Selected Abstracts from Artery 22

Background: Marfan Syndrome is a primary cause of thoracic aortic aneurysms; it arises from dysfunctional fibrillin-1, which normally sta-bilizes elastic fibers and promotes smooth muscle mechano-sensing of the matrix. Despite significant advancements, clear correlations between microstructural integrity and aortic functionality remain wanting. Methods: Age-matched wild-type, Fbn1C1041G/

Objectives: Prediabetes is recognized as a significant metabolic status, being a key factor in the occurrence of diabetes mellitus (DM). There is increasing evidence concerning microvascular complications in prediabetes most commonly in skin, kidneys and retina (1,2). Laser speckle contrast analysis (LASCA) is a non-invasive technique that can be used to evaluate skin microvascular function. Previous studies have shown skin microvascular dysfunction in patients with DM (3). However, to our knowledge, no previous study has evaluated skin microcirculation, using LASCA, in patients with prediabetes. Methods: In all subjects, forearm skin blood flow was recorded under standardized conditions using a laser speckle contrast imager (PeriCam PSI NR System, Perimed). Post-occlusive reactive hyperemia (PORH) was assessed following a standardized protocol and data were analyzed with a signal processing software (PIMSoft, Perimed). The amplitude of PORH responses was expressed as a percentage increase between peak and baseline perfusion (%). Results: Twenty-nine individuals (14 patients with prediabetes and 15 controls) were studied. There wasn't any statistically significant difference regarding age, sex, body mass index and blood pressure levels between the two groups. At baseline, skin microvascular perfusion was significantly higher in patients with prediabetes compared to controls (50.9 ± 11.5 vs. 39.2 ± 8.7, p = 0.006) while during occlusion, perfusion was similarly reduced in both groups. Post occlusion reperfusion was significantly lower in the prediabetes group as compared to the controls (145.0 ± 42.8 vs. 195.2 ± 47.3% respectively, p = 0.007). Conclusions: We showed, for the first time, that individuals with prediabetes demonstrated skin microvascular dysfunction, that may reflect a more generalized microvascular damage.
Arterial stiffness (AS) is one of the primary symptoms of vascular ageing (1). Stiffer arteries lead to increased pulse wave velocity (PWV) and decreased pulse transit time (PTT). PWV is considered the clinical gold standard for the diagnosis of AS, but direct measurement in daily life is challenging (2). Pulse arrival time (PAT), which consists of the pre-ejection period (PEP) and PTT, is defined as the time interval between the R-peak of electrocardiogram (ECG) and a characteristic point of photoplethysmogram (PPG) (3,4). Since most standard wearable devices can capture PPG and ECG signals, and PAT correlates highly with vascular properties, such as vascular tone, PAT extracted from wearable signals has the potential to indicate cardiovascular health (5). The study used a database of in silico pulse wave signals for 4,374 virtual subjects to calculate aortic PWV (aPWV), aortic-radial PTT (arPTT), and PEP (6). The strength of the correlation between PAT and aPWV was assessed using the correlation coefficient (R2). Relative sensitivity analysis was used to investigate the effects of cardiac and vascular properties on PAT. The R2 value between PAT and aPWV was 0.84. The inverse relationship between PAT and aPWV illustrates that stiffer arteries resulted in decreased PAT, even when considering specific age groups. According to the relative sensitivity analysis, PAT is mainly affected by stroke volume and PWV. Our in silico study suggests that PAT has the potential to be used as a marker for assessing the arterial stiffening component of vascular ageing.

University of North Carolina at Chapel Hill, Chapel Hill, United States
Background: Excessive Daytime Sleepiness (EDS) is associated with higher risk of cardiovascular disease (CVD) events (1,2) and mortality (3). However, the association between EDS and subclinical CVD, such as arterial stiffness, is not fully understood nor is the role of physical activity (PA) in this association. We examined the relationship between EDS and arterial stiffness, measured using carotidfemoral pulse wave velocity (cfPWV), with PA as a potential effect modifier. Methods: A cross-sectional analysis of ARIC Study participants (n = 2349, mean age: 79.6, 57.2% female, 19.2% black adults) who underwent cfPWV measures (VP-1000 Plus, Omron Co., Kyoto, Japan) and completed the Epworth Sleep Scale (ESS) and Baecke questionnaires in 2016-2019. EDS was defined as ESS ≥ 11. We calculated moderate-vigorous PA (min/week) and categorized PA based on the distribution and guidelines. We used multivariable linear regression to estimate the association between ESS, EDS, and cfPWV, and evaluated effect modification by PA. Results are presented as beta coefficients (β) and 95% confidence intervals (CI). Results: A total of 14.4% participants reported EDS. The association of ESS and EDS with cfPWV differed by PA level. The association of ESS ( Figure A) and EDS ( Figure B) with cfPWV became more negative with higher PA levels, although the associations with EDS were not statistically significant. Conclusion: A negative association was observed between ESS and cfPWV at the most intense level of PA in older adults. In those not meeting PA guidelines, other adverse life and participant characteristics could outweigh the effects of ESS and EDS on cfPWV.
Results are adjusted for age, race-study center, body mass index, diabetes, heart rate, mean arterial pressure, and blood-pressure medication use. AHA: American Heart Association: T: tertile.
Results: In Phase 1, β o was significantly greater in DM+ than DM− after adjusting for age and sex [27.5 (26.6-28.3) vs 23.6 (22. 4-24.8) au, p < 0.001]. Partial correlation analyses after adjusting for age and sex found that β o was significantly associated with HbA1c (r = 0.15 p < 0.001) and heart rate (r = 0.23 p < 0.001) in DM+. I Phase 2, percentage changes in β o were significantly greater in DM + than DM− [19.5 (14.9-24.0) vs 5.0 (− 0.6-10.6) %, p < 0.001] after adjusting for age, sex and baseline β o . Multivariable linear regression analyses revealed that the percentage changes in β o were independently associated with percentage changes in heart rate in DM + (overall R 2 = 0.19). Conclusion: β o was greater in DM + than DM−. Furthermore, β o changed over three years with ageing but it changed much more in DM + than DM−. These data suggest that intrinsic arterial wall stiffness may be a useful target for therapeutic intervention.

O.20 The bidirectional longitudinal relationships between arterial stiffness and hypertension and those between arterial stiffness and diabetes mellitus
Professor Hirofumi Tomiyama 1 1 Japan, Suginami, Japabn Background: Hypertension and diabetes mellitus frequently coexist; however, it has not yet been clarified if the bidirectional longitudinal relationships between arterial stiffness and hypertension are independent of those between arterial stiffness and diabetes mellitus. Methods: In this 16-year prospective observational study, 3960 middle-aged employees of a Japanese construction company without hypertension/diabetes mellitus at the study baseline underwent annual repeated measurements of the blood pressure, serum glycosylated hemoglobin A1c level (HbA1c), and brachial-ankle pulse wave velocity (baPWV). Results: By the end of the study period, 664, 779, 154, and 406 subjects developed hypertension, prehypertension, diabetes mellitus, and prediabetes, respectively. Increased baPWV at the baseline was associated with a significant odds ratio (per 1 standard deviation increase) for new onset of prehypertension/hypertension with (2.45/3.28, P < 0.01) or without (2.49/2.76, P < 0.01) coexisting prediabetes/diabetes mellitus, but not for new onset of prediabetes/diabetes mellitus without coexisting hypertension. Analyses using the latent growth curve model confirmed the bidirectional relationships between baPWV and hypertension, but no such relationship was observed between baPWV and abnormal glucose metabolism. Conclusions: In middle-aged Japanese subjects in contrast to the bi-directional relationships that exist between arterial stiffness and hypertension, increased arterial stiffness preceding the development of diabetes mellitus may represent that associated with the development of hypertension, as it is observed only in cases of diabetes mellitus coexisting with hypertension. Therefore, arterial stiffness may be associated to a greater degree with the development of hypertension than with the development of diabetes mellitus. Keywords: arterial stiffness; hypertension
with grade 1 HTN at low-moderate risk remain hypertensive after a period of lifestyle intervention. Our objective was to assess the predictive value of early vascular aging (EVA) to identifying patients who developed sustained HTN after baseline diagnosis.
Introduction: Vascular Age (VA) can assess cardiovascular disease risk, independently of chronological age, however it is not yet widely applied in routine clinical practice. A quantitative questionnaire was developed to assess current knowledge gaps related to VA and barriers to implementation in routine practice in both research and clinical settings. Methods: Using a stepwise mixed-methods approach, a quantitative questionnaire was constructed. The 22-item anonymous survey was based on a previous qualitative analysis including 80 participants with multiple scientific backgrounds, and included questions on perceptions/ beliefs, knowledge, and implementation of VA. The survey was disseminated to clinicians and researchers world-wide, via social media and targeted emails from well-known societies (including Artery, ESH, ISH, ESC). Results: 276 (50% female) completed the questionnaire, 46% were clinicians, 33% researchers, 10% students. Clinical specialties included cardiology (36%), internal medicine (22%) and General Practice (10%). While 84% of clinicians and researchers rate VA importance as high or very high ( Table), only 11% of clinicians measure VA in clinical settings. Limiting factors include cost, lack of guidelines and lack of knowledge. Discussion: These results show that implementation of VA is very low in clinical settings and awareness of VA needs to be improved via planned targeted awareness strategies and educational material. Background: Obstructive sleep apnea (OSA) is an independent cardiovascular risk (CVR) factor. The objective was to evaluate sympathetic tone and vascular disease in obese hypertensive with moderate and severe OSA. Methods: Individuals of both sexes, aged 40-70 years and body mass index (BMI) ≥ 30 and < 40 kg/m2, submitted to assessment of heart rate variability (HRV), central parameters by Mobil-O-Graph and carotid ultrasound. Sleep study was performed through a portable home sleep test device (WatchPAT). Results: Patients (n = 49) were divided into two groups based on the apnea-hypopnea index (AHI): absent-mild (AM) group (AHI < 15 events/h, n = 17) and moderate-severe (MS) group (AHI ≥ 15 events/h, n = 32). The mean BMI was similar (35 ± 3 vs 34 ± 2 kg/ m2, p = 0.248). Systolic blood pressure (120 ± 15 vs 131 ± 14 mmHg, p = 0.003), pulse pressure (43 ± 9 vs 49 ± 8 mmHg, p = 0.011), CVR (6.8 ± 4.1 vs 14.4 ± 10.7%, p = 0.003) and cardiometabolic age (48 ± 6 vs 52 ± 8 years, p = 0.034) were higher in the MS group. The same group presented higher low frequency/high frequency (LF/ HF) ratio (0.83 ± 0.56 vs 1.91 ± 1.98, p = 0.017), pulse wave velocity (PWV) (7.1 ± 0.7 vs 8.0 ± 1.2 m/s, p = 0.003), vascular age (50 ± 6 vs 56 ± 8 years, p = 0.014) and carotid intima-media thickness (0.58 ± 0.09 vs 0.70 ± 0.12 mm, p = 0.001). PWV was significantly correlated with LF/HF ratio (r = 0.609, p < 0.001) only in the MS group. Conclusion: In this sample of obese hypertensive patients, moderate to severe OSA was associated with sympathetic hyperactivity and evidence of early vascular aging with increased arterial stiffness and subclinical atherosclerosis.

