bluuebunny/crossref_metadata_2025_split huggingface dataset:
P66 Mathematical Model of the Renal Microcirculation and Effects of Chronic Kidney Disease
Authors: Fountoulakis Nikolaos , Sanchez-Cazares Karla , Parker Kim , Karalliedde Janaka 
Published: March 2020

Abstract
Background
Diabetes is one of the leading causes of chronic kidney disease (CKD) worldwide. CKD is directly linked to increased morbidity and mortality. The role of vascular changes in diabetes and underlying mechanism of kidney disease is not well understood.

Methods
We present a mathematical model of the small arteries in the kidney incorporating anatomical and dynamic features. It consists of a symmetrical bifurcating treeself-similar in length, cross-sectional area and wave speed. Each generation is related to the previous one by the scaling factors e.g. ln + 1 = λln, this gives properties (e.g. surface area, resistance) for each generation by a priori knowledge of the renal artery. We assume the flow is one-dimensional and laminar. Vessel walls are treated as porousmedia to find the glomerulus transmural flux. Effects of compliance are introduced by a pressure-area relationship based on circumferential stress in thin vessel walls. The set of ordinary differential equations is solved numerically.

Results
The results are in accordance with physiological measurements and indicate that pressure in the vasculature is highly sensitive to changes in vessel geometry, which also affects the transmural flux in the glomerulus. Changes in the structure of the arterial wall (e.g. Young’s modulus) alter the dynamics of the flow with an increased effect in the micro-circulation.

Conclusion
This is a functional model describing the behaviour of the small vasculature in the kidney. The model is computationally inexpensive, can be used for analysis and tested with in vivo data in pathological conditions.
P67 Detecting Preload Reduction with Machine Learning on Arterial Waveform Parameters
Authors: van der Ster Björn , Wijnberge Marije , Huntelaar Marthe , de Haan Job , van der Sluijs Koen , Veelo Denise , Westerhof Berend 
Published: March 2020

Abstract
Background
Hemodynamic optimization of unstable patients by means of fluid resuscitation improves patient outcome, but choosing the correct amount of fluid can be difficult. Too little fluid may not ensure adequate perfusion whereas too much fluid is associated with increased mortality. Static parameters are not sufficiently sensitive to detect a reduction in preload, and dynamic parameters rely on changes induced by mechanical ventilation. We hypothesized that the arterial wave form contains parameters that can be used as model input to identify patients that benefit from fluid administration.

Methods
Radial artery waveform parameters were extracted in patients after they had undergone a coronary artery bypass graft surgery (n = 20, all male). Three classes were defined: unchanged preload, preload reduction induced by positive end-expiratory breath holds (PEEP), and preload increase following fluid administration. A leave-one-out multinomial logistic regression was performed to train and evaluate the model. Model performance is reported as accuracy, sensitivity and specificity.

Results
In univariate analysis, left ventricular ejection time, augmentation index, dPdtmax and stroke volume showed the largest variation between the classes and were selected as model inputs. Following leave-one-out cross-validation the final model detected decreased preload with an accuracy, sensitivity and specificity of 87.5%, 85% and 90% respectively. Fluid administration did not give enough stimulus for modelling.

Conclusion
Arterial waveform parameters adequately distinguish unchanged from artificially reduced preload; preload increase could not be reliably detected. Since PEEP influences arterial compliance, future studies need to evaluate this effect, and also the applicability of the model in other populations.
P68 Usefulness of an Optimal Cut-off in Central Augmentation Pressure for the Detection of Left Ventricular Hypertrophy in Men
Authors: Obayashi Masakazu , Kobayashi Shigeki , Yamamoto Hirotaka , Hamada Yoriomi , Nanno Takumi , Kohno Michihiro , Yano Masafumi 
Published: March 2020

Abstract
Background
Recently, we showed an age-related increase in augmentation pressure (AP) measured using Mobil-O-Graph (MOG) in normotensive Japanese individuals. However, AP might be a poor index of wave reflection due to the overlap between the forward wave and reflected wave.

Methods
We enrolled untreated hypertensive patients and patients currently on antihypertensive treatment. For 70 patients (median age, 70.5 years; 34 men), M-mode echocardiography was performed for determination of left ventricular hypertrophy (LVH), while hemodynamic measurements were taken using MOG. We investigated the influence of central hemodynamic parameters on LVH.

