Perfused Boundary Region Research Articles

The Effects of High Salt and Western Diets on Microcirculatory and Glycocalyx Properties in Genetically Heterogeneous Young Mice

A prominent feature of cardiovascular disease is microcirculatory dysfunction, characterized by low capillary density and a deteriorated glycocalyx. In most industrialized societies, individuals consume a high salt diet in combination with a western diet, characterized by excess consumption of fat and sugar. Therefore, we sought to determine the effects of high salt and/or western diet in genetically heterogeneous young mice. At 3 mo old, male and female UM‐HET3 mice were randomized into 1 of 4 dietary interventions for 12 weeks: 1. Normal chow diet (NC) (fat 13.5% kcal fat, N=19) 2. NC diet with 4% salt (NC4%) (13.0% kcal fat, N=19) 3. Western diet (WD) (39.1% kcal fat, N=19) 4. WD with 4% salt (WD4%) (40.4% kcal fat, N=18) Microvascular density and glycocalyx barrier function were evaluated in 4‐25 µm diameter microvessel segments in the mesenteric microcirculation using an intravital microscope equipped with an automated capture and analysis system. After 12 weeks of dietary intervention, WD and WD4% had ~32‐42% greater body mass and ~13‐16% greater blood glucose level than NC and NC4% (P<0.05 for all). Microvascular density at each microvessel segment diameter is presented in Figure 1A. Total microvascular density summed across 4‐25 µm microvessel segment diameters was lower in NC4% compared to NC, WD, and WD4% (Figure 1B; P<0.05). Total microvascular density in WD4% was also lower than NC (P<0.05). After separating microvessels into capillaries (4‐6 µm diameter) and large microvessels (10‐25 µm diameter), capillary density was lower in NC4% compared to NC, WD, and WD4% (Figure 1C; P<0.05). Capillary density was higher in WD compared to NC (P<0.05). Large microvessel density was lower in NC4% and WD4% compared to NC (Figure 1D; P<0.05). Perfused boundary region (PBR), a marker of glycocalyx barrier function, at each microvessel segment diameter is presented in Figure 2A. PBR averaged across 4‐25 µm microvessel segment diameters was similar between NC and NC4%, as well as between WD and WD4% (Figure 2B; P>0.05). Surprisingly, PBR was lower in WD and WD4% compared to NC and NC4% (P<0.05), indicating augmented glycocalyx barrier function in WD and WD4%. Capillary PBR was also lower in WD and WD4% and trending toward lower in NC (P=0.07) compared to NC4% (Figure 2C; P<0.05). Large microvessel PBR was lower in WD and WD4% compared to NC and NC4% (Figure 2D; P<0.05). There were strong, inverse relationships between PBR and body mass (Figure 2E; r=‐0.60, P<0.05) and blood glucose (Figure 2F; r=‐0.47, P<0.05). In summary, NC4% decreased microvascular density and glycocalyx barrier function. Although WD increased body mass and blood glucose, it appeared to augment capillary density and glycocalyx barrier function. Interestingly, the combination of high salt, western diet in WD4% resulted in lower total microvascular density that was similar to NC4%, as well as an elevation in body mass, blood glucose, capillary density, and glycocalyx barrier function that was similar to WD. These data indicate that there are distinct microcirculatory adaptations to high salt and western diets that appear to superimpose when these diets are combined in genetically heterogeneous male and female mice.

Aortic Stiffness is Negatively Associated with Microvascular Glycocalyx Thickness and Microvascular Perfusion among Older Adults: Role of Carotid Pressure Pulsatility

IntroductionThe glycocalyx layer is essential to the maintenance of a healthy microvascular endothelium and diminishes with advancing age. Similarly, the aorta stiffens with aging and increases the risk of cardiovascular disease and target organ damage, possibly through pressure pulsatility‐associated microvascular damage. However, whether aortic stiffness and/or pressure pulsatility are associated with microvascular endothelial glycocalyx structure/function among older adults is unknown. Therefore, the objective of this analysis was to investigate the potential relation between aortic stiffness and pressure pulsatility with glycocalyx thickness and microvascular perfusion in older adults. We hypothesized that increased aortic stiffness and pressure pulsatility would be associated with less glycocalyx thickness and microvascular perfusion in older adults.MethodsSublingual microvessels were assessed using intravital microscopy in older adults (n=24; age 61 ± 6y, 46% women). Perfused boundary region (PBR) and red blood cell (RBC) filling %, indirect indices of glycocalyx thickness (larger PBR=smaller thickness) and microvascular perfusion respectively, were determined in vessels between 5‐25 µm RBC column width. Aortic stiffness was quantified by carotid‐femoral pulse wave velocity (cfPWV) and carotid pressure pulsatility as carotid pulse pressure (PP)/mean arterial pressure (MAP).ResultsAdjusting for age, sex and MAP, cfPWV was associated with larger PBR 5‐25 (β: 0.08; p=0.001) and lower RBC filling % (β: ‐0.02, p=0.002). Higher carotid pressure pulsatility was associated with lower RBC filling % (β: ‐0.12; p=0.03), but this relation was attenuated after adjusting for sex (p=0.11). Upon stratification by sex, higher carotid pressure pulsatility was associated with larger PBR 5‐25 (r=0.66, P=0.03) and lower RBC filling % (r=‐0.73, P=0.01) in women, but not men (P=0.94 and P=0.77 respectively).ConclusionHigher aortic stiffness was negatively associated with microvascular glycocalyx thickness and microvascular perfusion among older adults. Additionally, carotid pressure pulsatility was negatively associated with glycocalyx thickness and microvascular perfusion in women only. The mechanisms that contribute to sex differences in the relation between pressure pulsatility and glycocalyx structure/function in older adults require further study.

Sublingual microcirculatory alterations during the immediate and early postoperative period: A systematic review and meta-analysis.

