Selected Abstracts from Artery 21

S Artery Research https://doi.org/10.1007/s44200-021-00008-4 Selected Abstracts from Artery 21 Thursday 21 – Saturday 23 October 2021, Hôpital Européen Georges-Pompidou, Paris, France © The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. All content was reviewed and approved by the Society Committee, which held full responsibility for the abstract selections. 1.1 Central pulse pressure in adolescence is more strongly associated with future cardiovascular health than peripheral pulse pressure Dr Chloe Park, Dr Siana Jones, Dr Hannah Taylor, Dr Laura Howe, Professor Abigail Fraser, Professor Nish Chaturvedi, Professor Alun Hughes UCL, London, United Kingdom, Univeristy of Bristol, Bristol, United


Respective roles of hemodynamic conditions and inflammatory status in the degradation of endothelial glycocalyx in adults.
Phd Jeremy Lagrange 1 , PharmD PhD Simon Toupance 1 , Arthur Thomas 1 , PhD Carlos Labat 1 , PhD Véronique Regnault 1 , MD PhD Athanase Benetos 1 , MD PhD Patrick Lacolley 1 1 INSERM 1116, Vandoeuvre-lès-Nancy, France Background and objectives: Interactions between blood components and the vascular wall involve the glycocalyx, a thin layer of carbohydrates covering endothelial cells. Glycocalyx is implicated in processes such as circulating cells adhesion, inflammation, and coagulation regulation and can be damaged in some pathologies. The prevailing hypothesis is that hypertension is the primary factor involved in the glycocalyx degradation. However, our preliminary results 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 and thrombomodulin, two glycocalyx degradation markers, were quantified by ELISA in 327 atherosclerotic and non-atherosclerotic participants (62 ± 14 years) of the TELARTA cohort (telomere in arterial aging). 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). By contrast, no relation was observed between glycocalyx degradation markers and the hemodynamic parameters (systolic, diastolic and pulse pressure, pulse wave velocity), 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) were more prone to present clinical manifestation of atherosclerosis (65 vs 42%; p < 0.001) than those with lower concentration (first tertile). Conclusions: Inflammatory status appears as the major responsible of endothelial glycocalyx degradation in atherosclerosis. Deciphering the processes involved in this degradation and the possible treatment to limit it would be of interest in the next future.

Vascular Ageing Glossary: unifying language for knowledge diffusion
Results: Regular meetings of the dedicated team were conducted, and main decisions were agreed by all members. The key steps of the process for managing the creation and maintenance of the glossary were to determine: (1) the target audience; (2) a list of priority terms; (3) a template structure for definitions; (4) methods for collecting expert feedback; and (5) the dissemination plan. An implementation strategy was provided by the team for each point (Figure). Small groups of terms will be released on a regular basis and published openly at https:// vasca genet. eu/. Conclusions: The strategy for the first Vascular Ageing Glossary has been successfully designed and developed within VascAgeNet. It will be a living document, available to the scientific community, which aims to unify the vascular ageing language.

Acute and long-term effects of aortic banding on central hemodynamics
Stamatia Pagoulatou 1 , Dionysios Adamopoulos 2 , Vasiliki Bikia 1 , Georgios Rovas 1 , Nikolaos Stergiopulos 1 1 Laboratory of Hemodynamics and Cardiovascular Technology, Lausanne, Switzerland, 2 Department of Cardiology, Geneva University Hospitals, Geneva, Switzerland Background: Aortic compliance is an important determinant of cardiac afterload and a contributor to cardiovascular morbidity. The aim of the present study was to provide in-silico insights into the acute as well as long-term effects of aortic compliance decrease on central hemodynamics by means of a 1D, validated mathematical model of the cardiovascular system.

Methods:
Three hemodynamic states were simulated to represent a) a healthy young adult (baseline), b) acutely after banding of the proximal aorta, c) after the heart remodeled itself due to the increased afterload. The simulated pressure and flow waves were used for subsequent pulse wave and wave separation analysis. Results: Aortic banding induced hypertension, which was sustained after LV remodeling. The main mechanism that drove hypertension was the enhancement of the forward wave, which became even more significant after LV remodeling (forward amplitude 30 mmHg at baseline vs 60 mmHg acutely after banding vs 64 mmHg after remodeling). Accordingly, the forward wave's contribution to the total pulse pressure increased throughout this process. Finally, LV remodeling was accompanied by a decrease in augmentation index (AIx 13% acutely after banding vs -3% after remodeling) and a change of the central pressure wave phenotype from the characteristic Type A ("old") to Type C ("young") phenotype (Fig. 1). Simulated pressure phenotypes were in close agreement with previous experimental findings (1). Conclusion: These findings highlight the importance of the forward pressure wave in the development of hypertension and provoke us to reconsider our understanding of AIx as a solely arterial parameter.

The aortic-femoral arterial stiffness gradient is blood pressure independent in older adults: an atherosclerosis risk in communities (ARIC) study
Methods: Thirty-two participants (mean age 37 ± 8 years, 20 men) that received the BNT162b2 mRNA COVID-19 vaccine were studied in 3 sessions in a sequence-randomized, sham-controlled, assessorblinded, cross-over design. Primary outcome was endothelial function assessed by brachial artery flow-mediated dilatation (FMD), and secondary outcomes were aortic stiffness, evaluated with carotid-femoral pulse wave velocity (PWV), and inflammation measured by high-sensitivity C-reactive protein (hsCRP) in blood samples. The outcomes were assessed prior to, and at 8 h, 24 h post the 1st dose of vaccination, and 8 h, 24 h and 48 h post the 2nd. Results: There was an increase in hsCRP that was apparent at 24 h after both the 1st dose (− 0.60 [95% confidence intervals [CI] − 1.60 to − 0.20], p = 0.013) and the 2nd dose (max median difference at 48 h − 6.60 [95% CI − 9.80 to − 3.40], p < 0.001) compared to sham. The vaccine did not change PWV. FMD remained unchanged during the 1st dose but decreased significantly by 1.5% (95% CI 0.1-2.9%, p = 0.037) at 24 h post the 2nd dose. FMD values returned towards baseline at 48 h. Conclusions: Our study shows that the mRNA vaccine causes a prominent increase in inflammatory markers, especially after the 2nd dose and a transient deterioration of endothelial function at 24 h that returns towards baseline at 48 h. These results confirm the short-term cardiovascular safety of the vaccine.

Early vascular ageing in patients with hypoparathyroidism
Mr Saverio Fabbri 1,2 , Mr Pierre Boutouyrie 1 , Mr Hakim Kettab 1 , Mr Gérard Maruani 1 , Mr Pascal Houillier 1 , Ms Rosa Maria Bruno 1 1 University of Paris, Paris, France, 2 University of Perugia, Perugia, Italy Objectives: Hypoparathyroidism may induce arterial damage, but underlying mechanisms are not well established. Few papers have addressed the topic, reporting an increase in central values and in carotid intima-media thickness [1] [2]. The aim of this study was to determine the presence of early vascular ageing signs in large and small arteries.
Methods: 17 patients affected by hypoparathyroidism and 17 healthy controls (matched for age, sex, blood pressure and risk factors) were studied to obtain carotid-femoral PWV, carotid and digital intimamedia thickness and stiffness by standard and ultra-high frequency ultrasound respectively. In the patients affected by hypoparathyroidism, complete calcium-phosphorus metabolism blood tests were taken. Results: Carotid distensibility was significatively lower in the patients group (18.7 ± 6.0 vs 39.4 ± 10.5 p < 0.001), with a marked increase in carotid stiffness (7.6 ± 1.3 vs 5.3 ± 0.9 m/s, p < 0.001). No significant difference was reported in PWV and central pressure among the groups. A reduced digital artery diameter was present (mean diameter 0.8 ± 0.1 vs 1.0 ± 0.2 mm p = 0.005), with a reduced stiffness (5.6 ± 2.5 vs 9.2 ± 4.9 m/s p < 0.05). A positive correlation between carotid artery stiffness and Calcium-Phosphorus product was found in the patients group (r = 0.661 p = 0.037). Conclusions: Hypoparathyroidism is characterized by increased carotid artery stiffness. Digital stiffness (UFHS) is paradoxically reduced (possibly as compensatory mechanism), with hypotrophic remodeling. Our data support altered calcium-phosphorus metabolism as mechanism of arterial damage.

Associations of lower limb atherosclerosis and arteriosclerosis with cardiovascular risk factors and disease in older adults: the ARIC study
Methods: Consistent with CAVI/CAVI 0 assumptions, the arterial tree was modelled as a system of tubes with exponential pressurediameter relationship and uniform stiffness index. PWV then follows from [1,2]: where P = {DBP, P notch }, P ref = 100 mmHg and = 1050 kg/ m 3 . The resulting PWVs, together with the heart-to-ankle (L ha ) and heart-to-brachial (L hb ) path lengths [3], allow estimation of: a weighted average of which yields Given P notch = 0.55·DBP + 0.45·SBP [4].
Conclusions: DBP offers a more accurate approximation of P haPWV than P m. , supporting the utility of CAVI 0 as an enhancement of CAVI.

Antithrombotic therapy in secondary and tertiary prevention for peripheral arterial disease: a network meta-analysis
Dr Loes Willems 1 , Ms Dominique Maas 1 , Dr Michel Reijnen 2 , Dr Niels Riksen 1 , Dr Hugo Ten Cate 3 , Dr Rozemarijn Van der Vijver-Coppen 1 , Dr. Clark Zeebregts 4 , Dr. Gerjon Hannink 1 , Dr. Michiel Warlé 1 Methods: A systematic search was conducted of randomized controlled trials, published between 1995 and 2020. ASA was the universal comparator. The primary endpoint was major adverse cardiovascular events (MACE) and the safety endpoint was major bleeding. Secondary endpoints were all-cause mortality (ACM), major adverse limb events (MALE) and acute limb events (ALI  (B). All regimens were non-superior to ASA concerning ACM (C) and MALE (D). ASA + rivaroxaban was more effective in preventing ALI [RR0.67, 95% CI 0.55-0.80] (E). Conclusion: Both clopidogrel and ASA + rivaroxaban were more effective than ASA in secondary prevention, however, ASA + rivaroxaban increases the risk of major bleeding. Concerning tertiary prevention, information on clopidogrel is lacking, while ASA + rivaroxaban is more effective in preventing ALI.

3.9
Superior effect of community-based high-intensity interval exercise for reducing blood pressure and arterial stiffness in low-income older women Universidade Estadual Paulista, Bauru, Brazil Aim: To assess the effect of different community-based exercise programs on blood pressure, arterial stiffness, and functional capacity in low-income older women.
HIIT + RT: high-intensity interval training combined with resistance training; MICT + RT: moderate-intensity continuous training combined with resistance training; RT: resistance training alone; Asterisk indicates significant difference from before training (*: P = 0.01; **: P = 0.001). There is no consensus if different intensities of PE changes arterial stiffness-by pulse wave velocity (PWV) and augmentation index (AIx) -, a marker of cardiovascular risk 2 , related to blood pressure (BP).

Pulse Wave Velocity for 24-h Ambulatory Blood Pressure
Methods: Data was acquired from 10 subjects (35 ± 7 years) over 24 h in free living conditions. The novel wearable system (imec,NL) combines electrocardiogram (ECG) and photoplethysmogram (PPG) signals to obtain beat-to-beat pulse arrival time (PAT), converted to PWV via arterial path length (L). PWV and heart rate (HR) data was smoothed using a 1-h moving average window and values were extracted corresponding to simultaneously acquired intermittent ABPM readings (Suntech Medical Inc.,USA). Mean values were subtracted per subject to obtain changes per variable (D). Unbiased multivariate regression models were generated to estimate DSBP and DDBP responses from DPWV and DHR predictors. Results: BP tracking errors were conform with AAMI standard error criteria (5 mmHg and SD 8 mmHg) (3), achieving = − 0.2/0.0 mmHg and SD = 7.6/6.0 mmHg for SBP/ DBP. Accounting for the subtracted means demonstrated accurate estimations over a wide absolute range (55-105 mmHg mean BP) and a 90% classification accuracy for diagnostic hypertension thresholds, contrasting 62% if BP was assumed constant. Conclusion: The proposed system demonstrates significant predictive utility for BP changes and may facilitate unobtrusive and cuff-less ABPM at high temporal resolution.

