Perfused Boundary Region Research Articles

Abstract 4135229: Endothelial glycocalyx shedding during ST-elevation acute myocardial infarction

Background: Endothelial glycocalyx (eGC) is a layer of glycosaminoglycans adhered to proteoglycans that cover the inner surface of the vessels. The integrity of this structure sustains some vascular properties such as shear stress-induced nitric oxide release and the prevention of platelets and neutrophils adhesion on the vessel surface. eGC shedding could contribute to atherosclerotic plaque vulnerability and acute myocardial infarction (AMI) installation. This research investigated whether acute eGC damage and microvascular dysfunction occurred during AMI. Methods: Sublingual microcirculation was assessed through Capiscope HCVS Handheld Video Capillaroscopy System (KK Technology, Honiton, UK) during the first 72h of hospital admission because of ST-elevation AMI (before) and repeated around six months later (after). All images were automatically analyzed using the GlycoCheck (Alpine, UT, USA), which estimated the perfused vascular density (PVD), the red blood cell (RBC) filling of the vessels, the perfused boundary region (PBR) in µm, an inverse parameter of the eGC thickness; and the microvascular health score (MVHS). This score ranges from 0-10; the lower its numerical value, the greater the microvascular impairment. Results: Twenty patients were included (61±10 years old, 85% males, 55% anterior AMI, 70% hypertension, 25% diabetes, 45% current smoker, all underwent primary PCI). The time between the two sublingual assessments was 188±31 days. The PBR [1.96±0.22µm vs. 1.84±0.19µm]; p=0.047 and flow-adjusted PBR [1.40±0.25µm vs. 1.24±0.16µm]; p=0.045 decreased statistically significant over time. The RBC filling [71.56±4.33% vs. 74.02±3.88%]; p=0.016 and the MVHS [4.28 (interquartile range (IRQ) 3.38-4.90) vs. 5.04 (IQR 4.37-6.00)]; p=0.044 increased statistically significant over time. The PVD [500±86 x10-2µm/mm vs. 522±84x10-2µm/mm]; p=0.255 did not modify over time. Conclusion: This finding was compatible with eGC shedding and microvascular dysfunction during AMI and later reconstitution of this structure after six months.

Retinal Microvascular Changes in Association with Endothelial Glycocalyx Damage and Arterial Stiffness in Patients with Retinal Vein Occlusion: A Cross-Sectional Study

Background/Objectives: To investigate the potential association between the endothelial dysfunction and arterial stiffness with retinal changes observed through optical coherence tomography (OCT) and OCT-angiography (OCT-A) in patients with retinal vein occlusion (RVO). Methods: Participants in this cross-sectional study were 28 patients with RVO. The demographic and clinical characteristics of all participants were recorded. Comprehensive ophthalmologic examinations were performed, including fundus photography, OCT and OCT-A. Endothelial dysfunction was assessed by measuring the endothelial glycocalyx thickness via the perfused boundary region (PBR5-25). Arterial stiffness was evaluated by measuring the carotid-femoral pulse wave velocity (PWV), the central systolic and diastolic blood pressures (cSBP and cDBP) and the augmentation index (Aix). For each ophthalmological outcome, we generated a saturated linear regression model with demographic and systemic vascular parameters serving as independent variables. Regression coefficients with the corresponding 95% confidence intervals (CIs) were reported. A p value < 0.05 was considered as statistically significant. Results: A 1 m/s increase in PWV was associated with a 0.6% reduction in inferior macular vessel density (VD) (p = 0.050). A 10 mmHg increase in cSBP was associated with a 0.03 mm2 increase in foveal avascular zone (FAZ) area (p = 0.033). A 1% increase in Aix was associated with a 0.005 mm2 increase in FAZ area (p = 0.008). A 1 μm increase in PBR5-25 was associated, on average, with a 4.4% decrease in superior peripapillary VD (p = 0.027). Conclusions: In patients with RVO, structural and microvascular retinal parameters were significantly associated with markers of endothelial dysfunction and arterial stiffness.

Effects of sodium-glucose contrasporter-2 inhibitors and glucagon-like peptide-1 receptor agonists on arterial stiffness, coronary flow reserve and liver steatosis in diabetes

Abstract Background Patients with type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD) present an increased risk of cardiovascular disease. Sodium-glucose contrasporter-2 inhibitors (SGLT-2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) have been shown to significantly decrease the risk of cardiovascular complications. Purpose The aim of the study was to investigate the effect of treatment with SGLT-2i or GLP-1RA on cardiovascular function and liver steatosis and fibrosis in patients with T2DM and NAFLD. Methods Forty patients with T2DM and NAFLD (mean age: 58 ± 11 years) were randomized to receive SGLT-2i (dapagliflozin; n = 20) or GLP-1RA (dulaglutide; n = 20). At baseline and after 6 and 12 months of treatment, we measured: (1) perfused boundary region (PBR) of the sublingual microvessels with a diameter 5-25μm using Sidestream Dark Field camera (Microscan, Glycocheck). Increased PBR indicates reduced glycocalyx thickness. (2) Pulse wave velocity (PWV) using Complior (ALAM Medical), (3) coronary flow reserve (CFR) using Doppler echocardiography, (4) LV global longitudinal strain (GLS) using speckle-tracking echocardiography, (5) controlled attenuation parameter (CAP) score to assess steatosis grade and liver stiffness (E) to evaluate fibrosis score using liver elastography (FibroScan, Echosens), and (6) NAFLD fibrosis score (NFS). Results At baseline, patients between the two groups had similar age, sex, HbA1c, steatosis grade, fibrosis score and markers of cardiovascular function (p > 0.05). Compared with baseline, all patients had reduced PBR, PWV, CAP, E and NFS and increased CFR and GLS (p < 0.01) after 12-month treatment. In the whole study population, the percentage reduction of CAP and NFS was correlated with the corresponding decrease of PBR (r = 0.248 and r = 0.387), PWV (r = 0.290 and r = 0.281) and with the increase of GLS (r = -0.320 and r = -0.295) after 12-month treatment (p < 0.05 for all correlations). Both treatments with SGLT-2i and GLP-1RA reduced markers of liver steatosis and fibrosis (Table). Conclusion Both treatments with SGLT-2i and GLP-1RA improve cardiovascular function and reduce liver steatosis in patients with T2DM and NAFLD after 12 months.