The incidence of postoperative microcirculatory flow alterations and their effect on outcome have not been studied extensively. This systematic review and meta-analysis were designed to investigate the presence of sublingual microcirculatory flow alterations during the immediate and early postoperative period and their correlation with complications and survival. A systematic search of PubMed, Scopus, Embase, PubMed Central, and Google Scholar was conducted for relevant articles from January 2000 to March 2021. Eligibility criteria were randomized controlled and non-randomized trials. Case reports, case series, review papers, animal studies and non-English literature were excluded. The primary outcome was the assessment of sublingual microcirculatory alterations during the immediate and early postoperative period in adult patients undergoing surgery. Risk of bias was assessed with the Ottawa-Newcastle scale. Standard meta-analysis methods (random-effects models) were used to assess the difference in microcirculation variables. Thirteen studies were included. No statistically significant difference was found between preoperative and postoperative total vessel density (p = 0.084; Standardized Mean Difference (SMD): -0.029; 95%CI: -0.31 to 0.26; I2 = 22.55%). Perfused vessel density significantly decreased postoperatively (p = 0.035; SMD: 0.344; 95%CI: 0.02 to 0.66; I2 = 65.66%), while perfused boundary region significantly increased postoperatively (p = 0.031; SMD: -0.415; 95%CI: -0.79 to -0.03; I2 = 37.21%). Microvascular flow index significantly decreased postoperatively (p = 0.028; SMD: 0.587; 95%CI: 0.06 to 1.11; I2 = 86.09%), while no statistically significant difference was found between preoperative and postoperative proportion of perfused vessels (p = 0.089; SMD: 0.53; 95%CI: -0.08 to 1.14; I2 = 70.71%). The results of the non-cardiac surgery post-hoc analysis were comparable except that no statistically significant difference in perfused vessel density was found (p = 0.69; SMD: 0.07; 95%CI: -0.26 to 0.39; I2 = 0%). The included studies investigate heterogeneous groups of surgical patients. There were no randomized controlled trials. Significant sublingual microcirculatory flow alterations are present during the immediate and early postoperative period. Further research is required to estimate the correlation of sublingual microcirculatory flow impairment with complications and survival.

Microvascular rarefaction in patients with cerebrovascular events.

Capillary density rarefaction and endothelial dysfunction contribute to chronic hypoperfusion and cerebral small vessel disease. Previous animal experiments revealed spatiotemporal microvascular remodeling directing post-stroke brain reorganization. We hypothesized that microcirculatory changes during acute cerebrovascular events could be reflected systemically and visualized sublingually. In a prospective observational trial in vivo sublingual sidestream darkfield videomicroscopy was performed in twenty-one patients with either acute stroke (n=13 ischemic, n=1 ischemic with hemorrhagic transformation and n=2 hemorrhagic stroke) or transitory ischemic attacks (n=5) within 24h after hospital admission and compared to an age- and sex-matched control group. Repetitive measurements were performed on the third day and after one week. Functional and perfused total capillary density was rarefied in the overall patient group (3060 vs 3717μm/mm2, p=0.001 and 5263 vs 6550μm/mm2, p=0.002, respectively) and in patients with ischemic strokes (2897 vs. 3717μm/mm2, p<0.001 and 5263 vs. 6550μm/mm2, p=0.006, respectively) when compared to healthy controls. The perfused boundary region (PBR), which was measured as an inverse indicator of glycocalyx thickness, was markedly related to red blood cell (RBC) filling percentage (regarded as an estimate of microvessel perfusion) in the overall patient group (r=-0.843, p<0.001), in patients with ischemic strokes (r=-0.82, p=0.001) as well as in healthy volunteers (r=-0.845, p<0.001). In addition, there were significant associations between platelet count or platelet aggregation values (as measured by whole blood impedance aggregometry) and microvascular parameters in the overall patient collective, as well as in patients with ischemic strokes. In conclusion, cerebrovascular events are associated with altered systemic microvascular perfusion.

Differences in Left atrial stain, endothelial glycocalyx and arterial elasticity between ESUS, lacunar and atherosclerotic type of stroke

Abstract Funding Acknowledgements Type of funding sources: None. Background and Aims Patients with stroke are at high risk to develop cardiovascular complications. We assessed endothelial glycocalyx, aortic elastic properties, left atrial and ventricular function in patients with lacunar, atherosclerotic and stroke of undetermined source (ESUS). Patients and methods In 75 patients (age 55.2 ± 10.6) with acute cerebral stroke (25 lacunar, 20 atherosclerotic and 30 ESUS) and 20 controls with similar risk factors, we measured: (1) perfused boundary region (PBR) of the sublingual arterial microvessels (range 5–25 µm), a marker inversely related with glycocalyx thickness, (2) pulse wave velocity (PWV), central systolic blood pressure (cSBP), and augmentation index (AIx), (3) Left atrial (LA) strain using speckle-tracking imaging, and (4) left ventricular global longitudinal strain. Results Compared with controls, patients with stroke had higher PWV (11.38 ± 3.62 vs 9.51 ± 1.57 m/sec, p = 0.045), PBR (2.10 ± 0.27 vs 1.94 ± 0.20, p = 0.039) and central SBP (139.64 ± 26.31 vs 116.36 ± 37.23 mmHg, p = 0.039), while ventricular (-17.902 ± 3.77 vs - 19.87 ± 1.17%, p = 0.025) and atrial deformation (24.8 ± 9.99 vs 39.05 ± 2.08%, p &amp;lt; 0.001) were impaired in patients with stroke (p &amp;lt; 0.05). LA reservoir strain was more reduced in ESUS patients compared to other 2 stroke types (ESUS 21.7 ± 6.6%, Lacunar 25.6 ± 13.2%, atherosclerotic 22.3 ± 7.8%, P &amp;lt; 0.05). Regarding endothelial glycocalyx, PBR5-9 (the smallest vessels with diameter 5-9 μm) was higher in patients with ESUS than in the other two types of stroke (ESUS 1.22 ± 0.12 μm, LACUNAR 1.19 ± 0.12 μm, ATHEROSCLEROTIC 1.15 ± 0.09 μm, p &amp;lt; 0.05), despite the fact that PBR5-25 was similar between all stroke types (ESUS 2.09 ± 0.23 μm, LACUNAR 2.13 ± 0.33 μm, ATHEROSCLEROTIC 2.09 ± 0.24 μm, p = 0.8). PWV was significantly higher in patients with atherosclerotic stroke (15.57 ± 5.50 m/sec, p = 0.007), while in patients with lacunar it was mildly elevated (10.53 ± 3.22 m/sec) and in ESUS patients it was moderately increased (11.7 ± 3 m/sec). Conclusions Patients with stroke have impaired atrial strain, endothelial glycocalyx and arterial elasticity, compared with controls. Arterial stiffness is more affected in atherosclerotic stroke, while LA deformation and glycocalyx of small size micro vessels are more affected in ESUS patients.