Measurement setup
Signal processing E xample single subject Local biaxial deformation measurements are essential for the in-depth investigation of tissue properties and remodeling of the ascending thoracic aorta, particularly in aneurysm formation 1 . Current clinical imaging modalities pose limitations around the resolution and tracking of anatomical markers 2−4 .

Methods:
We evaluated a new intra-operative video-based method to assess local biaxial strains of the ascending thoracic aorta ( Figure  A).
In patients undergoing open-thorax surgery, two pairs of diametrically opposite felt markers were sutured on the adventitial surface of the aorta after the sternotomy ( Figure B). Videos of markers were captured at low-and high-pressure conditions (Figure C), and marker tracking was performed using an in-house tracking algorithm to determine local biaxial strains. We obtained in 30 patients repeated biaxial strain measurements, for each pressure condition. (Figure D, E). Results: Precision was acceptable, with coefficients of variation for biaxial strains remaining below 20% and the magnitude of strains we obtained (range: 0.02-0.05) is in line with previous reports, using clinical imaging. Interestingly, with our four-marker arrangement, we were able to detect significant local differences in longitudinal strain as well as in circumferential strain ( Figure D, E).

Conclusion:
The proposed method enables the assessment of local aortic biaxial strains and may enable new, clinically informed mechanistic studies using biomechanical modeling as well as mechanobiological profiling.

7.3
On the estimation of arterial compliance from carotid pressure waveform IBiTech, University of Ghent, Ghent, Belgium Abstract Background: Total arterial compliance (C T ) is a biomechanical property of the arterial tree with great pathophysiological importance (1,2) and thus its estimation via a simple, accurate method is valuable.
Direct noninvasive measurement of C T is not feasible in the clinical practice. Previous methods for indirect C T estimation require noninvasive, yet complex and expensive, recordings of the central pressure and flow (3,4). Methods: This study introduces a novel, noninvasive method for estimating C T from a single carotid waveform measurement using neural networks. Features were extracted from the carotid wave and were combined with demographic data. A prediction pipeline was adopted for estimating C T using (i) firstly, a feature-based analysis (ANN FB ), and (ii) secondly, the raw carotid pulse wave (ANN RAW ) as input. The methodology was evaluated using the large Asklepios cohort (n = 2256). Results: Accurate estimates of C T were yielded for both prediction schemes ( Figure); namely, r = 0.83/normalized-RMSE = 9.6% for ANN FB , and r = 0.83/normalized-MSE = 9.7% for ANN RAW , respectively.

Conclusions:
The method may allow for easily applicable and convenient CT monitoring. Such an approach could suggest promising applications, ranging from fast and cost-efficient hemodynamical monitoring by the physician to integration in wearable technologies.

7.4
Assessing radiotherapy-induced carotid vasculopathy using ultrasound after unilateral irradiation MD Judith Pruijssen 1 , MD PhD Joyce Wilbers 1 , MD Ashwin Wenmakers 1 , MD PhD Jacqueline Loonen 1 , Prof Dr Chris de Korte 1,2 , Prof MD PhD Johannes Kaanders 1 , PhD Hendrik Hansen 1 1 Radboud University Medical Center, Nijmegen, Netherlands, 2 University of Twente, Twente, Netherlands Background: Improved diagnostic and therapeutic regimens have increased head and neck cancer (HNC) survival. However, the younger, growing survivor population is prone to long-term treatment-related vascular complications. Irradiated patients have a minimally twofold stroke risk compared to the general population (1). However, the pathophysiology of radiation-induced vasculopathy is unclear. Vascular stiffness might be a biomarker of this injury. We investigated whether irradiated compared to unirradiated carotids in unilaterally irradiated patients showed alterations in stiffness-related parameters, shear wave velocity (SWV) and pulse wave velocity (PWV), and intimamedia thickness (IMT).

Methods:
Twenty-six patients (41 ± 9 years), median 7 years after unilateral radiotherapy for head and neck tumors underwent bilateral carotid ultrasounds with an Aixplorer Ultimate system (Supersonic Imagine, France) with SL18-5 and SL10-2 transducers. IMT, begin-and end-systolic PWV, and average SWV were assessed in the proximal-, mid-, and distal common (CCA) and internal carotid artery (ICA). Three consecutive measurements were averaged. Differences between irradiated and unirradiated carotids were tested using Wilcoxon signed-rank tests. Radiation dose-effect relations were explored with linear regression. Results: CCA-IMT was higher in the irradiated than unirradiated carotids (Table 1). Although overall stiffness seemed higher in irradiated carotids, differences were only statistically significant for anterior mid-CCA and posterior ICA SWV. A dose-effect relation seemed apparent for end-systolic PWV (β = 0.051/Gray, p = 0.07), not for IMT or SWV. Conclusion: Some IMT and stiffness increases were observed in irradiated carotids. To further investigate vascular stiffness as a biomarker for radiation-induced vasculopathy a larger, typical HNC cohorts (higher age/radiation doses/number of cardiovascular risk factors) is required.

Sublingual nitroglycerine ingestion is associated with an increase rather than decrease in brachial-artery retrograde blood flow in healthy human subjects
Dr Smriti Badhwar 1 , Dr. Dinu Chandran 1 , Prof Ashok Jaryal 1 , Prof Rajiv Narang 1 , Prof Chetan Patel 1 , Prof Kishore Kumar Deepak 1 1 All India Institute of Medical Sciences, New Delhi, India Background: Nitroglycerine can reduce left ventricular afterload by decreasing amplitude of wave reflections (1). Increase in brachialartery retrograde flow is associated with endothelial dysfunction. It was hypothesized that nitroglycerine mediated reduction in peripheral wave reflections would reduce brachial-artery retrograde flow. The current study aimed to evaluate effect of nitroglycerine on brachialartery retrograde flow.
Methods: Brachial artery retrograde flow velocity and diameter were measured in duplex mode using Pulsed-wave doppler (M7, MindRay) at baseline and 5 min after sublingual Isosorbide dinitrate (5 mg) ingestion in 32 healthy subjects. Time-averaged mean anterograde and retrograde blood flow velocity (ABRV and RBFV) were measured, and blood flows (ABF and RBF) were calculated from the velocities and corresponding diameters.

Results:
There was significant increase in RBFV at 4th and 5th min (

Methods:
We enrolled 500 patients undergoing coronary angiography for simultaneous measurements of invasive aortic BP with noninvasive BP (Mobil-o-Graph device). Linear regression and mediation analyses were used to adjust for potential confounders in the relationship between biological sex and brachial cuff BP accuracy. Results: Of 500 participants, 145 were females. Several characteristics were different in males and females (Table). Brachial cuff SBP was identical in both groups whereas aortic SBP was 6.2 mmHg higher in females (p < 0.001). As such, the brachial cuff appreciably underestimated aortic SBP in females but not in males. In an adjusted linear regression model, only height and pulse pressure were independently associated with the accuracy of brachial cuff SBP. This effect of sex on accuracy was mostly mediated by height (3.5 mmHg; 95% CI 1.4 to 5.6; 57% mediation) to an extent that the direct effect of sex became nonsignificant (2.9 mmHg; 95% CI -0.3 to 6.2). Conclusion: Females have higher aortic SBPs than males with identical brachial cuff SBP, which is mostly mediated by a lower height. This unrecognized higher aortic SBP provides indirect evidence to support the increased cardiovascular risk of females compared with males with similar brachial cuff SBP. We assessed the overall and repeated measures agreement between a criterion measure of carotid-wrist pulse wave velocity (cwPWV) and a PWV measure derived from a continuous non-invasive blood pressure device (PWV NIBP ). A continuous method of PWV velocity would allow for the detection of acute changes in arterial stiffness.
Methods: cwPWV was measured with carotid artery and wrist cuffs. PWV NIBP was continuously obtained, with pulse wave transit time measured as the delay between the R wave of the electrocardiogram and the foot of the finger cuff pressure wave. Measurements were made twice in the supine posture, and then once in the seated position. The seated posture was used as an orthostatic challenge, to cause vascular changes for ascertainment of repeated-measures agreement. Mixed model regression was used to calculate overall agreement (independent of posture), and repeated-measures correlation was used to determine whether changes in the two measures agree. Acceptable intraclass correlation coefficient (ICC) agreement was set at 0.70. Analysis of wave intensity provides valuable information about wave propagation in the arterial circulation. However, the need to measure both pressure and flow hinders its widespread use in large scale studies. A recently proposed method enables estimation of wave intensity patterns from non-invasive pressure waveforms. 1 We applied this method in type 2 diabetes (T2DM) to determine 1) whether it is feasible in T2DM, 2) whether wave intensity patterns differed between people with and without T2DM, and 3) whether the trajectories of those patterns, measured 3 years apart differed between cohorts.

Methods:
We studied 227 individuals with T2DM (66.9 ± 7.9 years, 87F) and 99 without T2DM (66.0 ± 9.0 years, 43F). Radial pressure waveforms were recorded using a SphygmoCor system and aortic pressure waveforms were derived; these were analysed using customwritten software to calculate wave intensity. Results: Wave intensity showed the typical pattern, and the magnitude of the forward compression and decompression waves were similar in both cohorts. However, the area of backward compression wave was smaller in people with T2DM than those without (152 × 10 4 vs 180 × 10 4 J/m 2 , p = 0.025), and wave reflection index was reduced (0.25 vs 0.29 au, p = 0.050). Both cohorts showed slightly upward trajectories in wave intensity patterns over 3 years, and the changes in magnitude of wave intensity were similar in both cohorts. Conclusions: It is feasible to estimate wave intensity using the pressure-only method in T2DM. Using the method, wave reflection was smaller in people with T2DM compared with those without T2DM.

P.4 Longitudinal changes in aPWV in chronic obstructive pulmonary disease
Mrs Mahfoudha AL Shezawi 1,2 , Maggie Munnery 2 , Laura Watkeys 2 , John Cockcroft 2 , Nichola Gale 1 , Barry McDonnell 2 1 Cardiff University, Cardiff, UK, 2 Cardiff Metropolitan University, Cardiff, UK Introduction: Chronic Obstructive Pulmonary Disease (COPD) is characterised by irreversible airflow obstruction, chronic inflammation, increased cardiovascular disease (CVD) risk and mortality. Increased arterial stiffness measured by aortic pulse wave velocity (aPWV) may reflect subclinical CVD and is increased in COPD patients. However, the time course of longitudinal changes in aPWV have not been investigated in COPD. This study aimed to compare changes in aPWV over a 2-year and 6-year period, in patients with COPD and aged-matched controls.
Methods: This longitudinal study included patients with COPD and age-matched controls from the ARCADE study. Measurements included aPWV using the SphygmoCor system. Lung function was assessed by forced expiratory volume in the first second/forced vital capacity (FEV 1 /FVC) using spirometry. Self-reported history of CVD and use of cardiovascular acting medications were recorded. Results: Data were available in seventy-five patients with COPD and seventy-one controls (mean age 65 ± 7 years) at baseline, 2-and 6-years follow up. At each assessment time-point, patients with COPD had higher aPWV, lower FEV 1 /FVC, and greater use of cardiovascular acting medications than controls (all at p < 0.05). Both groups showed a similar increase in aPWV over the 6 years (annual increase of 0.2 m/s/ year, p = 0.560).

Conclusion:
The similar relative change in aPWV observed in both groups may be explained by the progression in age. However, the higher baseline levels of aPWV in COPD were maintained and tracked over the 6-years, even in the presence of additional cardiovascular acting medications, suggesting a premature and consistently elevated vascular ageing process in COPD patients. Even without a rupture, AAA increases the risk of developing chronic heart failure and other major cardiovascular events.

P.5 Assessment of vascular markers of large artery dysfunction and circulating biomarkers of endothelial dysfunction and thromboinflammation in patients with psoriasis
Purpose: Even though AAA may lead to heart failure, no study has previously systematically explored the left ventricular function in patients with AAA. Thus, the aim of this echocardiographic study is to investigate whether AAA is associated with left ventricular dysfunction. Methods: Echocardiography was performed in 307 males (199 AAA and 108 controls) aged 55-80 years. The males were recruited from a regional ultrasound surveillance program of known AAA or an ongoing ultrasound screening program during 2011-2016. Results: Males with AAA had a 2.2% lower left ventricular ejection fraction and 1% lower global longitudinal strain compared to control. They had also a significantly thicker septal and posterior wall and a higher E/e' . Ischemic heart disease was reported eight times, hypertension and smoking four times more frequently in participants with AAA compared to controls. Conclusion: While hypertension, smoking and ischemic heart disease are far more common in males with AAA than controls the difference in left ventricular function is only mild. Subjects with AAA have a slight impaired left ventricular systolic and diastolic function.

