Vessel Stiffness Research Articles

Abstract P162: Cardiovascular Disease And Periodontal Disease In Type 1 Diabetes

Type 1 diabetes (T1D) is a condition in which the body’s immune system destroys insulin-producing beta cells, resulting in hyperglycemia. Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in those with T1D. Periodontal disease (PD) is the 6th major complication of T1D. Oral bacteria have been detected in atherosclerotic plaques. Thus, oral bacteria may play a causal role in cardiovascular disease. The aims of this study are to determine how subclinical measures of cardiovascular disease differ by diabetes status and how they are related to the extent of periodontal disease. It is hypothesized that people with T1D will have stiffer vessels with higher pulse wave velocity (PWV), lower brachial artery distensibility (BrachD), and higher carotid intima-media thickness (cIMT) compared to non-diabetic controls. It is also hypothesized that people with T1D will have a higher prevalence of PD compared to non-diabetic controls. Study visits were performed to assess cardiovascular and periodontal outcomes in people with T1D (n=144) and non-diabetic controls (n=147). Univariate analysis was performed using t-test and chi-square to test for significant differences in vascular measures and periodontal status between T1D and controls. Age and sex-adjusted multivariate linear and logistic regression was used to further examine differences in vascular measures and periodontal disease by diabetes status. PWV was significantly higher in people with T1D compared to controls (8.390 +/- 0.111 vs. 7.822 +/- 0.108, p=0.0003). BrachD was significantly lower in people with T1D compared to controls (5.795 +/- 0.095 vs. 6.413 +/- 0.094, p<0.0001). cIMT was significantly higher in people with T1D compared to controls (0.679 +/- 0.009 vs. 0.626 +/- 0.009, p<0.0001). Adults with T1D were significantly more likely to have moderate to severe PD compared to controls (OR = 2.759, 95% CI [1.310-5.811], p=0.0076). Adults with T1D have worse cardiovascular health as measured by stiffer central vessels, more subclinical atherosclerosis, and lower peripheral vessel distensibility. Adults with T1D had almost 3-fold higher risk of moderate to severe PD compared to non-diabetic adults. The relationship between PD and the increased CVD risk in people with T1D warrants further examination.

On component isolation of conceptual advanced reactors

Implementation of component isolation in nuclear industry is challenging due to gaps in research and the lack of specific guidelines. In this study, parameters affecting component-level isolation of advanced reactor vessels are identified based on a representative numerical model with explicit consideration of nonlinear soil-structure interaction (SSI). The objective of this study is to evaluate the effectiveness of, and to identify potential limitations of using conventional friction pendulum bearings to seismically isolate vessels. It is found that slender vessels or components are particularly vulnerable to rotational accelerations at the isolation interface, which are caused by rotation of the sub-structure and by excitation of higher modes in the horizontal direction of the seismically isolated system. Component isolation is found to be more effective for relatively stiffer vessels and at sites with stiff soil. Considering that conventional isolators are deficient in resisting axial tension, it is observed that the optimum location for supporting a component to achieve seismic isolation, is at a cross-sectional plane passing through the center of mass of the vessel. These findings are corroborated by numerous simulations of the response of seismically isolated reactor vessels at different nuclear power plant sites subject to a variety of ground motions.

Microsomal prostaglandin E synthase-1 is involved in the metabolic and cardiovascular alterations associated with obesity.

Microsomal prostaglandin E synthase-1 (mPGES-1) is an inducible isomerase responsible for prostaglandin E2 production in inflammatory conditions. We evaluated the role of mPGES-1 in the development and the metabolic and cardiovascular alterations of obesity. mPGES-1+/+ and mPGES-1-/- mice were fed with normal or high fat diet (HFD, 60% fat). The glycaemic and lipid profile was evaluated by glucose and insulin tolerance tests and colorimetric assays. Vascular function, structure and mechanics were assessed by myography. Histological studies, q-RT-PCR, and western blot analyses were performed in adipose tissue depots and cardiovascular tissues. Gene expression in abdominal fat and perivascular adipose tissue (PVAT) from patients was correlated with vascular damage. Male mPGES-1-/- mice fed with HFD were protected against body weight gain and showed reduced adiposity, better glucose tolerance and insulin sensitivity, lipid levels and less white adipose tissue and PVAT inflammation and fibrosis, compared with mPGES-1+/+ mice. mPGES-1 knockdown prevented cardiomyocyte hypertrophy, cardiac fibrosis, endothelial dysfunction, aortic insulin resistance, and vascular inflammation and remodelling, induced by HFD. Obesity-induced weight gain and endothelial dysfunction of resistance arteries were ameliorated in female mPGES-1-/- mice. In humans, we found a positive correlation between mPGES-1 expression in abdominal fat and vascular remodelling, vessel stiffness, and systolic blood pressure. In human PVAT, there was a positive correlation between mPGES-1 expression and inflammatory markers. mPGES-1 inhibition might be a novel therapeutic approach to the management of obesity and the associated cardiovascular and metabolic alterations.