Association of COVID-19 with impaired endothelial glycocalyx, coronary flow and longitudinal strain four months after infection

Abstract Funding Acknowledgements Type of funding sources: None. Aims SARS-CoV-2 infection may lead to endothelial and vascular dysfunction. We investigated alterations of arterial stiffness, endothelial coronary and myocardial function markers four months after COVID-19 infection. Methods In a case-control prospective study, we included 100 patients four months after COVID-19 infection, 50 age- and sex-matched healthy individuals. We measured a) perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced endothelial glycocalyx thickness), b) flow-mediated dilation (FMD), c) coronary Flow Reserve (CFR) by Doppler echocardiography d) pulse wave velocity (PWV) e) global left (LV) and right (RV) ventricular longitudinal strain (GLS), f) malondialdehyde (MDA), an oxidative stress marker, von-Willenbrand factor and thrombomodulin as endothelial biomarkers. Results COVID-19 patients had lower CFR and FMD values than controls (2.39 ± 0.39 vs 3.31 ± 0.59, p = 0.0122, 5.12 ± 2.95% vs 8.12 ± 2.23%, p = 0.006 respectively). Compared to controls, COVID-19 had greater PBR5-25 (2.11 ± 0.14μm vs 1.87 ± 0.16μm, p = 0.002), higher PWV (PWVc-f 12.32 ± 2.44 vs 10.11 ± 1.85 m/sec, p = 0.033) and impaired LV and RV GLS (-19.11 ± 2.14% vs -20.41 ± 1.61%, p = 0.001 and -16.45 ± 3.33% vs -20.11 ± 2.48%, p &amp;lt; 0.001). MDA and thrombomodulin were higher in COVID-19 patients than controls (10.55 ± 2.45 vs 1.01 ± 0.50 nmole/L, p = 0.001 and 3716.63 ± 188.36 vs 2590.02 ± 156.51pg/ml, p &amp;lt; 0.001). Residual cardiovascular symptoms at 4 months were associated with oxidative stress and endothelial dysfunction markers. Conclusions SARS-CoV-2 may cause endothelial and vascular dysfunction linked to impaired cardiac performance four months after infection.

Apremilast Improves Endothelial Glycocalyx Integrity, Vascular and Left Ventricular Myocardial Function in Psoriasis

The phosphodiesterase 4 inhibitor apremilast is used for the treatment of psoriasis. We investigated the effects of apremilast on endothelial glycocalyx, vascular and left ventricular (LV) myocardial function in psoriasis. One hundred and fifty psoriatic patients were randomized to apremilast (n = 50), anti-tumor necrosis factor-α (etanercept; n = 50), or cyclosporine (n = 50). At baseline and 4 months post-treatment, we measured: (1) Perfused boundary region (PBR), a marker of glycocalyx integrity, in sublingual microvessels with diameter 5–25 μm using a Sidestream Dark Field camera (GlycoCheck). Increased PBR indicates damaged glycocalyx. Functional microvascular density, an index of microvascular perfusion, was also measured. (2) Pulse wave velocity (PWV-Complior) and (3) LV global longitudinal strain (GLS) using speckle-tracking echocardiography. Compared with baseline, PBR5–25 μm decreased only after apremilast (−12% at 4 months, p < 0.05) whereas no significant changes in PBR5–25 μm were observed after etanercept or cyclosporine treatment. Compared with etanercept and cyclosporine, apremilast resulted in a greater increase of functional microvascular density (+14% versus +1% versus −1%) and in a higher reduction of PWV. Apremilast showed a greater increase of GLS (+13.5% versus +7% versus +2%) than etanercept and cyclosporine (p < 0.05). In conclusion, apremilast restores glycocalyx integrity and confers a greater improvement of vascular and myocardial function compared with etanercept or cyclosporine after 4 months.

Microcirculatory and glycocalyx properties are lowered by high-salt diet but augmented by Western diet in genetically heterogeneous mice.

Many individuals in industrialized societies consume a high-salt, Western diet(WD); however, the effects of this diet on microcirculatory properties and glycocalyx barrier function are unknown. Young genetically heterogeneous male and female mice underwent 12 wk of normal chow (NC) diet, NC diet with 4% salt (NC4%), Western diet (WD), or WD with 4% salt (WD4%). Microcirculatory properties and glycocalyx barrier function were evaluated in the mesenteric microcirculation, using an intravital microscope equipped with an automated capture and analysis system. Total microvascular density summed across 4- to 25-μm microvessel segment diameters was lower in NC4% than in NC and WD (P < 0.05). Perfused boundary region (PBR), a marker of glycocalyx barrier function, averaged across 4- to 25-μm microvessel segment diameters was similar between NC and NC4%, as well as between WD and WD4% (P > 0.05). PBR was lower in WD and WD4% than in NC and NC4% (P < 0.05), indicating augmented glycocalyx barrier function in WD and WD4%. There were strong, inverse relationships between PBR and adiposity and blood glucose (r = -0.44 to -0.61, P < 0.05). In summary, NC4% induces deleterious effects on microvascular density, whereas WD augments glycocalyx barrier function. Interestingly, the combination of high-salt, Western diet in WD4% resulted in lower total microvascular density like NC4% and augmented glycocalyx barrier function like WD. These data suggest distinct microcirculatory adaptations to high-salt and Western diets that coincide when these diets are combined in young genetically heterogeneous male and female mice.NEW & NOTEWORTHY Many individuals in industrialized societies consume a combination of high-salt and Western diet; however, the effects of this diet on microcirculatory and glycocalyx properties are unknown. This study reveals that a high-salt diet lowers microcirculatory and glycocalyx properties, whereas a Western diet augments glycocalyx barrier function and thickness. Taken together, these data indicate that there are distinct microcirculatory adaptations to high-salt and Western diets that coincide when high-salt and Western diets are combined.