O.26
Acute vasopressin neutralization with the aptamer NOX-F37 improves immediately cardiac but not peripheral endothelial dysfunction in rats with chronic heart failure Background: Vasopressin is one of the leading pathophysiological drivers of chronic heart failure (CHF) acting via V1a-, V1b-and V2 receptors. Selective V2 and dual V1a-V2 receptor antagonists ameliorate plasma sodium levels, but fail to reduce mortality in clinical studies. Vasopressin neutralization is an original alterative for receptor blockers but its effect in CHF is unknown. For this purpose, we sought investigated the short-term cardiac and vascular effects of the vasopressin neutralizing aptamer NOX-F37. Methods: Left ventricular (LV) function (hemodynamics by LV catherization) and LV tissue perfusion (MRI) as well as mesenteric artery endothelium function (flow mediated dilation by arteriograph) were determined 2 h after NOX-F37 administration (80 nM/kg; IP) to rats with well-established CHF induced by coronary artery ligation. Results: Two hours after administration, NOX-F37 significantly improved LV systolic function, illustrated by the significant increase in LV end-systolic pressure volume relation (CHF: 20.2 ± 0.0.7; CHF + NOX: 23.3 ± 1.0 mmHg/RVU) and diastolic function, illustrated by the significant decrease in LV end-diastolic pressure volume relation (CHF: 4.03 ± 0.48; CHF + NOX: 2.06 ± 0.21 mmHg/RVU), which were associated with a significant increase in LV tissue perfusion (CHF: 6.12 ± 0.24; CHF + NOX: 10.10 ± 0.26 ml/min/g LV tissue). However, mesenteric artery flow-induced dilatation was not modified and remained impaired (% dilatation at 150 µl/min; CHF: 10 ± 7; CHF + NOX: 9 ± 8). Conclusions: These results illustrate the immediate protective effects on cardiovascular function of vasopressin neutralization in chronic heart failure confirming the existence of a deleterious vasopressinergic tone in chronic heart failure. Whether these beneficial cardiac effects persist with chronic vasopressin neutralization needs to be confirmed. Background: Hypertension causes the aorta to remodel and potentially stiffen. We aimed to compare the aortic remodelling response to hypertension as induced by adrenergic receptor activation versus renin-angiotensin-aldosterone system activation. Methods: Adult male C57BL/6 J mice were studied under seven conditions: untreated, and after 7/14/28-day subcutaneous infusion of 3880 ng/kg/min norepinephrine (NE) or 1000 ng/kg/min angiotensin II (AngII). After euthanasia, ascending/descending thoracic (ATA/ DTA) and infrarenal abdominal (IAA) aortas were dissected, placed within a computer-controlled biaxial testing device, and subjected to isobaric (90 mmHg) vasoreactivity experiments to, among others, 1 µM phenylephrine + 1 mM L-NAME [1]. Under passive conditions, pressure-diameter tests were performed at 95/100/105% of the < i > in vivo < /i > axial stretch and axial force-length tests at 10/60/100/140 mmHg. Data were fit using a nonlinear constitutive model [1]. Results: Figure (bar charts, < i > n < /i > = 4-8 per group) shows passive metrics calculated at < i > in vivo < /i > axial stretch and groupspecific systolic blood pressures [2]. AngII caused larger increases in wall thickness than NE. Both NE and AngII led to significant structural arterial stiffening, driven by a combination of wall thickening and stiffening of the wall material. Figure also shows correlation of wall thickness with contractility (scatter plots, < i > n < /i > = 4-7 per group; symbols represent individual aortas). The stronger an individual aorta was able to contract (larger absolute stress change; to the left on < i > x < /i > -axis), the weaker its remodelling response. Conclusions: NE-and AngII-induced hypertension elicit distinct aortic remodelling responses. However, independent of the hypertensive stimulus, aortic contractile capacity emerged as protective against hypertensive arterial remodelling.

Background:
The invasive method of catheter pullback from ascending aorta (asc) to iliac bifurcation (bifu) is gold standard for aortic pulse wave velocity (aPWV) and the reference standard for validation of non-invasive devices that estimate aPWV [1]. In this work, we examine aPWV variability in invasive recordings of patients undergoing cardiac catheterization. Methods: Invasive measurements were performed in 56 patients (57% male, 67 ± 13 years, mean ± standard deviation (SD)) with a femoral catheter access. Catheter pullback method was used to measure aortic pulse transit time (aPTT) from asc to bifu. Pulse wave analysis using the intersecting tangent method (Sirius, Redwave Medical GmbH, Jena, Germany) provided the diastolic foot points for each recording site (asc, bifu) and recorded heartbeat (number of beats, asc: 86 ± 42, bifu: 82 ± 43). From the respective time difference with the R-wave of the time-synchronised electrocardiogram, the pulse transit time for the corresponding recording site (PTTasc, PTTbifu) was derived for each heartbeat. aPTT was then determined from the difference of the averaged PTTbifu and PTTasc. Based on aPTT, the known catheter pullback length and the estimated SD of aPTT, SD_aPTT = √(SD_PTTasc 2 + SD_ PTTbifu 2 ), the SD of the corresponding aPWV was calculated as SD_ aPWV = aPWV × SD_aPTT/aPTT for each patient. Results: aPTT was 44.01 ± 12.89 ms; aPWV was 9.7 ± 3.1 m/s. SD_aPTT was 3.72 ± 1.73 ms, resulting in an SD_aPWV of 1.0 ± 0.8 m/s. Conclusions: Our data indicate a substantial beat-to-beat SD in invasively determined aPWV by catheter pull-back method. The issue of aPWV variability in the invasive reference needs to be addressed in validation protocols for non-invasive estimation of aPWV.
Background: Aortic pulse transit time (aPTT) is not constant but fluctuates, which affects the accurate determination of aortic pulse wave velocity (aPWV). In this work, we investigate the influence of age, gender, anthropometric and haemodynamic parameters on aPTT variability determined by the catheter pull-back method. Methods: aPTT could be analysed in 69 patients (61% male, 68 ± 13 years) with femoral catheter access. A stepwise multiple linear regression analysis was performed with aPTT variability as dependent variable and age, gender, BMI, heart rate, aortic systolic blood pressure (aSBP), aortic diastolic blood pressure (aDBP) and variability of aSBP (aSBPV) and aDBP (aDBPV) as predictors. For the dependent haemodynamic variables, only data from the ascending aorta were used. Results: The regression model with the factors heart rate, aSBP, aSBPV, aDBPV achieved the highest goodness of fit of 0.49 (adjusted R-squared). aSBPV and heart rate proved to be the strongest factors (standardised regression coefficient beta 0.397 and 0.301, respectively) followed by 0.258 for aDBPV and -0.199 for aSBP (all p < 0.05). The unstandardised regression coefficients B were 0.489 for aSBPV, 0.322 for aDBPV, -0.020 for aSBP and 0.047 for heart rate. Conclusions: Our data show the influence of aortic systolic and diastolic blood pressure variations, heart rate and aSBP on aPTT variability whereas age, gender, and BMI had no significant influence. However, the adjusted R-squared of the model suggests that a considerable part of aPTT variability cannot be explained by the independent variables included in the model. Background: Ctip2/Bcl11b is a transcription factor with dual action (repression/activation) that couples epigenetic regulation to gene transcription in a variety of physiological responses under healthy and pathological conditions of various tissues. Single nucleotide polymorphisms of Ctip2/Bcl11b gene are associated with a higher susceptibility for aortic stiffness (1). although Ctip2/Bcl11b has been proposed as a crucial regulator of aortic smooth muscle function (2), its mechanism of action in smooth muscle cells is still to be uncovered. Methods: Morphological, cellular and molecular analysis were carried out on the arteries of smooth muscle cell-specific Ctip2-knockout (KO) mice at 3, 7, 28 days after tamoxifen injections. Results: There is no difference between control and mutant mice at the macroscopic level 3 days after Ctip2 KO induction, however, 7 day after Bcl11b inactivation, 65% of the Ctip2-SMKO mice showed signs of hemorrhage in the distal part of the thoracic aorta near the abdominal aorta. The histological examination of thoracic aorta at 7 indicated the presence of "bumpy region" in the mutant aorta. These areas is covered by a thicker layer of extracellular matrix and the presence of IgG positive cells, indicating that cell death is occurring. However, the hemorrhages is contained over time, do not impact mice survival. qPCR analysis indicated the altered expression of circadian-related genes such as genes of Bmal and ciart. Conclusions: Our data indicate the primary effect of Bcl11b inactivation on cell death, probably by necroptosis.

Keywords
Photos showing thoracic aorta from control (A) and mutant mice (B) at 7 days after the injection of tamoxifen to 3 month-old mice. Background: Integrin αv is a receptor for adhesion proteins expressed at high density in vascular smooth muscle cells (VSMC) whose phenotypic modulation plays a crucial role in arterial ageing. Objectives: To define the arterial phenotype in mice conditionally inactivated for the integrin αv subunit in VSMC and the role of this integrin in angiotensin II (Ang II)-induced arterial and VSMC stiffness. Methods and results: We used a VSMC specific knock-out αv mouse model induced in adult mice by injection of tamoxifen. Trangenic mice (αvSMKO) and control littermates (Ctrl) were infused with Ang II (1.5 mg/kg/day) for 4 weeks. The pressure effect of Ang II was similar in Ctrl and αvSMKO mice. The carotid distensibility/pressure and elastic modulus/wall stress curves were similar in control and αvSMKO mice, indicating comparable arterial stiffness. Ang II treatment resulted in increased carotid stiffness in both groups without changes in vascular reactivity and myogenic tone. Electronic microscopy revealed less vesicles containing fiber-like materials in the SMCs of Ang II-treated αvSMKO carotids Elastic modulus of cultured VSMCs determined using atomic force microscopy was higher after Ang II treatment in cells from both groups. At baseline and after treatment, elastic modulus was higher in cells from αvSMKO mice than in cells from Ctrl mice. Conclusion: Inactivation of αv-containing integrins on VSMCs increases cell stiffness. The general mechanism involves a cross-talk between extracellular matrix, αv integrins and cytoskeletal complex. The lack of distensibility changes suggests additional changes at the level of αv-mediated dynamics of focal adhesion. Although an estrogen-mediated vasculoprotective effect is widely accepted in premenopausal women, literature data indicate that estrogen therapy in transgender women confer an increased risk of cardiovascular events. Vascular smooth muscle cell (VSMC) reside in a 3-dimensional environment and are not normally exposed directly to the shear stresses of flowing blood in the vascular system, because the endothelial cell layer provides the contacting surface for blood flow. However, in cases of endothelial injury, the superficial layer of SMCs is exposed directly to blood flow shear stresses. We hypothesized that treatment of male VSMCs with estrogens alters cell behavior. Our aim was to study the effect of shear stress on male VSMCs in a 2D environment under flow model. Cells were treated with 17-β-estradiol and cultured in the Ibidi chamber under laminar flow and shear stress of 1-2 dyn.cm −2 . The cell orientation and morphology and phenotypic changes were analyzed. Results: We observed an increased expression of MYH10 exposed to shear stress. The expression of MYH10 seems to be correlated with the orientation of VSMCs. The orientation of VSMCs treated with estrogens is parallel to the culture medium flow. Our preliminary results further suggest an increased expression of the MMP-2 under estrogen treatment under flow conditions in the 2D model. Conclusion: The differential effects of laminar flow and shear stress flow may be due to the different phenotypic state of the VSMCs. Background: The angiotensin II type 1 (AT 1 ) receptor has a relevant role in the physiology and pathophysiology of the cerebrovascular system. Its vasoconstrictor effect, consecutive to Gq protein activation, reduces cerebral perfusion during stroke. In addition, AT 1 receptor activity is directly regulated by the β-arrestin pathway, involved in receptor internalization [1]. Recently, the development of biased agonists, able to selectively activate the β-arrestin pathway without Gq activation appears to be a promising new therapeutic strategy in cardiovascular pathologies [2]. In the current project, we explore the impact of an AT 1 biased agonist (TRV027) on the regulation of the cerebral circulation. Methods: We evaluated the TRV027 signaling on HEK293-cells overexpressing AT 1 using bioluminescence resonance energy transfer (NanoBRET) and calcium mobilization assays. In parallel, concentration-response curves to TRV027 were built on an ex vivo model of isolated and perfused middle cerebral arteries (MCA) by measuring changes in internal diameter. Results: BRET results show that TRV027 induces an activation of the β-arrestin pathway with a maximal increase of BRET ratio of 0.08 while inactivating the Gq pathway. Calcium mobilization assays confirm this Gq inactivation. As expected, results obtained in MCA show no effect of TRV027 on arterial diameter. Discussion: Tracking the AT 1 receptor using specific fluorescent tools to follow its internalization (confocal microscopy) is currently under development. The next step will be to assess in vivo the potential beneficial and protective effects of TRV027 in cerebrovascular pathologies, in collaboration with Maastricht University. Recently an extensive clinical experience in flap surgery has confirmed that its success depends on the correct identification of vital perforator vessels [1]. Unfortunately, the perforator vessels frequently have a variable location. So, the knowledge about perforator anatomy during preoperative planning is one of the most critical factors.