P.7
Heart rate modulates the relationship of augmented systolic blood pressure with the blood natriuretic peptide levels Professor Hirofumi Tomiyama 1 1 Tokyo Medical University Aims: The present study examined whether the association of the Central systolic blood pressure (cSBP) with the the serum N-terminal fragment B-type natriuretic peptide (NT-proBNP) levels might differ between subjects with high and low HRs.

Methods:
In 2257 middle-aged healthy Japanese men, serum NT-proBNP levels, radial augmentation index (radial AI), and the first and second peaks of the peripheral systolic blood pressure (SP1 and SP2, markers of the cSBP) were measured.

Results:
The serum NT-proBNP levels among three groups classified by the HR (i.e., ≤ 69, 70-79, and ≥ 80). While the serum NT-proBNP levels were similar among the three groups, the radial AI increased and the SBP1-2 (SBP1 minus SBP2, i.e., a low SBP1-2 corresponds to augmentation of the cSBP relative to the bSBP) decreased significantly with decreasing HR. In multivariate linear regression analyses, the SBP2 showed a significant association with the serum NT-proBNP levels in the overall study population. However, in subgroup analyses, the SBP2 showed a significant association with the serum NT-proBNP levels only in subjects with HR ≤ 69 beats/minute.

Conclusion:
In middle-aged Japanese men, the relationship between the cSBP and the cardiac afterload appears to differ depending on the heart rate; the results of our analysis showed that the relationship between the cSBP and cardiac overload may be more pronounced and strongly significant in patients with low HRs as compared to patients with high HRs.

P.8 Carotid enlargement is associated with the presence and severity of coronary artery disease assessed by Gensini Score in patients submitted to coronary angiography
Professor Luiz Bortolotto 1 , Dra Nadja Mendes 1 , Ms Valeria Costa-Hong 1 , Dr Stefano Garzon 1 , Professor Pedro Lemos 1 1 Instituto Do Coração, São Paulo, Brazil We evaluated the association of carotid measurements (intima-media thickness-cIMT, internal diameter and distensibility) obtained by radiofrequency ultrasound (Wall Track System ® ) with the presence and severity of coronary artery disease (CAD) assessed by Gensini Score in 69 patients prospectively submitted to coronary angiography due clinical suspicion of CAD. The presence of CAD was considered when the Gensini score ≥ 1. The mean age was 58.4 ± 8 years, 50% men, 85% arterial hypertension, 37% diabetes and 40% smoking. The presence of CAD was observed in 44 patients (63%), with a higher proportion of men in patients with CAD (59% vs. 28%, p < 0.05). Patients with CAD had a greater internal diameter of carotid artery [7758.2 (7096.1; 8797.2) µm vs. 7009.0 (6595.5; 7396.0) µm, p = 0.003), while it was not observed differences in cIMT or distensibility. In logistic regression analysis, the chance of presenting CAD by Gensini score increases by 6.7% at each 100 µm increase in the internal diameter regardless of gender. A significant correlation was observed between the carotid diameter and Gensini score (r = 0.289, p = 0.02). Among carotid artery measurements obtained by radio-frequency ultrasound, the internal diameter was the only significantly associated with the presence and severity of CAD estimated by Gensini score.

P.9
A novel ultrasound-based method for heart failure screening Albert Chang 1 , Dhruv Reddy 1 , Shashank Adapa 1 , Anenta Ratneswaren 1,2 , Ryan Reavette 2 , Peter Weinberg 2 1 Faculty of Medicine, 2 Department of Bioengineering, Imperial College London Background: Heart failure (HF) is prevalent and, although treatable, has a one-year prognosis of 40%. Moreover, 80% of diagnoses in England are made after a hospital admission despite 40% of patients visiting their GP with symptoms beforehand (1). The most common symptoms -breathlessness, fatigue and ankle swelling -are nonspecific, so patients are not always referred for echocardiography, the gold-standard for diagnosis. This motivates improved HF screening in Primary Care.
Studies have shown that arterial wave intensity is altered in HF (2, 3), but the technique relies on measuring pressure and velocity waveforms simultaneously; current methods are invasive, inaccurate or cumbersome. We propose a noninvasive method that uses ultrafast ultrasound to measure diameter and velocity instead; both variables can be accurately measured with one scan but give similar clinical indications. Methods: Patients undergoing echocardiography were recruited from outpatient Cardiology clinics, and B-mode ultrasound scans were taken of their left carotid, right carotid and left brachial arteries. Blood signal was enhanced using spatiotemporal filtering. Velocity and diameter waveforms were obtained using cross-correlation-based techniques. Results: Wave intensities have been computed for 100 patients. There is a significant difference (p < 0.05) in the intensities of waves that represent systolic contraction and peripheral reflection between patients with HF with reduced ejection fraction and those without symptoms of HF or reduced ejection fraction. Conclusions: Noninvasive wave intensity analysis has potential to improve HF screening in Primary Care. We gratefully acknowledge support from BHF, Imperial College BHF Centre of Research Excellence and EPSRC Impact Acceleration Award.

P.10 A comparison of aortic haemodynamic parameters between the SphygmoCor CvMS (radial tonometry) device and the PULSE (brachial oscillometry) device
Mr James Cox 1 , Dr Ahmad Qasem 2 , Dr Isabella Tan 1 , Emeritus Professor Alberto P. Avolio 1 , Dr Mark Butlin 1 1 Macquarie University, Sydney, Australia, 2 CardieX-AtCor, Sydney, Australia Background: Current cardiovascular outcomes are based primarily on the measurement of brachial arterial blood pressure (BP). Whilst this measurement is acceptable, aortic haemodynamic parameters offer a more representative assessment of an individual's cardiac load. Currently, there is a lack in devices assessing aortic parameters.

Methods:
We investigated the association of arterial stiffness with several biomarkers and with the degree of skin deposition of AGE in a sample of 867 subjects from general population, examined in the Czech post-MONICA study. Carotid-femoral pulse wave velocity (PWV) was measured by SphygmoCor device (AtCor Medical Ltd.) and skin AGE were measured using a dedicated autofluorescence method (AGE Reader mu ® ); the method is quick and easy to use. To quantify the circulating status of AGE, carboxymethyl lysine (CML) was assessed by ELISA; sRAGE concentrations were also assessed by ELISA. Results: When analyzing the whole sample using both multiple linear and logistic regression models and after adjustment for potential covariates, significant associations of PWV with fasting glycemia, HbA1c, sRAGE, skin AGEs, and the skin AGE-to-sRAGE ratio were found. Stepwise models identified strong association with the skin AGE and the ratio of skin AGE-to-sRAGE, independently of serum glucose level, age and mean arterial pressure; this was also true when diabetic subjects were excluded. In contrast, neither CML, nor its ratio to sRAGE showed any association with arterial stiffness.

Conclusion:
The amount of skin AGE and sRAGE, which prevents deposition of AGE into tissues, are important factors contributing to aortic stiffness over and above serum glucose level.

P.16
Central arterial pressure changes during and after head-down tilt bedrest.
Dr Catherine Fortier 1 , Dr Antoine Fayol 2 , Dr Hakim Khettab 1,2 , Dr Rosa-Maria Bruno 1,2 , Professor Pierre Boutouyrie 1,2 1 INSERM U970, Paris Cardiovascular Research Center (PARCC), Cellular molecular and physiological mechanisms of heart failure (Team 7), Paris, France, 2 AP-HP, Pharmacology Unit, Hôpital Européen Georges Pompidou, Université de Paris, Paris, France Background/objectives: Head-down tilt bed rest (HDTBR) induces a redistribution of blood volume from lower limbs to the upper and central parts of the body, which mimics physiological changes during long-term exposure to microgravity. However, the effects of HDTBR on central arterial pressure parameters during bedrest and after the return to verticality remain poorly described.

P.17
Radial-digital pulse wave velocity: response of small peripheral arteries to nitroglycerin We have already demonstrated that nitroglycerin (NTG) induces different regional stiffness response from elastic and muscular arteries, predisposing small peripheral arteries to increased pulsatility1. Peripheral smaller arteries may also respond differently to nitroglycerin. The objective of this study is to compare the changes in radial-digital pulse wave velocity (RD-PWV) following administration of NTG from healthy individuals to those with chronic kidney disease (CKD).

Method:
This study was conducted among 36 participants, 27 healthy (56% women, age 48.4 years) and 9 CKD (33% women, age 70.3 years). Piezoelectric sensors (Complior, France) were placed on the carotid and radial arteries, as well as on the tip of the index finger to obtain the carotid-radial PWV (CR-PWV) and the RD-PWV. These measurements were repeated 4 min after sublingual administration of 0.4 mg NTG. Results: At baseline, the CKD group had a significantly lower RD-PWV than the healthy group (3.27 ± 1.38 m/s vs. 4.72 ± 1.20 m/s, p = 0.008). After NTG administration, the RD-PWV of the healthy and CKD groups both significantly increased to reach 6.09 ± 2.23 m/s and 4.69 ± 1.87 m/s, respectively (p < 0, 01). However, in both populations, the stiffness of the entire upper limb (carotid-digital PWV) did not change significantly (p = 0.816 and p = 0.169). Conclusions: Again, we observed opposite changes in the stiffness of different vascular territories with vasodilator drug resulting in no change in stiffness for the entire upper limb. These are preliminary results, but this new technique may open up the path for a better understanding of the consequences of a modified stiffness gradient on the microcirculation.

P.18
Are arteries designed to minimise variation in arterial pressure of the blood volume stored during the systole?
Ph.d. Benjamin Gavish 1 1 Yazmonit Ltd., Jerusalem, Israel Background: Arterial compliance enables arteries to store blood during the systole ('pulse volume'). This temporary storage plays the important role of buffering arterial pressure pulsatility. Arterial compliance varies with pressure. Here, we investigate the pressure dependence of pulse volume using a model approach.
Methods: Expression of the pulse volume using two phenomena observed in individuals (figure): i) exponential relationship between arterial pressure (P) and arterial volume (or cross-sectional area) V, in normal and high pressures given by P = α + exp(V), where α, and are pressure-independent, and ii) linear relationship of repeated measurements of systolic blood pressure SBP and diastolic blood pressure DBP, i.e., SBP = A + K DBP, where A and K are constants. Results: Taking Vs and Vd to be the arterial blood volumes corresponding to SBP and DBP, respectively, it is straightforward to show that K = exp[(Vs-Vd)], where Vs-Vd is the pulse volume. Since K andare constants, this model shows that pulse volume is independent of blood pressure. Conclusions: The model supports the view that the pressure-volume relationship in arteries may play a role in regulating blood volume stored by arteries during the systole.

P.19
Comparison between invasive and noninvasive methods to determine subendocardial oxygen supply and demand imbalance from aortic pressure waveform Background: Evaluation of the balance between subendocardial oxygen supply and demand could be a useful parameter to assess the risk of myocardial ischemia. The subendocardial viability ratio (SEVR, also known as Buckberg index) determined by invasive recording of left ventricular and aortic pressure curves is a valid method to estimate the degree of myocardial perfusion relative to left ventricular workload. Arterial applanation tonometry allows a non-invasive estimation of SEVR as the ratio of the areas directly beneath the central aortic pressure curves obtained during diastole (myocardial oxygen supply) and during systole (myocardial oxygen demand). However, "traditional" non-invasive SEVR is affected by limitations that make it significantly different from the invasive SEVR.