Rapid Patient-Side Evaluation of Endothelial Glycocalyx Thickness in Healthy Sedated Cats Using GlycoCheck® Software.

The endothelial glycocalyx (EG) determines transvascular fluid fluxes, and influences inflammation, coagulation, and capillary blood flow. The GlycoCheck® software calculates EG thickness using sidestream dark field videomicroscopy recordings. This method has not been evaluated for use in cats. The aim of the present study was to evaluate the use of GlycoCheck® for estimating EG thickness in healthy cats, and to investigate the variability of EG thickness in this population. One hundred and one healthy research-purposed cats were included in the study. The cats were sedated, and a handheld videomicroscope, connected to GlycoCheck® software, was used to evaluate the sublingual microvasculature. The parameters measured included perfused boundary region (PBR, an indirect measurement of EG thickness) in vessels between 5 and 25 μm in diameter, valid vessel density, percentage red blood cell filling, and median red blood cell column width. Heart rate, respiratory rate, pulse oximetry and oscillometric blood pressure readings were also recorded. There were 35 neutered male cats, 11 intact males, 38 neutered females, and 17 intact females. The average age was 63 months (range, 11–160 months). Tolerance intervals for PBR (vessel diameter 5–25 μm) were 1.89–3.00 μm (95% CI, lower limit 1.76–2.04, upper limit 2.83–3.13 μm); for valid vessel density were 73.33–333.33 μm/mm2 (95% CI, lower limit 77.00–99.33, upper limit 312.67–350.33 μm/mm2); for percentage red blood cell filling were 59.85–85.07% (95% CI, lower limit 58.97–63.33, upper limit 83.07–88.20 %); and for median red blood cell column width were 5.63–8.59 μm (95% CI, lower limit 5.28–6.07, upper limit 8.14–9.51 μm). There was a negative association between median red blood cell column width and body weight (p = 0.007). The median red blood cell column was significantly wider in intact females when compared to spayed females (p = 0.033). The GlycoCheck® analysis was easily performed in healthy sedated cats. Clinical variables did not have an effect on the EG thickness. These results suggest that this technique could be valuable for evaluation of the EG and microvascular parameters in cats.

Maternal Vascular Lesions in the Placenta Predict Vascular Impairments a Decade After Delivery.

Women with adverse pregnancy outcomes later experience excess hypertension and cardiovascular disease, but how the events are linked is unknown. Examination of the placenta may provide clues to vascular impairments after delivery. Maternal vascular malperfusion lesions (MVMs) were abstracted from clinical reports, validated and characterized using clinical guidelines and severity score. A total of 492 women (170 with MVMs and 322 without MVMs) participated in a study visit 8 to 10 years after delivery to assess blood pressure, cardiometabolic factors, and sublingual microvascular features using sidestream dark field imaging. Covariates included age, race, adverse pregnancy outcomes (preeclampsia, small for gestational age, and preterm birth), and health behaviors. Women with versus without MVM had a distinct sublingual microvascular profile comprised of (1) lower microvascular density (-410 μm/mm2, P=0.015), (2) higher red blood cell filling as a marker of perfusion (2%, P=0.004), and (3) smaller perfused boundary region (-0.07 µm, P=0.025) as a measure of glycocalyx integrity, adjusted for covariates including adverse pregnancy outcomes. Women with MVM also had higher adjusted diastolic blood pressure (+2.6 mm Hg, P=0.021), total and LDL (low-density lipoprotein)-cholesterol (+11.2 mg/dL, P=0.016; +8.7 mg/dL, P=0.031). MVM associations with subsequent cardiovascular measures did not vary by type of adverse pregnancy outcome, except among women with preterm births where blood pressure was higher only among those with MVM. Results were similar when evaluated as MVM severity. A decade after delivery, women with placental vascular lesions had an adverse cardiovascular profile comprised of microvascular rarefaction, higher blood pressure and more atherogenic lipids. Placental histopathology may reveal a woman's early trajectory toward subsequent vascular disease.

Endothelial glycocalyx and microvascular perfusion are associated with carotid intima-media thickness and impaired myocardial deformation in psoriatic disease.

Psoriatic disease is associated with vascular and myocardial dysfunction. We aimed to evaluate endothelial glycocalyx barrier properties and microvascular perfusion in psoriatic patients, as well as their correlation with carotid intima-media thickness (cIMT) and markers of left ventricular (LV) myocardial deformation. We examined 297 psoriatic patients and 150 controls, adjusted for age, sex, and atherosclerotic risk factors. The severity of psoriatic disease was estimated using the psoriasis area and severity index (PASI). Perfused boundary region (PBR), a marker of glycocalyx barrier function, was measured non-invasively in sublingual microvessels with a diameter 5-25 μm using Sidestream Dark Field camera (Microscan, GlycoCheck). Increased PBR indicates reduced glycocalyx thickness. Indexes of microvascular perfusion, including red blood cells filling (RBCF) and functional microvascular density, were also calculated. We measured cIMT, coronary flow reserve (CFR) and markers of myocardial deformation by speckle-tracking imaging, namely global longitudinal strain (GLS) and percentage changes between peak twisting and untwisting at mitral valve opening (%dpTw-UtwMVO). Compared to controls, psoriatic patients had higher PBR5-25μm (2.13 ± 0.29μm versus 1.78 ± 0.25μm, p < 0.001) and lower RBCF and functional microvascular density (p < 0.001). Increased PASI was associated with elevated PBR and more impaired cIMT and GLS (p < 0.05). There was an inverse association of PBR with RBCF and functional microvascular density (p < 0.001). In psoriatic population, increased PBR was related to increased cIMT, reduced CFR, impaired GLS and decreased %dpTw-UtwMVO (p < 0.001). Glycocalyx thickness is reduced in psoriatic patients, which in turn impairs microvascular perfusion, and is associated with carotid IMT and impaired coronary and myocardial function.Clinical Trial Registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT02144857.