References
In this work, we present the method and experimental results for noncontact and fast localization of the cutaneous perforators using Infrared Thermography (IRT). This imaging technique can provide real-time information on skin perfusion by measuring body surface temperature. Validation of the method was performed against the ultrasound technology realized in the hand-held Doppler flowmeter, which is widely used in most hospitals and is an essential tool where a rapid analysis of the vascular status of a patient is routine. Both technics were applied in this work for the identification of forearm cutaneous perforator vessels. The reflection of sound waves, predominantly from intravascular blood flow of the forearm, was registered by a hand-held BT-200 V ® Vascular Doppler pan. The infrared images were obtained by two cameras: FLIR ® E6 with temperature sensitivity < 0.06 °C and (320 × 240)-pixel display resolution, and Thermal Expert with sensitivity < 0.05 °C and array format 640 × 480. Perforator mapping of the forearm area ware compared for accuracy, timing, and the operator's skills.
Obtained results show that IRT images provide valuable real-time information on the hemodynamic quality of perforators and their accurate location. Its potential to reveal underlying perforator vessels may also be used for postoperative monitoring of flap perfusion [2]. Background: Systemic sclerosis (SSc) is a disorder characterized by a massive vascular involvement. Imaging biomarkers of vascular involvement in SSc may have potential clinical implications for prediction of the pathogenesis of vascular complications [1]. This study is aimed at identifying possible patterns of vascular wall disarray and remodeling in radial arteries of SSc patients, by means of ultrahigh frequency ultrasound (UHFUS). Methods: 5 end-diastolic frames of the right radial arteries of 41 patients with SSc and 41 healthy controls were obtained by VevoMD (70 MHz probe, FUJIFILM, VisualSonics, Toronto, Canada). 74 radiomic features and 4 engineered parameters were extracted: inner and outer layer thickness, and presence of adjunctive acoustic interfaces (triple signal). A feature selection algorithm was applied to reduce the number of features. The selected features were used to train classification model, using Linear Support Vector Machine (SVM).

Results:
The SVM classification model showed good performance (sensitivity = 0.63, specificity = 0.88, accuracy = 0.75, AUC = 0.75) to discriminate SSc patients from controls using sixteen selected features. Inner layer (208 ± 61 vs 179 ± 47 µm, p = 0.04) and outer layer thickness (104 ± 22 vs 120 ± 36 µm, p = 0.03) were significantly higher in SSc than in controls, triple signal pattern more frequent in patients (p = 0.002). Conclusions: Wall ultrastructure of radial arteries of SSc patients is altered: inner and outer layer thickened, showing frequently a triple signal pattern. Radiomic approach allow to distinguish between radial images from SSc patients and controls with a 75% accuracy. Background: The intense exercise effect evaluation on the cardiovascular system can help to profile and reduce the risks (1)(2)(3). This work aims at assessing cardiovascular adaptation in runners by a multi-site non-invasive approach.
Methods: 49 runners (A) trained for 8.5 ± 8.9 years, 3.9 ± 1.4 days/ week and 15 sedentary (S) subjects matched by sex, age, BMI, baseline brachial pressures and heart rate underwent ultrasound semi-automatic assessment of the vascular system (arterial mean diameters, MD, and distensibility, DC, of abdominal aorta, common carotid, common femoral, brachial artery) and of cardiac parameters. Central pressurebased (applanation tonometry) hemodynamic properties according to the reservoir theory were derived. Results: Cardiac parameters related to dimensions, mass and volumes showed significantly higher values in A compared to S (A/S: Left Ventricular Internal diameter, 29 ± 3 mm/27 ± 3 mm; Left Ventricular Mass, 161 ± 31 g/141 ± 25 g; Aortic root size 30 ± 3 mm/27 ± 2 mm; Stroke Volume, 76 ± 13 mL/69 ± 16 mL; Arterial Elastance, 7 ± 1 mm HgmL -1 /6 ± 1 mm HgmL -1 ). MD was greater in each large arterial site in A than in S reporting a trend in the carotid and significant differences in aorta and femoral artery (aorta: 16 ± 2 mm/13 ± 1 mm; femoral: 10 ± 1 mm/9 ± 1 mm). DC evidenced a lowering trend in A for each arterial site except for the brachial artery. Hemodynamic parameters showed higher reservoir pressure in A compared to S (Pressure reservoir integral, 14 ± 4/11 ± 3). Conclusions: Strenuous exercise induced a well-known cardiac remodeling which can be hypothesized to be slower in the arterial tree because of highly differentiated and complex mechanism aiming to heart protection. Accordingly, the increased reservoir pressure in runners could be interpreted as sentinel parameter of vascular "fatigue". Background: Skin microcirculation is considered a window to assess generalized microvascular function. Changes in skin microvascular function (SMF) have been identified in several cardiovascular disease states. However, scarce data exists regarding SMF in healthy adults and the impact of gender on it [1,2]. In this study, we assessed SMF in healthy individuals with the dynamic technique Lase Speckle Contrast Imaging (LSCI). Methods: Healthy normotensives were included in the study. Office blood pressure (BP) was measured according to standard guidelines. SMF was assessed with LSCI (PeriCam PSI NR, Perimed, Sweden) coupled with post-occlusive reactive hyperemia (PORH). Results were expressed as perfusion during baseline, occlusion and peak period (arbitrary Perfusion Units,PUs), time until maximal perfusion (sec), the percentage increase of perfusion between baseline and peak period (%) and PORH amplitude calculated as peak cutaneous vascular conductance (CVC) -baseline CVC. CVC was calculated as mean perfusion during each PORH period divided by mean BP (LSPUs/mmHg). Results: We studied 86 healthy normotensives including 50 women and 36 age-matched men. Body mass index, creatinine, office systolic BP (SBP) and diastolic BP (DBP) were significantly higher in men compared to women. Regarding SMF, perfusion during baseline and occlusion, baseline CVC, peak CVC and PORH amplitude (0.89 ± 0.21 vs 0.75 ± 0.19, p < 0.01) were significantly higher in females compared to males. In addition, PORH was negatively associated with office SBP (r = − 0.258, p < 0.05). Conclusions: Healthy females present significantly higher SMF parameters compared to age-matched males. Further research is needed to clarify the impact of gender on microvascular function and its further implications. Background: We aimed to test the feasibility of MRI-based feature tracking (FT) to measure longitudinal strain and radial motion fraction of the proximal ascending aorta (AA) and to investigate how these measures are affected by aging and by the presence of calcified aortic valve stenosis (AVS). Methods: Twenty healthy volunteers (HV) < 40 years (29 ± 1.6 years, 10 males), 20 HV ≥ 40 years (58 ± 1.5 years, 10 males) and 31 patients with AVS (73 ± 1.6 years, 20 males) underwent 2D cine thoracic aortic MRI in sagittal and axial views immediately followed by carotid artery applanation tonometry. AA anterior wall (Figure a) was semi-automatically tracked on sagittal images throughout the cardiac cycle to estimate longitudinal strain and radial motion fraction peaks, while using custom FT software [1], which was previously dedicated to multi-chamber strain evaluation in the heart. Conventional global AA strain was also measured on axial views based on cross-sectional area [2]. Finally, distensibility was derived as strain/central pulse pressure. Results: Axial (Dist-axial: R = − 0.82, p < 0.0001) and sagittal (radial DistR-sagittal: R = − 0.54, p = 0.0004, longitudinal DistL-sagittal: R = − 0.37, p = 0.02) distensibility measures decreased significantly with age and even more in the presence of AVS (Figure b). When investigating the ability of distensibility measures to discriminate HV from patients, newly proposed DistR-sagittal (0.84) and DistL-sagittal (0.92) demonstrated higher area under the ROC curve than Dist-axial (0.81). Conclusions: MRI FT revealed that age has a stronger impact on AA axial distensibility, while longitudinal distensibility could be more sensitive to the effect of AVS probably because of valvular calcifications that limit this longitudinal motion specifically. accelerating collagen degradation [4]. We hypothesise that optimally strained fibres will gradually make up the bulk of collagen during hypertension, as overstrained collagen degrades faster. This implies that, as collagen returns to the optimal level of strain, increased collagen content is required to maintain luminal diameter and avoid dilatation (2 in Fig. B). We evaluated this hypothesis, expecting hypertensive rat aorta to exhibit less collagen strain under normotensive conditions compared to normotensive control (3 in Fig. B). Methods: One normotensive (NT, Wistar) and one hypertensive (HT, ZSF1 lean [5]) 22-week-old rat abdominal aorta were stretched to in vivo-like length and pressurised to 100 mmHg. Three-dimensional collagen structure was then imaged by second harmonic generation using a two-photon microscope. Results: At 100 mmHg, the HT artery visibly displayed a thicker collagen layer and curlier collagen fibres than the NT artery ( Conclusions: Strain-dependent collagen degradation may be a key process driving hypertension-induced arterial remodelling.

References
A: Straight-but-not-overstretched collagen experiences minimal degradation [3]. B: Diameter maintenance in hypertension requires additional collagen at minimum-degradation strain. More and curlier collagen in hypertension (E-F) than normotension (C-D). Background: Pulmonary hypertension (PH) leads to a mismatched right ventricular (RV)-pulmonary arterial (PA) relationship (uncoupling), which increases mortality [1]. Current diagnostic strategies utilize pulmonary vascular resistance (PVR) [2] but disregard the opposition to pulsatile flow as well as response to exercise [3,4]. We hypothesize that pulsatile pulmonary hemodynamics during exercise and their relationship to RV-PA coupling can differentiate PH phenotypes and refine diagnoses. Methods: 13 adult subjects with precapillary PH (PAH; n = 5), isolated postcapillary PH (Ipc-PH; n = 5), or no PH (No PH; n = 1) performed invasive cardiopulmonary exercise testing with echocardiographybased pulmonary vascular pressure-flow and catheter-based RV pressure-volume data collection. Characteristic impedance ZC, effective arterial elastance, Ea, and end-systolic elastance, Ees were computed during rest, exercise, and recovery. Results: At rest, subjects with Ipc-PH or No PH tended to have lower ZC and Ea than those with PAH (Fig. 1A&C); all Ees values were similar (Fig. 1b). During exercise, Zc decreased in the subject with No PH, whereas it increased in those with Ipc-PH and did not change in those with PAH. During exercise, both Ees and Ea increased for all subjects but the increase in Ea was larger than the increase in Ees for both the PAH and Ipc-PH groups, suggesting RV:PA uncoupling. Interestingly, the changes in ZC and Ees/Ea were inversely related in Ipc-PH during exercise.