4D flow cardiovascular magnetic resonance recovery profiles following pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension

BackgroundFour-dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR) allows comprehensive assessment of pulmonary artery (PA) flow dynamics. Few studies have characterized longitudinal changes in pulmonary flow dynamics and right ventricular (RV) recovery following a pulmonary endarterectomy (PEA) for patients with chronic thromboembolic pulmonary hypertension (CTEPH). This can provide novel insights of RV and PA dynamics during recovery. We investigated the longitudinal trajectory of 4D flow metrics following a PEA including velocity, vorticity, helicity, and PA vessel wall stiffness.MethodsTwenty patients with CTEPH underwent pre-PEA and > 6 months post-PEA CMR imaging including 4D flow CMR; right heart catheter measurements were performed in 18 of these patients. We developed a semi-automated pipeline to extract integrated 4D flow-derived main, left, and right PA (MPA, LPA, RPA) volumes, velocity flow profiles, and secondary flow profiles. We focused on secondary flow metrics of vorticity, volume fraction of positive helicity (clockwise rotation), and the helical flow index (HFI) that measures helicity intensity.ResultsMean PA pressures (mPAP), total pulmonary resistance (TPR), and normalized RV end-systolic volume (RVESV) decreased significantly post-PEA (P < 0.002). 4D flow-derived PA volumes decreased (P < 0.001) and stiffness, velocity, and vorticity increased (P < 0.01) post-PEA. Longitudinal improvements from pre- to post-PEA in mPAP were associated with longitudinal decreases in MPA area (r = 0.68, P = 0.002). Longitudinal improvements in TPR were associated with longitudinal increases in the maximum RPA HFI (r=-0.85, P < 0.001). Longitudinal improvements in RVESV were associated with longitudinal decreases in MPA fraction of positive helicity (r = 0.75, P = 0.003) and minimum MPA HFI (r=-0.72, P = 0.005).ConclusionWe developed a semi-automated pipeline for analyzing 4D flow metrics of vessel stiffness and flow profiles. PEA was associated with changes in 4D flow metrics of PA flow profiles and vessel stiffness. Longitudinal analysis revealed that PA helicity was associated with pulmonary remodeling and RV reverse remodeling following a PEA.

Non-Invasive Methods for PWV Measurement in Blood Vessel Stiffness Assessment.

In recent years, statistical studies highlighted an increasing incidence of cardiovascular diseases (CVD) which reflected on additional costs on the healthcare systems worldwide. Pulse wave velocity (PWV) measurement is commonly considered a CVD predictor factor as well as a marker of Arterial Stiffness (AS) since it is closely related to the mechanical characteristics of the arterial wall. An increase in PWV is due to a more rigid arterial system. Because of the prevalence of the elastic component, in young people the PWV is lower than in the elderly. Nowadays, invasive and non-invasive methods for PWV assessment are employed: there is an increasing attention in the development of non-invasive devices which mostly perform a regional PWV measurement (over a long arterial portion) rather than local (over a short arterial portion). The accepted gold-standard for non-invasive AS measurement is the carotid-femoral PWV used to evaluate the arterial damage, the corresponding cardiovascular risk and to adapt the proper therapy. This review article considers the main commercially available devices underlining their operating principles in terms of sensors, execution mode, pulse waveforms acquired, site of measurement, distance and time estimation methods, as well as their main limitations in clinical practice.

In Vitro Measurement of Contact Pressure Applied to a Model Vessel Wall during Balloon Dilation by Using a Film-Type Sensor.

