated with Kd (CFZ 20/56 mg/m² and dexamethasone) underwent serial endothelial function evaluation, using brachial artery flow-mediated dilatation (FMD) and 26S proteasome activity (PrA) measurement in PBMCs; patients were followed until disease progression or cycle 6 for a median of 10 months. FMD and PrA decreased acutely after the first dose (p < 0.01) and FMD decreased at cycles 3 and 6 compared to baseline (p ≤ 0.05). FMD changes were associated with CFZ-induced PrA changes (p < 0.05) and lower PrA recovery during first cycle was associated with more prominent FMD decrease (p = 0.034 for group interaction). During treatment, 25 patients developed Grade ≥3 CVAEs. Low baseline FMD (HR 2.57 lowest vs. higher tertiles, 95% CI 1.081-6.1) was an independent predictor of CVAEs. During treatment, an acute FMD decrease >40% at the end of first cycle was also independently associated with CVAEs (HR = 3.91, 95% CI 1.29-11.83). Kd treatment impairs endothelial function which is associated with PrA inhibition and recovery. Both pre- and posttreatment FMD predicted CFZ-related CVAEs supporting its role as a possible cardiovascular toxicity biomarker.

Non-Invasive Detection of Fetal Vascular Endothelial Function in Gestational Diabetes Mellitus

OBJECTIVES

Endothelial dysfunction in the fetuses of women with gestational diabetes mellitus (GDM) is associated with their subsequent cardiovascular events. Prenatal assessment of endothelial function in fetuses exposed to intrauterine hyperglycemic environment remains challenging. The aim of this study was to assess the fetal vascular endothelial function in GDM patients using color M-mode derived aortic propagation velocity (APV) and evaluate the correlation of APV with endothelial function biomarkers.

METHODS

This observational cross-sectional study included 31 gestational diabetic mothers and 30 healthy pregnant mothers from August 2019 to January 2020. Clinical data were compared between the groups. Fetal APV was measured using color M-mode echocardiography at late gestation. Concentrations of endothelial biomarkers including von Willebrand Factor (vWF), vascular endothelial-cadherin and endothelin-1 in umbilical cord serum were assessed. Measurements between diabetic group and controls were compared.

RESULTS

vWF was the only endothelial functional marker that differed between the two groups. Fetuses in the GDM group had significantly lower APV levels and higher vWF levels compared with the healthy controls (P < 0.05). There was a moderate but significant correlation between APV and vWF (r =-0.58, P < 0.001). There were no associations between APV and ventricular wall thickness or umbilical artery pulsatility index.

CONCLUSIONS

Color M-mode propagation velocity of aorta is a non-invasive, practical method that correlates well with GDM and fetal endothelial function. This novel metric could contribute to recognizing early vascular functional alterations and hence represents a potential strategy for early risk factor surveillance and risk modification.

Endothelial function in cardiovascular medicine: a consensus paper of the European Society of Cardiology Working Groups on Atherosclerosis and Vascular Biology, Aorta and Peripheral Vascular Diseases, Coronary Pathophysiology and Microcirculation, and Thrombosis

Endothelial cells (ECs) are sentinels of cardiovascular health. Their function is reduced by the presence of cardiovascular risk factors, and is regained once pathological stimuli are removed. In this European Society for Cardiology Position Paper, we describe endothelial dysfunction as a spectrum of phenotypic states and advocate further studies to determine the role of EC subtypes in cardiovascular disease. We conclude that there is no single ideal method for measurement of endothelial function. Techniques to measure coronary epicardial and micro-vascular function are well established but they are invasive, time-consuming, and expensive. Flow-mediated dilatation (FMD) of the brachial arteries provides a non-invasive alternative but is technically challenging and requires extensive training and standardization. We, therefore, propose that a consensus methodology for FMD is universally adopted to minimize technical variation between studies, and that reference FMD values are established for different populations of healthy individuals and patient groups. Newer techniques to measure endothelial function that are relatively easy to perform, such as finger plethysmography and the retinal flicker test, have the potential for increased clinical use provided a consensus is achieved on the measurement protocol used. We recommend further clinical studies to establish reference values for these techniques and to assess their ability to improve cardiovascular risk stratification. We advocate future studies to determine whether integration of endothelial function measurements with patient-specific epigenetic data and other biomarkers can enhance the stratification of patients for differential diagnosis, disease progression, and responses to therapy.

Assessment of Endothelial and Microvascular Function in CKD: Older and Newer Techniques, Associated Risk Factors, and Relations with Outcomes

BACKGROUND

Endothelium is the inner cellular lining of the vessels that modulates multiple biological processes including vasomotor tone, permeability, inflammatory responses, hemostasis, and angiogenesis. Endothelial dysfunction, the basis of atherosclerosis, is characterized by an imbalance between endothelium-derived relaxing factors and endothelium-derived contracting factors.

SUMMARY

Starting from the semi-invasive venous occlusion plethysmography, several functional techniques have been developed to evaluate microvascular function and subsequently used in patients with CKD. Flow-mediated dilatation of the forearm is considered to be the "gold standard," while in the last years, novel, noninvasive methods such as laser speckle contrast imaging and near-infrared spectroscopy are scarcely used. Moreover, several circulating biomarkers of endothelial function have been used in studies in CKD patients. This review summarizes available functional methods and biochemical markers for the assessment of endothelial and microvascular function in CKD and discusses existing evidence on their associations with comorbid conditions and outcomes in this population. Key Messages: Accumulated evidence suggests that endothelial dysfunction occurs early in CKD and is associated with target organ damage, progression of renal injury, cardiovascular events, and mortality. Novel methods evaluating microvascular function can offer a detailed, real-time assessment of underlying phenomena and should be increasingly used to shed more light on the role of endothelial dysfunction on cardiovascular and renal disease progression in CKD.