P.024 Effects of Nitroglycerin Induced Vasodilation on Elastic versus Muscular Artery Stiffness in Older Veterans
Conclusions: With the limitation that the sample size is small, our findings suggest that analysis of pulsatile pulmonary hemodynamics and RV:PA coupling with exercise can reveal distinctive PH phenotypes and have diagnostic value.

Uniftc, Salvador, Brazil
Obesity is one of the biggest health problems in the world. It is constituted as the second most important risk factor for the development of chronic non-communicable diseases. In this sense, it is assumed that the increase in arterial stiffness is on the path between obesity and cardiovascular diseases. The objective of this study was to evaluate the correlation between obesity and cardiovascular risk factors with arterial stiffness in patients treated at a teaching clinic in the university center, Salvador-Ba, in 2022. This is an observational, cross-sectional and analytical study. The studied population comprised individuals residing in the Valley of Ogunjá neighborhood, Acupe in Brotas, both sexes, over 18 years of age and obese. The indicators of obesity were: waist circumference (women > 88 cm and men > 90 cm), cervical (> 34 cm in women and > 37 cm in men), waist-hip ratio (> 0.80 in women and > 0.95 in men), body mass index (BMI) (> 30 kg/m 2 ) and evaluation of the carotid-femoral pulse wave velocity (PWV) (> 10 m/s). The results obtained denote a direct to statistically significant linear correlation: waist circumference indicator associated with PWV (p value 0.055), waist-hip ratio (p-value 0.003), cervical circumference (p-value 0.004). Only the BMI indicator associated with PWV (p value 0.584) was not statistically significant. It is concluded that the indicators of abdominal and cervical circumference and waist-hip ratio obtained statistical significance when attributed to PWV and can be used as indicators of arterial stiffness.  (T1D) is associated with arterial stiffening as assessed by carotid-femoral pulse wave velocity (cfPWV) [1]. To experimentally study the underlying mechanism of this stiffening, we investigated blood pressure (BP) and cfPWV in streptozotocin (STZ)-induced diabetes in mice. Methods: Twenty-four 9-week-old male C57BL/6 J mice were divided equally among diabetic (induced through once-daily 50 mg/kg STZ injections for five days) and control (sham injections using citrate buffer) groups, and were kept to an age of 24 weeks. Fasting glucose was measured every 4-5 weeks via tail blood collection with levels of 15 mmol/L and higher considered diabetic. Non-invasive tonometric cfPWV was measured in anaesthetised animals (1% isoflurane) 24 h prior to euthanasia; tail-cuff BP was measured directly prior to euthanasia. Results: Diabetic mice exhibited higher fasting glucose than controls (p < 0.0001, two-way ANOVA with Tukey post-hoc test; Fig. A). There was no difference in systolic BP (110 ± 4 vs. 104 ± 3 mmHg, p = 0.26, mean ± SE, unpaired t-test) and cfPWV (2.60 ± 0.14 vs. 2.55 ± 0.11 m/s, p = 0.80) between diabetic and control mice (Fig. B-C).

Discussion:
In the popular animal model of STZ-induced T1D, existing literature on systolic BP is not consistent [2,3]. Literature about cfPWV is limited: in contrast to our data, one report showed an STZ-induced increase in ultrasound-derived cfPWV [4]. Discrepancies between studies could be due to different methods of measuring BP and cfPWV [5]; the choice of measurement methods therefore needs critical appraisal. Conclusion: In the murine model of STZ-induced T1D, we did not find elevated BP or increased arterial stiffness.
Despite clearly increased fasting blood glucose (A), streptozotocininduced diabetic mice did not show increased blood pressure (B) or arterial stiffness (C). Shown are mean ± SE; ****p < 0.0001; ns, not significant. Background: Impaired systolic function of the left ventricle leads to shortening of the left ventricular ejection time (LVET) and heart rate adjusted LVET (iLVET) [1]. The aim of this study is the investigation of the improvement in left ventricular function using radial pulse waveforms compared to improvement assessed by ejection fraction (EF). Methods: 37 patients (7 females) with heart failure (HF) with reduced ejection fraction (HFrEF) were treated according to HF guidelines. EF and its changes under treatment were monitored with echocardiography (EPIQ, Philips, Simpson method with apical 4-chamber view), and LVET was monitored with tonometry (SphygmoCor, AtCor Medical, method based on numerical derivatives) [2]. Furthermore, LVET was adjusted for heart rate [3]. Visualization of differences between first and second visit was done by 4-quadrant plots ( Fig. 1)  Anthropometric, laboratory testing, and cardiovascular risk factors along with arterial parameters (carotid-radial pulse wave velocity (crPWV), carotid-femoral pulse wave velocity (cfPWV), carotid intimamedia thickness (CIMT), ankle-brachial index (ABI), cardio-ankle vascular index (CAVI) and atherosclerotic plaques) were evaluated. Results: After stratifying subjects into sex-specific METS-IR quartiles, we observed statistically significant differences in all arterial parameters among METS-IR quartiles, except for crPWV in men (p = 0.533). Differences between men and women in the METS-IR quartiles were observed only in cfPWV (p < 0.05), CAVI (p < 0.05), and CIMT (p < 0.001).
In a fully adjusted linear regression analysis, METS-IR was associated with CAVI in both men (p = 0.005) and women (p < 0.001). However, ABI-only in men (p = 0.040), and CIMT -in women (p = 0.025). Conclusion: Insulin resistance measured by METS-IR is associated with CAVI in both men and women in the middle-aged Lithuanian population with metabolic syndrome. Additionally, in men, it is also associated with ABI, whereas in women -with CIMT.

P.036 The effects of different types of calorie restriction on atherosclerosis-related miRNAs in mice
Atherosclerosis is a chronic inflammatory blood vessel disease.Studies highlight the importance of epigenetic modifications specifically miRNAs in the development and progression of atherosclerosis.Calorie restriction(CR) is one of the best-known interventions to prolong lifespan and impact lowering the risk of atherosclerosis.In the present study, the effects of different types of CR on atherosclerosis-related miRNA were studied.
Female mice were enrolled into three groups; ad-libitum (AL), Chronic-CR (CCR, 15% CR), and Intermittent-CR (ICR) which 60% CR was applied for one week (ICR-R, restricted) followed by three weeks of AL feeding (ICR-RF, refeed).Blood and brain samples were collected at week 49/50 to measure miRNA expression levels using Affymetrix GeneChip miRNA 4.1 Array.The targets of differentially expressed(DE) miRNAs that are enriched in atherosclerosis-related molecular pathways were analyzed.
In blood, a total of 12 miRNAs were DE among dietary groups.There were common miRNAs that differ in dietary regimes when compared to the AL group; miR-709(17,09-fold higher), miR-30b-5p(7,12-fold lower), and miR-19b-3p(5,72-fold lower) in CCR.The overexpression of miR-709 is shown to have a cardioprotective effect 1 , while miR-30b-5p 2 and miR-19b-3p 3 are considered pro-atherosclerotic.GO-KEGG analyses revealed that targets of atherosclerosis-related miRNAs that were affected with CR were also enriched in aging and cancerrelated molecular pathways.In the brain, a total of 6 miRNAs were differentially expressed.Interestingly, there was no significant change in atherosclerosis-related miRNAs between blood and brain.
In conclusion, even though CR has different effects on blood and brain tissues, some common miRNAs might have protective effects on atherosclerosis, suggesting the link between the brain and vascular axis. Pulse-Wave-velocity (cfPWV), central pulse pressure (CPP) (Sphygmocor); 6. Autofluorescence-Advanced glycation end-products (AGE-Reader); 7. Carotid intima-media thickness (CIMT). We performed one-way ANOVA to compare differences in the three groups. Results: Demographics and anthropometry (BMI and waist circumference) were comparable in all three groups. When compared to Groups 2 and 3, In Group 1: Troponin and the red cell distribution width (RDW) was higher (p < 0.05); Sphygmocor based cfPWV & CPP, was higher (p < 0.001); RHI-EndoPAT based AI (@75) was higher and HRV(SDNN) was lower (p < 0.05); AGE was higher (p < 0.01) (see Fig. 1).

Conclusion:
Measures of arterial-stiffness (cf-PWV & AI@75) and HRV are more significantly impaired in DM when compared to hypertension/hyperlipidemia, one year post COVID-19 recovery. These measures are higher when compared to similar matched diabetes patients with no history of COVID-19 infection. COVID-19 DM patients need to be followed up to study long-term impact on vascular complications and autonomic neuropathy. Tan Tock Seng Hospital, Singapore, Singapore Background: The Sphygmocor technology uses applanation tonometry to measure large artery stiffness. Although the carotid-femoral pulse wave velocity (cfPWV) is higher in diabetes, an association with pre-diabetes has not been observed. (1,2) There is limited data on augmentation index (AIx). We aimed to study the correlation of arterial stiffness among healthy, pre-diabetes, or diabetes in multi-ethnic Singapore. Methods: Population: n = 130; Age = 44.8 (9.6) years; Male = 41 (31%), Chinese = 93, Indians = 12, Malays = 15, Others = 10. All participants underwent a standard 75 g oral glucose tolerance test and applanation tonometry to assess cfPWV, central pulse pressure (CPP) and AIx. Oneway ANOVA was done to study the differences in the arterial measurements based on diabetes status. Results: Healthy (n = 81), Prediabetes (n = 27), Diabetes (n = 22). While cfPWV was higher in diabetes (mean (SD): 7.2(1.6)) compared to absence of diabetes (6.5(1.0)); p < 0.01), there was no difference between healthy 6.5(1.1) and pre-diabetes (6.4(1.0)); p > 0.01. An increasing trend was seen in AIx, healthy (mean (SD): 9.5(4.3)) < pre-diabetes (mean (SD): 11.1(5.4)) < diabetes (mean (SD):13.1(7.0)); p < 0.01. No statistically significant difference was seen in CPP (p > 0.01). Discussion: AIx may reflect early markers of impaired glucose tolerance or pre-diabetes. Moreover, as AIx is determined by the properties of the distal vasculature, it may be used as an early marker of distal circulatory dysfunction involving the small arterioles, which precede abnormalities in pulse wave velocities. AIx can be a valuable marker of early vascular dysfunction, especially among individuals with pre-diabetes. Further studies are needed to understand the mechanistic basis of this trend. Background: Remote ischemic preconditioning (RIPC) is a phenomenon in which short episodes of ischemia are applied to distant organs to prepare target organs for more prolonged ischemia and induce protection against ischemia-reperfusion injury [1]. The aim of this study was to evaluate whether preoperatively performed RIPC affects metabolome following vascular surgery and assess if metabolomic changes correlate with heart and kidney injury markers. Methods: A randomized-controlled, double-blinded trial was conducted in the Tartu University Hospital. Patients undergoing open surgical repair of abdominal aortic aneurysm, surgical lower limb revascularization, and carotid endarterectomy were recruited. A RIPC consisting of four cycles of 5 min of ischemia followed by 5 min of reperfusion was applied before the operation. The blood was collected preoperatively and approximately 24 h postoperatively. The metabolome was analyzed with the AbsoluteIDQ p180 Kit. Results: The final analysis included 45 patients from the RIPC and 47 from the sham group. Baseline characteristics and values of metabolites were statistically similar between groups. RIPC did not cause statistically significant changes in metabolites 24 h postoperatively. There was a significant positive correlation between the change Kynurenine/Tryptophan ratio and the changes of hs-Troponin T (r = 0.570, p ˂0.001), NT-proBNP (r = 0.552, p ˂0.001), Cystatin C (r = 0.534, p ˂0.001) and Beta-2-Microglobulin (r = 0.504, p ˂0.001).