Methods:
We have developed a new method for evaluation of SEVR with carotid tonometry by taking into account the intra-ventricular diastolic pressure and proper allocation to systole and diastole of left ventricular isometric contraction and relaxation. SEVR values estimated with carotid tonometry (PulsePen, DiaTecne, Italy) by "traditional" and "new" method were compared with those evaluated invasively by cardiac catheterization. Results: The "traditional" method provided significantly higher SEVR values than the reference invasive SEVR: average of differences ± SD = 0.44 ± 0.11 (limits of agreement: 0.23-0.65). The non-invasive "new" method showed a much better agreement with the invasive determination of SEVR: average of differences ± SD = 0.00 ± 0.08 (limits of agreement: − 0.15-0.16). Conclusions: Carotid applanation tonometry provides valid non-invasive SEVR values only when all the main factors determining myocardial supply and demand flow are considered.

P.20
Healthy young men show a larger response in carotid artery dilation during a cold pressor test compared to age-matched females dr. Yvonne Hartman 1 , Daniek Dinnissen 1 , Prof. dr. Dick Thijssen 1,2 1 Radboudumc, Nijmegen, Netherlands, 2 Liverpool John Moores University, Liverpool, United Kingdom Background: The carotid artery reactivity (CAR) test was recently identified as an early marker of conduit artery vascular health. This study examined potential sex differences in CAR between healthy young men and women.

Methods:
In this preliminary analysis on data of the ongoing Healthy Brain study (NTR7955), 245 participants (113 males) aged 30-39 were included. Ultrasound was used to measure common carotid artery diameter. After 1 min baseline measurements, a hand was immersed in ice water for 3 min. CAR% was defined as maximal diameter change during cold pressor test compared to baseline. After 4 months, measurements were repeated in a subgroup (n = 86, 45 males)). CAR% was compared between males and females, and whether these potential differences remain present across time. Results: Our cross-sectional data revealed a larger CAR% in males compared to females (3.1 ± 3.3 vs 2.2 ± 3.3%, P = 0.043). Males reported a significantly larger baseline diameter (6.9 ± 0.6 mm vs 6.3 ± 0.6 mm, P < 0.001). Correcting the CAR% for between group differences in baseline diameter reinforced the larger CAR%. Although CAR% increased from baseline to 4 months (2.5 ± 3.5 to 3.4 ± 2.7%, P = 0.027), the increase in CAR% did not differ between males and females. Conclusions: Young, healthy men show a consistently higher CAR% than females. This suggests that young healthy men have better carotid artery vascular health compared to age-matched women. Future studies are required to better understand how this difference in vascular health may translate to development of cardiovascular disease. This trial is registered at https:// www. trial regis ter. nl/ trial/ 7955. University of Manchester, Salford, United Kingdom Introduction: Type 2 diabetes mellitus (T2DM) represents a major/ increasing chronic health burden at a population level. T2DM frequently associates with increasing multi-morbidity/treatment complexity 1 . Longitudinal clinical histories of individuals both before and after diagnosis of T2DM are likely to provide additional insight into its aetiology and consequences.

P.21 Longitudinal clinical trajectory analysis of individuals before and after diagnosis of Type 2 Diabetes Mellitus (T2DM) indicates that vascular problems start early
Methods: This study utilised diabetes patients and controls enrolled in the DARE (Diabetes Alliance for Research in England). Longitudinal data of 281 individuals (T2DM n = 237 and matched non-T2DM controls n = 44) were extracted. Trajectory Analysis over a period of up to 70 years based on calculations of the proportions of most prominent clinical conditions for each year. Results: For individuals who eventually had a diagnosis of T2DM made, a number of clinical phenotypes were seen to increase consistently in the years leading up to diagnosis of T2DM. Of these documented phenotypes, the most striking were diagnosed hypertension (more than in the control group) and asthma. This trajectory over time was much less dramatic in the matched control group. Immediately prior to T2DM diagnosis a greater indication of ischaemic heart disease proportions was observed. Post-T2DM diagnosis, the proportions of T2DM patients exhibiting hypertension and infection continued to climb rapidly before plateauing. Ischaemic heart disease continued to increase in this group as well as retinopathy, impaired renal function and heart failure. Conclusion: These observations provide an intriguing and novel insight into the onset and natural progression of T2DM. They suggest an early phase of potentially-related disease activity well before any clinical diagnosis of diabetes is made.

Methods:
We measured carotid-femoral PWV in all new admissions to a single eating disorder unit from December 2020 who met inclusion criteria: 1) diagnosis of AN; 2) aged 12-18 years; 3) underweight (< 85% of average BMI for age and sex). PWV was measured using Vicorder by a single operator at admission and weekly for 12 weeks. Ethics approval was provided by a London ethics committee. Standardised PWV Z-score for age (PWVz) was derived from published data. Results: For 7 participants, baseline mean PWV was 7.19 (SD 0.40) m/s. Mean PWVz was 3.81 (SD 0.71, one sample t-test p < 0.01). Mean BMI was 15.62 (0.65 SD) kg/m 2 . Baseline PWV and PWVz were not associated with baseline BMI. In multi-level, mixed effects models PWV and PWVz decreased over time in weeks (coefficient − 0.05, 95% CI − 0.07 to 0.03; coefficient −0.10, 95% CI − 0.5 to − 0.05 respectively).

Conclusions:
We have demonstrated feasibility in collecting repeated PWV measures in this patient group. Interim findings suggest high standardised scores of PWV compared to population normative data, and temporal decreases in PWV and PWV z-score during admission.
Further research is needed on long term patterns of PWV in AN patients, and to understand possible underlying mechanisms.

P.23 Dynamic time warping for measuring incremental pulse wave velocity: demonstration on a porcine model
Mr. V Raj 1 , Dr. P M Nabeel 2 , Dr. Jayaraj Joseph 1 1 Indian Institute Of Technology Madras, Chennai, India, 2 Healthcare Technology Innovation Centre, Indian Institute of Technology Madras, Chennai, India Background: While outlining the clinical importance of incremental pulse wave velocity (PWV) (1), attempts were made to measure it by simultaneously acquiring pressure and diameter from a single arterial site. Owing to the methodological limitations of such methods (1,2), especially when applied to central arteries, we present a novel dynamic time-warping-based technique to measure incremental PWV from a pair of identical blood pulse signals captured from two proximal sites.
Methods: Its functionality was demonstrated on an anesthetized swine during baseline condition and infusion of vasoconstritive drugs (elevating BP). A pair of pressure waveforms (sampling rate = 20 kHz) was captured from the left common carotid artery using a dual-element pressure catheter (5F, sensor spacing = 30 mm, Millar SPR-751, ADInstruments, India), from which beat-to-beat end-diastolic (C D ) and peak-systolic PWVs (C S ) were measured. Results: Baseline C D and C S evaluated from the captured high-resolution pressure waveforms were repeatable (variability < 4.5%). Both measures were strongly associated (r > 0.88, p < 0.01) with pressure and increased (> 2.5 times) with the increment in mean pressure (~ 3 times) induced by the drug. C S measured significantly greater (p < 0.0001) than C D , 6.1 m/s versus 5.4 m/s during baseline (82/55 mmHg) and 18.9 m/s versus 12.8 m/s during peak-drug-effect (226/184 mmHg).

Conclusions:
The method reliably measured the incremental nature of PWV and its inter-beat dependence on blood pressure, invasively. Development of an ultrafast-fast ultrasound employing this method is underway, catering the need for a non-invasive technology that's amenable for clinical settings.
(1,2) Peripheral pulsewave morphology alterations might reflect these changes. Our aim is to showcase two patients to demonstrate how these effects can be captured with a remote patient monitor system with daily recordings and to compare the changes of the different parameters to start a scientific discussion about the possible clinical utility of such monitoring in COVID-19 patients.
Methods: Signals were recorded with a remote patient monitor system. (SCN4ALL, E-Med4All Europe Ltd., Hungary) (3) Patients were conducting measurements at rest, placing the device at one of their index fingers. All the parameters collected in the different clinical conditions (pre-;in-;post-COVID) were displayed with a box-plot method. Results: Both subjects had elevated heart rate and decreased oxygen saturation during the acute phase of the disease. There are parameters showing the same patterns during the acute phase (systolic slope inclination, b/a, early left ventricular ejection time1 and 2, ejection time and crest-time). However, there are certain other parameters with discrepancies between subjects. (Stiffness index, reflection index, d/a, dicrotic notch index, Ageing index, Left ventricular ejection time index).

Pulse rate variability time domain parameters (SDNN and RMSSD) both exhibited decreased values, as sign of ongoing infection (4).
Conclusions: This case presentation demonstrates certain pulsewave analysis based cardiovascular parameter changes during COVID-19 disease. Well-designed studies are needed to unfold the potential of daily pulsewave monitoring in the outcome prediction, phenotyping and the personalized therapy of COVID-19 and other diseases.

P.25
The relationship between intima-media thickness and global longitudinal strain value measured by 2D-strain ultrasound in obese patients Angela Cozma 1,2 , Andrada-Luciana Lazar 1,3 , Benjamin Guilherme Rodrigues 1 , Gaétan Masson 1 , Adela Sitar 1,2 , Olga Orasan 1,2 , Adriana Fodor 1,4 , Vasile Negrean 1,2 1 "Iuliu Hațieganu" University Of Medicine And Pharmacy, Cluj-Napoca, Romania, 2 4th Medical Department, Cluj-Napoca, Romania, 3 Dermatology Department, Cluj-Napoca, Romania, 4 Department of Diabetes and Nutrtion, Cluj-Napoca, Romania Background: There is a strong correlation between intima-media thickness (IMT) and several cardiovascular risk factors, and more importantly with clinical and subclinical atherosclerosis (1). Additionally, IMT assessment represents a valuable tool in order to anticipate the individual risk of coronary artery disease (2) and impaired left heart function (3). The aim of our study was to evaluate the IMT and global longitudinal strain (GLS) values in obese and overweight patients, compared to normal-weight patients, and to determine a potential relationship between these measurements and the patient's body mass index (BMI).

Methods:
A total of 31 patients were included in our study. The subjects were assigned to 3 groups as it follows: "obesity" group, "overweight" group and "normal weight" group. The assessment of left ventricle systolic function was performed by 2D-strain echocardiography. IMT measurements were also performed. Results: 31 patients were included in our study, 8 (25.81%) had normal weight, 12 (38.71%) were overweight and 11 (35.48%) suffered from obesity. Regarding the relationship between IMT and GLS value in the global population the correlation coefficient was 0.5758, while in the "overweight" group and "obesity" group the R value was equal to 0.6243 and 0.735, respectively. Our main results are illustrated in the following figures.   Methods: Twenty participants (11 female) had seated BP measured using the Casio BP-100 and a brachial automatic oscillometric BP device at rest and during a 5-min isometric hand-grip exercise. Results: There was no significant difference between the reference device and the BP-100, but a large bidirectional scatter of BP estimation by the Casio BP-100 (average differences 2 ± 20 and -1 ± 19 mmHg during baseline, and -1 ± 21 and 7 ± 23 mmHg during exercise for SBP and DBP respectively). There was poor correlation for both SBP (R = 0.36, p = 0.13) and DBP (R = 0.044, p = 0.37).

Conclusions:
Given the size, low processing power, and long battery life, it is impressive that the Casio BP-100 provided some directional information on BP. It is also one of the few commercial devices to this day using two-point individualisation calibration. Likely in part due to limitations in the algorithms for finding fiducial waveform points, BP estimation was poor. As we look to the future of cuffless BP, we should emulate the positive aspects of the Casio BP-100 whilst looking at ways to improve accuracy.

P.27 Comparison of Quantitative Reflection Indices of Forward-Backward Pulse Wave Decomposition Techniques: A Virtual Subject Study
Mr. Rahul Manoj 1 , Mr. Kiran V Raj 1 , Dr. P M Nabeel 2 , Dr. Jayaraj Joseph 1 1 Department of Electrical Engineering, Indian Institute Of Technology Madras, Chennai, India, 2 Healthcare Technology Innovation Centre-IIT Madras, Chennai, India Background: Studies of the forward-backward propagating pulses in arterial bed provide novel insights into vascular dynamics and clinical conditions. The conventional pulse wave separation techniquesflow-based Wave Separation Analysis (WSAMF) and Wave Intensity Analysis (WIA)-require measured pressure-flow waveforms (1). As alternatives, simplified methods that require pressure wave alone (modelled flow wave (2) or approximated to a triangular wave (WSATF) (3) have gained acceptance. This work compares performance of WIA, WSAMF, and WSATF using established wave reflection indices.