The effect of 6-month treatment with coenzyme Q10 on endothelial, vascular and myocardial function in patients with nonalcoholic fatty liver disease

Abstract Background Patients with Non-alcoholic fatty liver disease (NAFLD) hold an increased cardiovascular risk and present impaired markers of vascular, endothelial and myocardial function. Coenzyme Q10 (CQ10) is a powerful antioxidant that enhances mitochondrial function. Patients/methods: 52 patients (52±10 years old) with NAFLD were randomized to 240 mg CQ10 (n=25) or placebo (n=27). We measured at baseline and at six months post-treatment: i) Perfused boundary Region (PBR) of the sublingual arterial microvessels (Microscan, Glycocheck), ii) Carotid femoral pulse wave velocity - PWV (Complior ALAM), iii) Flow-mediated dilation (FMD) of the brachial artery, iv) Global left ventricular longitudinal strain (GLS) by speckle tracking imaging, v) Controlled attenuation parameter (CAP) measurement (FibroScan, Echosens). Results Six months post treatment with cQ10, values of PBR (2.12±0.19 vs. 2.28±0.23 μm), PWV (9.5±2.3 vs. 10.5±2.4m/s), CAP score (278.1±50, 2 vs. 305.3±44.5dB/m), FMD (6.61±4 vs. 5.02±2.6 %) and GLS (-19.3±1.9 vs -18.2±2 %) were improved (p<0.05 for all comparisons). On the contrary, the patients who were treated with placebo did not show statistically significant differences in PBR, PWV, CAP score, FMD and GLS after from 6 months (p>0.05). In the patients who received cQ10, the percentage reduction of CAP score at 6 months was directly proportional to the percent reduction in PWV (r=0.31, p=0.045) and inversely proportional to the percentage increase in FMD (r=-0.58, p=0.014). Conclusion Six-month treatment with CoQ10 reduces liver steatosis in patients with NAFLD. CoQ10 is associated with improved endothelial, vascular and LV myocardial function in patients with NAFLD.

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

Abstract Background Patients with stroke are at greater risk of developing cardiovascular complications. Purpose We addressed endothelial glycocalyx, arterial stiffness, left atrial and ventricular function in patients with lacunar, atherosclerotic, cardioembolic and stroke of undetermined source (ESUS). Methods We recruited 194 patients (aged 58.8± 10.8 years old) with acute cerebral stroke (47 lacunar, 50 atherosclerotic,48 ESUS and 49 cardioembolic) and 50 controls with similar risk factors and 40 controls with similar profile regarding common risk factors (diabetes, hypertension, hyperlipidemia, coronary artery disease, smoking; p>0.05 for all comparisons). We measured: (1) perfused boundary region (PBR) of the sublingual microvessels (diameter range 5–25 μm), a marker inversely related with glycocalyx thickness, (2) pulse wave velocity carotid-to-femoral (PWV), central systolic blood pressure (cSBP), and central diastolic blood pressure (cDBP), (3) Left atrial (LA) strain using speckle-tracking imaging, (4) left ventricular global longitudinal strain and (5) left ventricular myocardial work index (GWI), constructive work (GCW), wasted work (GWW) and work efficiency (GWE), (6) ventriculoarterial coupling, expressed by the ratio PWV/GLS. Results Compared with controls, patients with stroke had higher PWV (11.98±3.21 vs 9.61±1.28 m/sec, p=0.001), PBR (2.20±0.31 vs 1.94±0.20, p=0.019) and central SBP (137.41±24.83 vs 121.15±17.46 mmHg, p=0.018), while LV ventricular (-16.44±4.70 vs -20.89±2.45%, p=0.001) and atrial deformation (26.81±9.32 vs 37.05±5.08%, p<0.001) were more impaired in patients with stroke (p < 0.05). Patients with ESUS had more impaired LA reservoir strain and contraction strain compared to the other 2 stroke types (ESUS 22.9±8.72%, -13.90±4.96%, Lacunar 29.71±10.52%, -16.11±6.10%, atherosclerotic 26.78±10.14%, -13.74±5.65%, p<0.05). Also, patients with ESUS demonstrated better PBR compared to the lacunar and atherosclerotic types (ESUS 2.10±0.27 μm, Lacunar 2.26±0.29 μm, atherosclerotic 2.19±0.29μm, p<0.05). Patients with atherosclerotic stroke had higher PWV compared with other stroke types (Atherosclerotic: 13.59±3.87 m/sec, Lacunar: 11.41±2.35 m/sec, Cardioembolic: 10.66±3.28 m/sec, ESUS: 11.72±2.67 m/sec). Also, patients with atherosclerotic stroke demonstrated the worst PWV/GLS ratio (Atherosclerotic: -0.97±0.35, Lacunar: -0.69±0.25, Cardioembolic: -0.76±0.21, ESUS: -0.70±0.28). Patients with cardioembolic stroke showed similar trend with ESUS, as far LA strain is considered. Conclusion Patients with stroke have impaired atrial strain, endothelial glycocalyx and arterial stiffness, compared with controls. Arterial stiffness and ventriculoarterial coupling are more affected in atherosclerotic strokes. LA strain is more impaired in the ESUS and cardioembolic stroke albeit that endocalyx, though abnormal,is less impaired in these stroke types.