Results
Spearman correlation coefficients between various parameters [age, height, systolic blood pressure (SBP), mean BP, diastolic BP, central systolic BP (cSBP), and AP] were calculated for LV mass indexed to body surface area (LVMI; g/m2). In men, age (r = 0.600, p = 0.0002), height (r = −0.495, p = 0.003), SBP (r = 0.423, p = 0.013), cSBP (r = 0.454, p = 0.007), and AP (r = 0.661, p < 0.0001) were correlated to LVMI. In women, cSBP (r = 0.334, p = 0.044) and AP (r = 0.480, p = 0.003) were correlated to LVMI. In men, LVMI (R2 = 0.578, p = 0.0001) was significantly associated with AP (β = 1.32 ± 0.56, p = 0.027) in multivariate regression analysis. In women, no significant independent parameter for LVMI was observed. ROC curve analysis was performed to estimate the utility of AP for the detection of LVH (LVMI >115 g/m2) in men. Area under the ROC curve was 0.83 (95% CI: 0.68–0.99). The optimal cut-off point of 12.5 mmHg produced 79.0% sensitivity and 86.7% specificity.

Conclusion
Higher AP showing >12.5 mmHg calculated by MOG was a significant independent predictor of LVH in male hypertensive patients.
P72 Vascular Aging Prediction in High Cardiovascular Risk Cohort
Authors: Laucyte-Cibulskiene Agne , Ryliskyte Ligita , Kovaite Milda , Rimsevicius Laurynas , Balkeviciene Laura , Badariene Jolita , Laucevicius Aleksandras 
Published: March 2020

Abstract
Aim
To assess a time-dependent change of arterial stiffness gradient (PWVratio calculated by dividing carotid-femoral to carotid-radialPWV), a marker of vascular aging, in high cardiovascular risk cohort.

Methods
This cohort study (n = 689) was conducted during the period 2010–2019 at Vilnius University Hospital Santaros Klinikos. Participants were referred by the primary health care institutions according to Lithuanian High Cardiovascular Risk (LitHiR) primary prevention program which recruited men at the age of 40–55 years and women at the age of 50–65 years without overt cardiovascular disease; they underwent a detailed cardiovascular risk assessment and arterial stiffness evaluation and were repeatedly examined after the mean follow-up of 965.63 ± 511.98 days.

Results
The cohort was comprised of 40.2% male participants. Cardiovascular risk factors were distributed as follows: 19.5% subjects had diabetes mellitus, 52.69% left ventricular hypertrophy, 95.21% hypertension, 99.13% dyslipidemia. During the follow-up period 52.1% of patients presented PWV ratio increase. In spite of the difference in age between men and women, PWV ratio progression adjusted for follow-up time and age was more pronounced in males (OR 1.72, p = 0.032). In the subanalysis, we found that in men, as compared to women, there was a more pronounced decrease in carotid-radialPWV (p < 0.001). The carotid-femoralPWV increased both in men and in women. Glucose level, abdominal obesity, mean arterial blood pressure, menopause was related to the change of the PWV ratio.

Conclusion
In this high cardiovascular risk cohort, the change in arterial stiffness gradient is related to abdominal obesity, mean arterial blood pressure, and menopause.
P78 Endothelial Dysfunction and Arterial Stiffness During Type 2 Diabetes
Authors: Toure Maimouna , Hallab Magid , Thiam Souleymane , Mane Sheikh AB , Belem Farid , Samb Abdoulaye 
Published: March 2020

Abstract
Objective
We aimed to study Endothelial dysfunction and Arterial Stiffness in Diabetes mellitus.

Methods
29 women with type 2 diabetes and 8 non-diabetic controls were included. Vascular function was studied with pOpmetre® (Axelife SAS-France) to assess the foot to toe Pulse Wave Velocity; and EndoPAT2000® (ITAMAR-Israel) to measure endothelial vasodilatation dependent by measurement of reactive hyperhemic index (RHI).

Results
Diabetics were 56 ± 6 years vs 47 ± 9 years. Mean diabetes duration was 9.07 ± 6.15 years. RHI was normal in all controls (1.94 ± 0.68) and abnormal in 51.72% of diabetics (1.83 ± 0.12). An abnormal ftPWV was found in 38% of diabetic subjects (11.6 ± 7.7 m/s) vs 12% of controls (7.7 ± 2.3 m/s, normal <10 m/s). There was a positive correlation between ftPWV and age (r = 0.25; p = 0.001); ftPWV and duration of diabetes (r = 0.12; p = 0.03). At the same time we found a negative correlation between RHI and fasting blood glucose (r = −0.46; p = 0.01), HbA1c (r = −0.37; p = 0.04), triglycerides (r = −0.49; p = 0.03) and total cholesterol (r = −0.37; p = 0.04). In a rapid and non-invasive way, we found endothelial dysfunction in 51.72% of diabetics and arterial stiffness in 38% of them.