Impaired Endothelial Glycocalyx Predicts Adverse Outcome in Subjects Without Overt Cardiovascular Disease: a 6-Year Follow-up Study.

We investigated whether disturbance of glycocalyx integrity is related with increased cardiovascular risk. In 600 healthy subjects, we measured perfused boundary region (PBR), a marker of glycocalyx integrity, in sublingual microvessels withdiameter ranging 5-25µm using a dedicated camera (Sideview Darkfield Imaging). Increased PBR indicates reduced glycocalyx thickness. We prospectively monitored the occurrence of cardiovascular events (MACE-death, myocardial infarction, and stroke) during a 6-year follow-up. Fifty-seven MACE were documented. Increased values of PBR5-25 predicted higher risk for MACE in a model including sex, age, hyperlipidemia, diabetes, hypertension, smoking, family history of coronary disease, treatment with ACEi/ARBs, or lipid-lowering agents (hazard ratio (HR), 6.44, p = 0.011; net reclassification improvement (NRI), 28%; C-statistic: 0.761). PBR5-25 was an independent and additive predictor of outcome when added in a model including the European Heart SCORE, diabetes, family history of CAD,and medication (HR, 4.71; NRI: 39.7%, C-statistic from 0.653 to 0.693; p &lt; 0.01).Glycocalyx integrity is an independent and additive predictor to risk factors for MACE at 6-year follow-up in individuals without cardiovascular disease. ClinicalTrials.govIdentifier:NCT04646252. PBR5-25 was an independent and additive predictor of adverse cardiovascular events in a model including the European Heart SCORE, diabetes, family history of coronary disease, and medication (HR: 4.71, NRI: 39.7%, C-statistic from 0.653 to 0.693; p &lt; 0.01, NRI:37.9%).

COVID-19 patients present impaired endothelial glycocalyx, vascular dysfunction and myocardial deformation resembling those observed in hypertensives four months after infection

Background/IntroductionCOVID-19 infection has been associated with increase arterial stiffness, endothelial dysfunction, and impairment in coronary and cardiac performance. Inflammation and oxidative stress have been suggested as possible pathophysiological mechanisms leading to vascular and endothelial deregulation after COVID-19 infection.PurposeThe objective of our study is to evaluate premature alterations in arterial stiffness, endothelial, coronary, and myocardial function markers four months after SARS-CoV-2 infection.MethodsWe conducted a case-control prospective study, including 70 patients four months after COVID-19 infection, 70 age- and sex-matched untreated hypertensive patients (positive control) and 70 healthy individuals. We measured a) perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced endothelial glycocalyx thickness b) flow-mediated dilation (FMD), c) coronary Flow Reserve (CFR) by Doppler echocardiography d) pulse wave velocity (PWV) and central systolic (SBP) e) global LV longitudinal strain (GLS) by speckle tracking imaging and f) malondialdehyde (MDA) as oxidative stress marker.ResultsCOVID-19 patients had similar CFR and FMD with hypertensives (2.48±0.41 vs 2.58±0.88, p=0.562, 5.86±2.82% vs 5.80±2.07%, p=0.872 respectively), but lower CFR and FMD than controls (3.42±0.65, p=0.0135 9.06±2.11%, p=0.002 respectively) Both COVID-19 and hypertensive group had greater PBR than controls (PBR5–25: 2.07±0.15 μm and 2.07±0.26 μm p=0.8 vs 1.89±0.17 μm, p=0.001). COVID-19 patients and hypertensives had higher PWV and central SBP than controls (PWVcf 12.09±2.50 and 11.92±2.94, p=0.7 vs 10.04±1.80 m/sec, p=0.036). COVID-19 patients and hypertensives had impaired values of GLS compared to controls (−19.50±2.56% and −19.23±2.67%, p=0.864 vs −21.98±1.51%, p=0.020). Increased PBR5–25 was associated with increased SBP central which in turn was related with impaired GLS (p<0.05). MDA was found increased in COVID-19 patients compared to both hypertensives and controls (10.67±2.75 vs 1.76±0.30, p=0.003 vs 1.01±0.50 nmole/L, p=0.001).ConclusionsSARS-CoV-2 may cause impaired coronary microcirculatory, endothelial and vascular deregulation which remain four months after initial infection and are associated with reduced cardiac performance. The 10-fold increase of MDA compared to healthy individuals four months after COVID-19 infection indicate oxidative stress as possible pathophysiological mechanism.FUNDunding AcknowledgementType of funding sources: None.

The combination of dulaglutide and dapagliflozin improves arterial stiffness, endothelial glycocalyx and albuminuria vs DPP-4 inhibitors independently of glycemic control

Abstract Background Studies in recent years have shown that dulaglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA), and dapagliflozin, a sodium-glucose cotransporter-2 inhibitor (SGLT-2i), improve or prevent diabetic nephropathy and macrovascular complications in patients with type 2 diabetes mellitus (T2DM). Purpose The aim of this study is to determine whether the combination of dulaglutide and dapagliflozin exerts improves arterial stiffness, endothelial glycocalyx and albuminuria in T2DM compared to dipeptidyl-peptidase 4 inhibitors (DPP-4is). Methods Overall 37 patients with T2DM were included in our study. 21 patients were transitioned from DPP-4is to dulaglutide and dapagliflozin (treatment group) and were followed immediately prior (baseline) and 4 months after the initiation of treatment. 16 patients, matched for sex, age and glycemic control, remained on treatment with DPP-4is (control group). In each visit we measured a) Carotid-femoral PWV b) central systolic blood pressure (cSBP) c) perfused boundary region (PBR) of the sublingual arterial microvessels, d) urinary albumin-to-creatinine ratio (UACR), e) glycosylated hemoglobin (HbA1c). Results There were no statistically significant differences in cardiovascular markers, UACR and HbA1c at baseline (p&amp;gt;0.05). After 4 months, patients on dulaglutide and dapagliflozin combination improved HbA1c (7.9±1.5% vs 6.59±0.6%, p&amp;lt;0.001), PBR (2.3±0.3 vs. 2.1±0.2 μm, p&amp;lt;0.05), PWV (11.9±0.3.5 vs. 10.9±2.2m/s, p&amp;lt;0.05), cSBP (128.5±23.6 vs. 121.1±15.7 mmHg, p&amp;lt;0.05) and UACR (413.66±352.57 vs. 248.06±203.5 mg/g, p&amp;lt;0.001). There were no statistically significant differences in PBR (2.1±0.3 vs. 2.2±0.3 μm, p&amp;gt;0.05), PWV (10.7±3.4 vs. 12±3.3m/s, p&amp;gt;0.05), cSBP (125.4±21.2 vs. 127±20.1 mmHg, p&amp;gt;0.05) and UACR (240.8±103.6 vs. 204.9±119.6 mg/g), in the control group, despite a statistically significant improvement of HbA1c (8.2±1.9% vs 7.3±1.3%, p&amp;lt;0.01). Conclusions The combination of dulaglutide and dapagliflozin improves arterial stiffness, endothelial glycocalyx and albuminuria compared to DPP-4is in patients with T2DM. Funding Acknowledgement Type of funding sources: None.