Patients vaccinated against COVID-19 present better coronary flow, myocardial work and NTproNP levels than non-vaccinated at 4 months post COVID infection

Abstract Introduction COVID-19 affected patients present impaired subclinical markers of cardiovascular and endothelial function post resolution of infection. Whether vaccination impedes impairment of myocardial and vascular function has not been clarified. Purpose We investigated the effect of COVID-19 infection on markers of endothelial, vascular and myocardial function in vaccinated and non-vaccinated subjects at four months after the infection. Methods We recruited 60 vaccinated and 60 non-vaccinated patients with similar clinical characteristics, who were examined in a dedicated post-COVID-19 outpatient clinic during a scheduled follow-up visit at four months after a confirmed COVID-19 infection. We measured (i) perfused boundary region (PBR) of the sublingual arterial (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) and central systolic blood pressure (cSBP), (v) global left and right ventricular longitudinal strain (GLS), (vi) myocardial global work index (GWI) global constructive work (GCW), global wasted work (GWW) and the myocardial global work efficiency (GWE) and v) NTproBNP blood levels. Results Among vaccinated patients 54,2% had mild disease, 33,3% had moderate disease and 12,5% had severe disease, while among non-vaccinated 29,1% had mild disease, 32,9% had moderate disease and 38% had severe disease(p<0.05). At four months, vaccinated patients presented with higher LVGLS, GCW values and CFR compared to non-vaccinated (p>0.05 table), while GWI, GWW and GWE were similar between the two groups(p>0.5). Moreover, in vaccinated patients RVGLS and RV FWLS were significantly higher than in non-vaccinated patients (p>0.05). Also, NTproBNP leves were significantly lower in vaccinated than in non-vaccinated patients (p<0.05). At four months, in vaccinated patients , we observed a marginally lower brachial and central systolic blood pressure compared with non-vaccinated (p=0.045, p=0.048 respectively.) Vaccinated patients displayed similar FMD and PWV values compared to non-vaccinated (p>0.05 for all the comparisons). Conclusion Patients vaccinated against COVID-19 suffered from milder disease resulting to better cardiac function and lower NTproNP levels than non-vaccinated 4 months post COVID infection.

Early impairment of endothelial and myocardial function in patients with hidradenitis suppurativa

Abstract Background/Introduction Hidradenitis suppurativa (HS) is a chronic, recurrent, debilitating, inflammatory skin disease manifested by painful, deep-seated, inflamed lesions of the apocrine gland-bearing areas of the body (axillae, submammary folds, inguinal and anogenital region). HS has been associated, among others, with an increased cardiovascular risk. Purpose We aimed to investigate the endothelial, arterial and left ventricular (LV) myocardial function in patients with severe HS. Methods Twenty-eight, not previously treated patients (mean age: 36 ± 13 years) with Hurley stage III disease and a mean score of 19±8 on the International Hidradenitis Suppurativa Severity Score System (IHS4) scale, were studied. Twenty healthy sex-, age- and body mass index -matched individuals, who were also weighted for common cardiovascular risk factors, served as the control group. Both patients and controls were evaluated for: a) perfused boundary region (PBR) of the sublingual microvessels with a diameter of 5-25 μm (an increased PBR value is considered as an indicator of a decrease in thickness of the endothelial glycocalyx), using a dedicated camera (Microscan, GlycoCheck), b) carotid-femoral pulse wave velocity (PWV-Complior), c) flow-mediated dilation (FMD) of the brachial artery and d) LV global longitudinal strain (GLS) using the speckle-tracking echocardiography. Results Compared to healthy controls, HS patients had increased PBR value (2.32 ± 0.19 vs. 1.99 ± 0.14 μm, p < 0.001) and decreased FMD (5.7 ± 2.9 vs. 10.3 ± 1.9 %, p < 0.001) and GLS values (-18.6 ± 2.8 vs. -22.5 ± 2.3 %, p < 0.001). In contrast, similar PWV values (9.2 ± 2 vs. 9.1 ± 1.9 m/s, p = 0.937) were recorded between patients and controls (Table). Increased IHS4 score (more severe disease) was associated with increased PBR values (r = 0.42, p = 0.026) and decreased FMD values (r = -0.37, p = 0.045). Conclusion Patients with HS show early impairment of endothelial and LV myocardial function, which correlates with the severity of the underlying systemic inflammation.Table

Differential effects of heat-not-burn, electronic cigarettes and conventional cigarettes on endothelial glycocalyx

Abstract Background Heat-not-burn cigarette (HNBC) and electronic cigarette (Ecig) constitute non-combustible smoke products. Their effect on endothelial glycocalyx has not been investigated so far. Patients and Methods: Out of 100 subjects attending smoking cessation clinic: α) 50 smokers were randomized to usage of HNBC (n=25) or Ecig (n=25) and β) 50 smokers were used as control group. Participants randomized to the newer tobacco products had similar clinical and demographic characteristics to the control group. Smoking status was verified by measuring the concentration of exhaled carbon monoxide [(e CO) (ppm), Bedfont Scientific, Maidstone, Kent UK]. Perfused Boundary Region (PBR), which is inversely related to endothelial glycocalyx thickness in sublingual arterioles (range 5–25 μm) and blood levels of cotinine, a stable metabolite of nicotine, was assessed in all participants. Exhaled CO, endothelial glycocalyx, and blood cotinine were assessed at baseline and after 1 month. Results Conventional cigarette smokers were aged: 48 ± 5 years, 53% female and used 27 ± 9 cigarettes/day, 29 ± 9 pack-years. HNBC users were aged: 46 ± 14 years, 55% female and used 26 ± 8 cigarettes/day, 30 ± 8 pack-years. Ecig users were aged: 45 ± 8 years, 51% female and used 27 ± 10 cigarettes/day, 28 ± 10 pack-years. Compared to baseline, switching to HNBC for 1 month improved only PBR20-25 (2.55±0.49 vs 2.34±0.34 μm, p=0.002). Ecig use did not alter endothelial glycocalyx in any range of microvessels throughout the study (p>0.05). In contrast, Tcig smoking for one month further worsened endothelial glycocalyx in all microvessels ranges compared to baseline (p<0.05). Blood cotinine levels were similar at baseline and after 1 month using HNBC (p=0.432), Ecig (p=0.535) or conventional cigarette (p=0.489). Compared to baseline, exhaled CO decreased in HNBC or Ecig users (mean percent change: -55% and -58% respectively p<0.001), while remained unchanged in Tcig smokers (p=0.312) at 1 month. Thus, Tcig smokers had higher CO than those who switched to HNBC or E-cig after one month (p<0.01). Conclusion Conventional cigarette users further worsened endothelial glycocalyx after continuing to smoke for one month. In contrast, smokers who switched to Ecig maintained glycocalyx integrity, while those who switched to HNBC showed modest improvement in glycocalyx integrity in microvessels ranging from 20 to 25 μm. Cotinine levels, which reflect nicotine exposure, were similar between the Tcig, HNBC and Ecig groups. Thus, endothelial glycocalyx impairment in the conventional cigarette group was independent of nicotine consumption and possibly related to greater exposure to toxic emissions, such as CO, after Tcig use than after switching to HNBC or Ecig.