As an important evaluation index of vascular damage, the study aims to clarify the value of contact pressure applied to blood vessels and how it changes with respect to balloon pressure during balloon dilation. The contact pressure was evaluated through an in vitro measurement system using a model tube with almost the same elastic modulus as the blood vessel wall and our film-type pressure sensor. A poly (vinyl alcohol) hydrogel tube with almost the same elastic modulus was fabricated as the model vessel. The film-type sensor was inserted between the balloon catheter and the model vessel, and the balloon was dilated. The contact pressure applied to the blood vessel was less than 10% of the balloon pressure, and the increase in contact pressure was less than 1% of the increase in balloon pressure (8 to 14 atm). Moreover, the contact pressure and its increase were larger in the model with a high elastic modulus. The contact pressure to expand the soft vessel model was not high, and the balloon pressure almost appeared to act on the expansion of the balloon itself. Our experiment using variable stiffness vessel models containing film-type sensors showed that the contact pressure acting on the vessel wall tended to increase as the wall became harder, even when the nominal diameter of the balloon was almost identical to the vessel. Our results can be clinically interpreted: when a vessel is stiff, the high-pressure inflation may rupture it even if its nominal diameter is identical to the diameter of the vessel.

Assessment of the structural and functional state of blood vessels in patients with hypertrophic cardiomyopathy

Aim To evaluate the structural and functional condition of the vasculature using fingertip photoplethysmography and computerized videocapillaroscopy in patients with hypertrophic cardiomyopathy (HCMP).Material and methods The study included patients with HCMP (n=48; 28 (57 %) men; age, 54.3±13.6 years) and healthy volunteers (control group, n=33, 15 (45 %) men; age, 58.2±8.8 years). Standard laboratory and instrumental examination (blood count and biochemistry, electrocardiography, echocardiography, Holter electrocardiogram monitoring) were performed for all HCMP patients. The condition of vascular wall at various levels of the vasculature was evaluated by fingertip photoplethysmography (apparatus Angioscan-01) and computerized nail-fold videocapillaroscopy (apparatus Capillaroscan-01). The photoplethysmography study analyzed structural parameters, including the arterial wall stiffness index (aSI) of large blood vessels and the resistance index (RI) of small muscular arteries. Endothelial dysfunction was evaluated by the occlusion index (OI) and phase shift (PS). The capillaroscopy study assessed structural parameters, including the resting capillary density (rCD) and the capillary density following venous occlusion (voCD), and functional parameters, including the percentage of perfused capillaries (PPC), the percentage of restored capillaries (PRC), and the capillary density after the reactive hyperemia test (rhCD).Results The study showed increases in aSI (8.8 [6.8; 12.2] and RI (32.5 [17.4; 47.9] in the HCMP group. The OI was significantly lower in the HCMP group (1.3 [1.1; 1.5]) than in the control group (1.8 [1.5; 2.7], р&lt;0.001). Also, PS values were significantly decreased in the HCMP group (4.4 [2.3; 8.6]) compared to the control group (8.4 [5.1; 12.1]. p=0.018). Disorders of structural and functional capillary indexes were observed in HCMP patients compared to the control group; rCD and voCD were decreased in the HCMP group (60 [52.6; 68] and 88 [75; 90], respectively) compared to the control group (75.8 [60; 87] and 90 [73; 101]), however, no intergroup difference reached a statistical significance. The rhCD, PPC, and PRC values were decreased in the HCMP group (66.3 [55; 72], 86.7 [70.9; 104.2] and 1.7 [-6.95; 20.3], respectively) compared to the control group (86 [68.6; 100], 103 [96; 114] and 18.4 [8.1; 27.4], respectively); PPC and PRC values were significantly different (р&lt;0.005 and p&lt;0.004, respectively).Conclusion In patients with HCMP, fingertip photoplethysmography and computerized videocapillaroscopy showed increased wall stiffness in both large blood vessels and microvasculature, pronounced endothelial dysfunction, and decreases in capillary density and percentage of restored capillaries following respective tests.

Stressor-Induced "Inflammaging" of Vascular Smooth Muscle Cells via Nlrp3-Mediated Pro-inflammatory Auto-Loop.

Calcification of the vessel wall as one structural pathology of aged vessels is associated with high cardiovascular mortality of elderly patients. Aging is linked to chronic sterile inflammation and high burden of reactive oxygen species (ROS), leading to activation of pattern recognition receptors (PRRs) such as Nlrp3 in vascular cells. The current study investigates the role of PRR activation in the calcification of vascular smooth muscle cells (VSMCs). Therefore, in vitro cell culture of primary rat VSMCs and ex vivo aortic stimulations were used to analyze osteogenic, senescence and inflammatory markers via real-time PCR, in situ RNA hybridization, Western Blot, photometric assays and histological staining. Induction of ROS and DNA-damage by doxorubicin induces a shift of VSMC phenotype toward the expression of osteogenic, senescence and inflammatory proteins. Induction of calcification is dependent on Nlrp3 activity. Il-1β as a downstream target of Nlrp3 induces the synthetic, pro-calcifying VSMC phenotype. Inhibition of PRR with subsequent reduction of chronic inflammation might be an interesting target for reduction of calcification of VSMCs, with subsequent reduction of cardiovascular mortality of patients suffering from vessel stiffness.