Methods:
Methods' performance was evaluated on virtual subjects' data (4) (N = 500, age: 25-75 years). The pressure and flow waveform were extracted for the left carotid artery. Reflection Magnitude (RM), Reflection Index (RI), Pulse Pressure Backward (ΔPb) and Pulse Pressure Forward (ΔPf ) were obtained and compared for said three methods. Results: Samples of forward-backward pressure waves obtained from all the three methods are illustrated in Fig. 1. The comparative analysis is presented in Table I. Largest deviation in RM and RI was observed between WSATF and WSAMF (14.7% and 8.71%, respectively), and the minimum deviation was between WSAMF and WIA (6.66% and 3.71%, respectively). Deviation for ΔPb and ΔPf among methods ranged between 1.2% -8.34%, with highest deviations against WSATF.

P.28 Evaluation of Arterial Pulse Reflection Parameters using Multi-Gaussian Decomposition Model: Association with Stiffness Markers
Mr Methods: The MGD model decomposes the diameter-scaled pressure waveform into multiple Gaussians for WSA without requiring flow information. The method's functionality was investigated on 100 participants (35 ± 10 years, 50 hypertensives) where diameter measured using ARTSENS (2) were used to evaluate RM and RI. RM and RI are validated by their associations with stiffness markers and screening ability. Fig. 1(a). Separated waves using MGD, (b) Box and Whisker plots for RM and RI comparing normotensives versus hypertensives.

Results:
Adequately high-quality diameter waveforms were captured. The group averages of RM (= 0.69 ± 0.16) and RI (= 40.73 ± 6.1) % were comparable with earlier reported WSA studies (3-4). They exhibited significant correlation (r > 0.5, p < 0.0001) with the stiffness markers: β, elastic modulus, compliance, pulse wave velocity and AIx. Both RM and RI were significantly (p < 0.05) higher for hypertensives than normotensives, by 25.20% and 15.4%, respectively. Conclusion: The study demonstrated the method's functionality in estimating reliable RM and RI that evidently associated with other clinically popular stiffness markers and discriminated between hypertensives and normotensives. Given the advantage that the method requires strictly one pulse waveform alone, its potential clinical and research applications are further being explored. Vascular acute responses to successive bouts of exercise may cumulatively induce exercise-related adaptations in an intensitydependent manner. However, these responses are inconsistent across age groups, and whether there are age or physical activity associated response patterns on brachial artery flow-mediated dilation (FMD) and arterial stiffness indices to high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) remains unknown. We compared the response pattern of FMD and arterial stiffness indices, active young and older adults.

Methods:
Twenty four young (20-40 years; n = 12) and older (57-76 years; n = 12) healthy and active male adults performed an isocaloric acute bout of HIIE and MICE, or a non-exercise condition, in a randomized order. Pre-and-post condition changes in FMD, pulse wave velocity (PWV), and augmentation index (Aix) were analyzed with linear mixed models. Results: Relative FMD was similar between young and older adults but time-to-peak was higher in older adults (d = 14; 95% CI: 4 to 23 s; p < 0.01, h2 = 0.28). Carotid-femoral PWV (cfPWV) (d = 2.16; 95% CI: 1.13 to 3.19 m/s; p < 0.001, h2 = 0.46), and Aix (d = 27.90; 95% CI: 21.27 to 34.50%; p < 0.001, h2 = 0.78) were higher in older compared to young adults. FMD (p = 0.84) and cfPWV (p = 0.85) remained unchanged following HIIE and MICE in both groups (Figure). Conclusions: We found no evidence of age-associated response patterns on FMD and cfPWV to a single bout of HIIE or MICE in physically active young and older adults. Vertical bars correspond to the 95% CI. Open circles correspond to individual responses. There were no significant main effects for FMD (time, condition, group) or interaction effects between factors. A significant group effect for cfPWV was observed (p < 0.001). Technical validation and usability of an innovative, easy-to-use, and portable system to assess carotid function and structure by ultrasound was investigated [3]. Methods: The new integrated system is composed of hardware (the Interson SP-L01 embedded ultrasound probe) and software measuring the instantaneous diameter of the carotid artery in real-time from B-mode ultrasound image sequences (Carotid Studio, by Quipu Srl). 12 healthy volunteers were recruited for the pilot technical validation: intra-operator reproducibility of two acquisitions by an expert operator and agreement with state-of-the-art technique (Mylab25 Esaote and Carotid Studio 4.3) were evaluated. Questionnaires were administered to operators to assess the usability of the new portable integrated system. Results: Agreement with state-of-the-art technique was satisfactory, with no significant bias for the 12 subjects recruited (5 men, 44.5 ± 13.6 years). Coefficient of variation was 3.2% (2.5% SD) for Intima-Media Thickness, 0.9% (0.7% SD) for diameter, and 2.5% (2.2% SD) for distension. An average score greater than 4 on a Likert five-point scale positively reported the usability of our system.

Conclusions:
The innovative prototype for easier assessment of ultrasound carotid parameters of vascular ageing was successfully designed and developed. Usability in this pilot study was also satisfactory. Classical manifestations include changes in microcirculation, but macrovascular involvement hasn't fully understood. Arterial stiffness, measured using pulse wave velocity (PWV), is dynamic property determined by arterial wall structure, endothelial and vascular smooth muscle function, and arterial pressure. This measure is an independent predictor of cardiovascular events. The aim of study is comparison of arterial stiffness in SSc patients and healthy controls.

Methods:
Patients with SSc fulfilled ACR/EULAR 2013 classification criteria. Socio-demographic and clinical data were collected. Arterial stiffness studies was performed (PWV and augmentation index (AI)). In descriptive analysis, ANOVA and Kruskal-Wallis test were used to compare continuous variables and Fisher's exact test for categorical variables. p-value ≤ 0.05 was statistically significant. Results: Twenty-two patients were included (17 female and 5 men; mean age 58.95 ± 8.75) and 11 controls (7 female and 6 men; mean age 50.01 ± 10.09). PWV were significantly increased in SSc patients compared with controls (PWV: 8.08 ± 1.66 vs 6.85 ± 1.84), with significant differences in two groups (p = 0.01). Values of AI as also higher (8.57 ± 7.27 vs 6.26 ± 5.94), however no statistically significant differences was found (p = 0.35). Conclusion: Although we were able to demonstrate significant difference in PWV between two groups, but it was insufficient to detect difference in AI. This suggests that patients with SSc may have an increased prevalence of subclinical atherosclerosis, however more studies with larger sample size are warranted and may be beneficial to assess its evolution over time in order to understand its impact on the clinical outcome.

P.32 Correlation between arterial stiffness and nailfold capillary microscopic abnormalities in systemic sclerosis: results from a single centre cross-sectional study
Dr. Carolina Mazeda 1 , Dr. Susana Silva 1 , Dr. Renata Aguiar 1 , Dr. Anabela Barcelos 1 , Dr. José Mesquita Bastos 1 1 Centro Hospitalar Baixo Vouga, Aveiro, Portugal Introduction: Systemic Sclerosis (SSc) is a rare connective tissue disease with several systemic manifestations characterized by immune dysfunction, vascular abnormalities and fibrosis. Microvascular damage represents the earliest morphological and is a prominent feature of SSc easily accessible by nailfold video-capillaroscopy (NVC). While microangiopathy is well-documented, the macrovascular involvement has not been completely clarified. Arterial stiffness is an independent predictor of cardiovascular events and the carotid-femoral pulse wave velocity (PWV) are considered the gold standard for your measurement. The aim of this study is to assess changes in arterial stiffness and its relationship with NVC abnormalities in SSc patients.

Methods:
All patients included fulfilled ACR/EULAR 2013 classification criteria for SSc. Each participant underwent arterial stiffness studies (PWV and augmentation index(AI)) and NVC (nonspecific, early, active or late). To assess differences of macrovascular indices between NVC patterns, Kruskal-Wallis test was used. The Fisher's exact test was used for categorical variables. p-value ≤ 0.05 was statistically significant. Results: Twenty-two patients were included and clinical characteristics are listed in Table 1. Mean PWV was 8.08 ± 1.66 m/s and AI was 6.85 ± 1.84%. No significant differences between PWV and AI with NVC patterns (p = 0.36 and p = 0.39). Digital ulceration, disease subtype, pulmonary involvement and anti-topoisomerase-I antibodies were found statistically correlated with microangiopathic severity identified in NVC (p < 0.05), but no association was found between these findings and macrovascular indices.
Conclusion: Despite small sample size, wall stiffness parameters measurements don't seem to correlate to microangiopathic features. More studies with larger samples are needed, as well as understanding the evolution of stiffness parameters over time. Only patients with a normal left ventricle and aorta were included. Images from phase contrast MRI of the ascending aorta were segmented to obtain flow and cross-sectional area waveforms (the latter as a surrogate of pressure). Wave separation was performed with a) patient-specific flow, b) triangular flow waveforms with peak at 25% (Tri25) or 30% (Tri30) of ejection time, and c) a representative waveform obtained by averaging individual waveforms after amplitude and time normalisation and forcing late-diastolic flow to zero with a weighting function (Fig. 1). Results: Normalised flow waveforms were highly consistent (Fig. 1). Compared with reflection magnitude (ratio of backward/forward wave amplitude) using patient-specific flows (0.58 0.17), Tri25 and Tri30 differed by -13.2 7.5% (P < 0.001) and -6.1 9.8% (P = 0.003), but the representative waveform was no different (0.6 5.3%, P = 0.7). Conclusions: A representative population flow waveform is suitable for wave separation in children and adolescents, and provides superior accuracy compared with the triangulation approach.

P.34 Cross-sectional comparison of office and ambulatory pulse wave velocity by two methods, and their changes after lifestyle or medical interventions in hypertension
MD, Phd János Nemcsik 1 , MD Dóra Batta 1 , MD Beáta Zita Kőrösi 1 , Helga Gyöngyösi 1 , Zsófia Nemcsik-Bencze 1 , MD, PhD Andrea László 2 , MD, PhD Orsolya Cseprekál 1 , MD, PhD András Tislér 1 1 Semmelweis University, Budapest, Hungary, 2 Jula/Schindler praxis, Nurenberg, Germany Objective: Pulse wave velocity (PWV), the most accepted biomarker of arterial stiffening can be measured by different methods and in the past decade its 24-h monitoring has also become available. The aim of our study was to compare office and ambulatory PWVs and in a proportion of patients to compare the changes of PWVs after the initiation of lifestyle modifications or antihypertensive medication. Conclusions: The significant differences observed both in the crosssectional and in the prospective parts of our study suggests that the two methods are not interchangeable. Department of Internal Medicine, Iowa City, United States Background: Women with a history of preeclampsia (hxPE), a hypertensive pregnancy disorder, exhibit greater aortic stiffness postpartum compared with healthy pregnancy (HP). Greater relative carotid artery (CCA) compared with the aorta maintains a stiffness gradient that attenuates propagation of deleterious pulsatile pressure into the microcirculation.1 However, the relation between large artery stiffness, pulsatile hemodynamics and microvascular function among women with hxPE is unknown.

Conclusions:
HxPE is associated with greater large artery stiffness and attenuation of the CCA/aortic stiffness gradient. This may contribute in part to distal transmission of pulsatile pressure, reduced microvascular perfusion, and target-organ damage in women with hxPE.  (ABI) is currently the gold standard. However, ABI is time consuming and requires some expertise to perform which is a limiting factor for global screening. The measurement of the Systolic Rise Time (SRT) of the pulse wave of the lower limb may provide an easier alternative to detect PAD. In a retrospective pilot study, we analyzed the possibility of detecting PAD using the SRT of the toe waveform using the Photo-PlethysmoGraphic signal (PPG).

Methods:
We measured 79 subjects (41 patients diagnosed with different stages of PAD and 38 healthy volunteers without known PAD). In each subject, at least one lower limb was assessed with classical ABI (minimum of 2 tibial arteries using a Doppler probe). All subjects underwent a PPG assessment on the finger and the toe simultaneously using pOpmètre ® (Axelife-France). In-house software (JAVA) was used to calculate the SRT of all recorded signals.