Apremilast improves endothelial glycocalyx and microvascular perfusion: a possible protective mechanism against COVID-19

Abstract Background/Introduction The phosphodiesterase 4 inhibitor apremilast is an approved treatment option for psoriasis. Purpose We aimed to investigate the effects of apremilast on endothelial glycocalyx, vascular and left ventricular (LV) myocardial function in psoriasis. Methods Ninety patients with psoriasis were randomized to receive apremilast (n=30), anti-tumor necrosis factor-a (etanercept, n=30), or cyclosporine treatment (n=30). At baseline and 4 months post-treatment, we measured: (1)Perfused boundary region (PBR) of the sublingual microvessels with a diameter 5–25μm using a dedicated camera (Sidestream Dark Field imaging, Microscan, Glycocheck). Increased PBR indicates reduced glycocalyx thickness. Perfused microvascular density (PMD), an index of microvascular perfusion, was also measured. (2)Pulse wave velocity (PWV - Complior; ALAM Medical) and central systolic blood pressure (cSBP), and (3)LV global longitudinal strain (GLS) and percent difference between peak twisting and untwisting at mitral valve opening (%dpTw-UtwMVO) using speckle-tracking echocardiography. Results Compared with baseline, PBR20–25 decreased only after apremilast treatment (−13% at 4 months, P&amp;lt;0.05) whereas no statistically significant changes in PBR20–25 were observed after etanercept or cyclosporine. Compared with etanercept and cyclosporine, apremilast resulted in a greater increase of PMD (+12% versus +3% versus +3%) and in a higher reduction of PWV (−10% versus −3% versus +8%) and cSBP (−8% versus −2% versus +7%) at 4 months. Apremilast showed a greater increase of GLS (+12% versus +5% versus +2%) and %dpTw-UtwMVO (+15% versus +3% versus +3%) than etanercept and cyclosporine (P&amp;lt;0.05 for all comparisons). Changes of PBR and PMD post-apremilast treatment correlated with a concomitant reduction of PWV and cSBP (P&amp;lt;0.05). Conclusions In psoriasis, apremilast confers a greater improvement of endothelial glycocalyx, microvascular perfusion and LV myocardial function compared with etanercept or cyclosporine treatment. Apremilast restores glycocalyx integrity and thus reduces vascular permeability to pro-inflammatory molecules. This may explain the beneficial effects of apremilast on COVID-19. Funding Acknowledgement Type of funding sources: None.

Differences in left atrial stain, endothelial glycocalyx and arterial elasticity between ESUS, lacunar and atherosclerotic type of stroke

Abstract Background and purpose Patients with stroke are at high risk to develop cardiovascular complications. We assessed endothelial glycocalyx, aortic elastic properties, left atrial and ventricular function in patients with lacunar, atherosclerotic and stroke of undetermined source (ESUS). Methods In 68 patients (age 56,1±10.9) with acute cerebral stroke (22 lacunar, 19 atherosclerotic and 27 ESUS) and 20 controls with similar risk factors, we measured: (1) perfused boundary region (PBR) of the sublingual arterial microvessels (range 5–25 μm), a marker inversely related with glycocalyx thickness, (2) pulse wave velocity (PWV), central systolic blood pressure (cSBP), and augmentation index (AIx), (3) LA volume and strain using speckle-tracking imaging, and (4) left ventricular global longitudinal strain. Results Compared with controls, patients with stroke had higher PWV (11,38±3,62 vs 9,51±1,57 m/sec, p=0,045), PBR (2,10±0,27 vs 1,94±,020, p=0,039) and central SBP (139,64±26,31 vs 116,36±37,23 mmHg, p=0,039), while ventricular (−17,902±3,77 vs −19,87±1,17%, p=0,025) and atrial deformation (24,8±9,99 vs 39,050±2,08%, p&amp;lt;0.001) were impaired in patients with stroke (p&amp;lt;0.05). LA reservoir strain was more reduced in ESUS patients compared to other 2 stroke types (ESUS 21,7±6,6%, Lacunar 25,6±13,2%, atherosclerotic 22,3±7,8%, P&amp;lt;0.05). Regarding endothelial glycocalyx, PBR5–9 (the smallest vessels with diameter 5–9 μm) was higher in patients with ESUS than in the other two types of stroke (ESUS 1,22±0,12 μm, LACUNAR 1,19±0,12 μm, ATHEROSCLEROTIC 1,15±0,09 μm, p&amp;lt;0.05), despite the fact that PBR5–25 was similar between all stroke types (ESUS 2,09±0.23 μm, LACUNAR 2,13±0,33 μm, ATHEROSCLEROTIC 2,09±0,24 μm, p=0.8). PWV was significantly higher in patients with atherosclerotic stroke (15,57±5,50 m/sec, p=0,007), while in patients with lacunar it was mildly elevated (10,53±3,22 m/sec) and in ESUS patients it was moderately increased (11,7±3 m/sec). Conclusion Patients with stroke have impaired atrial strain, endothelial glycocalyx and arterial elasticity, compared with controls. Arterial stiffness is more affected in atherosclerotic stroke, while LA deformation and glycocalyx of small size micro vessels are more affected in ESUS patients. Funding Acknowledgement Type of funding sources: None.

