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The article presents the discussion on database of unoperated patients with ascending thoracic aneurysms has shown that the risk of an adverse aortic event. Topics include penetrating aortic ulcers or intramural hematoma at their first visit and those with congenital malformations of the aorta; and censored patients who underwent aortic surgery instead of eliminating them.

Introduction: Trendelenburg position (TP) is used to transport gaseous emboli away from the cerebral region during cardiac surgery. However, TP effectiveness has not been fully considered when combined with varying the cardiopulmonary bypass (CPB) flow. This study simulated the supine and TP at different pump flows and assessed the trapped emboli and embolic load entering the aortic arch branch arteries (AABA). Methods: A computational fluid dynamics (CFD) approach used a centrally cannulated adult patient-specific aorta model replicating a CPB circuit. Air emboli of 0.1 mm, 0.5 mm, and 1.0 mm (n = 700 each) were injected into the aorta placed in the supine position (0°) and the TP (−20°) at 2 L/min and 5 L/min. The number of emboli entering the AABA were compared. An aortic phantom flow experiment was performed to validate air bubble behaviour. Results: TP at 5 L/min had the lowest 0.1 mm mean (±SD) embolic load compared to the supine 2 L/min (55.3 ± 30.8 vs 64.3 ± 35.4). For both the supine and TP, the lower flow of 2 L/min had the highest number of simulated trapped emboli in higher elevated regions than at 5 L/min (541 ± 185 and 548 ± 191 vs 520 ± 159 and 512 ± 174), respectively. The flow experiment demonstrated that 2 L/min promoted bubble coalescence and high amounts of trapped emboli and 5 L/min transported air emboli away from the AABA. Conclusions: TP effectiveness was improved by using CPB flow to manage air emboli. These results provide insights for predicting emboli behaviour and improving emboli de-airing procedures. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effectiveness of a school-based exercise intervention on endurance performance (EP), blood pressure (BP), and arterial stiffness in children. Methods: A total of 105 students (mean age = 8.2 [0.6] y; 51% girls; body mass index = 17.8 [3.0] kg/m2) were randomized to the intervention group (IG, n = 51) and control group (CG, n = 54). During a 37-week experimental period, the IG received an exercise intervention (2 × 45 min/wk) in addition to their regular school physical education class (3 × 45 min/wk). EP, peripheral and central BP, pulse pressure, augmentation pressure, augmentation index, and aortic pulse wave velocity were assessed. Results: Following the intervention, significant changes (P <.05) in EP, peripheral and central systolic BP, pulse pressure, augmentation pressure, augmentation index, and aortic pulse wave velocity were found in the IG. Children in the CG displayed significant changes in peripheral and central diastolic BP. An analysis of the baseline-to-post changes revealed significant between-group differences in EP (P <.001), pulse pressure (P =.028), augmentation pressure (P =.007), and aortic pulse wave velocity (P =.037) that favored the IG and in peripheral and central diastolic BP that favored the CG. Conclusion: The school-based exercise intervention had beneficial effects not only on EP but also on different hemodynamic parameters. [ABSTRACT FROM AUTHOR]

Background: Computational fluid dynamics (CFD) is increasingly used for the assessment of blood flow conditions in patients with congenital heart disease (CHD). This requires patient-specific anatomy, typically obtained from segmented 3D cardiovascular magnetic resonance (CMR) images. However, segmentation is time-consuming and requires expert input. This study aims to develop and validate a machine learning (ML) method for segmentation of the aorta and pulmonary arteries for CFD studies. Methods: 90 CHD patients were retrospectively selected for this study. 3D CMR images were manually segmented to obtain ground-truth (GT) background, aorta and pulmonary artery labels. These were used to train and optimize a U-Net model, using a 70-10-10 train-validation-test split. Segmentation performance was primarily evaluated using Dice score. CFD simulations were set up from GT and ML segmentations using a semi-automatic meshing and simulation pipeline. Mean pressure and velocity fields across 99 planes along the vessel centrelines were extracted, and a mean average percentage error (MAPE) was calculated for each vessel pair (ML vs GT). A second observer (SO) segmented the test dataset for assessment of inter-observer variability. Friedman tests were used to compare ML vs GT, SO vs GT and ML vs SO metrics, and pressure/velocity field errors. Results: The network's Dice score (ML vs GT) was 0.945 (interquartile range: 0.929–0.955) for the aorta and 0.885 (0.851–0.899) for the pulmonary arteries. Differences with the inter-observer Dice score (SO vs GT) and ML vs SO Dice scores were not statistically significant for either aorta or pulmonary arteries (p = 0.741, p = 0.061). The ML vs GT MAPEs for pressure and velocity in the aorta were 10.1% (8.5–15.7%) and 4.1% (3.1–6.9%), respectively, and for the pulmonary arteries 14.6% (11.5–23.2%) and 6.3% (4.3–7.9%), respectively. Inter-observer (SO vs GT) and ML vs SO pressure and velocity MAPEs were of a similar magnitude to ML vs GT (p > 0.2). Conclusions: ML can successfully segment the great vessels for CFD, with errors similar to inter-observer variability. This fast, automatic method reduces the time and effort needed for CFD analysis, making it more attractive for routine clinical use. [ABSTRACT FROM AUTHOR]

Abdominal aortic aneurysms (AAAs) are lethal but treatable yet substantially under-diagnosed and under-monitored. Hence, new AAA monitoring devices that are convenient in use and cost are needed. Our hypothesis is that analysis of arterial waveforms, which could be obtained with such a device, can provide information about AAA size. We aim to initially test this hypothesis via tonometric waveforms. We study noninvasive carotid and femoral blood pressure (BP) waveforms and reference image-based maximal aortic diameter measurements from 50 AAA patients as well as the two noninvasive BP waveforms from these patients after endovascular repair (EVAR) and from 50 comparable control patients. We develop linear regression models for predicting the maximal aortic diameter from waveform or non-waveform features. We evaluate the models in out-of-training data in terms of predicting the maximal aortic diameter value and changes induced by EVAR. The best model includes the carotid area ratio (diastolic area divided by systolic area) and normalized carotid-femoral pulse transit time ((age·diastolic BP)/(height/PTT)) as input features with positive model coefficients. This model is explainable based on the early, negative wave reflection in AAA and the Moens-Korteweg equation for relating PTT to vessel diameter. The predicted maximal aortic diameters yield receiver operating characteristic area under the curves of 0.83 ± 0.04 in classifying AAA versus control patients and 0.72 ± 0.04 in classifying AAA patients before versus after EVAR. These results are significantly better than a baseline model excluding waveform features as input. Our findings could potentially translate to convenient devices that serve as an adjunct to imaging. [ABSTRACT FROM AUTHOR]

Background: Endurance training enhances exercise capacity and triggers cardiovascular adaptations in both males and females. We investigated the relationship between the dimensions of great vessels and exercise capacity in amateur cyclists while considering sex differences., Methods: Using resting transthoracic echocardiography, we measured the dimensions of the main pulmonary artery (PA), aorta, and inferior vena cava (IVC) in 190 participants, who subsequently underwent a cardiopulmonary exercise test (CPET) until exhaustion., Results: The mean age of study participants was 30 years. Males (71%) exhibited a larger aortic annulus (approximately 3.5 mm, p<0.0001) and PA diameter (2.4 mm, p<0.0001) than females. No significant sex differences were found in expiratory or inspiratory IVC diameters. Males achieved greater peak exercise capacity, including workload, O2 consumption (VO2), and O2 pulse. Aortic and PA dimensions showed strong correlations with energy expenditure, workload, VO2, and O2 pulse. However, these correlations weakened when analyzed separately by sex. Multivariate linear regression revealed associations between CPET results, vessels size, and sex, with sex differences observed only in the intercepts-not in interactions between sex and vessels size. Despite males having better CPET results and larger vessels, the relationships between peak exercise capacity parameters and vessel dimensions were similar in both sexes., Conclusion: Larger vessel dimensions (of the aorta, PA, and IVC) were associated with greater peak exercise capacity in amateur cyclists, with no significant sex differences in these associations., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: This study and the Open Access article publication charges was partially funded by the budget for the Project "Development of the University Centre for Sports and Medical Studies in Poznan, Poland" (Number: NdS/544750/2021/2022) with Principal Investigator Prof. Przemysław Guzik. The Ministry of Education and Science, Warsaw, Poland, funded the Project within the "Science for Society" Program. The funding for this scientific work was partially provided by the budget for the science of The Polish Ministry of Science and Higher Education as a research project of the program "Diamond Grant" (0184/DIA/2020/49). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ’Author Contributions’ Section. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2024 Pytka et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

As full-scale detailed hemodynamic simulations of the entire vasculature are not feasible, numerical analysis should be focused on specific regions of the cardiovascular system, which requires the identification of lumped parameters to represent the patient behavior outside the simulated computational domain. We present a novel technique for estimating cardiovascular model parameters using gappy Proper Orthogonal Decomposition (g-POD). A POD basis is constructed with FSI simulations for different values of the lumped model parameters, and a linear operator is applied to retain information that can be compared to the available patient measurements. Then, the POD coefficients of the reconstructed solution are computed either by projecting patient measurements or by solving a minimization problem with constraints. The POD reconstruction is then used to estimate the model parameters. In the first test case, the parameter values of a 3-element Windkessel model are approximated using artificial patient measurements, obtaining a relative error of less than 4.2%. In the second case, 4 sets of 3-element Windkessel are approximated in a patient's aorta geometry, resulting in an error of less than 8% for the flow and less than 5% for the pressure. The method shows accurate results even with noisy patient data. It automatically calculates the delay between measurements and simulations and has flexibility in the types of patient measurements that can handle (at specific points, spatial or time averaged). The method is easy to implement and can be used in simulations performed in general-purpose FSI software., (© 2024. The Author(s).)