Renal Resistive Index of the Main Renal Arteries and Transmitral Flow in Hypertensive Patients

In hypertensive patients, diastolic dysfunction is related to increased resistive index (RI) of parenchymal renal arteries. To determine the existence of a link between RI of the main renal arteries (RRI) and diastolic dysfunction, a group of 127 hypertensive patients, with glomerular filtration rates >50 mL/min (mean estimated glomerular filtration rate: 88.6 ± 15.2 mL/min) and no comorbidities, was studied. RRI and transmitral flow were evaluated using the deceleration time (DT) and E/A ratio. A statistically significant correlation between RRI and DT (>240 ms) was noted (p < 0.001). The RRI cutoff that best discriminated patients with DT >240 ms was 0.675. For each unitary increment of 10 mm in DT, the log-transformed RRI significantly increased by a mean of 0.006 point (p < 0.001). This study revealed the importance of the link between RRI and transmitral DT in addition to the renowned significance of the increase in RI as a cardiovascular risk factor in hypertensive patients without comorbidities.

Endothelial and Cardiac Dysfunction in Inflammatory Bowel Diseases: Does Treatment Modify the Inflammatory Load on Arterial and Cardiac Structure and Function?

Inflammatory bowel diseases (IBD), largely represented by Crohn's disease (CD) and ulcerative colitis (UC), alter gastrointestinal physiology and mucosal immunity through a complex inflammatory process. These diseases can lead to significant arterial endothelial dysfunction. There is also evidence linking IBD with a modification of cardiac structure and function. A growing body of research has associated IBD with an acceleration of arterial stiffness and atherosclerosis and an increased risk of cardiovascular (CV) morbidity and mortality. The focus of this review is two-fold. Firstly, the literature on IBD in relation to CV dysfunction was evaluated (mainly based on 25 relevant surveys carried out between 2005 and 2018). The vast majority of these studies support a significant association of IBD with a deterioration in CV function. Secondly, the literature available regarding the effect of IBD treatment on CV dysfunction was considered based on studies published between 2007 and 2018. This literature search suggests that IBD treatment may have the potential to ameliorate CV dysfunction resulting in CV benefits. This review will analyse the literature as well as consider emerging research perspectives regarding how IBD treatment could improve CV dysfunction.

Biased signaling in platelet G-protein coupled receptors

Platelets are small megakaryocyte-derived, anucleate, disk-like structures that play an outsized role in human health and disease. Both a decrease in the number of platelets and a variety of platelet function disorders result in petechiae or bleeding that can be life threatening. Conversely, the inappropriate activation of platelets, within diseased blood vessels, remains the leading cause of death and morbidity by affecting heart attacks and stroke. The fine balance of the platelet state in healthy individuals is controlled by a number of receptor-mediated signaling pathways that allow the platelet to rapidly respond and maintain haemostasis. G-protein coupled receptors (GPCRs) are particularly important regulators of platelet function. Here we focus on the major platelet-expressed GPCRs and discuss the roles of downstream signaling pathways (e.g., different G-protein subtypes or β-arrestin) in regulating the different phases of the platelet activation. Further, we consider the potential for selectively targeting signaling pathways that may contribute to platelet responses in disease through development of biased agonists. Such selective targeting of GPCR-mediated signaling pathways by drugs, often referred to as biased signaling, holds promise in delivering therapeutic interventions that do not present significant side effects, especially in finely balanced physiological systems such as platelet activation in haemostasis.

End-stage renal failure is associated with impaired coronary microvascular function

BACKGROUND

Cardiovascular disease is the leading cause of death in patients with chronic kidney disease. Studies investigating the disproportionate burden of cardiovascular disease have occurred predominantly in the peripheral vasculature, often used noninvasive imaging modalities, and infrequently recruited patients receiving dialysis. This study sought to evaluate invasive coronary dynamic vascular function in patients with end-stage renal failure (ESRF).

PATIENTS AND METHODS

Patients referred for invasive coronary angiography prior to renal transplantation were invited to participate. Control patients were recruited in parallel. Baseline characteristics were obtained. Coronary diameter (via quantitative coronary angiography) and coronary blood flow (via Doppler Flowire) were measured; macrovascular endothelial-dependent and independent effects were evaluated in response to intracoronary acetylcholine infusion (10 and 10 mol/l) and intracoronary glyceryl trinitrate, respectively. Microvascular function was evaluated by response to adenosine and expressed as coronary flow velocity reserve. Mean values were compared.

RESULTS

Thirty patients were evaluated: 15 patients with ESRF (mean age 52.1 ± 9, male 73%) and 15 control patients (mean age 53.3 ± 13, male 60%). Comorbidity profile, aside from ESRF, was well matched. Baseline coronary blood flow was similar between groups (101.6 ± 10.3 vs. 103.4 ± 9.1 ml/min, P = 0.71), as was endothelial-dependent response to acetylcholine (159.1 ± 16.9 vs. 171.1 ± 16.8 ml/min, P = 0.41). Endothelial-independent response to glyceryl trinitrate was no different between groups (14.3 ± 3.1 vs. 13.1 ± 2.3%, P = 0.73. A significantly reduced coronary flow velocity reserve was observed in the ESRF cohort compared to controls (2.34 ± 0.4 vs. 3.05 ± 0.3, P = 0.003).

CONCLUSION

Patients with ESRF had preserved endothelial-dependent function however compared to controls, demonstrated significantly attenuated microvascular reserve. An impaired response to adenosine may not only represent a component of the pathophysiological milieu in patients with ESRF but may also provide a basis for the suboptimal diagnostic performance of vasodilatory stress in this population.