Conclusion
During diabetes, endothelial dysfunction and arterial stiffness are therefore dependent on the glycemic balance, the duration of diabetes and lipid parameters. However, these two parameters appear independently and differently associated with diabetic disease.
P80 Predictors of Middle Cerebral Artery Pulsatility Index in Chronic Obstructive Pulmonary Disease and Healthy Controls; Data from the ACRADE Study
Authors: Shezawi Mahfoudha Al , Munnery Maggie , Cockcroft John , Watkeys Laura , Stohr Eric , Gale Nichola , McDonnell Barry 
Published: March 2020

Abstract
Background
Chronic obstructive pulmonary disease (COPD) is characterised by airway limitation which is an independent predictor of increased cardiovascular (CV) risk and mortality [1]. COPD is associated with increased arterial stiffness [2] and increased incidence of all stroke subtypes [3]. However, the mechanism linking this association is not fully understood. The study aims to identify predictors of middle cerebral artery pulsatility (MCAPI) in COPD and controls.

Method
MCAPI was measured using transcranial Doppler ultrasound. Aortic pulse wave velocity (aPWV) and central pulse pressure (CPP) were measured using the SphygmoCor system. Forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) was measured using spirometry. Use of CV acting medications were recorded.

Result
45 COPD patients and 50 healthy controls were included in the analyses. Age, gender, CPP and MCAPI were similar between groups, however the COPD patients showed higher aPWV, lower FEV1/FVC and were on more CV acting medication (all, p < 0.05). In COPD, MCAPI was significantly associated with CPP (r = 0.433, p = 0.003) and FEV1/FVC (r = 0.330, p = 0.027), but not aPWV. In controls, MCAPI was significantly associated with CPP (r = 0.601, p = 0.001) and aPWV (r = 0.452, p = 0.001). However, Stepwise Multiple Regression Analysis illustrated that only CPP remained an independent predictor of MCAPI (p = 0.003), in a model which included age, aPWV, FEV1/FVC and use of CV acting medications.

Conclusion
Within the COPD group, CPP was independently associated with MCAPI, even when accounting for use of CV acting medications. However, the interaction between CV acting medications and the relationship between aPWV and MCAPI remains unclear and needs further investigations.
P82 Impaired Skin Microvascular Function in Systemic Lupus Erythematosus
Authors: Koletsos Nikolaos , Gkaliagkousi Eugenia , Lazaridis Antonios , Anyfanti Panagiota , Triantafyllou Areti , Dipla Konstantina , Dolgyras Panagiotis , Galanopoulou Vasiliki , Aslanidis Spyros , Douma Stella 
Published: March 2020

Abstract
Objectives
Alterations in skin microcirculation have been associated with damage in various microvascular beds [1]. Endothelial dysfunction in microcirculation plays a central role in the pathophysiology of rheumatic diseases, contributing substantially to the increased cardiovascular risk of these patients. Laser speckle contrast analysis (LASCA) is a novel non-invasive technique that can be used to evaluate endothelial function of skin microcirculation [2]. Previous studies have shown impaired skin endothelial function in patients with systemic sclerosis. To our knowledge, no previous study has evaluated skin microcirculation in patients with SLE using LASCA [3,4].

Design and Methods
Fifty-two individuals (25 SLE patients and 27 matched controls) were studied. In all subjects, forearm skin blood flow was recorded under standardized conditions using a laser speckle contrast imager (PeriCam PSI NR System, Perimed). Post-occlusive reactive hyperemia (PORH) was assessed following a standardized protocol and data were analyzed with signal processing software (PIMSoft, Perimed). The amplitude of PORH responses was expressed as a percentage increase between peak and baseline perfusion (%).

Results
There were no differences among the two groups in age, sex, body mass index and hypertension status. Post occlusion reperfusion in SLE patients, was significantly lower as compared to non-SLE controls (155.5 ± 53.1 vs 194.5 ± 40.5% respectively, p = 0.004).

Conclusion
Patients with SLE demonstrate impaired skin microvascular endothelial function, providing a link that could explain the increased cardiovascular risk that these patients bear.
P84 Prediction of Cardiovascular Events and Mortality by Pulse Wave Velocity: a Comparison of Invasive Measurements and Noninvasive Estimation Methods
Authors: Hametner Bernhard , Wassertheurer Siegfried , Mayer Christopher Clemens , Danninger Kathrin , Binder Ronald , Weber Thomas 
Published: March 2020

Abstract
Introduction
Arterial properties are linked to the presence and severity of coronary artery disease (CAD). Coronary blood flow is strongly and inversely related to arterial stiffness. Thus, the aim of this prospective study was to evaluate the prognostic value of PWV in high-risk patients with suspected CAD and to compare three different methods for assessing PWV.