Background: Substantial evidence indicates trace amines can induce vasoconstriction independently of noradrenaline release. However, the mechanism underlying noradrenaline-independent vasoconstrictor responses to trace amines has not yet been established. This study evaluates the role of trace amine-associated receptor 1 (TAAR1) and other biogenic amine receptors in mediating β-phenylethylamine and the TAAR-1 selective agonist RO5256390-induced vasoconstriction., Methods: Vasoconstrictor responses to β-PEA and the TAAR1-selective agonist, RO5256390 were assessed in vitro in endothelium-denuded aortic rings and third-order mesenteric arteries of male Sprague Dawley rats., Results: β-PEA and RO5256390 induced concentration-dependent vasoconstriction of aortic rings but not third-order mesenteric arteries. Vasoconstrictor responses in aortic rings were insensitive to antagonists of 5-HT. The murine-selective TAAR1 antagonist, EPPTB, had no effect on either β-PEA or RO5256390-induced vasoconstriction. The α 1 -adrenoceptor antagonist, prazosin, and the α 2 -adrenoceptor antagonist, yohimbine, induced a shift of the β-PEA concentration response curve too small to be ascribed to antagonism of α 1 -or α 2 -adrenoceptors, respectively. The α 2 -adrenoceptor antagonist atipamezole had no effect on β-PEA or RO5256390-induced vasoconstriction., Conclusion: Vasoconstrictor responses to trace amines are not mediated by classical biogenic amine neurotransmitter receptors. Insensitivity of β-PEA vasoconstrictor responses to EPPTB, may be explained by its low affinity for rat rather than murine TAAR1. Therefore, TAAR1 remains the most likely candidate receptor mediating vasoconstrictor responses to trace amines and that prazosin and yohimbine have low affinity for TAAR1., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

(1) Background and Objectives : Flow assessment using cardiovascular magnetic resonance (CMR) provides important implications in determining physiologic parameters and clinically important markers. However, post-processing of CMR images remains labor- and time-intensive. This study aims to assess the validity and repeatability of fully automated segmentation of phase contrast velocity-encoded aortic root plane. (2) Materials and Methods: Aortic root images from 125 patients are segmented by artificial intelligence (AI), developed using convolutional neural networks and trained with a multicentre cohort of 160 subjects. Derived simple flow indices (forward and backward flow, systolic flow and velocity) and complex indices (aortic maximum area, systolic flow reversal ratio, flow displacement, and its angle change) were compared with those derived from manual contours. (3) Results : AI-derived simple flow indices yielded excellent repeatability compared to human segmentation ( p < 0.001), with an insignificant level of bias. Complex flow indices feature good to excellent repeatability ( p < 0.001), with insignificant levels of bias except flow displacement angle change and systolic retrograde flow yielding significant levels of bias ( p < 0.001 and p < 0.05, respectively). (4) Conclusions : Automated flow quantification using aortic root images is comparable to human segmentation and has good to excellent repeatability. However, flow helicity and systolic retrograde flow are associated with a significant level of bias. Overall, all parameters show clinical repeatability.

Objectives: Central aortic BP may predict cardiovascular outcomes better than upper arm brachial BP. In recent years, technology has enabled central BP estimation by recording a peripheral BP waveform from a standard upper arm cuff. The accuracy of these devices is not well documented, and this study aimed to address this issue., Methods: This study was a systematic review, conducted according to PRISMA guidelines, of observational studies published between 2008 and 2023 that reported accuracy testing of cuff-based central BP devices, compared with reference invasive aortic BP. The primary analysis was stratified according to each commercially available device. Pooled estimates were calculated using random-effects models based on mean differences and standard errors., Results: Six thousand four hundred and fifteen studies were screened, and 27 studies met inclusion criteria (plus one unpublished study). This generated data for seven devices that are commercially available, which were tested among 2125 adult participants. There was very high heterogeneity when all devices were pooled ( I2  = 97.5%), and, when stratified by device, the accuracy of estimated central BP was highly device-dependent (range of accuracy across different devices -12.4 mmHg (-16.3 to -8.5) to 3.2 mmHg (0.2-6.1). Two of the seven commercially available devices had not undergone external validation testing., Conclusion: The accuracy of commercially available cuff-based central BP devices is highly device-specific and not all are accurate for the estimation of central SBP. These findings have major implications for the appropriate interpretation of studies that use cuff-based estimated central BP., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Postmenopausal women experience augmented aortic hemodynamic responses to isometric handgrip (IHG) exercise and metaboreflex activation post-exercise muscle ischemia (PEMI). Relationships between endothelial function brachial artery flow-mediated dilation (FMD) and aortic stiffness carotid-femoral pulse wave velocity (cfPWV) with aortic pulsatile hemodynamics during IHG and PEMI have not been determined. The relationships between aortic hemodynamic responses to PEMI were evaluated., Methods: Aortic blood pressure (BP), wave reflection, and pressure of forward (Pf) and backward (Pb) waves were measured using arterial tonometry at rest, IHG at 30% maximal force, and PEMI in 30 (15/group) postmenopausal women with low (≤ 4.5%) and normal (≥ 5.5%) FMD. Hemodynamic responses were analyzed as the change (Δ) from rest to the last minute of IHG and PEMI., Results: Brachial and aortic systolic BP (SBP) responses to IHG were higher in the low vs normal FMD group (P < 0.05). Aortic SBP (Δ20 ± 8 vs Δ11 ± 7 mmHg), pulse pressure (PP) (Δ12 ± 8 vs Δ6 ± 4 mmHg), augmented pressure (AP) (Δ5 ± 3 vs Δ2 ± 2 mmHg), and Pb (Δ6 ± 4 vs Δ3 ± 2 mmHg) responses to PEMI were greater (P < 0.05) in women with low vs. normal FMD. FMD was negatively correlated with aortic SBP, PP, AP, and Pb (P < 0.05) responses to PEMI. cfPWV was not correlated with responses to PEMI., Conclusion: Endothelial dysfunction relates to augmented aortic pulsatile load during metaboreflex activation, which may increase cardiovascular risk in postmenopausal women., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Contrary to most vessels, the ascending thoracic aorta (ATA) not only distends but also elongates in the axial direction. The purpose of this study is to investigate the biomechanical behavior of the ascending thoracic aorta (ATA) in response to dynamic axial stretching during the cardiac cycle. In addition, the implications of neglecting this dynamic axial stretching when estimating the constitutive model parameters of the ATA are investigated. The investigations were performed through in silico simulations by assuming a Gasser-Ogden-Holzapfel (GOH) constitutive model representative of ATA tissue material. The GOH model parameters were obtained from biaxial tests performed on four human ATA tissues in a previous study. Pressure-diameter curves were simulated as synthetic data to assess the effect of neglecting dynamic axial stretching on estimating constitutive model parameters. Our findings reveal a significant increase in axial stress (~ 16%) and stored strain energy (~ 18%) in the vessel when dynamic axial stretching is considered, as opposed to assuming a fixed axial stretch. All but one artery showed increased volume compliance while considering a dynamic axial stretching condition. Furthermore, we observe a notable difference in the estimated constitutive model parameters when dynamic axial stretching of the ATA is neglected, compared to the ground truth model parameters. These results underscore the critical importance of accounting for axial deformations when conducting in vivo biomechanical characterization of the ascending thoracic aorta., (© 2024. The Author(s).)

Blood pressure or flow measurements have been associated with vascular health and cognitive function. We proposed that energetic hemodynamic parameters may provide a more nuanced understanding and stronger correlation with cognitive function, in comparisons with conventional aortic and carotid pressure and flow parameters. The study comprised 1858 participants, in whom we assessed cognitive function via MoCA method, and measured central aortic and carotid pressure and flow waveforms. In addition to various pressure and flow parameters, we calculated energetic hemodynamic parameters through integration of pressure multiplying flow with respect to time. Energetic hemodynamic parameters, particularly aortic and carotid mean and pulsatile energy and pulsatility index (PI), were significantly associated with MoCA score more than any aortic and carotid pressure and flow parameters, after adjusting for age, sex, education, depression score, heart rate, BMI, HDL-cholesterol, and glucose levels. MoCA exhibited a strong positive relationship with carotid mean energy (standardized beta = 0.053, P = 0.0253) and a negative relationship with carotid energy PI (standardized beta = -0.093, P = 0.0002), exceeding the association with all traditional pressure- or flow-based parameters. Aortic pressure reflection coefficient at the aorto-carotid junction was positively correlated with mean carotid energy and negatively correlated with PI. Aortic characteristic impedance positively correlated with carotid energy PI but not mean energy. Our research indicates that energetic hemodynamic parameters, particularly carotid mean energy and carotid energy PI, have a stronger association with MoCA scores than traditional pressure- or flow-based metrics. This correlation with cognitive function is notably influenced by the properties of the aorto-carotid interface., (© 2024. The Author(s).)