Twelve-months treatment with dapagliflozin improves endothelial glycocalyx and cardiovascular function in patients with type 1 diabetes mellitus

Abstract Background Individuals diagnosed with type 1 diabetes mellitus (T1DM) exhibit indications of vascular and endothelial dysfunction earlier in comparison to healthy individuals. Evidence shows that SGLT-2 inhibitors (SGLT-2i) have a beneficial impact on cardiovascular health in individuals with type 2 diabetes mellitus (T2DM). We investigated the effects of dapagliflozin on endothelial and cardiovascular function in patients with T1DM. Methods We recruited in total 40 patients with T1DM and pour glycemic control who were treated with insulin and received dapagliflozin (n=20) or intensification of insulin treatment (n=20) (control group). We measured at baseline and at twelve months post-treatment the: a) Carotid-femoral pulse wave velocity (PWV-Complior; ALAM Medical) b) Central systolic blood pressure (cSBP) c) Perfused boundary region (PBR) of the sublingual arterial microvessels (marker of endothelial glycocalyx thickness) and d) Left ventricular global longitudinal strain (GLS) using speckle-tracking echocardiography. Results At baseline, patients among the two groups had similar age, sex, HbA1c and markers of endothelial and cardiovascular function (p>0.05). After 12 months of treatment, patients who received dapagliflozin displayed an improvement in PBR5–25 (−16%, p<0.05), in PWV (−9.3%, p<0.05), in cSBP (−6%, p<0.05) and in GLS (+4%, P<0.05) compared to baseline. However, no statistically significant changes in PBR5–25, in PWV, in cSBP and in GLS were observed after intensification of insulin treatment (PBR5–25: +0.4%, PWV: -1%, cSBP: −2%, GLS: −1% at 4 months, P>0.05), despite a similar HbA1c reduction (Table 1). Changes of PBR after one year treatment with dapagliflozin correlated with a concomitant reduction of PWV and cSBP (P<0.05). Conclusions Twelve months treatment with dapagliflozin improves endothelial glycocalyx and cardiovascular function in patients with T1DM, independently of glycemic control.

The effect of the combined treatment with dulaglutide and dapagliflozin in arterial elasticity, cardiac function, albuminuria and endothelial thickness in type 2 diabetes mellitus after 12 months

Abstract Background The association between diabetes mellitus and diabetic nephropathy with vascular and endothelial properties is well established. Purpose In this study, we compared the effect of combined treatment with dulaglutide and dapagliflozin versus DPP-4 inhibitors on endothelial glycocalyx, arterial stiffness, myocardial function and albuminuria in patients with type 2 diabetes mellitus and albuminuria. Methods A total of 60 patients with type 2 diabetes mellitus and albuminuria were randomized to combined dulaglutide and dapagliflozin treatment (n=30) or DPP-4 inhibitors (DPP-4is, n=30). We measured at baseline and 4 and 12 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 (cSBP), (c) global left ventricular longitudinal strain (GLS) (d) urine albumin-to creatinine ratio (UACR). Results Twelve months post-treatment, the combination of dulaglutide and dapagliflozin showed a greater improvement in all indices compared to DPP-4is, despite a similar reduction in glycosylated hemoglobin. Specifically, dual therapy showed greater improvements vs DPP-4is in PBR (2,10±0,31 to 1,93±0,23 μm vs 2,11±0,31 to 2,08±0,28 μm, p<0,001), in UACR (326±61 to 142±47 mg/g vs 345±48 to 306±60 mg/g, p<0,01), and in PWV (11,77±2,37 to 10,7±2,29 m/s vs 10,64±2,44 to 10,54±2,84 m/s, p<0,001), while only dual therapy showed improvement in cSBP (130,21±17,23 to 123,36±18,42 mmHg). Regarding GLS, both treatments were effective, but dual therapy showed a significantly higher percentage improvement compared to DPP-4is (18,19% vs 6,01%, respectively). Conclusions Twelve-month treatment with dulaglutide and dapagliflozin showed a greater improvement in vascular markers an albuminuria than DPP-4is in patients with type 2 diabetes mellitus and albuminuria. Early initiation of combined therapy as add-on to metformin should be considered in these patients.

Sidestream dark field video microscopy demonstrates shelf-stable blood products preserve the endothelial glycocalyx in a canine hemorrhagic shock model.