Fig. 1 (A) augmentation index and (B) pulse wave velocity in healthy, pre-diabetes and diabetes
Conclusions: Preoperatively performed RIPC did not significantly affect metabolome 24 h after vascular surgery. The positive linear correlation between Kynurenine/Tryptophan ratio and heart and kidney injury markers suggests that the Kynurenine-Tryptophan pathway can play a role in RIPC-associated cardio-and nephroprotective effects.
Results: From 17,966 individuals, 2,378 had a MACE during the follow-up. SBP values at baseline were 126.5 mmHg (SBP 1 ), 123.2 (SBP 2 ) and 122.5 (SBP 2 ). After adjustment, SBP 3 had the strongest association with MACE. This association was significantly greater than that observed for SBP 1 , SBP 12 , or SBP 123 . In comparison to SBP 1 , SBP 2 and SBP 3 increased the risk attributable to SBP by up to two times. When included in ASCVD scores, SBP 3 yielded the highest C-statistic, which was significantly higher than all other SBP parameters except SBP 23 . Conclusion: Averaging SBP measurements during a single visit improves cardiovascular prediction compared to a single measurement. Discarding the first SBP value maximises predictive performance. Introduction: Mexico is a country with high mortality due to diabetes complications (1); constant hyperglycemia in patients with diabetes leads to endothelial damage, which is the main risk factor for the development of macro and microvascular complications, leading to an increased risk of mortality (2). Flow-mediated vasodilation (FMD) is one of the most widely used techniques for the evaluation of endothelial function and can be used as predictor of cardiovascular risk (3,4). Objective: The objective of this study is to determine the FMD values and hemodynamic characteristics in Mexican patients with type 2 diabetes mellitus in western Mexico. Methods: FMD were measured with a high-resolution semi-automatic ultrasound UNEX-EF 38G (UNEX Co. Ltd Nagoya Japan). Measurement of arterial tension were made with an OMRON electronic digital sphygmomanometer (HEM 907 XL). Results: 65 patients, (28 men and 37 women) with a mean age of 52.46 ± 11.71, we found a difference between the basal and final diameters and blood flow between men and women (4.67 ± 0.76 vs 3.42 ± 0.69 p 0.001; 4.96 ± 0.76 vs 3.66 ± 0.70 p 0.001; (10.5 ± 8.05 vs 4.59 ± 3.56 p 0.020); an inverse correlation was found between FMD and SBP (r = − 0.265 p 0.33).

Conclusion:
We found a lower FMD in women than in men, it is also noteworthy the differences found in the flow and bIMT between the individuals in the study, the above can be explained by the inherent hormonal effects of each sex. 1

King's College London, London, United Kingdom
Background: Sodium glucose co-transporter 2 (SGLT-2) inhibitors have demonstrated renal benefits in people with type 2 diabetes (T2DM) 1 . Arterial stiffness as measured by aortic pulse wave velocity (Ao-PWV) is an index of arterial ageing and predicts cardio-renal outcomes 2 . The effect of SGLT-2 inhibitors on Ao-PWV and other markers of arterial ageing is unknown.

Methods:
We performed a 24-week single center randomized controlled trial comparing dapagliflozin and ramipril (D + R) versus ramipril (R) on markers of arterial ageing in people with T2DM with residual albuminuria despite maximum tolerated renin angiotensin system (RAS) inhibition. Primary endpoint was change in urine albumin excretion rate (AER).Secondary endpoints included Ao-PWV (by applanation tonometry),central aortic blood pressure, mediators of the RAS (plasma renin activity,aldosterone,ACE-2 and angiotensin 1-7/1-9 levels) and biomarkers of arterial ageing [soluble Klotho (sKlotho) and fibroblast growth factor 23 (FGF-23)]. Background: The mechanical role of contraction of vascular smooth muscle cells (VSMCs) in large arteries is often overlooked. Recently, Pewowaruk and Gepner proposed a clinically applicable mathematical model separating the passive and active contributions to arterial mechanics [1]. Subsequently, they applied the model to < i > in vivo < /i > data from human carotid arteries (< i > n < /i > = 40) at baseline and after nitroglycerin-mediated vasodilation (Fig. A) [2]. In two participants, the VSMCs' active contribution decreased with increasing pressure from diastolic to systolic, which could not be captured with the original model (Fig. B). VSMC tension, generated by actin-myosin interaction, is maximal at the length with optimal filament overlap and is lower at other lengths. We hypothesised that, in these two participants, VSMCs operated beyond their optimal length. Accordingly, we modelled active VSMC tension as a function of length using a Gaussian-shaped function [3].

Methods:
The baseline tension-diameter data for the two participants were fitted using the combined exponential (passive) and Gaussian (active) expression in Fig. G [3]. Results: In participant 1, VSMC contribution to tension was nearly diameter-independent, indicating VSMC was near its maximum contraction length (Fig. C-D). In participant 2, the VSMC contribution showed a strong negative relation with diameter ( Fig. E-F), indicating VSMCs were beyond their maximum contraction length. Conclusions: Our proposed Gaussian function enables capturing VSMC active tension behaviour in patients with VSMCs operating beyond their optimal length, based on pressure-diameter data. We speculate that in such case, actin-myosin unit rearrangement may be impaired [4], as typically VSMCs operate below their optimal length. Example of original model fit without (< b > A < /b >) and with (< b > B < /b >) residual errors; < b > C < /b > , < b > E < /b > : Passive and active contributions to baseline data; < b > D < /b > , < b > F < /b > : Total and contraction model curves; < b > G < /b > : Proposed model equation.
Keywords: Central aortic pressure waveform, finger photoplethysmography, central hemodynamic parameters, Augmentation Index, isometric hand-grip manoeuvre, central systolic blood pressure, sub-endocardial viability ratio, pulse pressure amplification, Transfer Function Background: Changes in the mechanical properties of arteries due to growth, remodeling, or aging are related with cardiovascular diseases. These changes can quantitatively be assessed if a set of suitable biomaterial constitutive parameters could be fitted onto the in vitro response pressure-diameter curve(s). The aim of this study is to determine the multi-variable optimization and parameter identification by using inverse deformation mapping. Methods: For this purpose, in vitro pressure-diameter relations were measured from published experimental results where the excised arterial sample was tethered between axially aligned canulae. An analytical continuum-based computational procedure is defined to pull the current state back to the excised (reference) state. Before applying the multi-variable optimization for parameter identification, the data is first pulled-back using this procedure, if required. Results: In Simon et al. (1970) [1], a pressure-diameter dataset reflecting the internal pressurization (P) stage was provided. However, this data did not include the excised (E) state. When the above procedure was applied to the simple exponential model, a nearly tenfolds decrease in the shear modulus and about 60% increase in the exponential constant were observed as a result of the pull-back to the excised state (coefficient of determination was found as 0.991, for both cases of with and without pull-back). Similar observations were accounted for in the hyperelastic fibre-reinforced continuum model [2].

Conclusions:
The parameter identification process may be hindered as a result of an incomplete or partial dataset. Inverse deformation mapping may be used to produce the missing data.
The procedure is depicted in the above diagram (a). Fitting of the exponential model is shown in (b) while the fiber-reinforced (HOG) model is fitted in (c).
Keywords: Arterial stiffness, 1-D modelling, limb amputees P.066 Experimental arterial models (phantoms) that stiffen when distended: a structural design and direct 3D-print approach Bruce Guest 1 , Luis Arroyo 1 , John Runciman 1 1 University Of Guelph, Guelph, Canada Background: Despite the arterial pulse wave's pathophysiologic importance its basis is not fully elucidated 1 . Experimental cardiovascular modelling is useful in arterial mechanical and haemodynamic research 2 ; however, current phantom construction techniques limit replication of arterial elastic and anatomic complexities 3 . The elastic-pressure response of phantoms incorporating longitudinal structural corrugations was investigated. Methods: Polyester-polyurethane phantoms (160 mm length) were printed with a fused filament fabrication 3D printer. Five designs differing by corrugation number or magnitude (B-F) were compared to a traditional smooth wall phantom (A). Diametrical compliance behavior was observed under quasistatic hydraulic inflation and pulse wave velocities were measured over a range of mean pulse wave pressures. Results: As luminal pressure increased , corrugated phantom diametrical compliance decreased (p < 0.01) whereas smooth wall phantom compliance did not. Compliance was axially anisotropic (p < 0.05), increased in the axial mid-span and towards the upper build height. Corrugated phantom pulse wave velocities increased (1.7-4 m/s) as did pulse wave velocity slopes (p < 0.01) with increased mean wave pressure . Pulse wave velocity was lower in the 50 vs 100 mm axial mid-span region (p < 0.01). Conclusions: As determined by quasistatic diametrical compliance and pulse wave velocity, corrugated phantom circumferential elastic response was consistent with the physiologic behaviour of arteries, stiffening with increasing pressure. Elasticity varied significantly with wall design (p < 0.05); however, height associated printing artefacts decreased while end fixation increased compliance. The functional structure wall approach is novel in arterial phantom construction and further development will improve the utility of phantoms in pulse wave behavior research.
Background: Invasive foot-to-foot pulse wave velocity (PWV) shows beat-to-beat variability due to acute changes in haemodynamic conditions and data processing issues. Though current device validation guidelines suggest averaging over n_beats ≥ 3 heartbeats to cope with variability [1], quantitative data on PWV's beat-to-beat variability is lacking. We aimed to quantify this variability and its impact on the confidence of the PWV estimate for intersecting tangent (PWVIT) and second derivative (PWV2nd) foot detection methods. Methods: Pressure waveforms were simultaneously acquired in n = 40 individuals in the ascending aorta and iliac bifurcation via intra-aortic catheters. We calculated PWV_IT and PWV_2nd over m = 40 consecutive heartbeats and used Kernel density plots to visualise the variability and distribution of PWV values. Furthermore, we estimated how averaging over n_beats (with n_beats = 2 to 40) affects the standard deviation (SD) of such n_beats-averaged assessment of PWV. Results: PWV_IT was significantly higher (10.40 ± 2.65 vs 10.00 ± 2.65 m/s, mean ± SD, p = 0.015) and showed lower beat-tobeat SD than PWV_2nd (0.52 ± 0.33 vs 0.62 ± 0.32 m/s, p = 0.046). This is also visible in subject-specific density plots of PWV_IT (Figure, Background: Regular exercise is widely recommended to reduce cardiovascular disease (CVD) risk. Recent healthcare guidelines for CVD primary prevention stipulates that individuals with a relatively low risk of CVD (10-year risk score ≥ 10%;) should take a statin. Exercise provides a variety of cardiovascular benefits, including improvements in vascular function. Moreover, statin therapy primarily reduces CVD risk by lowering cholesterol, however, may also improve vascular function. Whilst both therapies can independently reduce CVD risk, the interaction between exercise training and statin therapy on vascular function has never been directly compared in the primary prevention setting.
Methods: 80 sedentary male and female participants (40 statin naïve and 40 statin users) aged between 50 and 65 years, with a 10-year CVD-risk score ≥ 10% (estimated via QRISK3) and no established CVD will be recruited onto the study. The statin naïve and statin user groups will be further randomised into the exercise intervention or standard (no exercise) primary care comparator group. The intervention will consist in a 12-week supervised aerobic exercise programme of moderate-intensity. Both groups will complete baseline and 12-week (post intervention) vascular function and structure assessments. Changes in flow-mediated dilation (FMD) and aortic pulse wave velocity (aPWV) will serve as the primary outcome measures. Secondary outcome measures include changes in cardiorespiratory fitness (CPET), carotid intima-media thickness (CIMT), 24-h brachial and aortic blood pressure and lipid profiles. Conclusion: Using a randomised controlled protocol, the study aims to evaluate the interaction between exercise training and statin therapy on vascular structure and function in the primary care setting. Background: Angiodysplasia is a vascular malformation associated with gastrointestinal bleeding, generally observed in the elderly. This condition is unexpectedly more frequent in patients with von Willebrand disease (VWD)-type 2A having low levels of VWF high-molecular-weight-multimers (HMWMs) and increased VWF-degradation fragments (1). Aim: To develop an innovative murine model of VWD-type 2A and study the role of degraded-VWF in vascular processes. Methods: Mice expressing human (h) VWF, carrying the type 2A (p.R1597W) variant or wild-type (as control) and human GPIbα, have been generated (hVWF(p.R1597W) + / + /hGP1BA + / + and hVWF + / + /hGP1BA + / +). Haemoglobin (Hb), VWF:Ag, propeptide, multimer pattern and factor VIII activity were analyzed. Tail-clip and tail-vein-transection (TVT) bleeding assays were assessed.