Methods
In 1040 patients, invasive PWV (iPWV) was measured during catheter pullback. Additionally, PWV was estimated with a model incorporating age and the central pulse waveform obtained from non-invasive measurements (ePWV). As a third method, PWV was calculated with a formula solely based on age and blood pressure (fPWV). Survival analysis was done for continuous PWV as well as using cut-off values.

Results
After a median follow up duration of 1565 days, 24% of the patients reached the combined endpoint (cardiovascular events and mortality). Cox proportional hazard ratios per m/s were 1.13 for iPWV, 1.17 for ePWV and 1.13 for fPWV (p < 0.0001 for all three methods). Significant differences between patient groups according to a cut-off value of 10 m/s were found as well for all three methods. However, multivariable Cox models revealed a different performance of the three methods, indicating weaknesses of fPWV to mimic iPWV.

Conclusion
All three methods for the determination of PWV predicted cardiovascular events and mortality in patients with suspected coronary artery disease. This indicates that iPWV as well as both non-invasive estimation methods are suitable for the assessment of arterial stiffness, bearing in mind their individual characteristics.
P89 Non-invasive Blood Pressure Measurement System Using Three-axis Tactile Force Sensor
Authors: Lee Hae-Young 
Published: March 2020

AbstractBlood pressure is most important parameter reflecting hemodynamic factors, however it is continuously variable in 24 hours. Here, we made a non-invasive and continuous BP measurement device using a three-axis tactile force sensor. All the data was collected every 2 min for the short-term experiment, and every 10 min for the long-term experiment. In addition, the effects on the BP measurement of external physical factors such as the tension to the radial artery on applying the device and wrist circumference were evaluated. A high correlation between the measured BP with the proposed system and with the cuff-based non-invasive blood pressure, and reproducibility, were demonstrated. All data satisfied the Association for the Advancement of Medical Instrumentation criteria. The external physical factors did not affect the measurement results. In addition to previous research indicating the high reliability of the arterial pulse waveforms, the present results have demonstrated the reliability of numerical BP values, and this implies that the three-axis force sensor can be used as a patient monitoring device.
P96 Soluble Receptor for Advanced Glycation End-products Independently Influenced Individual Age-dependent Increase of Arterial Stiffness
Authors: Gelžinský Július 
Published: March 2020

Abstract
Background
Soluble receptors for advanced glycation end-products (sRAGEs) have been suggested to have a protective role neutralizing the advanced glycation end-products (AGEs) and their pathological effect on vessel walls. We aimed to investigate the association between circulating concentrations of sRAGEs and dynamic of arterial wall stiffening as a manifestation of vascular ageing in general population.

Methods
In a prospective cohort study, we longitudinally followed 530 general-population-based subjects (subsample of Czech post-Monica study). Aortic pulse wave velocity (PWV) was measured twice (at baseline and after ≈8 years of follow-up) using a Sphygmocor device (AtCor Medical Ltd.) and intra-individual change of PWV per year (∆PWV/year) was calculated. Concentrations of sRAGE were assessed at baseline by ELISA methods (R&D Systems).

Results
Average ∆PWV/year significantly increased across the sRAGE quintiles (p = 0.0008) and drop by one sRAGE quintile was associated with ≈21% increase in the relative risk of accelerated age-dependent stiffening (∆PWV/year ≥0.2 m/sec). In a categorized manner, subjects in the bottom quintile of sRAGE (<889.74 pg/mL) had fully adjusted odds ratio of accelerated stiffening 1.72 (95% CI: 1.06–2.79), p = 0.028, while those with high sRAGE concentrations (≥1695.2 pg/mL) showed opposite effect [with odds ratio 0.55 (95% CI: 0.33–0.90), p = 0.017].