To utilize sidestream dark field video microscopic technology to evaluate the endothelium in a canine hemorrhagic shock and resuscitation model. 6 purpose-bred adult dogs were anesthetized, instrumented, and subjected to hemorrhagic shock from September 2021 through June 2022. Each dog was resuscitated with 5 resuscitation strategies in an experimental crossover design study: (1) lactated Ringer's solution (LRS) and hydroxyethyl starch (HES) solution; (2) canine chilled whole blood (CWB); (3) canine fresh frozen plasma (FFP) and packed RBCs (pRBC); (4) canine freeze-dried plasma (FDP) and hemoglobin-based oxygen carrier (HBOC); or (5) HBOC/FDP and canine lyophilized platelets. Sidestream dark field video microscopic evaluation was performed at 5 time points: commencement, after hemorrhage, after shock, after resuscitation (T135), and conclusion (T180). There was a significant difference between the perfused boundary region (PBR) measurements when comparing the LRS/HES resuscitation arm to the CWB and FFP/pRBC resuscitation arms at T180. A significant difference in PBR was appreciated in the LRS/HES arm at T135 and T180 compared to its baseline. No other significant differences in PBR were appreciated when resuscitation arms were compared longitudinally or to each other. Shelf-stable blood products preserved the endothelial glycocalyx similarly to CWB and pRBC/FFP as evaluated by sidestream dark field video microscopy. Lactated Ringer and HES solutions did not adequately preserve the endothelial glycocalyx compared to CWB and pRBC/FFP. Shelf-stable blood products are a viable option to preserve the endothelial glycocalyx when used during hemorrhagic resuscitation in dogs.

Retinal Microvascular Changes in Association with Endothelial Glycocalyx Damage and Arterial Stiffness in Patients with Diabetes Mellitus Type 2: A Cross-Sectional Study in a Greek Population.

To evaluate the potential association between endothelial glycocalyx damage, as well as arterial stiffness, and the retinal changes on optical coherence tomography (OCT) and OCT-angiography (OCT-A) in patients with type 2 diabetes mellitus (DM). Participants in this cross-sectional study were 65 patients with DM type 2 and 42 age- and gender-matched controls without DM. The demographic and clinical characteristics of the participants were recorded. All patients underwent a thorough ophthalmological examination and multimodal imaging, including fundus photography, OCT, and OCT-A. In addition, evaluation of the endothelial glycocalyx thickness by measuring the perfused boundary region (PBR5-25) of the sublingual microvessel, as well as of the arterial stiffness, by measuring the carotid-femoral pulse wave velocity (PWV), the central aortic pressures and the augmentation index (Aix) was performed. Univariate and multivariate logistic regression analysis was performed for the examination of the potential association between the eye imaging variables and the cardiovascular-related variables. The odds ratios (OR) with the respective 95% confidence intervals (CI) were calculated. A p-value < 0.05 was considered statistically significant. Patients with DM presented significantly higher PBR5-25 compared to controls without DM (p = 0.023). At the univariate analysis, increased PBR5-25 (≥2.19 μm vs. <2.19 μm) was associated with decreased peripapillary VD at the superior quadrant (univariate OR (95% CI) = 0.34 (0.12-0.93), p = 0.037). Multivariate logistic regression analysis showed that increased PWV (≥13.7 m/s vs. <13.7 m/s) was associated with an increased foveal avascular zone (FAZ) area on OCT-A (p = 0.044) and increased FAZ perimeter (p = 0.048). Moreover, increased Aix (≥14.745% vs. <14.745%) was associated with diabetic macular edema (DME) presence (p = 0.050) and increased perifoveal and parafoveal superior and temporal thickness on OCT (p < 0.05 for all associations). Markers of endothelial damage and arterial stiffness were associated with structural and microvascular retinal alterations in patients with DM, pointing out that OCT-A could be a useful biomarker for detecting potential cardiovascular risk in such patients.

The Effect of 4-Month Treatment with Glycocalyx Dietary Supplement on Endothelial Glycocalyx Integrity and Vascular Function in Patients with Psoriasis.

Psoriasis predisposes to cardiovascular dysfunction. We investigated whether glycocalyx dietary supplement (GDS), which contains glycosaminoglycans and fucoidan, improves endothelial glycocalyx and arterial stiffness in psoriatic patients. Fifty participants with psoriasis under biological agents were randomly assigned to GDS (n = 25) or placebo (n = 25) for 4 months. We measured at baseline and at follow-up: (a) perfused boundary region (PBR) of the sublingual microvessels (range 4 to 25 μm), a marker of endothelium glycocalyx integrity; (b) carotid-femoral pulse wave velocity (PWV-Complior SP-ALAM) and augmentation index (AIx), markers of arterial stiffness and (c) psoriasis area and severity index (PASI) score. Both groups displayed a similar decrease in PASI at four months (p < 0.05), and no significant differences were found between groups (p > 0.05). Compared to the placebo, participants in the GDS showed a greater percentage reduction in PBR4-25 μm (-9.95% vs. -0.87%), PBR 4-9 μm (-6.50% vs. -0.82%), PBR10-19 μm (-5.12% vs. -1.60%), PBR 20-25 μm (-14.9% vs. -0.31%), PWV (-15.27% vs. -4.04%) and AIx (-35.57% vs. -21.85%) (p < 0.05). In the GDS group, the percentage reduction in PBR 4-25 μm was associated with the corresponding decrease in PWV (r = 0.411, p = 0.015) and AΙx (r = 0.481, p = 0.010) at follow-up. Four-month treatment with GDS improves glycocalyx integrity and arterial stiffness in patients with psoriasis. Clinical trial Identifier: NCT05184699.