First-degree relatives of type-2 diabetic patients and dysglycaemic patients have impaired endothelial function due to decreased bioavailability of nitric oxide

Abstract Background/Introduction Oxidative stress plays an important role in the pathogenesis of type 2 diabetes. Purpose We investigated oxidative stress in first-degree relatives of type-2 diabetes patients (FDR) since they are more prone to develop type-2 diabetes, at baseline and during postprandial hyperglycemia in comparison with dysglycaemic or normoglycaemic subjects. We evaluated these results in relation to vascular function. Methods We studied 40 FDR with normal oral glucose test (OGTT), 40 subjects with abnormal OGTT (dysglycaemic) and 20 subjects with normal OGTT without parental history of diabetes (normoglycaemic) with similar demographical and clinical characteristics. Glucose and insulin levels, pulse wave velocity (PWV-Complior, ALAM), central systolic blood pressure (cSBP) and augmentation index (AI) were measured at baseline, 30, 60, 90 and 120min during OGTT. Perfused boundary region (PBR-Microscan, Glycocheck) of the sublingual arterial microvessels (high PBR values represent reduced glycocalyx thickness), plasma concentrations of malondialdehyde (MDA) and protein carbonyls (PCs) as markers of lipid peroxidation and protein oxidation, respectively, and nitrite/nitrates levels as markers for NO biosynthesis, were assessed at baseline and at 120min of OGTT. Insulin sensitivity was evaluated using Matsuda and insulin sensitivity index (ISI). Results FDR and dysglycaemics patients had higher fasting insulin, reduced ISI, Matsuda index as well as increased PBR (2.5±0.5 vs. 2.5±0.6 vs. 2.4±0.3μm), increased PWV (8.9±1.1 vs. 10.3±2.4 vs. 8.0±1.5m/s), AI, MDA, PCs and nitrite/nitrate than normoglycaemic subjects (p&amp;lt;0.05 for all comparisons). ISI was negatively related with PBR and MDA (r=−0.35 and r=−0.34, p&amp;lt;0.05) at baseline in FDR and dysglycaemics. During OGTT, AI was similarly reduced in both normoglycaemics and FDR whereas AI was significantly increased in dysglycaemics at 120min (p&amp;lt;0.05). PBR was increased by 7.5% and 4% at 120min in dysglycaemics and FDR, respectively, while remained unchanged in normoglycaemics (p&amp;lt;0.05). In dysglycaemics and FDR, nitrite/nitrate levels were significantly decreased at 120min (52.85±8.22 vs. 36.31±4.36 and 48.23±7.20 vs. 34.70±4.71nmol/ml, respectively, p&amp;lt;0.05) while they were remained unchanged in normoglycaemics likely leading to a greater decrease of MDA (−83% vs. −40% vs. −48%) and of PCs (−28% vs. −7% vs. −16%) in normoglycaemics compared with dysglycaemics and FDR (p&amp;lt;0.05). Conclusions Insulin resistance determines acute endothelial responses during postprandial hyperglycemia leading to reduced NO production and thus facilitating augmentation of oxidative stress during postprandial hyperglycemia in dysglycaemic patients and FDR of diabetic patients. Funding Acknowledgement Type of funding sources: None.

Effect ofglucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter-2 inhibitors and their combination on left atrial strain and arterial function

Abstract Background We investigated the effects of insulin, glucagon-like peptide-1 receptor agonists (GLP-1RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and their combination on left atrial function of patients with type 2 diabetes mellitus and we searched for a relation with arterial function. Methods A total of 213 patients (59,5±9,1 year old, 161 male) with type 2 diabetes mellitus treated with metformin were randomized to insulin (n=46 served as controls), liraglutide (n=40), empagliflozin (n=46) or their combination (GLP-1RA + SGLT-2i) (n=50) as add-on. We measured at baseline and 6 months posttreatment: (a) perfused boundary region of the sublingual arterial microvessels (marker of endothelial glycocalyx thickness), (b) pulse wave velocity (PWV) and central systolic blood pressure, (c) global left ventricular Longitudinal strain, (d) left atrial strain. Results Six months after intervention, all patients improved left atrial reservoir strain (GLP1RA 30,7±9,3 vs 33,9±9,7%, p=0,011 / SGLT2i 30±8,3 vs 32,3±7,3%, p=0,04 / GLP1 &amp; SGLT2i 29,1±8,7 vs 31,3±8,2, p=0,007) in comparison with controls (33±8,3% vs 32,8±7,4, p=0,829). Also, patients treated with GLP1RA and their combination improved left atrial conduction strain (p&amp;lt;0.05). GLP-1RA or GLP-1RA + SGLT-2i provided a greater improvement in GLS compared with insulin or SGLT-2i (controls −18,5±3,9% vs −19,1±3%, p=0,202 / GLP1RA −18,2±4,1% vs −19,1±3,5%, p=0,03 / SGLT2i −19±4,1% vs −19,1±3,8%, p=0,764 / GLP1 &amp; SGLT2i −16,7±3,9% vs −17,5±4,3%, p=0,026). SGLT-2i or GLP-1RA and SGLT-2i showed a greater decrease of PWV (Controls 12,06±3,02 vs 11,62±2,79 m/sec, p=0,142 / GLP1 11,54±2,91 vs 11,45±2,52 m/sec, p=0,822 / SGLT2 11,86±2,51 vs 11,33±2,28 m/sec, p=0,047 / GLP1 &amp; SGLT2 12,01±2,46 vs 10,85±1,79 m/sec, p=0,021) and central and brachial systolic blood pressure than insulin or GLP-1RA. At baseline, there was a correlation of LA reservoir strain with PWV (r=−0,209, p=0,008), central SBP (r=−0,151, p=0,030), EF (r=0,214, p=0,004), GLS (r=−0,279, p=0,009). At 6 months follow up, there was a correlation of LA reservoir strain with PWV (r=0,217, p=0,003), central SBP (r=0,214, p=0,004), EF (r=−0,221, p=0,049), GLS (r=0,275, p=0,014). Conclusions Treatment with GLP-1RA, SGLT-2i, and their combination for 6 months showed a greater improvement of left atrial function compared to insulin treatment in parallel with improvement arterial and myocardial function. Funding Acknowledgement Type of funding sources: None.