Results:
From the 154 lower limbs recorded, 8 were excluded for technical reasons: problematic cuff measurement of the ABI (in very severe PAD, medial calcification & amputation) or bad quality of the PPG signal with very low amplitude. Finally, 146 lower limbs were analyzed including 72 healthy and 74 subjects with PAD. The mean age of the population was 69 ± 12 years with 75% men, 28% diabetics, 47% hypertensive, 49% without clinical PAD defined as stage 0 in this study; 16% in stage 1; 32% in stage 2; 2% in stage 3 and 1% in stage 4 according to the Leriche classification. The SRT cut-off value of 160 ms identifies PAD according to Leriche starting at stage 1 with a sensitivity of 78% vs 73% for ABI < 0.9 and a specificity of 86% vs 87%; a positive predictive value (PPV) of 85% vs 86% and a negative predictive value (NPV) of 79% vs 75%. In addition, the ratio between toe-SRT and finger-SRT cut-off value of 1 identifies PAD with a sensitivity of 76% and a specificity of 74%. Conclusion: SRT measured using a PPG pulse signal of the toe is promising as a facile non-invasive method to diagnose PAD (duration < 14 s) and determine PAD stages 1 to 4 with similar specificity and sensitivity as the reference method. These results need to be confirmed through a prospective study. Methods: MMTV-TGF-α mice fed ad libitum (AL) divided into 3 groups; ad libitum(AL), chronic CR fed with %15 restriction of AL group, intermittent CR group fed AL for 3 weeks (ICR-ReFeed) which followed by %60 restriction for 1 week (ICR-Restricted). Mice euthanized at 10, 17/18 and 49/50 weeks and blood and aorta were collected respectively. Blood miRNA profile obtained by microarray (n = 3). Differentially expressed miRNAs were analyzed and miRNAtap package was used to obtain miRNAs targeting TG2 gene. TG2 levels of aorta were determined by western blot (n = 4). Results: Compared to AL group at week 10, TG2 targeting miRNAs: miR-484, miR-700-5p and miR-423-5p were expressed statistically significant increase in ICR-R group at week 49/50. 17 weeks AL mice had increased TG2 protein levels compared to 10 weeks. However, the levels were decreased at 50 weeks group compared to both time points. CCR group had increased TG2 levels with ageing. ICR-R groups remained lower than CCR at both 17/18 and 49/50 week. Conclusion: These results may provide a translational insight for understanding the roles of TG2 in vascular ageing and mechanism of epigenetic regulations by CR on providing better vascular health. In future studies, miRNAs that evaluated in this study will be validated in aorta samples to have more perception. Purpose/background/objectives: Aortic stiffness (AS) has been associated with accelerated cognitive decline, possibly due to increased cerebral blood flow (CBF) pulsatility and resulting microcirculatory damage. Hence, this study aimed to examine the association between aortic and carotid stiffness and their impact on the CBF pulsatility in a group of subjects composed of healthy controls and patients with chronic kidney disease (CKD), covering a wide range arterial stiffness measures.

Methods:
In 19 participants aged 61 19 years (12 male, 13 CKD), we evaluated AS by carotid-femoral pulse wave velocity (CF-PWV). Common carotid diameter and distention (echotracking) and local pulse pressure (tonometry) were used to derive carotid pulse wave velocity (C-PWV) based on the Bramwell-Hill equation. Middle cerebral artery blood flow velocity (MCAv) was determined using transcranial Doppler ultrasound. MCAv pulsatility index (PI) was computed as (systolic MCAv-diastolic MCAv/mean MCAv. Spearman-rho correlation coefficients were examined to assess the extent of associations between stiffness parameters and MCAv PI.

Results:
The CF-PWV and C-PWV were respectively 11. was significantly associated with C-PWV (r = 0.645, p = 0.004), however the association with CF-PWV did not reach significance (r = 0.447, p = 0.055). There was no association between MCAv PI and aortic-tocarotid PWV ratio (r = − 0.257, p = 0.303). Conclusions: This preliminary data shows a strong correlation between carotid stiffness and CBF pulsatility.  1-3). In fact, it was previously shown that mis-sensing of mechanical stimuli play a major role in ATAA (2,4). Accordingly, there is a pressing need to quantify the mechanobiological effects of the changes operating at single cell level.

Methods:
To address this need, we applied a previously developed Traction Force Microscopy (TFM) technique (5,6) on primary human aortic SMC, extracted from three healthy and three aneurysmal donors with matching age and gender. We measured the cell basal tone by measuring the traction forces applied by each SMC onto compliant hydrogels of different stiffness (4, 8, 12, 25 kPa), with embedded fluorescent microbeads (Matrigen, Softwell ™ 24, collagen pre-coated, Softrack 0.2 µm Y/G).

Results:
Although the range of measured force suggested some heterogeneity, we observed that: 1. the traction forces increased with the substrate stiffness; 2. For aneurysmal SMC, traction forces were significantly higher than for healthy ones. We also found the existence of larger traction forces in the aneurysmal SMC were related to the larger size of these cells (6).

Conclusion and perspectives:
We conclude that there is a reduced expression of elongated and contractile SMCs in ATAA. This tends to promote stronger SMCs, which are less responsive to vasoactive agents. Future work aims at understanding further these alterations in aortic aneurysms. Here, we aim to analyze and compare the DM patients' flow dynamics to healthy control using a computational model. We also aim to find out the effects of wall roughness on the WSS for the DM patient model. Methods: Two different in silico models have been generated and simulated using computational fluid dynamics (CFD). For simplicity and isolate the geometrical contribution into the hemodynamics, idealized coronary artery models have been designed. Results: WSS is higher at the proximity of the wall compared to the center of the artery for all cases: healthy control, DM patient and rough and smooth wall. Preliminary results of our study show that the natural wall roughness does not cause any SAWSS change for neither DM patients nor healthy subjects. But when the wall roughness is around 3•10 -4 m, the SAWSS decreases moderately. Discussion: After deployment, stents can have and cause roughness [2]. Actually, these roughness values can be changed by designing novel stents or bypass grafts. Decreasing the WSS values around the stenosis region could help to improve the outcome of interventions or surgical operations.

P.42 Effect of COVID-19 disease on vascular aging: a pilot study with before-and-after comparison in persons who have had COVID19.
Podrug M 1 , Koren P 2 , Šunjić B 1 , Mudnic I 2 , Boban M 2 , Jerončić A 1 2 University of Split School of Medicine, 1 University of Split Department of Health Studies Background: While respiratory symptoms dominate clinical manifestations of COVID-19 disease, the disease also affects the cardiovascular system at multiple levels. The aim of this study was to evaluate individual before-and-after COVID19-induced changes in vascular-aging biomarkers.
Methods: Previously, we collected data on baseline values of arterial stiffness and central and peripheral hemodynamic measures; in participants who were afterwards infected with SARS-CoV-2. Fifteen (7 men) agreed to an additional visit that was scheduled at median 2.4 months (range 1.8-3.1) after person acquired infection (determined by the positive PCR test). SphygmoCor-CvMS and Arteriograph were used to acquire the data in duplicate.

Results:
The median age of participants was 35 years (range 24-61), and median time-span between the visits was 5 months (3-16). Regardless of limited sample size, we showed that after COVID-19 infection there was a significant mean increase of diastolic (5 mmHg, 95%CI 0.6-9) and mean arterial pressure (4 mmHg, 95%CI 0.1-8) recorded with Arteriograph; and median increase in aortic AIx (4%, 95%CI -2%_to_6%) recorded with SphygmoCor (p < 0.05 for all). We also found a strong association between the time from infection, and variability of pulse wave velocity or end-systolic pressure (Kendall's_τ ≥ 0.418, p ≤ 0.035). For several measures, the intensity of changes depended on age.

Conclusions:
The results suggest widespread, complex changes in vascular biomarkers after the COVID-19 infection. While small sample size limits the certainty of our findings, overall the study prompts for implementation of powered, larger studies with adequate follow up to fully assess the effect of COVID-19 disease on vascular aging.

P.43 Prevalence of fibromuscular dysplasia in radial arteries of cerebral aneurysms through ultra-high frequency ultrasound: a radiomic approach
Biomedical  (FMD) (1). We recently identified a pattern of vascular wall disarray and remodeling in radial arteries strongly and specifically associated with FMD. The aim of this study was to determine the prevalence of this pattern in radial arteries of patients with cerebral aneurysms.
Methods: 10 end-diastolic frames (5 left, 5 right) of the radial arteries of 30 patients with aneurisms and 24 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). The same logistic regression (LR) model developed to discriminate FMD patients was used in this cohort. The possible association between this classification and the presence of ruptured aneurysm, multiple aneurysm and aneurysm size were investigated. Results: Inner layer (196 ± 51 vs 160 ± 39 mm, p =) and outer layer thickness (115 ± 45 mm vs 101 ± 41 mm, p =) were significantly higher in aneurysms than in controls. Triple signal was also more frequent in aneurysm than in control images (p =). 17 patients with aneurysms (56.6%) were classified as FMD by the LR model. There was no significant association between classification as FMD and ruptured, multiple aneurysms, aneurysm size. Conclusions: More than half patients with cerebral aneurysm showed a radial artery pattern associated with FMD; this finding suggest that a non-negligible proportion of patients with cerebral aneurysms may be part of the socalled FMD spectrum.

P.44 Validation and feasibility of an automated system for the assessment of vascular structure and mechanical properties in the digital arteries through ultra-high frequency ultrasound
Introduction: The impact of alterations in arterial flow and pressure on the derived reservoir and excess pressure are not fully understood yet. The aim of this work was to generate pressure waveforms using a 3-element Windkessel model and apply the reservoir algorithm to analyze the changes in the output by varying the input parameters of flow and Windkessel.
Methods: An artificial flow curve (aF) was built, depending on the height (Fmax), time (tFmax) of its peak, and the ejection duration (ED). Pressure curves were afterwards simulated using aF and a 3-element Windkessel (peripheral resistance (R), compliance (C), aortic resistance (Z) and asymptotic pressure (P ∞ )). The reservoir algorithm then was applied to the simulated pressure waves (1). By parameter variation, a sensitivity analysis on reservoir pressure (P res ) and excess pressure (P ex ) was conducted. If the difference between every respective pair of output curves was below a certain threshold, the curves were counted as not being affected by the parameter variation.

Results:
The sensitivity analysis of parameter variations (Fig. 1) shows that P ex is mostly sensitive towards t Fmax , ED, and Z, while P res is sensitive towards R, C and P ∞ . When varying several parameters at once, cancelling effects of certain combinations were found. Discussion/conclusion: The sensitivity analysis revealed that P res is mostly affected by Windkessel parameters, except for Z, while P ex is mostly affected by Z and flow parameters. However, P res and P ex also partly depend on the remaining parameters. The variation of parameters also revealed cancelling effects of certain combinations.

Fig. 1
Results from sensitivity analysis: left P res , right P ex . The y-axis shows the normalized count of pairs of curves that remained similar (mean square error < 1 for P res , mean square error < 0.25 for P ex ), despite changes in the input parameter that are shown on the x-axis.

P.46 The Role of Blood Pooling during Prolonged Sitting on Cerebral Arterial Stiffness
Alexander Pomeroy 1 , Katie Stanford 1 , Dr. Lee Stoner 1 1 University of North Carolina At Chapel Hill, Chapel Hill, United States Purpose: Vascular dementia (VaD) affects 15% of people 80 + years old. A primary risk factor for VaD is atherosclerosis of the cerebral arteries. Prolonged sitting has been associated with precursors of atherosclerosis, including arterial stiffening (AS) and acute reductions in cerebral blood flow (CBF), but the mechanism for cerebral hemodynamic changes is unclear. Venous blood pooling (VBP) in the calves due to gravity has been suggested as a potential cause for acute hemodynamic changes in the central vasculature, but the claim hasn't been evaluated in the cerebral vasculature. Radboud university medical center, 2 University Twente Background: Rupture of carotid artery plaques may lead to stroke. Plaques with a large lipid-rich core are more prone to rupture than predominantly fibrous plaques. Noninvasive detection of lipid-rich cores is challenging, but promising results have been reported using ultrasound shear wave elastography (SWE)(1,2). However, no available SWE method enables stiffness estimation, and thus, lipid-core detection, for the entire circumference. We introduce a SWE method designed for 360°-stiffness mapping and evaluate its performance in a carotid artery phantom.