Six-month supplementation with high dose coenzyme Q10 improves liver steatosis, endothelial, vascular and myocardial function in patients with metabolic-dysfunction associated steatotic liver disease: a randomized double-blind, placebo-controlled trial

BackroundMetabolic-dysfunction Associated Steatotic Liver Disease (MASLD) has been associated with increased cardiovascular risk. The aim of this Randomized Double-blind clinical Trial was to evaluate the effects of coenzyme-Q10 supplementation in patients with MASLD in terms of endothelial, vascular and myocardial function.MethodsSixty patients with MASLD were randomized to receive daily 240 mg of coenzyme-Q10 or placebo. At baseline and at 6-months, the a)Perfused boundary region of sublingual vessels using the Sideview Darkfield imaging technique, b)pulse-wave-velocity, c)flow-mediated dilation of the brachial artery, d)left ventricular global longitudinal strain, e)coronary flow reserve of the left anterior descending coronary artery and f)controlled attenuation parameter for the quantification of liver steatosis were evaluated.ResultsSix months post-treatment, patients under coenzyme-Q10 showed reduced Perfused boundary region (2.18 ± 0.23vs.2.29 ± 0.18 μm), pulse-wave-velocity (9.5 ± 2vs.10.2 ± 2.3 m/s), controlled attenuation parameter (280.9 ± 33.4vs.304.8 ± 37.4dB/m), and increased flow-mediated dilation (6.1 ± 3.8vs.4.3 ± 2.8%), global longitudinal strain (-19.6 ± 1.6vs.-18.8 ± 1.9%) and coronary flow reserve (3.1 ± 0.4vs.2.8 ± 0.4) compared to baseline (p < 0.05). The placebo group exhibited no improvement during the 6-month follow-up period (p > 0.05). In patients under coenzyme-Q10, the reduction in controlled attenuation parameter score was positively related to the reduction in Perfused boundary region and pulse wave velocity and reversely related to the increase in coronary flow reserve and flow-mediated dilation (p < 0.05 for all relations).ConclusionsSix-month treatment with high-dose coenzyme-Q10 reduces liver steatosis and improves endothelial, vascular and left ventricle myocardial function in patients with MASLD, demonstrating significant improvements in micro- and macro-vasculature function.Trial RegistrationNCT05941910

Semaglutide Concurrently Improves Vascular and Liver Indices in Patients With Type 2 Diabetes and Fatty Liver Disease.

The cardiovascular benefits of semaglutide are established; however, its effects on surrogate vascular markers and liver function are not known. To investigate the effects of semaglutide on vascular, endothelial, and liver function in patients with type 2 diabetes (T2DM) and nonalcoholic fatty liver disease (NAFLD). Overall, 75 consecutive subjects with T2DM and NAFLD were enrolled: 50 patients received semaglutide 1 mg (treatment group) and 25 patients received dipeptidyl peptidase 4 inhibitors (control group). All patients underwent a clinical, vascular, and hepatic examination with Fibroscan elastography at 4 and 12 months after inclusion in the study. Treatment with semaglutide resulted in a reduction of Controlled Attenuation Parameter (CAP) score, E fibrosis score, NAFLD fibrosis score, Fibrosis-4 (FIB-4) score and perfused boundary region (PBR) at 4 and at 12 months (P < .05), contrary to controls. Patients treated with semaglutide showed a greater decrease of central systolic blood pressure (SBP) (-6% vs -4%, P = .048 and -11% vs -9%, P = .039), augmentation index (AIx) (-59% vs -52%, P = .041 and -70% vs -57%, P = .022), and pulse wave velocity (PWV) (-6% vs -3.5%, P = .019 and -12% vs -10%, P = .036) at 4 and at 12 months, respectively. In all patients, ΔPWV and ΔPBR were correlated with a corresponding reduction of CAP, E fibrosis, NAFLD fibrosis, and FIB-4 scores. Twelve-month treatment with semaglutide simultaneously improves arterial stiffness, endothelial function, and liver steatosis and fibrosis in patients with T2DM and NAFLD.

Doxycycline protects against sepsis-induced endothelial glycocalyx shedding

Endothelial glycocalyx (eGC) covers the inner surface of the vessels and plays a role in vascular homeostasis. Syndecan is considered the “backbone” of this structure. Several studies have shown eGC shedding in sepsis and its involvement in organ dysfunction. Matrix metalloproteinases (MMP) contribute to eGC shedding through their ability for syndecan-1 cleavage. This study aimed to investigate if doxycycline, a potent MMP inhibitor, could protect against eGC shedding in lipopolysaccharide (LPS)-induced sepsis and if it could interrupt the vascular hyperpermeability, neutrophil transmigration, and microvascular impairment. Rats that received pretreatment with doxycycline before LPS displayed ultrastructural preservation of the eGC observed using transmission electronic microscopy of the lung and heart. In addition, these animals exhibited lower serum syndecan-1 levels, a biomarker of eGC injury, and lower perfused boundary region (PBR) in the mesenteric video capillaroscopy, which is inversely related to the eGC thickness compared with rats that only received LPS. Furthermore, this study revealed that doxycycline decreased sepsis-related vascular hyperpermeability in the lung and heart, reduced neutrophil transmigration in the peritoneal lavage and inside the lungs, and improved some microvascular parameters. These findings suggest that doxycycline protects against LPS-induced eGC shedding, and it could reduce vascular hyperpermeability, neutrophils transmigration, and microvascular impairment.