The Temporal Pattern of Arterial Stiffness during Aging: A Large-Scale Cross-Sectional Study.

Brachial-ankle pulse wave velocity (baPWV) is a noninvasive clinical test that provides quantification for the stiffness of both the aorta and peripheral arteries by measuring the brachial and tibial arterial wave velocities. The temporal pattern of baPWV values during aging was investigated in this paper. A gradual increase in baPWV with respect to age was observed, suggesting an increase in the stiffness of arterial vessels as age increases. The ΔbaPWV value, defined as the absolute value of the difference between bilateral baPWV, also showed a positive correlation with aging. Many underlying physiological conditions such as hyperlipidemia, hypertension, diabetes, and hyperglycemia have previously been shown to elevate baPWV and contribute to the decline of arterial function. The effect of factors including biological sex, blood pressure, and blood glucose levels on the baPWV temporal pattern were also investigated. Between the ages of 18 and 50, men in the study had significantly higher baPWV readings than females of comparable age on average. However, after the age of 50, mean baPWV values increased at a greater rate in females than in males. In addition, blood pressure and blood glucose were shown to be associated with baPWV values. The results will improve existing prediction models for future cardiovascular episodes induced by arterial hardening in different age groups.

On the Evaluation of a Novel Hypoxic 3D Pancreatic Cancer Model as a Tool for Radiotherapy Treatment Screening.

Simple SummaryPancreatic cancer challenges global health with non-specific symptoms, devastatingly low survival rates, and high treatment resistance profiles. Tissue engineering is advancing to facilitate animal free tissue biomimicry, allowing the replication of tumour tissue specific hallmarks of pancreatic cancer that challenge modern treatments. Here, we report the development and characterisation of a low oxygen (hypoxic) 3D polyurethane scaffold system for long-term analysis of radiation responses. This finely tuned platform more accurately recapitulates bio-physical, bio-chemical, and structural-bio-mechanical in vivo tissue niches as well as tumour hypoxia. The latter is a treatment-limiting feature for radiotherapy, allowing the system to streamline the transition of clinical testing from bench to bedside.Tissue engineering is evolving to mimic intricate ecosystems of tumour microenvironments (TME) to more readily map realistic in vivo niches of cancerous tissues. Such advanced cancer tissue models enable more accurate preclinical assessment of treatment strategies. Pancreatic cancer is a dangerous disease with high treatment resistance that is directly associated with a highly complex TME. More specifically, the pancreatic cancer TME includes (i) complex structure and complex extracellular matrix (ECM) protein composition; (ii) diverse cell populations (e.g., stellate cells), cancer associated fibroblasts, endothelial cells, which interact with the cancer cells and promote resistance to treatment and metastasis; (iii) accumulation of high amounts of (ECM), which leads to the creation of a fibrotic/desmoplastic reaction around the tumour; and (iv) heterogeneous environmental gradients such as hypoxia, which result from vessel collapse and stiffness increase in the fibrotic/desmoplastic area of the TME. These unique hallmarks are not effectively recapitulated in traditional preclinical research despite radiotherapeutic resistance being largely connected to them. Herein, we investigate, for the first time, the impact of in vitro hypoxia (5% O2) on the radiotherapy treatment response of pancreatic cancer cells (PANC-1) in a novel polymer (polyurethane) based highly macroporous scaffold that was surface modified with proteins (fibronectin) for ECM mimicry. More specifically, PANC-1 cells were seeded in fibronectin coated macroporous scaffolds and were cultured for four weeks in in vitro normoxia (21% O2), followed by a two day exposure to either in vitro hypoxia (5% O2) or maintenance in in vitro normoxia. Thereafter, in situ post-radiation monitoring (one day, three days, seven days post-irradiation) of the 3D cell cultures took place via quantification of (i) live/dead and apoptotic profiles and (ii) ECM (collagen-I) and HIF-1a secretion by the cancer cells. Our results showed increased post-radiation viability, reduced apoptosis, and increased collagen-I and HIF-1a secretion in in vitro hypoxia compared to normoxic cultures, revealing hypoxia-induced radioprotection. Overall, this study employed a low cost, animal free model enabling (i) the possibility of long-term in vitro hypoxic 3D cell culture for pancreatic cancer, and (ii) in vitro hypoxia associated PDAC radio-protection development. Our novel platform for radiation treatment screening can be used for long-term in vitro post-treatment observations as well as for fractionated radiotherapy treatment.