Background. Cardiovascular autonomic dysfunction, which leads to hemodynamic disorders, is commonly observed in patients with Parkinson's disease (PD). Central aortic pressure (CAP) is the systolic blood pressure (SBP) at the root of the aorta. In young people, CAP is lower than peripheral arterial blood pressure. In older people, the difference between CAP and peripheral arterial blood pressure decreases depending on the extent of arterial stiffness (AS). In patients with AS, CAP increases. CAP is thus regarded as an indicator of AS. Objective. To compare CAP and other hemodynamic parameters for AS between patients with Parkinson's disease and control group. We also aimed to evaluate changes in these hemodynamic parameters after the levodopa (LD) intake. Methods. We included 82 patients with PD and 76 healthy controls. Age, sex, disease duration, disease subtype, Hoehn–Yahr stage (H&Y), and nonmotor symptoms (NMS) were documented. TensioMed Software v.3.0.0.1 was used to measure CAP, peripheral arterial blood pressure, pulse pressure (PP), heart rate (HR), mean arterial pressure (MAP), augmentation index (AI), pulse wave velocity, and ejection time. All patients were being treated with LD, and measurements were performed 1 h before and 1 h after LD intake. Results. Baseline peripheral arterial blood pressure and CAP values were significantly higher in the PD group than in the control group (p < 0.001 and p = 0.02 , respectively). Most cardiac hemodynamic parameters, including peripheral arterial blood pressure and CAP, decreased significantly (p < 0.02 and p < 0.001 , respectively) after LD intake in the PD group. Disease subtype, duration, and severity did not affect any of the hemodynamic parameters. When NMS were evaluated, patients with psychosis and dementia showed higher baseline parameters. Conclusion. Loss of postganglionic noradrenergic innervation is well-known with PD. Several cardiac hemodynamic parameters were affected, suggesting cardiac autonomic dysfunction in these patients. The data obtained were independent of disease severity, duration, and subtype. After LD intake, most of these parameters decreased, which might have a positive effect on the vascular burden. [ABSTRACT FROM AUTHOR]

Background: Abdominal aortic aneurysms (AAA) can lead to catastrophic events such as dissection or rupture, and are an expression of general aortic disease. Low wall shear stress (WSS), high oscillatory shear index (OSI), and high relative residence time (RRT) have been correlated against increased uptake of inflammatory markers in the vessel wall and may improve risk stratification of AAA. We sought to obtain a comprehensive view of WSS, OSI, and RRT in the whole aorta for patients with AAA and age-matched elderly controls and young normal controls. Methods: 4D Flow cardiovascular magnetic resonance images of the whole aorta were acquired in 18 AAA patients (70.8 ± 3.4 years), 22 age-matched controls (71.4 ± 3.4 years), and 23 young subjects (23.3 ± 3.1 years), all males. Three-dimensional segmentations of the whole aorta were created for all timeframes using a semi-automatic approach. The aorta was divided into five segments: ascending aorta, arch, descending aorta, suprarenal and infrarenal abdominal aorta. For each segment, average values of peak WSS, OSI, and RRT were computed. Student's t-tests were used to compare values between the three cohorts (AAA patients vs elderly controls, and elderly controls vs young controls) where the data were normally distributed, and the non-parametric Wilcoxon rank sum tests were used otherwise. Results: AAA patients had lower peak WSS in the descending aorta as well as in the abdominal aorta compared to elderly controls (p ≤ 0.001), similar OSI, but higher RRT in the descending and abdominal aorta (p ≤ 0.001). Elderly controls had lower peak WSS compared to young controls throughout the aorta (p < 0.001), higher OSI in all segments except for the infrarenal aorta (p < 0.001), and higher RRT throughout the aorta, except the infrarenal aorta (p < 0.001). Conclusions: This study provides novel insights into WSS, OSI, and RRT in patients with AAA in relation to normal ageing, highlighting how AAA patients have markedly abnormal hemodynamic stresses not only in the infrarenal, but in the entire aorta. Moreover, we identified RRT as a marker for abnormal AAA hemodynamics. Further investigations are needed to explore if RRT or other measures of hemodynamics stresses best predict AAA growth and/or rupture. [ABSTRACT FROM AUTHOR]

Background and Objective: Modelling patient-specific aortic biomechanics with advanced computational techniques, such as Fluid-Structure Interaction (FSI), can be crucial to provide effective decision-making indices to enhance current clinical practices. To effectively simulate Ascending Thoracic Aortic Aneurysms (ATAA), the stress-free configuration must be defined. The Zero Pressure Geometry (ZPG) and the Prestress Tensor (PT) are two of the main approaches to tackle this issue. However, their impact on the numerical results is yet to be analysed. Computed Tomography Angiography (CTA) and Magnetic Resonance Imaging (MRI) data were used to develop patient-specific 2-way FSI frameworks., Methods: Three models were developed considering different tissue prestressing approaches to account for the reference configuration and their numerical results were compared. The selected approaches were: (i) ZPG, (ii) PT and (iii) a combination of the PT approach with a regional mapping of material properties (PTCAL)., Results: The pressure fields estimated by all models were equivalent. The estimation of Wall Shear Stress (WSS) based metrics revealed good correspondence between all models except the Relative Residence Time (RRT). Regarding ATAA wall mechanics, the proposed extension to the PT approach presented a closer agreement with the ZPG model than its counterpart. Additionally, the PT and PTCAL approaches required around 60% fewer iterations to achieve cycle-to-cycle convergence than the ZPG algorithm., Conclusion: Using a regional mapping of material properties in combination with the PT method presented a better correspondence with the ZPG approach. The outcomes of this study can pave the way for advancing the accuracy and convergence of ATAA numerical models using the PT methodology., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Xavier, José reports financial support was provided by the Foundation for Science and Technology. Xavier, José reports a relationship with NOVA University Lisbon NOVA School of Science & Technology that includes: employment. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background and Objectives: The higher clinical significance of central aortic blood pressure (CABP) compared to peripheral blood pressures has been extensively demonstrated. Accordingly, many methods for noninvasively estimating CABP have been proposed. However, there still lacks a systematic comparison of existing methods, especially in terms of how they differ in the ability to tolerate individual differences or measurement errors. The present study was designed to address this gap., Methods: A large-scale 'virtual subject' dataset (n = 600) was created using a computational model of the cardiovascular system, and applied to examine several classical CABP estimation methods, including the direct method, generalized transfer function (GTF) method, n-point moving average (NPMA) method, second systolic pressure of periphery (SBP2) method, physical model-based wave analysis (MBWA) method, and suprasystolic cuff-based waveform reconstruction (SCWR) method. The errors of CABP estimation were analyzed and compared among methods with respect to the magnitude/distribution, correlations with physiological/hemodynamic factors, and sensitivities to noninvasive measurement errors., Results: The errors of CABP estimation exhibited evident inter-method differences in terms of the mean and standard deviation (SD). Relatively, the estimation errors of the methods adopting pre-trained algorithms (i.e., the GTF and SCWR methods) were overall smaller and less sensitive to variations in physiological/hemodynamic conditions and random errors in noninvasive measurement of brachial arterial blood pressure (used for calibrating peripheral pulse wave). The performances of all the methods worsened following the introduction of random errors to peripheral pulse wave (used for deriving CABP), as characterized by the enlarged SD and/or increased mean of the estimation errors. Notably, the GTF and SCWR methods did not exhibit a better capability of tolerating pulse wave errors in comparison with other methods., Conclusions: Classical noninvasive methods for estimating CABP were found to differ considerably in both the accuracy and error source, which provided theoretical evidence for understanding the specific advantages and disadvantages of each method. Knowledge about the method-specific error source and sensitivities of errors to different physiological/hemodynamic factors may contribute as theoretical references for interpreting clinical observations and exploring factors underlying large estimation errors, or provide guidance for optimizing existing methods or developing new methods., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background and objectives: The main problem of vascular preservation is the maintenance of vessel graft quality and function following extended storage. Conventional preservation solutions such as histidine-tryptophan-ketoglutarate (HTK) solution, Phosphate-Buffer Solution (PBS), or sodium chloride 0.9% has been shown to be inadequate in preserving vascular physiological function after 3 days of cold storage. This study aimed to evaluate whether adenosine and lidocaine (AL) in a modified Krebs-Henseleit (KH) solution can preserve the function and histological structure of rat aortic rings after 6 days. Materials and Methods: Thirty-five aortic rings from male Wistar rats (200-300 g) were harvested and immediately immersed in one of the assigned cold preservation solutions: standard KH, modified KH (mod KH) with lower calcium (Ca 2+ ) and higher magnesium content (Mg 2+ ) with or without adenosine and lidocaine (mod KH-AL), and modified KH with AL, insulin, and melatonin (Mod KH-ALMI). The contraction and relaxation function of the aortic rings were examined using an isometric force transducer after 6 days of cold preservation. Hematoxylin and eosin staining were used to analyze the rings' histological structure. Results: Vascular contraction and relaxation functions were severely affected after a 6-day cold storage period in standard KH. Modifying the KH solution by reducing the Ca 2+ and increasing the Mg 2+ levels greatly recovered the vessel functions. The addition of AL or ALMI to the modified KH did not further recover vascular contractility. However, only the addition of AL to the modified KH increased the ACh-induced relaxation at 6 days when compared to the conventional KH, suggesting that endothelium preservation is improved. From histological analysis, it was found that the addition of AL but not ALMI further improved the endothelial lining and the structure of the elastic membrane layers of the preserved vessels after 6 days of cold preservation. Conclusions: The addition of AL to low calcium-high magnesium KH solution significantly enhanced endothelial preservation and improved endothelial-induced relaxation of preserved vessels after 6 days of cold storage.