Identifying the time course and contributors for Western diet-induced increase in glycocalyx barrier function

The endothelial glycocalyx is a dynamic gel-like structure bound to the vascular endothelium composed of glycosaminoglycans, such as hyaluronan. The glycocalyx plays a critical role in cardiovascular health, acting as a physical barrier to the contents of flowing blood, including red blood cells. Interestingly, we have shown that 12 weeks of Western diet (WD), characterized by excess saturated fat and sugar content, results in greater glycocalyx barrier function in the mesenteric microcirculation that is strongly related to blood glucose values. Currently, the time course that WD induces an increase in glycocalyx barrier function is unknown, as are the contributors to that increase. Thus, we first examined glycocalyx barrier function 1, 2, 4, and 12 weeks after initiating WD in non-fasted male and female UM-HET3 mice (n=9-14/group). Glycocalyx barrier function was assessed in the mesenteric microcirculation by determining perfused boundary region (PBR), which represents red blood cell penetration into the glycocalyx. A higher PBR indicates worse glycocalyx barrier function. Compared to age-matched normal chow (NC) control mice, PBR was lower in WD at week 1 (NC: 2.35±0.05 vs. WD: 1.94±0.04 μm, p&lt;0.05), 2 (NC: 2.36±0.04 vs. WD: 2.01±0.07 μm, p&lt;0.05), 4 (NC: 2.38±0.04 vs. WD: 1.91±0.1 μm, p&lt;0.05), and 12 (NC: 2.41±0.03 vs. WD 1.99±0.04 μm, p&lt;0.05). While blood glucose was higher in WD compared to NC mice at week 12 (NC: 166±3 vs. WD 179±4 mg/dL, p&lt;0.05), it was similar between NC and WD at week 1, 2, and 4 (P&gt;0.05). These data indicate that the WD-induced increase in glycocalyx barrier function occurs as early as 1 week after initiating WD and appears to be independent of blood glucose. Because glycocalyx barrier function was assessed in the mesenteric microcirculation in non-fasted mice, we then sought to determine if the WD-induced increase in glycocalyx barrier function was due to postprandial state. Thus, we determined PBR in non-fasted and fasted (6h) male and female UM-HET3 mice 1 week after initiating WD (n=14-16/group). Fasting status did not affect PBR in age-matched NC (non-fasted 2.32±0.05 vs. fasted: 2.25±0.04 μm, P&gt;0.05) or WD mice (non-fasted 1.94±0.04 vs. fasted: 2.06±0.05 μm, P&gt;0.05), though WD had lower PBR than NC mice in non-fasted and fasted states (p&lt;0.05). These data indicate that glycocalyx barrier function is unaffected by fasting status. Given the role of hyaluronan in the glycocalyx, we then sought to determine if the WD-induced increase in glycocalyx barrier function was due to higher hyaluronan content in the glycocalyx. Thus, we examined PBR pre- and 30 min post-hyaluronidase administration (35 U) in male and female UM-HET3 mice 1 week after initiating WD (n=5/group). There was a tendency for hyaluronidase administration to increase PBR in age-matched NC mice (Pre: 2.37±0.07 vs. Post: 2.65±0.12 μm, P=0.11), whereas PBR increased in WD mice after hyaluronidase administration (Pre: 2.13±0.04 vs. Post: 2.53±0.09 μm, p&lt;0.05). Additionally, the difference in PBR between NC and WD mice was no longer present post-hyaluronidase administration (P&gt;0.05). Taken together, these data indicate that glycocalyx barrier function is increased as early as 1 week after initiating WD and appears to be independent of blood glucose or fasting status but is at least partially due to increased hyaluronan content in the glycocalyx. This study was partly funded by a grant from the National Institutes of Health (R00 AT010017). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Lactobacillus plantarum 299v administration prevents high-sodium diet-induced glycocalyx degradation and arterial dysfunction

A central feature of cardiovascular disease (CVD) is arterial dysfunction (i.e., elevated systolic blood pressure [BP], aortic stiffening, and endothelial dysfunction), which may be initiated by a degraded endothelial glycocalyx. The glycocalyx is a negatively charged structure bound to the vascular endothelium that appears to play a critical role in cardiovascular health, particularly by buffering sodium in blood, although excessive sodium degrades the glycocalyx. In the United States, a high-sodium (HS) diet is consumed by ~90% of the population with average sodium intake ~2.3x greater than recommended by the American Heart Association. We have previously shown that HS diet induces glycocalyx degradation and arterial dysfunction in outbred, genetically diverse UM-HET3 mice. Others have shown that HS diet lowers Lactobacillus abundance in mouse gut microbiome. However, it is unknown whether maintaining Lactobacillus would prevent HS diet-induced glycocalyx degradation and arterial dysfunction. To test this concept, male and female UM-HET3 mice (n=21-35/group) were randomized into a low-sodium (LS) diet (1% NaCl), HS diet (4% NaCl), or HS diet with Lactobacillus plantarum 299v (Lp299v) administration (60 million CFU/ml in drinking water) for 12 weeks. Glycocalyx barrier function was determined by assessing perfused boundary region (PBR), which represents red blood cell penetration into the glycocalyx. At week 12, we observed higher PBR in HS mice (2.36±0.04 μm) compared to LS and HS+Lp299v mice (2.09±0.03 and 2.20±0.04 μm, respectively; p&lt;0.05), indicating a worse glycocalyx barrier function in HS mice. PBR was similar between LS and HS+Lp299v mice (P&gt;0.05), indicating a preserved glycocalyx barrier function in HS+Lp299v mice. Systolic BP was higher in HS (127±1 mmHg) compared to LS and HS+Lp299v mice (113±1 and 118±1 mmHg, respectively; p&lt;0.05). Aortic stiffness, determined by aortic pulse wave velocity (PWV), was also higher in HS (345±5 cm/s) compared to LS and HS+Lp299v mice (268±5 and 300±3 cm/s, respectively; p&lt;0.05). However, systolic BP and aortic PWV were higher in HS+Lp299v compared to LS mice (p&lt;0.05). Ex vivo endothelial function, determined by the maximal vasodilatory response to acetylcholine in the carotid artery, was lower in HS (83.9±1.3%) compared to LS and HS+Lp299v mice (89.8±1.3 and 90.1±1.0%, respectively; p&lt;0.05). Endothelial function was similar between LS and HS+Lp299v mice (P&gt;0.05). In summary, Lp299v administration prevents HS diet-induced glycocalyx degradation and endothelial dysfunction, while mitigating HS diet-induced elevations in systolic BP and aortic stiffness. These findings suggest that Lp299v administration may be a novel strategy to lower the risk of CVD in humans that consume a HS diet. This study was funded in part by a grant from the National Institutes of Health (R00 AT010017). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Advanced age and reduced hyaluronan synthesis impair glycocalyx integrity resulting in endothelial dysfunction