Stiffness characteristic of high temperature superconducting upper maglev system

High temperature superconducting (HTS) magnetic levitation (maglev) train, by virtue of its passive stabilization, has the potential to become the next generation high-speed rail transit mode. For the further practical HTS maglev dynamic study and design, the levitation stiffness between the superconductors and the permanent magnet plays a significant role. Due to the nonlinear characteristics and the hysteresis phenomenon of the levitation force, the levitation stiffness is a variadic value. This varying stiffness complicates the vibration reduction design. And the violent vibrations caused by the lack of reasonable design can endanger the safety and comfort of the vehicle. In this paper, the levitation stiffness of a YBaCuO superconductor vessel levitating above a permanent magnetic guideway (PMG) in Halbach-array was measured and analyzed. First, a quasi-static experiment was designed to measure the levitation stiffness, which will be assessed during different vessel movement, separately. Subsequently, the natural frequencies of the levitation system under different working loads were measured by a series of dynamic experiments, and the levitation stiffness calculated by vibration was compared with the test result of the quasi-static experiment. Finally, a systematic differential equation was proposed to describe the levitation stiffness varying phenomena, and its dynamic characteristics were analyzed and verified by simulations as well. The result of this paper shows that the levitation stiffness does not have a strong regular relation with the levitation height as prediction but has a linear relation with the levitation force in the limit space above the PMG. And the studies about the stiffness characteristics with the proposed stiffness model in this paper can provide reference for engineering application and relative dynamic calculations.

Abstract 10730: Vascular Smooth Muscle Cell Phenotypic Switch and Replication Stress as a Key Contributors in CVD in HGPS

Hutchinson Gilford Progeria Syndrome is a premature aging disease caused by LMNA gene mutation and production of a truncated lamin A protein “progerin” that elicits cellular and organismal toxicity. Patients show severe aging phenotypes, including alopecia, reduced fat and bone density, and cardiovascular disease (CVD), which ultimately causes their death as teenagers. HGPS has no cure and clinical trials obtained only minor benefits. It is urgent to identify mechanisms of progerin toxicity to target therapeutically. Progerin accumulates preferentially in the vasculature, being especially toxic for vascular smooth muscle cells (VSMC). Patients' autopsies show that vessel stiffening and aortic atherosclerosis are accompanied by VSMCs depletion in the media, increased extracellular matrix (ECM), and adventitia thickening. Mechanisms whereby progerin causes massive VSMC loss and ECM accumulation are unknown. We previously demonstrated that progerin expression in fibroblasts hinders DNA replication, causes genomic instability, and triggers a phenotypic switch towards activated fibroblasts/myofibroblasts. These cells are known to promote tissue fibrosis by ECM deposition and release of inflammatory cytokines. VSMCs can also undergo phenotypic modulation or de-differentiation, a process whereby contractile cells revert to a synthetic/proliferative phenotype, leading to pathological accumulation of ECM and CVD. Here we show that progerin expression in VSMCs causes a switch towards the synthetic/proliferative phenotype. Similarly to fibroblasts, progerin represents a challenge for DNA replication in VSMC, triggering replication stress, genomic instability and ultimately VSMC death. Importantly, we found that calcitriol -hormonal active form of vitamin D- prevents VSMC switch and replication stress. Our data suggest that replication stress might be an underlying cause of VSMC loss in progeria and that preventing the phenotypic switch-induced replication stress with compounds such as calcitriol might prevent the massive loss of VSMC and the vascular stiffness in HGPS patients.

Abstract 10371: Trajectories of Glycemic Control and Early Markers of Cardiovascular Disease in Canadian Adolescents with Type 1 Diabetes: The Cardea Study