Background: Physics-informed neural networks (PINNs) have emerged as a powerful tool for solving inverse problems, especially in cases where no complete information about the system is known and scatter measurements are available. This is especially useful in hemodynamics since the boundary information is often difficult to model, and high-quality blood flow measurements are generally hard to obtain., Methods: In this work, we use the PINNs methodology for estimating reduced-order model parameters and the full velocity field from scatter 2D noisy measurements in the aorta. Two different flow regimes, stationary and transient were studied., Results: We show robust and relatively accurate parameter estimations when using the method with simulated data, while the velocity reconstruction accuracy shows dependence on the measurement quality and the flow pattern complexity. Comparison with a Kalman filter approach shows similar results when the number of parameters to be estimated is low to medium. For a higher number of parameters, only PINNs were capable of achieving good results., Conclusion: The method opens a door to deep-learning-driven methods in the simulations of complex coupled physical systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Properly understanding the origin and progression of the thoracic aortic aneurysm (TAA) can help prevent its growth and rupture. For a better understanding of this pathogenesis, the aortic blood flow has to be studied and interpreted in great detail. We can obtain detailed aortic blood flow information using magnetic resonance imaging (MRI) based computational fluid dynamics (CFD) with a prescribed motion of the aortic wall., Methods: We performed two different types of simulations-static (rigid wall) and dynamic (moving wall) for healthy control and a patient with a TAA. For the latter, we have developed a novel morphing approach based on the radial basis function (RBF) interpolation of the segmented 4D-flow MRI geometries at different time instants. Additionally, we have applied reconstructed 4D-flow MRI velocity profiles at the inlet with an automatic registration protocol., Results: The simulated RBF-based movement of the aorta matched well with the original 4D-flow MRI geometries. The wall movement was most dominant in the ascending aorta, accompanied by the highest variation of the blood flow patterns. The resulting data indicated significant differences between the dynamic and static simulations, with a relative difference for the patient of 7.47±14.18% in time-averaged wall shear stress and 15.97±43.32% in the oscillatory shear index (for the whole domain)., Conclusions: In conclusion, the RBF-based morphing approach proved to be numerically accurate and computationally efficient in capturing complex kinematics of the aorta, as validated by 4D-flow MRI. We recommend this approach for future use in MRI-based CFD simulations in broad population studies. Performing these would bring a better understanding of the onset and growth of TAA., (© 2024. The Author(s).)

Background and Objective: Enhanced external counterpulsation (EECP) is a mechanically assisted circulation technique widely used in the rehabilitation and management of ischemic cardiovascular diseases. It contributes to cardiovascular functions by regulating the afterload of ventricle to improve hemodynamic effects, including increased diastolic blood pressure at aortic root, increased cardiac output and enhanced blood perfusion to multiple organs including coronary circulation. However, the effects of EECP on the coupling of the ventricle and the arterial system, termed ventricular-arterial coupling (VAC), remain elusive. We aimed to investigate the acute effect of EECP on the dynamic interaction between the left ventricle and its afterload of the arterial system from the perspective of ventricular output work., Methods: A neural network assisted optimization algorithm was proposed to identify the ordinary differential equation (ODE) relation between aortic root blood pressure and flow rate. Based on the optimized order of ODE, a lumped parameter model (LPM) under EECP was developed taking into consideration of the simultaneous action of cardiac and EECP pressure sources. The ventricular output work, in terms of aortic pressure and flow rate cooperated with the LPM, was used to characterize the VAC of ventricle and its afterload. The VAC subjected to the principle of minimal ventricular output work was validated by solving the Euler-Poisson equation of cost function, ultimately determining the waveforms of aortic pressure and flow rate., Results: A third-order ODE can precisely describe the hemodynamic relationship between aortic pressure and flow rate. An optimized dual-source LPM with three energy-storage elements has been constructed, showing the potential in probing VAC under EECP. The LPM simulation results demonstrated that the VAC in terms of aortic pressure and flow rate yielded to the minimal ventricular output work under different EECP pressures., Conclusions: The ventricular-arterial coupling under EECP is subjected to the minimal ventricular output work, which can serve as a criterion for determining aortic pressure and flow rate. This study provides insight for the understanding of VAC and has the potential in characterizing the performance of the ventricular and arterial system under EECP., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Biological tissues decay over time after harvesting, which alters their biomechanical properties. This poses logistical challenges for studies investigating passive arterial biomechanics as tissues need to be characterized shortly after excision. Freezing and cryopreservation methods can help alleviate the need for biomechanical testing of fresh tissue in human ex vivo studies. However, these methods tend to eliminate or reduce arterial cell functionality and affect passive biomechanics. Furthermore, their impact on dynamic arterial biomechanics remains unknown despite arterial viscoelastic properties being an integral component contributing to arterial stiffness under in vivo loading conditions. The present study aims to investigate the impact of rapid cooling and subsequent storage at -80 °C on the passive viscoelastic properties of arterial tissue and aid in ascertaining whether this is a suitable method to delay tissue analysis for studies investigating passive arterial biomechanics. Control and frozen abdominal rat aorta segments were quasi-statically and dynamically tested using a biaxial testing set-up. The results were modeled using a constituent-based quasi-linear viscoelastic modeling framework, yielding directional stiffness parameters, individual constituent biomechanical contributions, and a quantification of viscoelastic stiffening under dynamic pressurization conditions. Frozen samples displayed significantly decreased wall thickness, viscoelastic dissipation, viscoelastic stiffening, and significantly decreased circumferential deformation with changes in luminal pressure. Furthermore, frozen samples displayed significantly increased circumferential stiffness, pulse wave velocity, and collagen load bearing. Consequently, these changes should be considered when utilizing this tissue preservation method to delay biomechanical characterization of rat aortic tissue., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Arterial studies indicate that biomechanical changes in the arteries play an important role in the onset and progression of aortic degenerative diseases. It is well known that the organization of collagen fibers determines the mechanical behavior of the arterial wall, through their orientation and dispersion. However, regional differences in the organization and mechanics of collagen fibers along the aorta are only vaguely investigated, and understanding local mechanobiological processes may lead to the identification of key points in the wall remodeling mechanism. Objective: The aim of this study is to evaluate the regional biomechanical differences of the abdominal aorta. Material and methods: We analyzed 60 samples of human aorta (12 from the ascending thoracic aorta, 16 from the aortic cross, 16 from the descending thoracic aorta and 16 from the infrarenal aorta). We used the BioTester® 5000 (CellScale, Waterloo, ON, Canada) for the biaxial biomechanical analysis of the aortic tissue. As for the protocol, we initiated a preconditioning cycle of stretching the sample until reaching the force of 50 mN, followed by 10 cycles of 50 seconds each (25 seconds of stretch and 25 seconds of recovery) until reaching 125% of the initial size. The data generated by the device at the last cycle were used for statistical analysis. Results : After the biomechanical analysis, we observed that, when it comes to Cauchy stress for the longitudinal axis, the infrarenal aorta had the highest tensile stress (p=0.017), meanwhile, for the circumferential one, we observed a difference between all four segments (p=0.003), the most resistant being the descending aorta, followed by the infrarenal, the aortic cross and, lastly, the ascending aorta. Regarding the Young's modulus in the longitudinal axis, there wasn't any significant difference between the samples, but for the circumferential one, the infrarenal aorta showed a higher rigidity than the cross (p=0.024) and the ascending (p=0.046). Conclusions: Descending and infrarenal aorta present greater biomechanical properties than the other 2 segments. This comes to explain why there is a higher incidence of the aneurysms in the ascending and aortic cross, respectively a more frequent apparition of aortic dissection in the descending thoracic aorta. [ABSTRACT FROM AUTHOR]