The glycocalyx (GC) is a densely structured, gel-like matrix that coats the inner lining of the vascular endothelium. The GC plays a pivotal role in regulating the integrity of the vascular endothelium, primarily through mechano-sensing and -transducing shear stress, while also preserving endothelial barrier function. With advancing age, the GC deteriorates concomitantly with its essential constituent, hyaluronan (HA), which may lead to endothelial dysfunction. Therefore, we hypothesized that advanced age and reduced HA synthesis alone or together will impair GC integrity resulting in endothelial dysfunction. We have generated a tamoxifen-inducible, endothelial cell-specific, knockout mouse model of a hyaluronan producing enzyme, hyaluronan synthase 2 (HAS2), in young (4-6 mo) and old (22-23 mo, n=9-12/group). HAS2 mRNA expression in carotid endothelial cell lysates were reduced by ~47% in endothelial cell HAS2 knockout (ecHAS2KO) vs wildtype (ecHAS2WT, p=0.004) after tamoxifen treatment. The perfused boundary region (PBR), indicative of GC barrier function, was evaluated in vivo in the mesenteric microcirculation. The PBR was significantly impaired with aging (young vs old ecHAS2WT, p=0.047) and genotype (young ecHAS2WT vs KO, p=0.012) but there was no additive effect of aging and genotype (old ecHAS2WT vs KO, p=0.989). Subsequently, GC thickness was determined by measuring the depth of GC collapsed by leukocyte passage through the mesenteric segments. GC thickness was diminished by ~53% with aging (young vs old ecHAS2WT, p&lt;0.0001) and ~59% with genotype (young ecHAS2WT vs KO, p&lt;0.0001) but there was no synergistic effect of aging and genotype (old ecHAS2WT vs KO, p=0.893). Mechano-sensing and -transducing properties of the GC were assessed using ex vivo flow-induced vasodilation in isolated carotid arteries with and without the intra-luminal infusion of HA degrading enzyme, hyaluronidase (HYAL). Flow-induced vasodilation was diminished with aging (young vs old ecHAS2WT, p&lt;0.0001) but this age-related decline was dampened with HYAL (p=0.212). The vasodilatory response to flow was reduced with genotype (young ecHAS2WT vs KO, p&lt;0.0001) but this effect was weakened with HYAL (p=0.953). There was no augmentative effect of aging and genotype with and without HYAL (all p≥0.883). Acetylcholine induced endothelium-dependent dilation (EDD), a measure of endothelial function, was examined ex vivo in isolated mesenteric arteries. The maximal EDD was diminished by ~23% with aging (young vs old ecHAS2WT, p=0.04) but not genotype (young ecHAS2WT vs KO, p=0.962). There was an additive reduction in maximal EDD by ~46% with aging and genotype (old ecHAS2KO vs WT, p=0.021). Endothelium-independent dilation in response to sodium nitroprusside, an exogenous nitric oxide donor, was not different across groups with either aging, genotype, or both (ALL p&gt;0.05). In conclusion, aging and reduced HA synthesis independently impaired GC integrity. As a result, mechano-sensing and -transducing property of GC was disturbed and further diminished by HYAL activity. In addition, endothelial function was impaired with aging and further exacerbated after a reduction in HA synthesis. Funded in part by awards from National Institutes of Health Awards R01 AG060395, R01 AG077751, R01 AG076748, T32 HL007576, T32 HL139451, Veteran's Affairs Merit Review Award I01 BX004492 and Nora Eccles Treadwell Foundation. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Microcirculation, endothelium and glycocalyx changes associated with the use of milrinone in children with septic shock.

The goal of fluid resuscitation and the use of inotropes in septic shock has traditionally focused on improving blood pressure and cardiac output, without considering the microcirculatory changes. Reaching macrocirculatory goals but with persistent microcirculatory abnormalities (hemodynamic incoherence) in septic shock has been associated with greater organ dysfunction and mortality. The objective of this study was to evaluate the microcirculation (flow and capillary density) and endothelial glycocalyx changes associated with the use of milrinone in children with septic shock, as well as their relationship with clinical variables and organ dysfunction. A prospective cohort study from February 2022 to January 2023 at a university hospital (Fundación Cardioinfantil-Instituto de Cardiología). Sublingual video microscopy was used to evaluate capillary density, microvascular flow rates and perfused boundary region (PBR-inverse parameter of glycocalyx thickness-abnormal if >2.0 microns). The primary outcome was the association between microcirculation and endothelial glycocalyx changes related to the use of milrinone. A total of 140 children with a median age of two years [interquartile range (IQR) 0.58-12.1] were included. About 57.9% (81/140) of the patients received milrinone infusions. Twenty-four hours after receiving milrinone, the patients maintained functional capillary density (P<0.01) and capillary recruitment capacity (P=0.04) with no changes in capillary blood volume versus those who did not receive milrinone. Children under two years old who received milrinone had better 4-6-micron capillary density than older children [odds ratio (OR) 0.33; 95% confidence interval (95% CI): 0.12-0.89; P=0.02] and less endothelial glycocalyx degradation [adjusted OR (aOR) 0.34 95% CI: 0.11-0.99; P=0.04]. These changes persisted despite elevated ferritin (aOR 0.41; 95% CI: 0.18-0.93; P=0.03). Prolonged capillary refill and elevated lactate were correlated with microcirculation changes in both groups. The patients who died had the highest PBR levels (P=0.04). Children with septic shock who receive milrinone infusions have microcirculation changes compared with those who do not receive them. The group that received milrinone was found to maintain functional capillary density and capillary recruitment capacity and have less endothelial glycocalyx degradation 24 hours after administration. These changes were present despite the inflammatory response and were more significant in those under two years of age.