Introduction: Adequate glycemic control can prevent or delay complications of diabetes. Little is known about the role of glycemic control trajectories on early markers of CVD in youth. Hypothesis: Poor glycemic control trajectory will be associated with increased vascular ageing and altered myocardial structure. Methods: Cross-sectional study of 100 youth with T1D recruited at Sainte-Justine Hospital, Canada. Trajectories of glycated hemoglobin (Hb A1c ) were estimated with group-based trajectory modelling, using 3 to 6 values retrieved from patients’ medical records over the preceding year. Vessel stiffness was assessed by pulse-wave velocity (PWV) and distensibility by velocity time integral (VTI) and acceleration during a brachial flow-mediated dilation test. Cardiac magnetic resonance assessed ejection fraction, left ventricular mass indexed by height (LVMH), papillary mass and wall thickness. Linear regression models were estimated between Hb A1c trajectory group and each CVD marker, with age, sex, ethnicity and duration of diabetes at baseline as covariates. Results: Mean age was 16.4 yrs (SD=1.3) and median diabetes duration 6.1 yrs (IQR=3.4-10.4). Forty-eight percent were girls, 63% were White and 43% had overweight/obesity. Three trajectories of Hb A1c were identified ( Figure ). Compared with the optimal trajectory, belonging to the high Hb A1c trajectory was associated with a lower ejection fraction (beta [95% CI]: -2.1% [-6.2; 2.0]), LVMH (-6.3 g/m [-15.4; 2.8]) and papillary mass (-1.2 g [-2.2; -0.2]). Youth in the high Hb A1c trajectory displayed higher PWV (0.2 m/s [-0.4; 0.8]) and lower VTI (-2.9 cm/s 2 [-8.4; 2.7]) and acceleration (-63.6 cm/s 2 [-188.7; 61.5]) compared with the optimal trajectory group. Conclusions: Poor glycemic control is linked to increased vascular ageing and a lower myocardial mass in youth with T1D, which is consistent with our prior finding that youth with T1D exhibit a lower myocardial mass than healthy controls.

Arterial Stiffness in Renal Transplant Recipients: 5-Year Follow-up

Chronic kidney disease is a risk factor for cardiovascular diseases. After renal transplant, some traditional and chronic kidney disease-specific risk factors vanish, but new risk factors emerge. This retrospective study aimed to define the long-term impact of renal transplant and diabetes mellitus on arterial stiffness, evaluated by measuring pulse wave velocity (PWV) and augmentation index (AI) and on myocardial perfusion, evaluated by subendocardial viability ratio (SEVR). PWV, AI, and SEVR were evaluated noninvasively by applanation tonometry using SphygmoCor in the first 4 weeks after kidney transplant and 4 to 5 years thereafter. A total of 48 graft recipients (18 women, 30 men; mean ± standard deviation age, 47.9 ± 11.8 years) were included. The follow-up period was 57.4 ± 8.0 months. PWV did not change significantly during the follow-up period (9.1 ± 1.8m/s and 8.7 ± 1.8m/s, respectively; P=.137). In the subgroup of patients without diabetes mellitus, we observed a trend of PWV reduction, whereas in the subgroup of patients with diabetes we observed the trend of PWV increase. The duration of smoking before transplant correlated significantly with PWV (P=.012). AI in the whole group increased significantly during the study period (from 18.3% ±10.3% to 25.9% ±9.4%; P < .01) as well as SEVR (from 134.9 ± 23.1 to 155.4 ± 28.6; P=.001). PWV, reflecting the central vessel stiffness, did not change significantly in the whole group during the follow-up period. The AI, which indicates systemic stiffness, increased significantly within 5 years after transplant, indicating the progression of vascular processes of elastic and muscular arteries. Significant increases in the SEVR values in both diabetics and nondiabetics indicate the long-term favorable effect of kidney transplant on myocardial perfusion.

High Pulsatile Load Decreases Arterial Stiffness: An ex vivo Study.

Measuring arterial stiffness has recently gained a lot of interest because it is a strong predictor for cardiovascular events and all-cause mortality. However, assessing blood vessel stiffness is not easy and the in vivo measurements currently used provide only limited information. Ex vivo experiments allow for a more thorough investigation of (altered) arterial biomechanical properties. Such experiments can be performed either statically or dynamically, where the latter better corresponds to physiological conditions. In a dynamic setup, arterial segments oscillate between two predefined forces, mimicking the diastolic and systolic pressures from an in vivo setting. Consequently, these oscillations result in a pulsatile load (i.e., the pulse pressure). The importance of pulse pressure on the ex vivo measurement of arterial stiffness is not completely understood. Here, we demonstrate that pulsatile load modulates the overall stiffness of the aortic tissue in an ex vivo setup. More specifically, increasing pulsatile load softens the aortic tissue. Moreover, vascular smooth muscle cell (VSMC) function was affected by pulse pressure. VSMC contraction and basal tonus showed a dependence on the amplitude of the applied pulse pressure. In addition, two distinct regions of the aorta, namely the thoracic descending aorta (TDA) and the abdominal infrarenal aorta (AIA), responded differently to changes in pulse pressure. Our data indicate that pulse pressure alters ex vivo measurements of arterial stiffness and should be considered as an important variable in future experiments. More research should be conducted in order to determine which biomechanical properties are affected due to changes in pulse pressure. The elucidation of the underlying pulse pressure-sensitive properties would improve our understanding of blood vessel biomechanics and could potentially yield new therapeutic insights.