Conclusion
Circulating status of sRAGE independently influenced individual progression of arterial stiffness overt time. This finding strongly supports hypothesis, that high sRAGE have protective role against vascular ageing.
P102 Large Artery Stiffness is Associated with Lower Brain pH and Memory Performance in Middle-aged and Older Adults
Authors: DuBose Lyndsey , Magnotta Vincent , Moser David , Mitchell Gary , Nuckols Virginia , Ward Ryan , Pierce Gary , Ponto Laura Boles 
Published: March 2020

Abstract
Background/Objectives
Large artery stiffening is a novel risk factor for cognitive impairment including Alzheimer’s disease. Loss of impedance mismatch between central and cerebral arteries promotes cerebrovascular dysfunction via chronic transmission of excessive pulsatile pressure and flow to the brain. Cerebrovascular dysfunction uncouples cerebral blood flow supply from metabolic demand, contributing to hypoperfusion and acidosis. Conversely, greater impedance mismatch may protect against cerebrovasculature dysfunction, brain acidosis and cognitive impairment. Values for brain T1rho, a novel pH-sensitive MRI biomarker, are higher (more acidic) in patients with cognitive impairment compared with healthy controls. However, relations of T1rho with 1) large artery stiffness and central pulsatile hemodynamics and 2) memory performance are unknown.

Methods/Results
Middle-aged/older adults (n = 31, 68 ± 2 years) underwent vascular, global T1rho MRI and memory testing. In a subset (n = 17), common carotid artery (CCA) intima-medial thickness (IMT) and pulsatile pressure/flow hemodynamics were measured (applanation tonometry, Doppler ultrasonography). In the entire cohort, higher T1rho was associated with greater aortic stiffness (cfPWV; r = 0.36, p = 0.054, covariate: MAP) and lower memory performance (r = −0.43, p = 0.03, education). In the subset, greater CCA IMT was correlated with higher cfPWV (r = 0.45, p = 0.08, MAP), suggesting that elevated aortic stiffness may promote concentric CCA remodeling. Higher CCA characteristic impedance was associated with lower T1rho (r = −0.57, p = 0.02) and higher memory performance (r = 0.46, p = 0.08). T1rho was not correlated with CCA reflection coefficient or pulsatile flow parameters (p > 0.05).

Conclusion
These preliminary data suggest that compensatory remodeling of the CCA artery associated with elevated aortic stiffness may be protective against alterations in brain pH and cognitive performance.
P104 White Coat Hypertension is Associated with Increased Small Vessel Disease in the Brain
Authors: Kirkham Fran , Drazich E. , Vundavalli A. , Rankin P. , Timeyin J. , Bunting E. , Ali K. , Rajkumar C. 
Published: March 2020

Abstract
Objective
Small vessel disease, measured by brain white matter hyperintensity (WMH), is associated with increased stroke risk and cognitive impairment. This study aimed to explore the relationship between WMH on computerised tomography (CT) and white coat hypertension (WCH) in patients with recent transient ischaemic attack (TIA) or lacunar stroke (LS).

Methods
Ninety-six patients recruited for the ASIST trial (Arterial Stiffness in Lacunar Stroke and TIA) underwent measurement of clinic blood pressure (BP) and ambulatory BP monitoring (APBM) within two weeks of TIA or LS. Patients were grouped by BP phenotypes. Twenty-three patients had normotension (clinic BP <140/90 mmHg and day-time ABPM <135/85 mmHg) and 25 patients had WCH (clinic BP >140/90 mmHg and day-time ABPM <135/85 mmHg). CT brain images were scored for WMH using the four-point Fazekas visual rating scale. Patients were grouped into no-mild WMH (scores 0–1) or moderate-severe (scores 2–3) groups. The relationship between BP and WMH was explored with chi-square and logistic regression accounting for known cardiovascular risk factors (age, gender, smoking, diabetes and hyperlipidaemia).

Results
44% of WCH patients had moderate-severe WMH compared to 17% of normotensives (p = 0.047). Logistical regression incorporating WCH as the independent factor and cardiovascular risk factors as independent variables showed WCH to be the only independent significant factor contributing to WMH (p = 0.024).

Conclusion
Patients with WCH were more likely to have moderate-severe WMH on CT brain than normotensives. WCH was associated with increased WMH, independent of other cardiovascular risk factors. This study suggests that WCH is associated with increased small vessel disease in the brain and may benefit from treatment.

Normotension (n = 23)
WCH (n = 25)
Statistical significance

Female n(%)
8 (35%)
7 (28%)
p = 0.613

Age (years)
69.7 ± 11.79
76.52 ± 8.69
p = 0.026

Ever Smoker n(%)
12 (52%)
18 (72%)
p = 0.156

Hyperlipidaemia n(%)
18 (78%)
15 (60%)
p = 0.458

Diabetes n(%)
4 (17%)
7 (28%)
p = 0.173

No-Mild WMH n(%)
19 (83%)
14 (66%)
p = 0.047

Moderate-Severe WMH n(%)
4 (17%)
11 (44%)
p = 0.047