Methods:
A vessel-mimicking phantom with a stiff outer and soft inner layer (lipid-core) was created by freeze-thawing polyvinylalcohol solutions. An Aixplorer Ultimate system (Supersonic Imagine, France) with an SL18-5 transducer and research interface was used to perform SWE acquisitions in transverse cross-sections of the phantom. The 360° circumference was divided in segments. Custom-made software was developed to track the wave circumferentially in every segment, instead of along straight horizontal paths (current SWE approaches). Additionally, we investigated if segment-wise electronic ultrasound beam-steering improved tracking. Obtained 360° shear wave velocity (SWV) maps were compared to a reference map constructed from SWE data acquired by physical phantom rotation. Results: Without steering, the new method provided SWV estimates with a median absolute error of ~ 0.5 m/s for ~ 60% of the circumference. With steering, this area increased to 80%. The soft layer could clearly be identified. Conclusions: A novel SWE method was introduced that enabled accurate SWV estimation in ~ 80% of the cross-section of a vessel-mimicking phantom. Next the method will be tested in real carotid arteries.

P.49 Comparison of artery wall motion-based vascular index with conventional carotid stiffness markers for detection of vascular ageing
Mrs R Arathy 1 , Mr V Raj 2 , Dr P M Nabeel 1 , Dr Jayaraj Joseph 2 1 Healthcare Technology Innovation Centre-IIT Madras, Chennai, India, 2 Dept. of Electrical Engineering, Indian Institute of Technology Madras, Chennai, India Background: Large artery stiffness is a proxy for age-related vascular degradation and related events. Vascular ageing index (VAI), a metric of stiffness evaluated by pulse contour analysis of acceleration plethysmogram, was introduced to assess vascular ageing(1), but commonly used photoplethysmogram do not precisely capture artery wall dynamics. This study explores VAI assessment using precise carotid diameter recorded using an image-free ultrasound device (ARTSENS ® ) (2).

Methods:
A cohort of 445 subjects (20-79 years) were recruited. Left common carotid diameter and blood pressure were recorded. VAI was estimated from carotid diameter adopting established methods (3).
Age-trends of VAI were compared with conventional stiffness markers (2) for normotensives/hypertensives and males/females. Results: Group average VAI (− 0.64 ± 0.48) measured were within the expected range (1),(4). Carotid stiffness markers (r > 0.82, p < 0.01) and VAI (r = 0.6, p < 0.01) were significantly correlated with subjects' age. Concomitant with stiffness markers, VAI manifested an increasing age trend ( Fig. 1) with more negative values for younger populations. There was no significant difference for VAI (p > 0.05) between normotensive/hypertensive and male/female except for age ≥ 60 and 40-49 year's group (p < 0.05), respectively. Males showed higher VAI than females across age groups, whereas the trend was inverted for stiffness markers.

Conclusion:
Reliably evaluated VAI from ARTSENS ® carotid diameter demonstrated an age-related trend similar to stiffness markers. This suggests that the index obtained from diameter alone yields agerelated modifications of large arteries. However, unlike the stiffness markers, the rate of increase in VAI was attenuated for the older population. Further studies are in progress to assess clinical utility and evaluate the predictive capability of VAI for monitoring vascular ageing.

P.50 Effect of the pharmacological reduction of heart rate by ivabradine on arterial wall viscosity in young and middle-aged healthy subjects
Dr Frédéric Roca 1 , Dr Michèle Iacob 1 , Mrs Caroline Thill 1 , Pr Jeremy Bellien 1 , Dr Robinson Joannides 1 1 Rouen University Hospital, Rouen, France Purpose/background/objectives: Changes in arterial wall viscosity (AWV), which dissipates the energy stored within the arterial wall, may contribute to the higher cardiovascular risk and arterial stiffening associated with high heart rate (HR) and to the controversial benefit of HR reduction during aging. We evaluated the effect of ivabradine, a selective HR-lowering agent, on carotid AWV considering changes in arterial mechanics and hemodynamics, and aging impact on this effect.

Methods:
This randomized, placebo-controlled, double-blind, crossover study, performed in 19 healthy volunteers (8 young and 11 middle-aged), evaluates the effect of ivabradine (5 mg b.i.d, one week) on carotid AWV, mechanics and hemodynamics and cardiovascular coupling. AWV was evaluated by the area of the hysteresis loop of the pressure-cross sectional area relationship, representing the energy dissipated (W V ), and by the relative viscosity (W V /W E ), with W E representing the elastic energy stored. Results: Ivabradine increased stroke and end-diastolic volumes, augmentation pressure, augmentation index, Buckberg index and carotid distensibility compared to placebo. In parallel, W V and W E increased, and W V /W E remained stable. In middle-aged, baseline arterial stiffness and cardiovascular coupling were less favorable, W E was similar but W V and thus W V /W E were lower than in young subjects. Ivabradine induced an increase in W V /W E in middle-aged subjects but not in young, due to a higher increase in W V, despite similar increase in W E . Conclusions: Ivabradine-induced HR reduction increases arterial wall energy dissipation proportionally to the increase in elastic energy stored. Aging results in a larger than expected relative energy dissipation, the impact of which should be assessed. Registration: URL: https:// clini caltr ials. gov/ ct2/ show/ NCT02 584439, Identifier: 2015/077/HP. , and than HIIPE24h (32.2 ± 1.9). SystolicBP (2 h) reduced after both sessions -MICPE (128 ± 2) and HIIPE (127 ± 2 mmHg), compared to baseline (131 ± 2 mmHg; p = 0.02). There was no difference in PWV among times, and between individuals with normal BP and high normal BP.

P.53 Comparison of vascular and hemodynamic responses between a continuous exercise session of moderate intensity and high intensity interval exercise in normotensive individuals.
Miss Sara Rodrigues 1 , Miss Renata Verardino 1 , Mr Marcel Costa 1 , Miss Valéria Costa-Hong 1 , Miss Maria Alves 1 , Mr Luiz Bortolotto 1 1 InCor HC FM USP, Sao Paulo, Brazil Introduction: Moderate-intensity continuous aerobic physical exercise (MICPE) is known to help prevent hypertension, due to its postexercise hypotensive effect 1. High-intensity interval physical exercise (HIIPE) has shown positive results in preventing cardiovascular disease. Arterial stiffness, measured by pulse wave velocity (PWV) is a marker of cardiovascular risk 2, related to blood pressure (BP). There is no consensus on the possible changes in PWV after a physical exercise session.

P55. Evaluation of image-free wall tracking based measurement of low flow mediated arterial constriction in comparison to B mode imaging
Ms Sakshi Sen 1 , Mr V Raj 2 , Dr P M Nabeel 3 , Dr Dinu S Chandran 1 , Dr Jayaraj Joseph 2 , Dr Kishore K Deepak 1 1 Department of Physiology, All India Institute of Medical Sciences, New Delhi, India, 2 Dept. of Electrical Engineering, Indian Institute of Technology Madras, Chennai, India, 3 Healthcare Technology Innovation Centre-Indian Institute of Technology Madras, Chennai, India Background: Low flow mediated constriction (LFMC) has been reported as a promising non-invasive tool for assessing the endothelial functioning in resting state (1). LFMC is the constriction shown by a peripheral conduit artery in response to decreased blood flow through the lumen produced by distal circulatory arrest. LFMC is conventionally performed with B-mode ultrasound systems that involve recording of the image sequences as DICOM files or video-graphic files and processing them offline. We did a pilot evaluation to assess the correlation of imaging free wall tracking based measurements of LFMC with that of B mode imaging.
Methods: 29 healthy young adults (25.45 ± 2.58 years, 17 men] participated in the study. Brachial artery LFMC was measured using simultaneous and sequential protocols; imaging (M7, Mind Ray; Nanshan, Shenzhen, China) and wall tracking (ARTSENS ® ) based measurements were done in the same anatomical location with a gap of 30 min between the two measurements (sequential protocol) and imaging and wall tracking measurements done simultaneously at two contiguous locations (simultaneous protocol). Results: LFMC responses showed strong positive correlation between ultrasonographic imaging and wall tracking based measurements when done simultaneously (r = 0.96, p < 0.001) and modest correlation when done sequentially (r = 0.59, p = 0.02) as shown in Fig. 1. Conclusion: Wall tracking based measurements of brachial artery LFMC correlates strongly with imaging based measurements when recorded simultaneously. The study demonstrated that the wall tracking based ARTSENS ® technology can be reliably employed for performing LFMC and assessing endothelial dysfunction. Fig. 1 Correlation between %LFMC measured by B mode imaging and image free wall-tracking in sequential and simultaneous protocols.

P.56 Preserved muscle extraction during maximal exercise in active breast cancer survivors.
Sara Sherman 1 , Georgios Grigoriadis 1,2 , Bo Fernhall 1 , Tracy Baynard 1 1 Integrative Physiology Lab, University of Illinois at Chicago, Chicago, United States, 2 Department of Physical Therapy, Chicago, United States Introduction: Mitochondrial capacity is pivotal to skeletal muscle function and is altered with breast cancer treatment. Physical activity may ameliorate the detrimental effects of such treatments on muscle function.
Objectives: This pilot study investigates the repeatability and accuracy of BP estimation from PTT using contact-based photoplethysmography (PPG) and tonometry. Methods: Six subjects performed one-minute seated rest and 3-min isometric handgrip exercise on two consecutive days. Continuous finger BP was recorded. A PPG sensor was placed adjacent to a tonometer on the temporal pulse and a second PPG sensor on the left index finger and tonometer on left radial pulse. Beat-to-beat PTT was calculated for tonometry and PPG as the delay between the foot of temporal and wrist/finger signals. DBP/PTT linear regression on day 1 was used as calibration for prediction of DBP from PTT on day 2, and the regression from day 2 applied retrospectively for day 1. DBP was predicted using every 1, 5, 10, 20 and 30 beats observations. Predicted DBP was compared to measured finger DBP. Results: Isometric exercise successfully increased DBP (average increase 23 ± 11 mmHg). The minimum error of DBP estimation from PPG sensors was from 30-beats long observations (MAE ± ESD = 15 ± 0.5 mmHg) and from tonometers was from 20-beats long observations (MAE ± ESD = 13 ± 1 mmHg). Conclusion: Cuffless BP estimated from PTT measured by PPG and tonometry provide a large error. In comparison, tonometry provides slightly better results as it requires less number of beats for estimation.

Dr. Anna Torunova 1 1 Irkutsk State Medical Academy of Postgraduate Education-Branch Campus of the FSBEI FPE RMACPE MOH Russia, Irkutsk, Russian Federation
The aim: to study the dynamics of the relationship between aortic stiffness and nighttime BP decrease during the hypertension (HTN) treatment.