Application of enhanced external counterpulsation in treating patients with stable ischemic heart disease

Abstract Introduction Currently, enhanced external counterpulsation (EECP) is one of the safest non-invasive treatments for patients with coronary artery disease (CAD). In combination with traditional drug therapy, EECP can significantly improve the quality of life of patients by increasing coronary perfusion, improving myocardial contractile function, and improving endothelial function. Aim To study the effect of EECP on clinical status, quality of life (QL) and structural-functional state of blood vessels in patients with stable coronary artery disease. Materials and methods In the present study 67 CAD patients were included (average age 65.7±5.66 years; men 71.9%, angina pectoris of functional class II-III (FC)). All patients were on optimal medical therapy (ACE inhibitors, beta-blockers, antiplatelet agents, statins, nitrates), which remained unchanged during the follow-up. Patients were given a course of EECP (35 procedures 220–280 mmHg.art.). Test 6-minute walk (T6MW), QL (Minnesota Satisfaction Questionnaire (MSQ)), echocardiography (ejection fraction of the left ventricle (LVEF)) were performed at baseline and after 6 months. In addition, all the patients underwent laser photoplethysmography (Stiffness index (SI, m/s), phase shift (PS m/s) occlusion index (OI), nail fold videocapillaroscopy (capillary density at rest, after reactive hyperemia and venous occlusion (CDr, CDrh, CDvo, respectively, cap/mm2) and applanation tonometry (central aortic systolic pressure (CASP), (radial augmentation index (RAI)) in order to assess structural and functional characteristics of blood vessels. Results In six months after EECP, significant improvement in patient's condition was found. T6MW distance (212±32 vs 251±29 m, p&amp;lt;0.05), QL MSQ (20.1±6.2 vs 41,6±7,1, p&amp;lt;0.05) and LVEF (40.9±7,6% vs 45.2±10.1%, p&amp;lt;0.05) increased significantly. Stiffness of large vessels was found to be decreased. CASP, RAI and SI decreased significantly, (CASP: 131±15.8 vs 129±14.8 mmHg, p&amp;lt;0.05), (RAI: 97.2±25.1 vs 97±21.6%, p&amp;lt;0.05), (SI: 8.9±1.5 vs 8.8±,1.6 m/s, p&amp;lt;0.05), Functional characteristics of large blood vessels significantly improved (PS (5.6±1.2 vs 6.8±1.4 m/s, p&amp;lt;0.05). Microcirculation - Reflection index (106.7 vs 95.3%, p&amp;lt;0.05) and OI (1.5±0.3 vs 1.66±0.26, p&amp;lt;0.05) for all. Increase CDrest (44±12.2–44.6±11.5 capillaries, p&amp;gt;0.05), in samples with CDrh (45±14 vs 57±16 capillaries, p&amp;lt;0.05) and CDvo (55±15–56 vs 4±14.2 capillaries, p&amp;lt;0.05). Conclusion ECCP treatment of patients with stable CAD, in addition to optimal drug therapy, led to an increase in load tolerance and improvement of the QL, myocardial contractile function, accompanied by improvement of the structural and functional state of large vessels and microcirculatory bed. Funding Acknowledgement Type of funding sources: None.

Transluminal compression increases mechanical stability, stiffness and endothelialization capacity of fibrin-based bioartificial blood vessels

Fibrin is used successfully as a biological matrix in various bioengineering approaches. Its unique combination of autologous availability, hemocompatibility and biological activity makes it an almost ideal matrix material for vascular tissue engineering. However, clinical application of fibrin-based bioartificial blood vessels is still limited due to insufficient mechanical stability and stiffness of fibrin matrices. Biomechanical properties of fibrin-based constructs can potentially be modified by adjusting matrix density. Thus, as an attempt to optimize strength and elasticity of fibrin matrices for vascular tissue engineering applications, we developed a simple and reproducible method for transluminal compression of small-diameter fibrin-based vessels: After initial polymerization of high-concentration fibrin matrices in a vascular mold, vessels were compressed using an intraluminal angioplasty balloon. Vessels compacted with different pressures were compared for ultimate strength, elastic and structural properties and cellularization capacity.Transluminal compression increased fibrin network density and facilitated rapid production of homogenous vessels with a length of 10 cm. Compared to non-compressed controls, compacted fibrin vessels showed superior maximal burst pressure (199.8 mmHg vs. 94.0 mmHg), physiological elastic properties similar to the elastic behavior of natural arteries and higher luminal endothelial cell coverage (98.6% vs. 34.6%). Thus, transluminal compaction represents a suitable technique to enhance biomechanical properties of fibrin-based bioartificial vessels while preserving the biological advantages of this promising biomaterial.