Results:
Control hVWF + / + /hGP1BA + / + -mice expressed 15 ± 4% VWF:Ag, 44 ± 8% FVIII activity and normal VWF multimers. hVWF(p. R1597W) + / + /hGP1BA + / + -mice are viable and do not display spontaneous bleeding manifestations. These mice expressed 3 ± 1% VWF:Ag and 7 ± 1% FVIII activity combined with an abnormal multimer pattern, with only low multimers and few degradation bands visible. Despite the relatively low VWF:Ag levels, hVWF + / + /hGP1BA + / + -mice displayed normal haemostatic responses in both the severe-(tail-clip) and milder-(TVT) bleeding assays. In contrast, hVWF(p.R1597W) + / + / hGP1BA + / + -mice had a severe bleeding phenotype. Interestingly, in the TVT model, although the amount of blood shed was consistent with severe bleeding, 57% of type 2A mice were capable of forming an occlusive, although unstable clot within 15 min of the injury, differing from the bleeding profile of VWF-deficient mice. Conclusion: We developed a unique humanized mouse models for VWD-type 2A. Experiments are ongoing to study the vasculature of these mice. Background: Medial vascular calcification (VC) is associated with an increased risk of cardiovascular disease and it is particularly prevalent in patients with chronic kidney disease (CKD). Currently, computed tomography is a conventional method of VC assessment. However, exposure to radiation and high costs of the examination are potential concerns. Moreover, it cannot distinguish between medial and intimal VC. Therefore, we propose a novel, non-invasive technique of detecting medial VC in patients with CKD which utilizes brachial pulse wave measurements.

Methods:
In 97 patients who underwent kidney transplant, medial VC presence was examined in epigastric artery. Additionally, the patients' brachial pulse waves were non-invasively measured (SphygmoCor, AtCor Medical, Australia). We analyzed the waveforms in the frequency domain and extracted features based on the first 20 frequencies. Additionally, patients' characteristics such as age, sex and diabetes were utilized as input variables. An ensemble of three logistic regression models in combination with different subsets of features was built to identify medial VC presence. Results: Results show that the features derived from brachial pulse wave signal contribute to prediction of medial VC presence in CKD patients. The model, assessed using leave-one-out cross-validation, achieved accuracy = 0.91 and F-score = 0.94. Figure 1 shows receiver operating characteristic (ROC) curve of the proposed classifier.

Conclusions:
In this proof-of-concept research, we showed that medial VC in CKD patients can be detected using the features derived from brachial pulse waveforms. The proposed method is easy to implement and may contribute to a higher accessibility of medial VC detection in CKD patients. Introduction: Flow alteration can affect endothelial function, which is associated with cardiovascular disease (1). Peripheral arterial flow is determined by the pressure gradient between the proximal and distal points in the vessel. The pressure gradient could be a potential alternative for assessing vascular health. Methods: Anterograde and retrograde brachial artery pressure gradients were estimated from the positive and negative components of the first derivative of the non-invasive beat-to-beat brachial pressure waveform and carotid-radial pulse wave velocity in 90 patients with ischemic heart disease. Retrograde flow was assessed using a pulsedwave doppler. Cardiovascular disease severity was evaluated using Single Positron Emission Computerized Tomography imaging and quantified as %perfusion defect from the summed stress score, using a 20-segment cardiac model. Endothelial function was assessed by ultrasound-based measurement of flow-mediated dilation (FMD). Results: A significant association was seen between retrograde flow velocity (RBFVAUC and RBFVpeak) and retrograde pressure gradient (Rt-dP/dxAUC and Rt-dP/dxpeak) (r = 0.34, p = 0.003 and r = 0.38, p = 0.0006 respectively). RBFVAUC and Rt-dP/dxpeak showed a significant negative correlation with %FMD (r = − 0.24, p = 0.026 and r = − 0.22, p = 0.047 respectively). Ratio of retrograde to total pressure gradient (Rt-dP/dxpeak/(At-dP/dxpeak + Rt-dP/dxpeak) showed a significant positive correlation with %perfusion defect (r = 0.24, p = 0.025). This association was independent of aortic systolic pressure, age, heart rate and total cholesterol. Conclusion: Brachial pressure gradient is related to pathophysiological alterations in arterial flow and can be incorporated into developing an alternative method for assessing endothelial dysfunction and cardiovascular disease severity.
Anterograde and Retrograde brachial pressure gradients were calculated separately from the peak and mean of the first derivative of the brachial pressure waveform and the carotid-radial pulse wave velocity. Background: Aortic stiffness and inflammation are predictors of cardiovascular risk. Anti-vascular endothelial growth factor agents (anti-VEGF), injected intravitreally, can reverse the course of exudate age-related macular degeneration (AMD). We investigated the association of changes in aortic stiffness and inflammation with response to anti-VEGF therapy. Methods: 54 patients (mean age: 76 ± 10 years) with AMD received two consecutive monthly intravitreal injections of ranibizumab (0.5 mg). The primary outcome measure was change in carotid-femoral pulse wave velocity (PWV) from baseline to 1 month after the second injection. Results: Ranibizumab caused a decrease in PWV after the first (by 0.36 ± 1.4 m/s) and the second injection (by 0.31 ± 1.4 m/s) and remained decreased 1 month after the second injection (overall P < 0.05). PWV decreased significantly in good responders (according to clinical criteria and fundus findings, P = 0.004), whereas it increased numerically in poor responders (P = 0.21) over the study period. In responders, hsIL-6 decreased after the first injection and remained decreased 1 month after the second injection (by 0.63 ± 0.35 pg/ml, overall P = 0.02). PWV (P = 0.005) and hsIL-6 (P = 0.042) were independent predictors of improvement after adjusting for age, hypertension and diabetes. The decrease in PWV throughout the study period correlated with the reduction in hsIL-6 (r = 0.36, P < 0.01). Conclusions: Intravitreal ranibizumab injections lead to a decrease in PWV and hsIL-6. Both parameters predict clinical improvement and may aid in improving treatment targeting and therapeutic outcome in AMD patients. Keywords: Arterial stiffness, inflammation, anti-VEGF, hypertension Introduction: There are similarities in etiology and pathophysiology between aortic valve stenosis and arterial stiffness. We studied whether arterial stiffness, measured as arterial pulse wave velocity (aPWV), was associated to aortic valve stenosis in both men and women. Method: We included 333 patients (172 men and 161 women) with aortic valve stenosis and information on the aPWV who were included in an ongoing observational cohort study. The aPWV was measured with a brachial cuff-based oscillometric measurement (Mobil-O-Graph 24 h PWA Monitor, I.E.M. Gmbh, Stolberg, Germany). The median aPWV was used to differ between low and high arterial stiffness group. Aortic valve stenosis was assessed with use of an echocardiogram and multislice computed tomography. Results were stratified for sex. Results: In men the peak aortic valve velocity and mean aortic valve pressure gradient were both higher in patients with a high aPWV (3,8 m/s vs 4,05 m/s (P = 0.018) and 32 mmHg vs 41 mmHg (P = 0.010), respectively). In women there were no differences found in diagnostic measurements of aortic valve stenosis between the low or high aPWV groups. Conclusion: We found aortic valve peak velocity and the mean aortic valve pressure gradient was higher in men with a high aPWV. We found no relation between aortic valve stenosis and arterial stiffness in women.

Keywords: Aortic valve stenosis, Arterial stiffness, Vasculair aging
Methods: In a cross-sectional study of heterogeneous group of subjects, aortic stiffness was assessed by the Complior Analyse device using 2nd derivative. The pulse waveforms were extracted and used for analysis by custom MATLAB algorithm for intersecting tangents, and the results were then compared to Millasseau's formula. Background: There is an association between frailty and arterial stiff-ness1. However, arterial stiffness does not uniformly correlate with the spectrum of frailty states. Both oxidative stress and inflammation contribute to vascular aging2. There are no human studies exploring links between arterial stiffness, oxidative stress, inflammaging and frailty. Methods: An observational longitudinal cohort study will be used to examine the association between arterial stiffness, oxidative stress, and inflammation in 50 older adults (≥ 70 years) with clinical frailty scores (CFS) ≤ 6 over six months. Frailty assessments include hand-grip strength, timed-up and go test, mini-mental state examination, geriatric depression scale and sarcopenia using body composition measurements. Arterial stiffness measurements includes carotid-femoral pulse wave velocity and carotid-radial pulse wave velocity using Complior. CAVI device will measure Cardio-ankle vascular index and ankle brachial index. Oxidative stress blood markers nitrotyrosine and 8-hydroxy-2'-deoxyguanosin and inflammation markers high-sensitive C-reactive protein and interlukin-6 will be measured at baseline and 6-months. Data Analysis: Descriptive statistics for continuous data using means and standard deviations for normality distributed variables or medians and inter-quartile ranges for skewed variables will be used. Participants will be categorized into CFS 1-3, and CFS 4-6. Categorical data will use frequencies and comparison between groups. Change in frailty between the groups over 6 months will be compared using paired t-test. Simple linear regression will be done between frailty measures, and exposure variable with significance at p < 0.5.