Methods:
The 24-h BP monitoring was conducted in 189 patients (101 men and 88 women, aged 50.8 ± 8.3) with untreated HTN. Dipping status, central BP (cBP), augmentation index (AIx), carotid-femoral pulse wave velocity (PWV) were determined. Then the patients were assigned to standard antihypertensive therapy. The studies were repeated after 6 months of treatment. Spearman correlations between parameters of aortic stiffness and diurnal index (DI) were calculated twice-at baseline and at the end of follow-up period. Results: During the treatment the average daily BP decreased from 143.6 ± 14.7/88.1 ± 11.1 to 123.9 ± 10.3/76.0 ± 7.2 mmHg, cBP-from 149.8 ± 19.4/98.3 ± 11.6 to 121.3 ± 14.0/83.2 ± 8.7 mmHg, AIx -from 25.9 ± 9.8 to 20.6 ± 12.2% and PWV from 9.2 ± 1.8 to 8.4 ± 1.5 m/s. Initially there were 117 (61.9%) dippers, 42 (22.2%) non-dippers, 22 (11.6%) over-dippers and 8 (4.3%) night-pickers. After 6 months of treatment, the proportion of dippers decreased from 61.9 to 48.1% while nondippers increased from 22.2 to 32.2% (p = 0.01). At baseline, systolic DI correlated with systolic cBP (r = − 0.22, p = 0.002), AIx (r = − 0.15, p = 0.046), PWV (r = − 0.14, p = 0.048). The diastolic DI correlated with diastolic cBP (r = − 0.23, p = 0.001) and AIx (r = − 0.22, p = 0.003). After 6 months of treatment there were no correlations between aortic stiffness and nocturnal dipping parameters. Conclusion: In untreated HTN patients, the degree of nighttime BP decrease declines as aortic stiffness increases. Antihypertensive therapy leads to a loss of this relationship. Background: Blood pressure (BP) control is an important treatment strategy in reducing arterial stiffness, as with lower BP the cyclical pressure-load on the arterial wall is reduced [1]. There is increasing evidence that anti-hypertensive drugs which antagonize the reninangiotensin system (RAS) are superior in reducing arterial stiffness compared to other anti-hypertensive drugs [2]. In the current longitudinal follow-up study, we investigated if RAS-inhibitors reduced arterial stiffness more than other types of anti-hypertensive drugs.
Methods: Data was obtained from the Hypertensive Unit of two Italian hospitals (north Italy, n = 447, and Pisa n = 101) [3]. Carotid-femoral pulse wave velocity (cfPWV), brachial BP, and information on several confounders were obtained as part of clinical follow-up routine. Associations between ΔcfPWV and anti-hypertensive drugs class were assessed using multivariable linear regression analysis adjusting for age, sex, Δmean arterial pressure (MAP), Δheart rate, lifestyle factors, and use of other medication. Since cfPWV is intrinsically pressure dependent, we additionally performed our analysis replacing cfPWV with a pressurecorrected counterpart (carotid-femoral stiffness index β 0 , [1]).
Results: Participants had a mean age of 54 ± 12 years, 47.1% were female, and mean follow-up time was 45 ± 8 months. A total of 431 participants used RAS-inhibitors at follow-up (32.5% RAS-inhibitor only, 67.5% combination therapy). Neither ΔPWV nor Δβ 0 was associated with the use of RAS-inhibitors in the regression models (p = 0.33, p = 0.68 respectively; Table). Conclusion: RAS-inhibitors did not have a favorable effect on arterial stiffness progression compared to other types of antihypertensive drugs. Our next step is to evaluate cfPWV/β 0 changes in individuals starting RAS-inhibitors.

P.60 Central arterial pressure: validation of new cost-effective device against sphygmocor
Dr. Valentina Vassilenko 1,2,3 , Andreia Serrano 1,2,3 , Filipa Cardoso 1,2,3 , Dr. Pedro Cunha 3,4,5 1 Nova School of Science and Technology, Nova University of Lisbon, Caparica, Portugal, 2 NMT, S.A., Caparica, Portugal, 3 Iberian Network on Arterial Structure, Central Hemodynamics and Neurocognition,, Portugal, 4 Internal Medicine Department, Center for the Research and Treatment of Arterial Hypertension and Cardiovascular Risk, Guimarães-Centro Hospitalar do Alto Ave/Minho University, Guimarães, Portugal, 5 Life and Health Science Research Institute (ICVS), School of Health Science, University of Minho, Braga, Portugal Central aortic pressure (CAP) is an important marker to evaluate blood pressure to prevent cerebral vessels diseases as the most frequent causes of stroke and dementia.
A new small and cost-effective device, recently developed in our group, uses a novel wireless technology for non-invasive CAP estimation without special clinical training. Referred device was calibrated against invasive CAP measurements in the hemodynamic room. Based on European Society Cardiology guidelines [1], its alternative validation was performed by comparison with another clinical device as the reference standard (Sphygmocor), and calibration of both devices with the same brachial blood pressure (BP), to assess inter-device concordance. The measurements were performed in Hospital Senhora da Oliveira de Guimarães, Portugal, in a sample of 68 adults, between 20 and 88 years old with a gender distribution of 46% female and 54% male, over a following range of BP: estimated central SBP was ≤ 100 mmHg (7% of readings), ≥ 140 mmHg (13% of readings), and ≥ 160 mmHg (3% of readings); estimated central DBP was ≤ 60 mmHg (1% of readings), ≥ 85 mmHg (31% of readings), and ≥ 100 mmHg (3% of readings). From the analysis of obtained results was concluded that CAP measured by novel device fulfill the proposed pass criteria [1]: data for mean difference between devices was 0.93 mmHg (< 5 mmHg) and a standard deviation of the difference of 7,9 mmHg (< 8 mmHg). From another side, the present CAP measurements may contribute to the database of Guimarães/Vizela study on determining blood pressure in a Portuguese cohort [2]. Recently an extensive clinical experience on flap surgery has confirmed that its success depends on correct identifying 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.
In this work the principles of two non-invasive technologies with the capability to localize the cutaneous perforators are described and analysed: i) ultrasound technology realized in hand-held nondirectional 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; ii) Infrared Thermography (IRT) as an imaging technique that can provide indirect and real-time information on skin perfusion by measuring body surface temperature. Both technics were applied in this work for the identification of forearm cutaneous perforator vessels (CPVs). 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 (Super High Resolution). 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].

P.62 Correlation of coronary artery calcium-and different cardiovascular risk score-based methods for the estimation of vascular age
Dr. Milan Vecsey-Nagy 1 , Dr. János Nemcsik 1 Heart and Vascular Center of Semmelweis University, Budapest, Hungary Abstract Background: A number of methods are available for the calculation of vascular age, including those derived from the Framingham Risk Score (FRS) and Systematic Coronary Risk Evaluation (SCORE). Recently, coronary artery calcium score (CACS) was proposed as a means of assessing biological age. Our aim was to compare these approaches for the assessment of vascular age. Methods: 241consecutive patients were enrolled who underwent coronary CT angiography due to suspected coronary artery. CACS was calculated using the Agatston method. FRS-, SCORE-, and CACSderived vascular age were defined according to previously described methods. Results: The mean age of our patient cohort was 57.4 ± 11.2. The median vascular age based on FRS, SCORE, and CACS were 68.0 (55.0-82.0), 63.0 (53.0-75.0), and 47.1 (39.1-72.3) years, respectively, and all comparison combinations proved to differ significantly among the 3 methods (p < 0.001). FRS-and SCORE-derived biological age showed strong correlation (r = 0.84), while vascular age based on CACS moderately correlated with FRS and SCORE (r = 0.50, r = 0.52; respectively). Based on FRS, SCORE, and CACS 83.4%, 93.8%, and 42.3% of the subjects had increased vascular age compared with chronological age (FRS + , SCORE + , CACS +), and 53.2% of the FRS + (107/201) and 57.1% of the SCORE + (129/226) groups were classified as CACS-. Conclusions: CACS can be conveniently used to calculate vascular age, however, it demonstrates a tendency of underestimation as compared to traditional risk equations. Prospective studies are warranted to further evaluate the contribution of CACS-based vascular age calculations to coronary risk assessment.

P.63 Carotid artery reactivity to predict cardiovascular events in abdominal aortic aneurysm patients: Preliminary results
Msc. Jenske JM Vermeulen 1,2 , PhD Suzanne Holewijn 1 , MD PhD, Prof Michel MPJ Reijnen 1,3 , PhD, Prof Dick TH Thijssen 2 1 Department of surgery, Rijnstate, Arnhem, Netherlands, 2 Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, Netherlands, 3 Multimodality Medical Imaging Group, Techmed Centre, University of Twente, Enschede, Netherlands Background: The SMART risk score calculates the risk to develop major cardiovascular events (MACE) in cardiovascular disease patients. The efficacy of this tool for abdominal aortic aneurysm (AAA) patients is unknown, while they often develop MACE. MACE is strongly linked to vascular health, which can be measured with the carotid artery reactivity (CAR)-test. Therefore, this study investigates the predictive capacity of the CAR-test for the occurrence of MACE in AAA patients compared to the SMART risk score.
Method: In this study, 167 patients who are under surveillance for AAA were included. All patients underwent the CAR-test to assess carotid artery diameter changes to sympathetic stimulation. Follow-up data was obtained including aneurysm progression and MACE. MACE was defined as myocardial infarction, transient ischemic attack, angina pectoris, atrial fibrillation de novo and aortic valve stenosis. Results: This interim analysis had a median follow-up of 44  weeks. Nine patients (5.4%) experienced ≥ 1 MACE, five patients (3.0%) died and 144 patients (86.0%) experienced no event during follow up. SMART risk score was highest in patients who died (60.9%, [46.8-92.3]) and in the MACE group (48.7%, [40.6-75.0]). The MACE group showed the largest dilation during CAR-test (4.5%, [1.7-5.4]) and AAA progression (6.2 mm/year, [3.0-15.6]). Conclusion: In conclusion, these preliminary results suggest a relation between the CAR-test and the development of MACE in AAA patients. Patients who developed MACE showed an average dilation of the carotid artery in contrast to literature. Completion of this study should determine whether and to what extent this is a predictor for MACE. P.64 New method to estimate central systolic blood pressure from peripheral pressure Chemla D 1 , Millasseau S 2 , Hamzaoui O 1 , Teboul J 1 , Monnet X 1 , Michard F 3 , Jozwiak M 4 1 Medical Faculty Paris-Saclay, 2 Pulse Wave Consulting, 3 MiCo, 4 APHP Cochin-Paris University Objective: Cardiovascular complications may be more closely related to central than peripheral blood pressure (BP). The noninvasive estimation of central systolic BP (cSBP) is increasingly performed using new devices based on various pulse acquisition techniques and mathematical analyses. These devices are calibrated assuming unchanged mean (MBP) and diastolic (DBP) BP from aorta to peripheral artery, an assumption which is evidence-based. We tested the accuracy and precision of a new empirical formula for the Direct Central Blood Pressure estimation of cSBP (DCBP) using MBP and DBP only.

Methods and Results:
First, we performed a post-hoc analysis of our prospective high-fidelity pressure database (n = 139, age 49 ± 12 years, 78% males). The measured aortic CSBP was 146.0 ± 31.1 mmHg. The error between aortic DCBP and aortic cSBP was − 0.9 ± 7.4 mmHg, and there was no bias across the cSBP range (82.5-204.0 mmHg). Second, we retrospectively analyzed 64 patients from the only two independent studies of the literature in whom high-fidelity pressures were simultaneously obtained in the aorta and brachial artery. The weighed mean error between brachial DCBP and aortic cSBP was 1.1 mmHg. Finally, 30 intensive care unit patients equipped with radial intra-arterial fluid-filled catheter were prospectively studied. The cSBP (115.7 ± 18.2mmHg) was obtained by carotid tonometry. The error between radial DCBP and carotid cSBP was − 0.4 ± 5.8 mmHg and there was no bias across the range. Conclusion: Our study shows that cSBP could be reliably estimated from peripheral MBP and DBP without the need for any supplementary device or waveform recording, providing MBP and DBP measurement errors are minimized. The recently established association of quinolone use with the formation and rupture of aortic aneurysms is critical not only due to the widespread use of quinolones but also due to the severity of the induced disease. Arterial biomarkers are established predictors of cardiovascular events. The present study is designed to investigate for the first time the effect of quinolones on arterial stiffness and aortic size.
Methods/Design: This will be a randomized, open-label, active-comparator, assessor-blinded clinical trial of 2 parallel groups of short-term (<15 days) antibiotic therapy involving quinolones or an alternative to quinolones antibiotic agent (2 groups of 70 people each, with a patient allocation ratio of 1: 1). The study will involve individuals > 40 years of age with an indication for quinolone due to localized infection, but not sepsis, or planned procedure/surgery. The follow-up will last 6 months. The primary endpoint of the study is the estimation of the mean difference in pulse wave velocity (PWV) between the 2 groups from baseline (time 0) at 2 months after initial administration of the therapy. Secondary endpoints are PWV values at 6 months, augmentation index, central pressures (systolic, diastolic, pulse pressure) and echocardiographically-assessed aortic root diameter, as well as any adverse event (including aortic dissection and aortic rupture) at 2 and 6 months after initial treatment. Discussion: To our knowledge, FRAGILES will be the first study to provide insight into the possible effects of quinolones on the aortic function. It will also investigate the possible value of arterial biomarkers on risk assessment for possible aortic dilation in this population. Š Šunjić, B P.42 T Taddei, S P.44 Tagawa, K 1.5 Tan, I P.10, P.19, P.26 P.57 Tanaka Wilbers, J 7.4 Willems, L 3.8 X Xydis, P 3.3 Y Yiannaki, E P.5 Z Zanini, G 3.9 Zax, C 7.1 Zeebregts, C 3.8 Zieff, G 3.1, 3.5, P.2, P.54