Background: Phase contrast (PC) cardiovascular magnetic resonance (CMR) imaging with parallel imaging acceleration is established and validated for measuring velocity and flow. However, additional acceleration to further shorten acquisition times would be beneficial in patients with complex vasculature who need multiple PC-CMR measurements, especially pediatric patients with higher heart rates. Methods: PC-CMR images acquired with compressed sensitivity encoding (C-SENSE) factors of 3 to 6 and standard of care PC-CMR with sensitivity encoding (SENSE) factor of 2 (S2) acquired as part of clinical CMR examinations performed between November 2020 and January 2021 were analyzed retrospectively. The velocity and flow through the ascending aorta (AAo), descending aorta (DAo), and superior vena cava (SVC) in a transverse plane at the level of pulmonary artery bifurcation were compared. Additionally, frequency power distribution and dynamic time warp distance were calculated for these acquisitions. To further validate the adequate temporal resolution requirement, patients with S2 PC-CMR in the same acquisition plane were added in frequency power distribution analysis. Results: Twenty-eight patients (25 males; 15.9 ± 1.9 years; body surface area (BSA) 1.7 ± 0.2 m2; heart rate 81 ± 16 bpm) underwent all five PC-CMR acquisitions during the study period. An additional 22 patients (16 males; 17.5 ± 7.7 years; BSA 1.6 ± 0.5 m2; heart rate 91 ± 16 bpm) were included for frequency power spectrum analysis. As expected, scan time decreased with increasing C-SENSE acceleration factor = 3 (37.5 ± 6.5 s, 26.4 ± 7.6%), 4 (28.1 ± 4.9 s, 44.7 ± 5.6%), 5 (21.6 ± 3.6 s, 57.6 ± 4.4%), and 6 (19.1 ± 3.2 s, 62.3 ± 4.2%) relative to SENSE = 2 (51.3 ± 10.1 s) PC-CMR acquisition. Mean peak velocity, net flow, and cardiac output were comparable (p > 0.87) between the five PC-CMR acquisitions with mean differences less than < 4%, < 2%, and < 3% respectively. All individual blood vessels showed a non-significant dependence of difference in fmax99 (< 4 Hz, p > 0.2), and dynamic time warp distance (p > 0.3) on the C-SENSE acceleration factor used. There was a strongly correlated (r = 0.74) increase in fmax99 (10.5 ± 2.2, range: 7.1–16.4 Hz) with increasing heart rate. The computed minimum required cardiac phase number was 15 ± 2.0 (range: 11–20) over the heart rate of 86 ± 15 bpm (range: 58–113 bpm). Conclusions: Stroke volume, cardiac output, and mean peak velocity measurements using PC-CMR with C-SENSE of up to 6 agree with measurements by standard of care PC-CMR with SENSE = 2 and resulted in up to a 65% reduction in acquisition time. Adequate temporal sampling can be ensured by acquiring 20 cardiac phases throughout the entire cardiac cycle over a wide range of pediatric and young adult heart rates. [ABSTRACT FROM AUTHOR]

Introduction: Background: an association between low 25(OH)D levels and blood lipids has been identified in children, adolescents, and adults but not in the early stages of life, and a relation to carotid and aortic intima-media thickness has not been well studied and is controversial. Objective: to identify whether 25(OH)D levels are correlated with blood lipids and aortic and carotid intima-media thickness in infants aged 3 to 9 months. Methods: a cross-sectional study was conducted in 109 healthy term infants between the ages of 3 and 9 months. Serum vitamin D [25(OH)D], total cholesterol, HDL-cholesterol, non-HDL-cholesterol, and aortic and carotid intima-media thickness were measured. Feeding method, vitamin D supplementation, and sun exposure habits were recorded. Results: only 2.8 % (n = 3) and 10.1 % (n = 14) had vitamin D deficiency and insufficiency, respectively. Infants with inadequate levels of vitamin D were younger (< 6 months) (p = 0.004), and a lower percentage of their body surface area was exposed to the sun (p = 0.006). A significant positive correlation was found between 25(OH)D levels and non-HDL-cholesterol in the infants that consumed breastmilk substitutes (rho = 0.600, p < 0.001) or were partially breastfed (rho = 0.371, p = 0.026), whereas a positive correlation was found with total cholesterol in the infants receiving breastmilk substitutes (rho = 0.618, p < 0.001). No significant correlation was found between vitamin D and aortic or carotid intima-media thickness. Conclusions: there was a positive correlation between 25(OH)D levels and both total and non-HDL-cholesterol only in infants receiving breastmilk substitutes. The frequency of vitamin D deficiency and insufficiency was low. [ABSTRACT FROM AUTHOR]

Background: Pre- and post-procedural hemodynamic changes which could affect adverse outcomes in aortic stenosis (AS) patients who undergo transcatheter aortic valve replacement (TAVR) have not been well investigated. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) enables accurate analysis of blood flow dynamics such as flow velocity, flow pattern, wall shear stress (WSS), and energy loss (EL). We sought to examine the changes in blood flow dynamics of patients with severe AS who underwent TAVR. Methods: We examined 32 consecutive severe AS patients who underwent TAVR between May 2018 and June 2019 (17 men, 82 ± 5 years, median left ventricular ejection fraction 61%, 6 self-expanding valve), after excluding those without CMR because of a contraindication or inadequate imaging from the analyses. We analyzed blood flow patterns, WSS and EL in the ascending aorta (AAo), and those changes before and after TAVR using 4D flow CMR. Results: After TAVR, semi-quantified helical flow in the AAo was significantly decreased (1.4 ± 0.6 vs. 1.9 ± 0.8, P = 0.002), whereas vortical flow and eccentricity showed no significant changes. WSS along the ascending aortic circumference was significantly decreased in the left (P = 0.038) and left anterior (P = 0.033) wall at the basal level, right posterior (P = 0.011) and left (P = 0.010) wall at the middle level, and right (P = 0.012), left posterior (P = 0.019) and left anterior (P = 0.028) wall at the upper level. EL in the AAo was significantly decreased (15.6 [10.8–25.1 vs. 25.8 [18.6–36.2]] mW, P = 0.012). Furthermore, a significant negative correlation was observed between EL and effective orifice area index after TAVR (r = − 0.38, P = 0.034). Conclusions: In severe AS patients undergoing TAVR, 4D flow CMR demonstrates that TAVR improves blood flow dynamics, especially when a larger effective orifice area index is obtained. [ABSTRACT FROM AUTHOR]

Background: Chronic type B aortic dissection (TBAD) is associated with poor long term outcome, and accurate risk stratification tools remain lacking. Pressurization of the false lumen (FL) has been recognized as central in promoting aortic growth. Several surrogate imaging based metrics have been proposed to assess FL hemodynamics; however, their relationship to enlarging aortic dimensions remains unclear. We investigated the association between aortic growth and three cardiovascular magnetic resonance (CMR) derived metrics of FL pressurization: false lumen ejection fraction (FLEF), maximum systolic deceleration rate (MSDR), and FL relative pressure (FL ΔPmax). Methods: CMR/CMR angiography was performed in 12 patients with chronic dissection of the descending thoracoabdominal aorta, including contrast enhanced CMR angiography and time-resolved three-dimensional phase-contrast CMR (4D Flow CMR). Aortic growth rate was calculated as the change in maximal aortic diameter between baseline and follow up imaging studies over the time interval, with patients categorized as having either 'stable' (< 3 mm/year) or 'enlarging' (≥ 3 mm/year) growth. Three metrics relating to FL pressurization were defined as: (1) FLEF: the ratio between retrograde and antegrade flow at the TBAD entry tear, (2) MSDR: the absolute difference between maximum and minimum systolic acceleration in the proximal FL, and (3) FL ΔPmax: the difference in absolute pressure between aortic root and distal FL. Results: FLEF was higher in enlarging TBAD (49.0 ± 17.9% vs. 10.0 ± 11.9%, p = 0.002), whereas FL ΔPmax was lower (32.2 ± 10.8 vs. 57.2 ± 12.5 mmHg/m, p = 0.017). MSDR and conventional anatomic variables did not differ significantly between groups. FLEF showed positive (r = 0.78, p = 0.003) correlation with aortic growth rate whereas FL ΔPmax showed negative correlation (r = -0.64, p = 0.026). FLEF and FL ΔPmax remained as independent predictors of aortic growth rate after adjusting for baseline aortic diameter. Conclusion: Comparative analysis of three 4D flow CMR metrics of TBAD FL pressurization demonstrated that those that focusing on retrograde flow (FLEF) and relative pressure (FL ΔPmax) independently correlated with growth and differentiated patients with enlarging and stable descending aortic dissections. These results emphasize the highly variable nature of aortic hemodynamics in TBAD patients, and suggest that 4D Flow CMR derived metrics of FL pressurization may be useful to separate patients at highest and lowest risk for progressive aortic growth and complications. [ABSTRACT FROM AUTHOR]

Introduction: High-intensity endurance training can elicit profound cardiac adaptations; however, the current evidence as to its impact on the proximal aorta is limited. The purpose of this study was to investigate the morphological and functional characteristics of the proximal aorta in endurance athletes. Methods: Fifteen young male middle- and long-distance runners were compared with 19 age- and sex-matched sedentary control participants. CINE phase-contrast magnetic resonance imaging was used to measure blood flow velocities and cross-sectional areas of the ascending and proximal descending aorta. Aortic blood pressure was measured simultaneously during the phase-contrast magnetic resonance imaging scan using a generalized transfer function. Maximal oxygen uptake (V˙O2max) was measured in the athletes. Left ventricular morphology was assessed in a subgroup of participants (n = 16) with cardiac magnetic resonance imaging. Results: The athlete group exhibited an average V˙O2max of 69.5 ± 3.1 mL·kg−1⋅min−1, which is above the 90th percentile of men with similar age according to the American College of Sports Medicine guideline. The athletes had significantly higher stroke volume and slower heart rate at rest and greater left ventricular end-diastolic volume and mass than the sedentary participants. Significantly larger cross-sectional areas and higher compliance of the ascending and proximal descending aorta were also found in the athletes, independently of body surface area. Moreover, higher compliance of the ascending aorta was associated with greater stroke volume (r = 0.382, P = 0.026) and slower heart rate (r = −0.442, P = 0.009) across all participants. Conclusions: The proximal aorta of young male endurance athletes undergoes morphological and functional adaptations that may be resulting from the significant hemodynamic alterations associated with their cardiac function. [ABSTRACT FROM AUTHOR]