Conclusion:
This study data will inform a larger, multi-centre study exploring further the interplay between frailty, biomarkers, and arterial stiffness parameters.
Background: Health scores such as the Life's Simple 7 (LS7) from the American Heart Association and the assessment of carotid intimamedia thickness (cIMT) are independently used to predict future cardiovascular health burden. However, evidence of their association remains scarce, especially in healthy populations.
Methods: A community sample of the healthy Swiss population aged 50-91 years was included as part of the COmPLETE cohort study. CIMT was measured with a semiautomatic state-of-the-art ultrasound system. The LS7 cardiovascular health score was calculated from body-mass index, cholesterol, systolic blood pressure, hemoglobin A1c, smoking status, physical activity, and diet. For every biomarker two points were given for an ideal health metric level, intermediate scores 1 point, and poor scores 0 points. Intermediate health corresponded to a total of 5-9 points and ideal health to 10-14 points. Results: 280 participants (50.7% male) were included in statistical analyses. Age-and sex-adjusted analyses showed an association of "ideal health" with lower cIMT (− 0.038 mm, 95% CI − 0.069 mm to − 0.007 mm, p = 0.017) compared to "intermediate health". Conclusions: Even in a healthy community-dwelling sample of middle-aged to older adults, individuals with an ideal cardiovascular health score showed more favorable carotid properties than those with an intermediate score. This stresses the relevance of promoting an optimal lifestyle, even among the healthy population, for optimal vascular aging. Results: Aortic stiffness occurred in 234 (6.6%) subjects. Mean age decreased gradually between all three SPA categories, with the highest mean age observed in subjects who perceived themselves as younger than same-aged/sex peers (49 ± 1 vs. 40 ± 1 vs. 32 ± 1 years, p < 0.001). In crude model, subjects with aortic stiffness perceived themselves as younger than same-aged/sex peers (OR: 0.40, p = 0.002). Adjustment for sex did not change this association (OR: 0.67, p = 0.003). Upon adjustment for sex and chronological older SPA was associated with almost twofold increased likelihood of aortic stiffness (OR: 1.97, p = 0.038). Sex-stratification demonstrated a stronger 2.5-fold likelihood of aortic stiffness in men (OR: 2.50, p = 0.042), but no significant association in women (OR: 1.46, p = 0.43).
Conclusions: A negative self-perceived age (feeling older than sameaged/sex peers) is associated with a 2.5-fold increased likelihood of aortic stiffness (vascular ageing) in men when adjusted for chronological age, but not in women.
Comparison of self-perceived age with same-aged/sex peers between men and women with and without aortic stiffness (vascular ageing) in the general population. Conclusions: In a population of individuals undergoing cardiovascular screening, a good agreement between cfPWV an baPWV was found. These preliminary results need to be confirmed in a larger cohort.
multi-beam laser-doppler vibrometry. It can measure pulse-induced vibrations of high spatial and temporal resolution on bare skin the neck and groin. Two methods of estimating carotid-femoral pulse transit time (cfPTT) were tested. Methods: We applied a dedicated beamforming algorithm to combine and improve the data from 6 parallel signals of simultaneous measurements at both carotid and femoral measurement sites. This was done on a subset of N = 54 high-quality carotid-femoral LDV measurements [2]. We then calculated cfPTT (1) using all pair-wise combinations of the raw signals from all channels (brute-force method) and (2) using the beamformed signals. The final cfPTT estimate, in each case, was computed as the average of all estimated cfPTT's per dataset. These cfPTT's were then compared to reference cfPTT's (Sphygmocor system).
Results: As the number of generated cfPTT's in a given measurement increased (> 75), so did the correspondence of the final cfPTT estimate with the reference (see Fig. 1). The same effect was observed with increasing number of timepoints (> 5) at which a cfPTT was able to be calculated. This held true for cfPTT's estimated using both beamforming and brute-force techniques. Conclusions: Accurate cfPTT estimates are obtained for good-quality LDV-measurements, where sufficient discernable heartbeats were recognized using the beamforming and brute-force methods.  Background: Carotid artery longitudinal motion (CALM) describes movement of the arterial wall with (anterograde, forward) and against (retrograde, backward) blood flow 2 . Determinants of beat-to-beat regulation of CALM are not fully understood. Influences of blood flow and cardiac contraction on CALM have previously been investigated 1 , although separation of these factors in vivo is challenging. Human cadaveric specimens allow the opportunity to view the isolated impact of central force application versus the influence of shear forces on longitudinal motion. Accordingly, we aimed to study the potential influences of central cardiovascular factors on longitudinal wall motion. Methods: A thoracic dissection of a 19-year-old male donor was performed to reveal the ascending aorta. A clamp fastened in series to a load cell was attached to the aortic root, and caudal force was applied up to 11.5 and 13.2 N over 3.5 s. Longitudinal wall displacement was measured via vascular ultrasound at the left common carotid artery. Results: Longitudinal wall displacement was measured as 1.44 mm and 1.27 mm, for each respective force application. The longitudinal pre-stretch value was 1.24 for the left common carotid artery (3.00 cm in situ, 2.41 cm excised) 3 . For comparison, the representative maximum displacement for a 19-year-old active male is 0.70 mm over a single cardiac cycle. Conclusion: Caudal force application on the aorta generates a trace similar to the retrograde phase seen in CALM. This is the first evidence to suggest direct influence of cardiac contraction on retrograde motion, providing a plausible mechanistic theory on 2D arterial wall motion 1 .
A: longitudinal displacement from 11.5 N (black) and 13.2 N (blue) force applications; B: representative CALM trace over a single cardiac cycle for a 19-year-old male.

P.124
Optogenetic control of PI3K gamma reveals its role in smooth muscle cell contractility. Background: PI3Kγ is a major signaling enzyme of the immune and cardiovascular compartments downstream of Gi-coupled GPCR. This kinase is composed of three subunits, one catalytic (p110γ) and one of the two adapters (p84 and p101) and forms two distinct complexes. To date, the molecular mechanism underlying PI3Kγ functions and the implication of the two PI3Kγ complexes is still unclear. Methods: Here, using optogenetic manipulation of each PI3Kγ complexes, primary cells and original mice models, we investigate the selective functions of the p101 and p84 PI3Kγ complexes in order to modulate the cellular PI3Kγ-dependent processes. Results: We demonstrate that the p84/p110γ but not p101/ p110γ complex control cell contractility through its kinase activity and calcium signaling in human vascular smooth muscle cells. Moreover, we demonstrated that p84 but not p101 is specifically engaged under angiotensin II stimulation, a typical regulator of VSMC function. Finally, new mouse models of p84 and p101 invalidation allowed us to demonstrate the p84/p110γ critical role in VSMC contractile phenotype maintenance in primary cells and characterize the in vivo consequences of p84 deletion in entire aortas. Conclusions: Altogether, our study shed in light how a particular PI3K-adaptor module could differentially control key physiological responses according to its regulatory partner.

P.126
Effects of lower-extremity digital subtraction angiography on arterial stiffness and metabolome in patients with peripheral artery disease Holger Post 1,2 , Kaido Paapstel 1,3,4 , Kalle Kilk 5,6 , Aigar Ottas 5,6 , Anneli Piir 5,6 , Jaak Kals 1,2,5, Background: Arterial stiffness has been shown to predict future cardiovascular events and mortality [1,2]. Assessment of metabolites in biological systems has been increasingly applied to several diseases, leading to recent discoveries in disease-specific biomarkers and their mechanistic implications. The potential effect of angiographic studies with iodine contrast on arterial stiffness and metabolome has not yet been addressed in the literature. The aim of this study was to provide insight into the subacute effects of digital subtraction angiography (DSA) on arterial stiffness and metabolomic profiles of patients with peripheral artery disease (PAD).
Methods: 32 male patients with symptomatic PAD (aged 62 ± 9 years) undergoing DSA for the assessment and/or endovascular therapy of lower-extremity arteries were studied. Aortic pulse wave velocity, a gold standard indicator of arterial stiffness, was measured at baseline and 24 h after DSA. Venous blood samples were drawn from subjects at baseline, 2 h after DSA and 24 h after DSA, and analysed primarily for metabolic alterations. Results: No statistically significant subacute influence on arterial stiffness was observed in our study. Various shifts in metabolome were observed 2 h and 24 h after DSA. The iodine contrast dose administered during DSA independently influenced the levels of two lowmolecular metabolites at 2 h after DSA: lysophosphatidylcholine a C20:3 and putrescine.

Conclusions:
The results appear to be reassuring for the general safety of DSA in patients with PAD and provide some novel insight into DSA-s effect on the metabolome of these patients.

Introduction:
The aortic wall is composed of different functional elements, such as vascular smooth muscle cells (VSMCs), that together define its viscoelastic properties. This study aimed to investigate how VSMCs influence the viscous and elastic properties of aortic tissue and whether the focal adhesion -F-actin axis is involved. Methods: Aortic segments from C57Bl6/J mice were mounted in a Rodent Oscillatory Set-up for Arterial Compliance (ROTSAC) and subjected to high frequency cyclic stretch. Diastolic and systolic diameter as well as the Peterson modulus (Ep), as a measure of aortic stiffness, were determined. Viscous modulus (Eη) was extracted from pressure-diameter tracings by eliminating loop hysteresis. Afterwards, the elastic modulus (EE) was calculated as the slope of the resulting pressure-diameter tracing. Phenylephrine (2 µM, PE) was used to elicit VSMC contraction. PP2 (10 µM) and cytochalasin D (10 µM, CytoD) were used to inhibit focal adhesion and F-actin function, respectively. The thoracic ascending aorta (ASC) and the abdominal infrarenal aorta (AIA) were investigated in parallel. Results: PE increased both Eη and EE this effect was more pronounced in the AIA as compared to the ASC, indicating a larger impact of VSMC tonus in distal aortic regions. Moreover, increasing pulsatile load by increasing pulse frequency from 1 to 25 Hz decreased Eη. The effect of pulse frequency was attenuated by both PP2 and CytoD. High pulsatile load decreased the contractility of aortic segments. Background and Objectives: Glycocalyx, a thin layer of carbohydrates covering endothelial cells, is important for interactions between blood components and the vascular wall. It is implicated in circulating cells adhesion, inflammation, and coagulation regulation and can be damaged in some diseases. The prevailing hypothesis is that hypertension is the primary factor involved in glycocalyx degradation. However, our preliminary data challenge this view and point to a more important role of inflammation. The objective of this study was to assess the respective roles of inflammation and hemodynamic on the endothelial glycocalyx degradation. Methods and Results: Plasma concentrations of syndecan-1, a glycocalyx degradation marker, IL-6, IL-8, IL-10, ICAM-1 and VCAM-1 were quantified by ELISA in 327 participants (62 ± 14 years). Subjects were categorized as atherosclerotic cardio-vascular diseases (ASCVD) patients or controls and performed all a blood pressure and pulse wave velocity assessment. Syndecan-1 was positively associated with circulating IL-6 (p < 0.001), IL-8 (p = 0.002), and IL-10 concentrations (p = 0.006) and with adhesion molecules ICAM-1 and VCAM-1 (p < 001). No relation was observed between syndecan-1 and hemodynamic parameters, thus confirming the major role of inflammatory status in the degradation of endothelial glycocalyx. Interestingly, subjects with higher plasma concentration of syndecan-1 (third tertile) displayed more clinical manifestation of atherosclerosis (65 vs 42%; p < 0.001) than those with lower concentration (first tertile). Conclusions: Endothelial glycocalyx degradation is rather associated with inflammatory status than hemodynamic parameters. Higher degradation of glycocalyx is associated with increased percentage of ASCVD suggesting a direct relation between glycocalyx degradation and increased risk of atherosclerotic diseases. Introduction: Inflammatory bowel disease (IBD) represents an independent risk factor for thrombosis. However, the causes of this increased risk of thrombosis are still elusive.