IMPROVEMENT OF CARDIOVASCULAR FUNCTION HEALTH LEVEL BY REGULAR SPORTS

ABSTRACT Introduction Regular physical activity helps improve cardiovascular and cerebrovascular skills. How to evaluate the nervous tension of the cardiovascular and cerebrovascular vessels through sports is a hot topic. Objective The paper discusses the influence of regular participation in sports on people’s cardiovascular function and blood-related indicators. Methods We select 30 healthy older adults who regularly participate in sports, record their ECG changes, blood pressure, heart rate and other related cardiovascular function indicators, and analyze the blood function of the elderly. Detection of blood cell count (RBC), red blood cell volume (MCV) and hemoglobin (Hb), serum creatinine (Cr), blood glucose (BGS), triglycerides (TG), cholesterol (TC), low-density lipoprotein (LDL) and high-Density lipoprotein (HDL) is measured. Results Older adults who persist in exercise for a long time have better indicators than those who do not exercise. Conclusions Appropriate aerobic exercise can reduce the stiffness of blood vessels in the elderly. Exercise can help the elderly increase heart rate variability and improve the heart’s autonomic nerve function’s blood indicators, and body mass. Level of evidence II; Therapeutic studies - investigation of treatment results.

Relationship between Psoriasis and Prevalence of Cardiovascular Disease in 88 Japanese Patients.

Psoriasis is a systemic inflammatory disease known to affect survival in the presence of cerebral or cardiovascular comorbidities. However, no clear guidelines have been defined regarding the extent of vascular lesion testing that should be performed in patients with psoriasis. We therefore performed coronary computed tomography angiography (CCTA) in 88 Japanese patients with psoriasis who visited Kansai Medical University Hospital between 2015 and 2019 and determined the ankle–brachial pressure index (ABI) for 44 of these patients. CCTA abnormalities were found in 39 of the 88 patients, and a need for treatment was identified in 14 patients. The prevalence of cardiovascular lesions in these patients was 15.9%, significantly higher than that in the healthy Japanese population (6.38% according to the Suita Study). In the 44 patients with results for both ABI and CCTA, the rates of CCTA vascular lesions were significantly higher in cases with ABIs indicating hard vessels or above than in cases with supple, normal, or slightly stiff vessels. This is the first report to show a correlation between CCTA and ABI in psoriasis patients. ABI was considered useful as a preliminary test before CCTA. The univariate analysis of the abnormal and normal CCTA groups showed that the prevalence differed significantly among patients with psoriatic arthritis, erythrodermic psoriasis, older age, pre-existing conditions, drinking, and hypertension. The multivariate analysis showed correlations with arthritic or erythrodermic psoriasis.

Advances in vascular anatomy and pathophysiology using high resolution and multiparametric sonography.

B-mode and Color Doppler are the first-line imaging modalities in cardiovascular diseases. However, conventional ultrasound (US) provides a lower spatial and temporal resolution (70–100 frames per second) compared to ultrafast technology which acquires several thousand frames per second. Consequently, the multiparametric ultrafast platforms manage new imaging algorithms as high-frequency ultrasound, contrast-enhanced ultrasound, shear wave elastography, vector flow, and local pulse wave imaging. These advances allow better ultrasound performances, more detailed blood flow visualization and vessel walls’ characterization, and many future applications for vascular viscoelastic properties evaluation.In this paper, we provide an overview of each new technique’s principles and concepts and the real or potential applications of these modalities on the study of the artery and venous anatomy and pathophysiology of the upper limb before and after creating a native or prosthetic arterio-venous fistula. In particular, we focus on high-frequency ultrasound that could predict cannulation readiness and its potential role in the venous valvular status evaluation before vascular access creation; on contrast-enhanced ultrasound that could improve the peri-operative imaging evaluation during US-guided angioplasty; on shear wave elastography and local pulse wave imaging that could evaluate preoperative vessels stiffness and their potential predictive role in vascular access failure; on vector flow imaging that could better characterize the different components of the vascular access complex flow.