Introduction: Poor glycemic control in maternal type 1 diabetes mellitus during pregnancy can affect fetal cardiac and placental function. However, studies concerning fetal central hemodynamics have revealed conflicting results. We hypothesized that in pregnancies complicated by maternal type 1 diabetes, fetal cardiovascular and placental hemodynamics are comparable to the control fetuses at near-term gestation. In addition, we investigated the relation between newborn serum biomarkers of cardiac function and fetal cardiovascular and placental hemodynamics. Furthermore, we studied whether maternal diabetes is associated with placental inflammation.Material and Methods: In this prospective case-control study, fetal central and peripheral hemodynamics were assessed by ultrasonography in 33 women with type 1 diabetes and in 67 controls with singleton pregnancies between 34+2 and 40+2 gestational weeks. Newborn umbilical cord serum was collected to analyze cardiac natriuretic peptides (atrial and B-type natriuretic peptides) and troponin T concentrations. Placental tissue samples were obtained for cytokine analyses.Results: Fetal ventricular wall thicknesses were greater and weight-adjusted stroke volumes and cardiac outputs were lower in the type 1 diabetes group than in the control group. Pulsatility in the aortic isthmus and inferior vena cava blood flow velocity waveforms was greater in the type 1 diabetes group fetuses than in the controls. A positive correlation was found between branch pulmonary artery and aortic isthmus pulsatility index values. Umbilical artery pulsatility indices were comparable between the groups. Umbilical cord serum natriuretic peptide and troponin T concentrations were elevated in the type 1 diabetes fetuses. These cardiac biomarkers correlated significantly with cardiovascular hemodynamics. Placental cytokine levels were not different between the groups.Conclusions: In maternal type 1 diabetes pregnancies, fetal cardiovascular hemodynamics is impaired. Maternal type 1 diabetes does not seem to alter placental vascular impedance or induce placental inflammation. [ABSTRACT FROM AUTHOR]

Aortic pressure can be estimated using one-dimensional arterial flow simulations. This study demonstrates that two peripheral pressure measurements can be used to acquire the central pressure curve through the patient-specific optimization of a set of system parameters. Radial and carotid pressure measurements and parameter optimization were performed in the case of 62 patients. The two calculated aortic curves were in good agreement, Systolic and Mean Blood Pressures differed on average by 0.5 and -0.5 mmHg, respectively. Good agreement was achieved with the transfer function method as well. The effect of carotid clamping is demonstrated using one resulting patient-specific arterial network.

Background: Noninvasive pulse waveform analysis is valuable for central cardiovascular assessment, yet controversies persist over its validity in peripheral measurements. Our objective was to compare waveform features from a cuff system with suprasystolic blood pressure hold with an invasive aortic measurement., Methods and Results: This study analyzed data from 88 subjects undergoing concurrent aortic catheterization and brachial pulse waveform acquisition using a suprasystolic blood pressure cuff system. Oscillometric blood pressure (BP) was compared with invasive aortic systolic BP and diastolic BP. Association between cuff and catheter waveform features was performed on a set of 15 parameters inclusive of magnitudes, time intervals, pressure-time integrals, and slopes of the pulsations. The evaluation covered both static (subject-averaged values) and dynamic (breathing-induced fluctuations) behaviors. Peripheral BP values from the cuff device were higher than catheter values (systolic BP-residual, 6.5 mm Hg; diastolic BP-residual, 12.4 mm Hg). Physiological correction for pressure amplification in the arterial system improved systolic BP prediction ( r 2 =0.83). Dynamic calibration generated noninvasive BP fluctuations that reflect those invasively measured (systolic BP Pearson R =0.73, P <0.001; diastolic BP Pearson R =0.53, P <0.001). Static and dynamic analyses revealed a set of parameters with strong associations between catheter and cuff (Pearson R >0.5, P <0.001), encompassing magnitudes, timings, and pressure-time integrals but not slope-based parameters., Conclusions: This study demonstrated that the device and methods for peripheral waveform measurements presented here can be used for noninvasive estimation of central BP and a subset of aortic waveform features. These results serve as a benchmark for central cardiovascular assessment using suprasystolic BP cuff-based devices and contribute to preserving system dynamics in noninvasive measurements.

Background: Hemocompatibility-related adverse events (HRAE) occur commonly in patients with left ventricular assist devices (LVADs) and add to morbidity and mortality. It is unclear whether the outflow graft orientation can impact flow conditions leading to HRAE. This study presents a simulation-based approach using exact patient anatomy from medical images to investigate the influence of outflow cannula orientation in modulating flow conditions leading to HRAEs., Methods: A 3D model of a proximal aorta and outflow graft was reconstructed from a computed tomography (CT) scan of an LVAD patient and virtually modified to model multiple cannula orientations (n = 10) by varying polar (cranio-caudal) (n = 5) and off-set (anterior-posterior) (n = 2) angles. Time-dependent computational flow simulations were then performed for each anatomical orientation. Qualitative and quantitative hemodynamics metrics of thrombogenicity including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell platelet activation potential (ECAP), particle residence time (PRT), and platelet activation potential (PLAP) were analyzed., Results: Within the simulations performed, endothelial cell activation potential (ECAP) and particle residence time (PRT) were found to be lowest with a polar angle of 85°, regardless of offset angle. However, polar angles that produced parameters at levels least associated with thrombosis varied when the offset angle was changed from 0° to 12°. For offset angles of 0° and 12° respectively, flow shear was lowest at 65° and 75°, time averaged wall shear stress (TAWSS) was highest at 85° and 35°, and platelet activation potential (PLAP) was lowest at 65° and 45°., Conclusion: This study suggests that computational fluid dynamic modeling based on patient-specific anatomy can be a powerful analytical tool when identifying optimal positioning of an LVAD. Contrary to previous work, our findings suggest that there may be an "ideal" outflow cannula for each individual patient based on a CFD-based hemocompatibility profile., (© 2023 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

The failure of the aortic heart valve is common, resulting in deterioration of the pumping function of the heart. For the end stage valve failure, bi-leaflet mechanical valve (most popular artificial valve) is implanted. However, due to its non-physiological behaviour, a significant alteration is observed in the normal haemodynamics of the aorta. While in-vivo experimentation of a human heart valve (native and artificial) is a formidable task, in-silico study using computational fluid dynamics (CFD) with fluid structure interaction (FSI) is an effective and economic tool for investigating the haemodynamics of natural and artificial heart valves. In the present work, a haemodynamic model of a natural and mechanical heart valve has been developed using meshless particle-based smoothed particle hydrodynamics (SPH). In order to further enhance its clinical relevance, this study employs a patient-specific vascular geometry and presents a successful validation against traditional finite volume method and 4D magnetic resonance imaging (MRI) data. The results have demonstrated that SPH is ideally suited to simulate the heart valve function due to its Lagrangian description of motion, which is a favourable feature for FSI. In addition, a novel methodology for the estimation of the wall shear stress (WSS) and other related haemodynamic parameters have been proposed from the SPH perspective. Finally, a detailed comparison of the haemodynamic parameters has been carried out for both native and mechanical aortic valve, with a particular emphasis on the clinical risks associated with the mechanical valve., (© 2024. The Author(s).)

Central aortic diastolic pressure decay time constant ( τ ) is according to the two-element Windkessel model equal to the product of total peripheral resistance ( R ) times total arterial compliance ( C ). As such, it is related to arterial stiffness, which has considerable pathophysiological relevance in the assessment of vascular health. This study aimed to investigate the relationship of the constant τ with the product T MBP cPP , given by heart period ( T ) times the ratio of mean blood pressure (MBP) to central pulse pressure ( cPP ). The relationship was derived by performing linear fitting on an in silico population of n 1  = 3818 virtual subjects, and was subsequently evaluated on in vivo data (n 2  = 2263) from the large Asklepios study. The resulted expression was found to be τ = k ' T MBP cPP , with k ' = 0.7 (R 2  = 0.9). The evaluation of the equation on the in vivo human data reported high agreement between the estimated and reference τ values, with a correlation coefficient equal to 0.94 and a normalized RMSE equal to 5.5%. Moreover, the analysis provided evidence that the coefficient k ' is age- and gender-independent. The proposed formula provides novel theoretical insights in the relationship between τ and central blood pressure features. In addition, it may allow for the evaluation of τ without the need for acquiring the entire central blood pressure wave, especially when an approximation of the cPP is feasible. This study adds to the current literature by contributing to the accessibility of an additional biomarker, such as the central diastolic pressure decay time constant, for the improved assessment of vascular ageing., (© 2024. The Author(s).)

Clinical studies have extensively demonstrated that central aortic blood pressure (CABP) has greater clinical significance in comparison with peripheral blood pressure. Despite the existence of various techniques for noninvasively measuring CABP, the clinical applications of most techniques are hampered by the unsatisfactory accuracy or large variability in measurement errors. In this study, we proposed a new method for noninvasively estimating CABP with improved accuracy and reduced uncertain errors. The main idea was to optimize the estimation of the pulse wave transit time from the aorta to the occluded lumen of the brachial artery under a suprasystolic cuff by identifying and utilizing the characteristic information of the cuff oscillation wave, thereby improving the accuracy and stability of the CABP estimation algorithms under various physiological conditions. The method was firstly developed and verified based on large-scale virtual subject data (n = 800) generated by a computational model of the cardiovascular system coupled to a brachial cuff, and then validated with small-scale in vivo data (n = 34). The estimation errors for the aortic systolic pressure were -0.05 ± 0.63 mmHg in the test group of the virtual subjects and -1.09 ± 3.70 mmHg in the test group of the patients, both demonstrating a good performance. In particular, the estimation errors were found to be insensitive to variations in hemodynamic conditions and cardiovascular properties, manifesting the high robustness of the method. The method may have promising clinical applicability, although further validation studies with larger-scale clinical data remain necessary., (© 2024 John Wiley & Sons Ltd.)