Objectives:
We aim to decipher the main players in the procoagulant phenotype associated with IBD.
Methods and results: Coagulation phenotype assessment was performed in IBD patients included in the "I-BANK project" (CHRU Nancy), a prospective monocentric study recruiting 1000 IBD patients and in a mouse model of IBD (dextran sulphate sodium: DSS). We found an increase in platelet count in active IBD patients and an increased thrombin generation (TG) in platelet-rich plasma. Similar results were obtained in mice treated with DSS. In platelet-poor plasma, TG was not increased, highlighting the role of platelets in this phenotype. In addition, both mice and active patients showed platelet agglutination on blood smears. As circulating von Willebrand factor (VWF), which has a procoagulant function and may be involved in platelet agglutination, is elevated in IBD patients, we used VWF-deficient mice. In these mice, TG in platelet-rich plasma was not increased in response to DSS treatment. In contrast, VWF-deficient mice receiving DSS showed worsened colonic tissue damage, highlighting the importance of maintaining a normal coagulation balance in IBD. Conclusion: The procoagulant phenotype in IBD depends on platelet agglutination via VWF. Further studies are needed to assess the possible beneficial effect of VWF inhibition in IBD patients at high risk of thrombosis without aggravating tissue damage. Inserm1116, Vandoeuvre-lès-nancy, France, 2 inserm1148, Paris, France, 3 Vascular surgery department CHRU Nancy, Vandoeuvre-lès-Nancy, France Introduction: Aneurysms of the ascending (TAA) and the abdominal aorta (AAA) share the common feature of dilation of the aorta but differ by their respective physiopathology and tissue environment in human. AAA is characterized by associated thrombosis forming an intraluminal clot, whereas thrombotic events are extremely rare in TAA, suggesting different coagulant properties between AAA and TAA.
Objectives: To compare coagulation capacities at tissue and cellular levels, derived from both AAA and TAA. Methods and results: Human healthy aorta, AAA or TAA tissues and primary cultures of aortic smooth muscle cells (SMCs) were used. Thrombin generation was monitored by thrombography in the presence of healthy plasma. AAA tissues and SMCs have a higher ability to promote fibrin formation, to activate prothrombin, and to mobilize the tissue factor (TF) pathway, whereas TAA tissues and derived SMCs express an anti-thrombotic phenotype. Activation of the TF pathway in AAA tissue and SMCs is provoked by oxidative stress, protease-activated receptor 2 (PAR-2) overexpression and nuclear factor-kappa B (NF-κB) mobilization which could be reproduced by SMC efferocytosis of senescent red blood cells. Moreover, the high coherence between what was observed ex vivo in tissue and in passaged SMCs in vitro, demonstrated a procogulant phenotype shift in AAA SMCs, potentially as an imprinting of environmental pro-oxidative conditions of AAA. Conclusion: Our data indicate that oxidative stress-induced activation of the PAR-2 -NF-κB axis and leads to an increase in TF activity and prothrombotic properties of SMCs from AAA.
Keywords: Vascular smooth muscl cells, Aneurysm, thrombotic properties P.133 Impact of β3-adrenergic receptor modulation on vascular function during experimental septic shock Eugénie Hagimont 1 , Manon Durand, Antoine Kimmoun 1 UMR_S1116 Acute and chronic cardiovascular failure, Vandoeuvre-Lès-Nancy, France Rationale: Dysautonomia, an adverse event in septic shock (SC) associated with loss of cardiovascular variability, is due to an excess of catecholamines. Blockade of β1-adrenergic receptors (AR) is associated with vasoreactivity benefits however this receptor is not expressed at the vascular level (1). Unlike β1-AR, β3-ARs are widely expressed on endothelial cells and, when stimulated, cause vasorelaxation (2,3). We hypothesize that during SC, vascular function could also be mediated by β3-ARs.
Objective: To evaluate the impact of the modulation of β3-ARs at the level of endothelial cells on vascular function during SC. Methods and results: The modulation of β3-ARs is studied in vitro with an endotoxin-induced inflammatory model on human microvascular endothelial cells (HMVECs). First, we demonstrate that endotoxine induce an increase in the expression of endothelial surface inflammatory markers (VCAM1, ICAM1) and an activation of NFκB. Moreover, a decrease of eNOS was found, while iNOS was increased. Second, the transcriptional expression of β1 and 2-ARs decrease. At the same time, protein expression of β3-AR was unchanged. These in vitro results correlate with those found in clinical and experimental studies. Thus, we now focus on evaluating the modulation of β3-ARs. Conclusion: The concept of decatecholamines emerged in order to minimize the use of catecholamines in SC. Blockade of β-AR receptors is a therapeutic approach aimed at downregulating adrenergic stimulation during SC. While β1-ARs have been widely studied, there are no data on β3-ARs. The characteristics of this AR could make it a major player in vasoreactivity.
Keywords: Septic shock, β-blockers, β3-adrenergic receptor, Vascular P.134 Arterial stiffness and obstruction in western Mexican healthy population and patients with type 2 diabetes, a cross-sectional study Erick Gonzalez Campos 1 , Luis Ricardo Balleza Alejandri 1 , Fernando Grover Paez 1 , Carlos Gerardo Ramos Becerra 1 , David Cardona Müller 1 , Ernesto German Cardona Munoz 1 1 Universidad De Guadalajara, Guadalajara, Mexico Background: Nowadays does not exist enough studies related with cutoff points of arterial stiffness and obstruction in Mexican population compared with patients with T2DM [1]; also, is important to have a landmark on these clinical assessments to identify arterial stiffness and obstruction timely to provide also an early treatment [2][3].
Aim: To identify cutoff points, differences and correlations of arterial stiffness and obstruction between healthy/T2DM population. Methods: In a cross-sectional study, a total of 296 western Mexican individuals (163 healthy, 133 with T2DM according with ADA 2022 [4]) Keywords: Arterial stiffness, Arterial obstruction, Type 2 Diabetes Mellitus, brachial-ankle PWV P.136 Characterization of an ANGPTL6 variant predisposing to intracranial aneurysm formation Milene Freneau 1 , Celine Baron-Menguy 1 , Vincent L' Allinec 1 , Marc Rio 1 , Anne-Clemence Vion 1 , Gervaise Loirand 1 1 Nantes Université, CHU Nantes, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France, Nantes, France Background: Intracranial aneurysms (IA) are abnormal dilations of cerebral artery arising at bifurcations of the circle of Willis that can rupture and cause subarachnoid hemorrhage (1). By whole exome sequencing in familial IA, we identified a rare variant of the ANGPTL6 gene that predisposes to IA. This variant leads to the expression of a non-secreted truncated angiopoietin-like 6 (p.Lys460Ter-ANGPTL6) protein (2). Our aim is to understand why this variant predisposes to IA. Methods: We generated Angptl6-knock in (Angptl6-KI) mice expressing the identified variant. Morphology of cerebral arteries was assessed by micro-computed tomography and confocal imaging on thick slices of adult cerebral arteries and on mouse pup retinas Functional analyses were done ex vivo on cerebral arteries and in vitro on smooth muscle cells (SMC). Results: Mean diameter of linear parts of cerebral arteries was significantly larger in Angplt6-KI mice than in controls. Mutant mice also displayed hyperdensities corresponding to focal dilations and local wall deformations adjoining the center of arterial bifurcations. During retinal angiogenesis, arterial coverage by SMC was delayed in Angplt6-KI mice compared to controls. Consistently, in vitro, SMC adhered faster on ANGPTL6-coated plates than on uncoated surface. Ex vivo, cerebral arteries of mutant mice exhibited a reduced flow-mediated dilation resulting from a decreased endothelial NO production. Conclusions: These data suggest that the expression of the IA-predisposing ANGPTL6 variant is sufficient to induce alterations of the cerebral arteries and impact both vascular SMC and endothelial cell functions. How these alterations favor IA formation now need to be understood. Background: Altered polycystin-mediated endothelial flow mechanosensitivity contribute to the development of hypertension and cardiovascular complications in patients with autosomal dominant polycystic kidney disease (ADPKD). Stimulation of dopamine receptors may compensate polycystin deficiency but the chronic impact of this approach has to be evaluated in patients with ADPKD. Methods and Results: ADPKD patients on standard care therapy were randomized to receive during 2 months the dopamine receptor agonist rotigotine using transdermal patches at 2 mg/24 h (n = 10) and 4 mg/24 (n = 9) h or were not treated (n = 10). Rotigotine at the dose of 4 mg/24 h increased radial artery endothelium-dependent flowmediated dilatation, measured by high-resolution echotracking, and NO release in response to hand skin heating. Systemic hemodynamics were not significantly modified but aplanation tonometry showed that rotigotine at 4 mg/24 h reduced aortic augmentation index and pulse pressure without affecting carotid-to-femoral pulse wave velocity. Plasma creatinemia and urea levels, the urinary levels of copeptin, a surrogate marker of vasopressin, and cAMP that contribute to the growth of kidney cysts in ADPKD, were not affected by rotigotine. Furthermore, chronic infusion of fenoldopam, a dopamine receptor agonist that does not cross the blood-brain barrier in contrast to rotigotine, also improved mesenteric artery flow-mediated dilatation and reduced blood pressure in mice with a specific deletion of polycystin-1 in endothelial cells. Conclusion: Chronic stimulation of dopamine receptors improves conduit artery endothelial function through the increase in flowinduced NO release as well as hemodynamics in ADPKD, representing thus a promising pharmacological approach to prevent the cardiovascular complications of this disease. Background: With aging and atherosclerosis plaque development, endothelial permeability increases leading to blood and platelets (PLT) infiltration into the vascular wall. In the media, vascular smooth muscle cells (VSMCs) are crucial for clearance of infiltrated molecules and cells including senescent red blood cells (1). Moreover, blood has a high concentration of macromolecules making it a macromolecularly crowded environment (MMC). The objective is to decipher the clearance mechanisms of PLT by VSMCs and the influence of MMC on it. Methods: Human VSMCs were cultured with either human: (i) fresh PLT, (ii) ADP-activated PLT, (iii) senescent PLT. PLT and VSMCs were stained with fluorescent tracers prior their co-culture. We also cultured VSMC in media supplemented with crowders to mimic MMC. Results: After three or seven days of co-culture, we observed that activated and/or senescent PLT, which are characterized by phosphatidylserine exposure, were localized within VSMCs. In contrast to fresh red blood cells that are not phagocytosed by VSMCs, fresh PLT were also entrapped within VSMCs. We then stained VSMCs with phalloidin, an actin filament dye, revealing that PLT are surrounded by an actin shell within the VSMC. In addition, we observed that MMC modified the deposition of extracellular matrix (fibronectin, laminin and sugar moieties) by VSMCs. Conclusions: VSMCs engulf PLT with an actin-dependent endocytosis process and MMC modifies the secretory phenotype of VSMC. PLT engulfment could be an inducible pathogenic event that is responsible for VSMC phenotypic switching in atherosclerosis and their procoagulant status.  (1). Mathematical models and comparative physiology (2,3) suggest that the lower limbs are the primary source of reflected waves; however, in vivo human evidence corroborating these observations is lacking. This study was designed to determine whether the lower or upper limbs contribute more to the summated reflected wave. We hypothesized that heating of the lower limb will result in larger changes in central wave reflection compared to heating of the upper limb. Methods: Fifteen healthy adults (8 females, 24 ± 3.6 years) completed a within-subjects experimental crossover protocol with a washout period. The right arm and leg were warmed in a randomized order using 38 °C water-perfused tubing with a 30-min break between protocols. Wave reflection was estimated at baseline and after 30 min of heating from pressure-flow relationships derived from aortic blood flow and carotid blood pressure. Results: There was a main effect of time for reflected wave magnitude (12.8 ± 2.7 to 12.2 ± 2.6 mmHg) and augmentation index (− 7.49 ± 8.92 to − 4.45 ± 9.07%) (p = 0.029 and 0.034, respectively), but no significant differences for condition or interactions. Conclusion: Proximal limb heating reduced central wave reflection magnitude; however, the lack of a difference between conditions does not support the hypothesis that the lower limbs are the primary source of wave reflection. Further research is required to confirm the role of the limbs in generating central wave reflections, with recommendations for future studies to consider the role of the gastrointestinal vasculature.