Association of COVID-19 with impaired endothelial glycocalyx, vascular function andmyocardial deformation 4 months after infection.

AimsSARS‐CoV‐2 infection may lead to endothelial and vascular dysfunction. We investigated alterations of arterial stiffness, endothelial coronary and myocardial function markers 4 months after COVID‐19 infection.Methods and resultsIn a case‐control prospective study, we included 70 patients 4 months after COVID‐19 infection, 70 age‐ and sex‐matched untreated hypertensive patients (positive control) and 70 healthy individuals. We measured (i) perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced endothelial glycocalyx thickness), (ii) flow‐mediated dilatation (FMD), (iii) coronary flow reserve (CFR) by Doppler echocardiography, (iv) pulse wave velocity (PWV), (v) global left and right ventricular longitudinal strain (GLS), and (vi) malondialdehyde (MDA), an oxidative stress marker, thrombomodulin and von Willebrand factor as endothelial biomarkers. COVID‐19 patients had similar CFR and FMD as hypertensives (2.48 ± 0.41 vs. 2.58 ± 0.88, P = 0.562, and 5.86 ± 2.82% vs. 5.80 ± 2.07%, P = 0.872, respectively) but lower values than controls (3.42 ± 0.65, P = 0.0135, and 9.06 ± 2.11%, P = 0.002, respectively). Compared to controls, both COVID‐19 and hypertensives had greater PBR5–25 (2.07 ± 0.15 µm and 2.07 ± 0.26 µm, P = 0.8 vs. 1.89 ± 0.17 µm, P = 0.001), higher PWV (carotid–femoral PWV 12.09 ± 2.50 vs. 11.92 ± 2.94, P = 0.7 vs. 10.04 ± 1.80 m/s, P = 0.036) and impaired left and right ventricular GLS (−19.50 ± 2.56% vs. −19.23 ± 2.67%, P = 0.864 vs. −21.98 ± 1.51%, P = 0.020 and −16.99 ± 3.17% vs. −18.63 ± 3.20%, P = 0.002 vs. −20.51 ± 2.28%, P < 0.001). MDA and thrombomodulin were higher in COVID‐19 patients than both hypertensives and controls (10.67 ± 0.32 vs 1.76 ± 0.03, P = 0.003 vs. 1.01 ± 0.05 nmol/L, P = 0.001 and 3716.63 ± 188.36 vs. 3114.46 ± 179.18 pg/mL, P = 0.017 vs. 2590.02 ± 156.51 pg/mL, P < 0.001). Residual cardiovascular symptoms at 4 months were associated with oxidative stress and endothelial dysfunction markers.ConclusionsSARS‐CoV‐2 may cause endothelial and vascular dysfunction linked to impaired cardiac performance 4 months after infection.

380-P: Endothelial Glycocalyx Dimensions and Cardiovascular Risk Factors in Type 1 Diabetes

Background: The glycocalyx lines the inner surface of the capillary endothelium. Capillaroscopy enables visualization of the sublingual capillaries and measurement of the perfused boundary region (PBR) as an estimate of the glycocalyx. Novel software enables assessment of the PBR estimated at a fixed high flow level (PBR-hf) and the microvascularity by the MicroVascular Health Score (MVHS). Damaged glycocalyx may represent microvascular damage in diabetes and assessment of its dimension might improve early cardiovascular (CV) risk stratification. Aim: To assess the associations between PBR, PBR-hf and MVHS and CV risk factors in persons with type 1 diabetes (T1D); and to compare PBR, PBR-hf and MVHS in persons with T1D and healthy controls. Methods: Cross-sectional study including 161 persons with T1D stratified by stage of diabetic kidney disease according to level of albuminuria and 50 healthy controls without diabetes. The PBR, PBR-hf and MVHS were assessed by the GlucoCheck device (valid measurements were available in 136 (84.5%) with T1D and in all the controls). Higher PBR and PBR-hf indicate smaller glycocalyx width and lower MVHS represents a worse microvascular health. Results: There were no associations between PBR, PBR-hf or MVHS and the CV risk factors in persons with T1D, except for a higher PBR-hf and a lower MVHS in females (p = 0.01 for both). There was no difference in PBR, PBR-hf or MVHS in persons with normo-, micro- or macroalbuminuria (p ≥ 0.34). PBR was higher and MVHS was lower in persons with T1D as compared to the healthy controls (p ≤ 0.02). After adjustment for CV risk factors the difference in PBR remained significant (p = 0.001). Conclusions: The endothelial glycocalyx dimension was impaired in persons with T1D compared to healthy controls. We found no association between the endothelial glycocalyx dimension and the level of albuminuria or CV risk factors among persons with T1D. The use of the GlucoCheck device in T1D may not contribute to CV risk stratification. Disclosure E. Buur stougaard: Employee; Spouse/Partner; Novo Nordisk, Stock/Shareholder; Spouse/Partner; Novo Nordisk. S. Winther: None. H. Amadid: Stock/Shareholder; Self; Novo Nordisk A/S. M. Frimodt-moeller: None. F. Persson: Advisory Panel; Self; AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Mundipharma International, Novo Nordisk, Advisory Panel; Spouse/Partner; AstraZeneca, Bristol-Myers Squibb Company, Research Support; Self; Amgen Inc., AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk, Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Mundipharma International, Novo Nordisk. T. W. Hansen: Stock/Shareholder; Self; Novo Nordisk A/S. P. Rossing: Advisory Panel; Self; Astellas Pharma Inc., AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Gilead Sciences, Inc., Merck KGaA, Merck Sharp &amp; Dohme Corp., Novo Nordisk A/S, Sanofi, Vifor Pharma Management Ltd. Funding Novo Nordisk Foundation (NNF14SA0003)