Purpose: High intensity interval training (HIIT) has been shown to improve important health parameters, including aerobic capacity, blood pressure, cardiac autonomic modulation and left ventricular (LV) mechanics. However, adaptations in left atrial (LA) mechanics and aortic stiffness remain unclear.Methods: Forty-one physically inactive males and females were recruited. Participants were randomised to either a 4-week HIIT intervention (n = 21) or 4-week control period (n = 20). The HIIT protocol consisted of 3 × 30-s maximal cycle ergometer sprints with a resistance of 7.5% body weight, interspersed with 2-min of active unloaded recovery, three times per week. Speckle tracking imaging of the LA and M-Mode tracing of the aorta was performed pre and post HIIT and control period.Results: Following HIIT, there was significant improvement in LA mechanics, including LA reservoir (13.9 ± 13.4%, p = 0.033), LA conduit (8.9 ± 11.2%, p = 0.023) and LA contractile (5 ± 4.5%, p = 0.044) mechanics compared to the control condition. In addition, aortic distensibility (2.1 ± 2.7 cm2 dyn-1 103, p = 0.031) and aortic stiffness index (- 2.6 ± 4.6, p = 0.041) were improved compared to the control condition. In stepwise linear regression analysis, aortic distensibility change was significantly associated with LA stiffness change R2 of 0.613 (p = 0.002).Conclusion: A short-term programme of HIIT was associated with a significant improvement in LA mechanics and aortic stiffness. These adaptations may have important health implications and contribute to the improved LV diastolic and systolic mechanics, aerobic capacity and blood pressure previously documented following HIIT. [ABSTRACT FROM AUTHOR]

Background: Although the breath-hold cine balanced steady state free precession (bSSFP) imaging is well established for assessment of biventricular volumes and function, shorter breath-hold times or no breath-holds are beneficial in children and severely ill or sedated patients. Methods: Clinical cardiovascular magnetic resonance (CMR) examinations from September 2019 to October 2019 that included breath-hold (BH) and free-breathing (FB) cine bSSFP imaging accelerated using compressed sensitivity encoding (C-SENSE) factor of 3 in addition to the clinical standard BH cine bSSFP imaging using SENSE factor of 2 were analyzed retrospectively. Patients with structurally normal hearts who could perform consistent BHs were included. Aortic flow measured by phase contrast acquisition was used as a reference for the left ventricular (LV) stroke volume. Comparative analysis was performed for evaluation of biventricular volumes and function, imaging times, quantitative image quality, and qualitative image scoring. Results: There were 26 patients who underwent all three cine scans during the study period (16.7 ± 6.4 years, body surface area (BSA) 1.6 ± 0.4 m2, heart rate 83 ± 7 beats/min). BH durations of 8 ± 1 s with C-SENSE = 3 were significantly shorter (p < 0.001) by 33% compared to 12 ± 1 s with SENSE = 2. Actual scan time for BH SENSE (4.9 ± 1.2 min) was comparable to that with FB C-SENSE (5.2 ± 1.5 min; p= NS). Biventricular stroke volume and ejection fraction, and LV mass computed using all three sequences were comparable. There was a small but statistically significant (p < 0.05) difference in LV end-diastolic volume (− 3.0 ± 6.8 ml) between BH SENSE and FB C-SENSE. There was a small but statistically significant (p < 0.005) difference in end-diastolic LV (− 5.0 ± 7.7 ml) and RV (− 6.0 ± 8.5 ml) volume and end-systolic LV (− 3.2 ± 4.3 ml) and RV(− 4.2 ± 6.8 ml) volumes between BH C-SENSE and FB C-SENSE. The LV stroke volumes from all three sequences had excellent correlations (r = 0.96, slope = 0.98–1.02) with aortic flow, with overestimation by 2.7 (5%) to 4.6 (8%) ml/beat. The image quality score was Excellent (16 of 26) to Good (10 of 26) with BH SENSE, Excellent (13 of 26) to Good (13 of 26) with BH C-SENSE, and Excellent (3 of 26) to Good (21 of 26) to Adequate (2 of 26) with FB C-SENSE. Conclusions: Image quality and ventricular volumetric and functional indices using either BH or FB C-SENSE cine bSSFP imaging were comparable to standard BH SENSE cine bSSFP imaging while maintaining nominally identical spatio-temporal resolution. This accelerated image acquisition provides an alternative to accommodate patients with impaired BH capacity. [ABSTRACT FROM AUTHOR]

Background. Asymptomatic atherosclerosis is a common entity even at young age. Studies have suggested a strong relationship between increased arterial stiffness and asymptomatic carotid atherosclerosis (ACA) in general population, particularly in those with high cardiovascular risk, but no data exist from a younger population free from recognized cardiovascular disease. Hypothesis. We hypothesized there is an association between ACA and aortic pulse wave velocity (PWVao) in middle-aged, apparently healthy, normotensive population to reveal increased cardiovascular risk. Methods. We examined the relationship between ACA and PWVao in 236 apparently healthy, asymptomatic, normotensive, middle-aged subjects (age 47 ± 8 years; 52% women). PWVao was measured with the oscillometric method (Arteriograph). ACA was assessed by carotid artery ultrasonography. Results. ACA was present in 51 subjects. Subjects with ACA were older (p < 0.009), more likely to be smokers (p < 0.001), and had higher systolic blood pressure (SBP, 128 ± 9 vs. 125 ± 10 mmHg, p = 0.048) and PWVao (9.3 ± 1.6 vs. 7.9 ± 1.3 m/s, p < 0.001) than subjects without ACA. In a stepwise logistic regression analysis, only PWVao (odds ratio: 1.88, p < 0.001), smoking habit (odds ratio 3.79, p = 0.003), systolic blood pressure (odds ratio 1.05, p = 0.046), and diastolic blood pressure (odds ratio: 0.94, p = 0.038) were independently associated with ACA. PWVao >8.3 m/s identified ACA with a 71% sensitivity, 65% specificity, 36% positive and 89% negative predictive value, 2.04 relative risk, and 4.54 odds ratio, respectively. Conclusions. PWVao measured by the Arteriograph proved to be an independent marker of ACA. Our study may reveal high CV risk, detected as increased PWVao, which according to our study is related in a very high probability to asymptomatic carotid atherosclerosis in apparently healthy, young, and middle-aged subjects. [ABSTRACT FROM AUTHOR]

Introduction: Peripheral and aortic systolic blood pressure (pSBP and aoSBP) were measured using different methodological and calibration approaches to analyze the association and agreement between pSBP and/or aoSBP, and the association of pSBP and aoSBP with left ventricle (LV) and atrium (LA) structural–functional characteristics. Methods: In healthy subjects (n = 269, age: 9–85 years; n = 147, age < 24 years) LV and LA parameters were echocardiography-derived. pSBP and aoSBP were obtained by brachial sub-diastolic (Mobil-O-Graph®) and supra-systolic oscillometry (Arteriograph®) and aortic diameter waveform re-calibration (RCD; ultrasonography), using three calibration schemes: systo-diastolic (SD), calculated mean (CM), and oscillometric mean (OscM). Results: Always pSBP and aoSBP were positively associated; aoSBP obtained with the Mobil-O-Graph® and calibrated to CM or OscM were the ones that showed the lowest levels of association with the remaining forms of aoSBP and pSBP. Bland-Altman related mean errors varied noticeably (e.g. − 27, − 23, − 17, − 12 or 8 mmHg when aoSBP obtained with MOG (OscM) was compared with data from other methodological and calibration schemes). The aoSBP data obtained with Mobil-O-Graph® (calibration: CM and OscM) showed the highest levels of association with cardiac structural characteristics. aoSBP values obtained calibrating to OscM were higher than those obtained calibrating to SD or CM. Conclusions: aoSBP obtained with Mobil-O-Graph® and calibrated to CM or OscM showed (1) lower association with other forms of aoSBP and pSBP determination and (2) higher levels of association with LV and LA structural characteristics. Differences in aoSBP data between approaches were more sensitive to the calibration method than to the device used. [ABSTRACT FROM AUTHOR]

Aims Accurate assessment of aortic dimensions can be achieved using contrast-enhanced computed tomography. The aim of this study was to define normal values and determinants of aortic dimensions throughout multiple key anatomical landmarks of the aorta in healthy individuals from the Copenhagen General Population Study. Methods and results The study group consisted of 902 healthy subjects selected from 3000 adults undergoing cardiovascular thoracic and abdominal computed tomography-angiography (CTA), where systematic measurements of aortic dimensions were performed retrospectively. Individuals included were without any of the following predefined cardiovascular risk factors: (i) self-reported angina pectoris; (ii) hypertension; (iii) hypercholesterolaemia; (iv) taking cardiovascular prescribed medication including diuretics, statins, or aspirin; (v) overweight (defined as body mass index ≥30 kg/m2); (vi) diabetes mellitus (self-reported or blood glucose >8 mmol/L); and (vii) chronic obstructive pulmonary disease. Maximal aortic diameters were measured at seven aortic regions: sinuses of Valsalva, sinotubular junction, ascending aorta, mid-descending aorta, abdominal aorta at the diaphragm, abdominal aorta at the coeliac trunk, and infrarenal abdominal aorta. Median age was 52 years, and 396 (40%) were men. Men had significantly larger aortic diameters at all levels compared with women (P  <   0.001). Multivariable analysis revealed that sex, age, and body surface area were associated with increasing aortic dimensions. Conclusion Normal values of maximal aortic dimensions at key aortic anatomical locations by contrast-enhanced CTA have been defined. Age, sex, and body surface area were significantly associated with these measures at all levels of aorta. Aortic dimensions follow an almost identical pattern throughout the vessel regardless of sex. [ABSTRACT FROM AUTHOR]

Background: The cells that form the arterial wall contribute to multiple vascular diseases. The extent of cellular heterogeneity within these populations has not been fully characterized. Recent advances in single-cell RNA-sequencing make it possible to identify and characterize cellular subpopulations.Methods: We validate a method for generating a droplet-based single-cell atlas of gene expression in a normal blood vessel. Enzymatic dissociation of 4 whole mouse aortas was followed by single-cell sequencing of >10 000 cells.Results: Clustering analysis of gene expression from aortic cells identified 10 populations of cells representing each of the main arterial cell types: fibroblasts, vascular smooth muscle cells, endothelial cells (ECs), and immune cells, including monocytes, macrophages, and lymphocytes. The most significant cellular heterogeneity was seen in the 3 distinct EC populations. Gene set enrichment analysis of these EC subpopulations identified a lymphatic EC cluster and 2 other populations more specialized in lipoprotein handling, angiogenesis, and extracellular matrix production. These subpopulations persist and exhibit similar changes in gene expression in response to a Western diet. Immunofluorescence for Vcam1 and Cd36 demonstrates regional heterogeneity in EC populations throughout the aorta.Conclusions: We present a comprehensive single-cell atlas of all cells in the aorta. By integrating expression from >1900 genes per cell, we are better able to characterize cellular heterogeneity compared with conventional approaches. Gene expression signatures identify cell subpopulations with vascular disease-relevant functions. [ABSTRACT FROM AUTHOR]

Purpose: Phase‐contrast cardiovascular magnetic resonance (PC‐CMR) quantification of intracardiac shunt (measuring the pulmonary to systemic flow ratio, Qp/Qs) is typically determined by measuring flow through planes perpendicular the pulmonary trunk (PA) and ascending aorta (Ao). This method is subject to error from presence of background velocity offsets and requires two scan acquisitions. We evaluated an alternate PC‐CMR technique for quantifying Qp/Qs using a single modified plane that encompasses both the PA and Ao. Material and Methods: In 53 patients evaluated for intracardiac shunting, PC‐CMR measurement in the individual Ao and PA planes and also in a single‐acquisition plane was obtained and Qp/Qs calculated by each method. Bland–Altman analysis was performed to evaluate the agreement between the two methods. Results: The 95% confidence limits of agreement ranged from −0.52 to +0.34 indicating good agreement between the two methods. There was excellent agreement on the clinically relevant threshold value of Qp/Qs ratio of 1.5 (representing criteria for surgical correction of shunt). Conclusions: Qp/Qs determined from the single‐acquisition approach agrees well with that of the individual PA and Ao method and offers potential improved accuracy (due to background velocity offset). [ABSTRACT FROM AUTHOR]

The early vascular adaptation to indoor cycling, a popular activity at many fitness centres, is incompletely evaluated. Forty two healthy women (21–45 years) underwent measurements of arterial wall properties and geometry as well as a maximal bicycle exercise test before and after a 3 months period during which 21 of the women joined indoor cycling classes at a gym 2–3 times per week, while 21 women served as time controls. Peak work load increased by in average 16% (p<0.001) and ascending aortic diameter by 4% (p<0.01) in the exercise group, while unchanged in control group. The exercise intervention had no significant influence on the local intima-media thickness, blood pressure or the pulse pressure wave configuration while the carotid artery distensibility (p<0.05) was higher after the intervention. There was a positive correlation between change in (Δ) peak work load and Δ-diameter of tubular ascending aorta (r=0.42, p<0.01) in the exercise group. In conclusion, after only 3 months of bicycle exercise training, signs of central arterial remodelling were seen in premenopausal women, which was associated to improvement in exercise capacity. [ABSTRACT FROM AUTHOR]

Background: The prevalence of hypertension among people with chronic kidney disease is high with over 60% of people not attaining recommended targets despite taking multiple medications. Given the health and economic implications of hypertension, additional strategies are needed. Exercise is an effective strategy for reducing blood pressure in the general population; however, it is not known whether exercise would have a comparable benefit in people with moderate to advanced chronic kidney disease and hypertension.Methods: This is a parallel-arm trial of adults with hypertension (systolic blood pressure greater than 130 mmHg) and an estimated glomerular filtration rate of 15-45 ml/min 1.73 m2. A total of 160 participants will be randomized, with stratification for estimated glomerular filtration rate, to a 24-week, aerobic-based exercise intervention or enhanced usual care. The primary outcome is the difference in 24-h ambulatory systolic blood pressure after 8 weeks of exercise training. Secondary outcomes at 8 and 24 weeks include: other measurements of blood pressure, aortic stiffness (pulse-wave velocity), change in the Defined Daily Dose of anti-hypertensive drugs, medication adherence, markers of cardiovascular risk, physical fitness (cardiopulmonary exercise testing), 7-day accelerometry, quality of life, and adverse events. The effect of exercise on renal function will be evaluated in an exploratory analysis. The intervention is a thrice-weekly, moderate-intensity aerobic exercise supplemented with isometric resistance exercise delivered in two phases. Phase 1: supervised, facility-based, weekly and home-based sessions (8 weeks). Phase 2: home-based sessions (16 weeks).Discussion: To our knowledge, this study is the first trial designed to provide a precise estimate of the effect of exercise on blood pressure in people with moderate to severe CKD and hypertension. The findings from this study should address a significant knowledge gap in hypertension management in CKD and inform the design of a larger study on the effect of exercise on CKD progression.Trial Registration: ClinicalTrials.gov, ID: NCT03551119 . Registered on 11 June 2018. [ABSTRACT FROM AUTHOR]

Objective: Subclinical target organ damage (TOD) is an important long‐term complication of hypertension and is associated with cardiovascular events and death. Aortic‐flow propagation velocity (APV) is one of the arterial stiffness parameters. The aim of this study was to investigate the predictive value of APV on left ventricular hypertrophy (LVH) and proteinuria. Methods: A total of 149 newly diagnosed HT patients were included in the study. Urine samples and blood tests were obtained from each patient for diagnosis of proteinuria. All patients underwent echocardiographic examination. All patients' APV measurements, carotid intima‐media thicknesses (CIMT), and ankle‐brachial indexes (ABI) were measured and recorded. Results: The LVH (+) group consisted of 47 patients, and the LVH (−) group consisted of 102 patients. The proteinuria (+) group consisted of 32 patients, and the proteinuria (−) group consisted of 117 patients. Average CIMT was significantly higher in both proteinuria (+) and LVH (+) groups compared with the (−) groups. ABI and APV were significantly lower in both proteinuria (+) and LVH (+) groups compared with the (−) groups. APV was negatively correlated with LVH, proteinuria, and CIMT and positively correlated with ABI. In the multivariate binary logistic regression analysis, APV was the significant independent predictor of proteinuria. Additionally, APV and ABI were found to be independent predictors of LVH or/and proteinuria. Conclusion: Hypertensive patients who had TOD had worse consequences of APV, CIMT, and ABI. APV had a powerful predictive value to identify the patients with higher risk of TOD among newly diagnosed hypertensive patients. [ABSTRACT FROM AUTHOR]

Background: The change of aortic stiffness, but not the particular baseline value, plays a crucial role in estimating the patient risk with end-stage renal disease. Therefore, we aimed to analyze the evolution of central and peripheral arterial stiffness in hemodialysis population without previous cardiovascular events during a 2-year follow-up.Methods: 60 hemodialysis patients (mean age 57.61 ± 13.01 years) were prospectively interviewed, and they underwent blood tests, chest X-ray for aortic calcification evaluation and pulse wave velocity (PWV) measurements at the baseline, after 6 months and after 2 years of observation period.Results: We found significant progression of aortic PWV (12.73 vs. 14.24 m/s, p = 0.032) and regression of brachial PWV (11.53 vs. 8.85 m/s, p < 0.001). CRP increase influenced evolution of aortic PWV (β = 0.331, p = 0.031, R2 = 0.599). Higher β2-microglobulin values was related to the progression of aortic PWV (β = 0.219, p = 0.022, R2 = 0.568). Mean arterial blood pressure had influence only on the short-term arterial stiffness evolution.Conclusions: Patients on maintenance hemodialysis experience pronounced changes of arterial stiffness during the 2-year follow-up period. The progression of aortic stiffness is related to inflammatory response and particularly is influenced by β2-microglobulin concentration and aortic calcification. [ABSTRACT FROM AUTHOR]