Pressure-strain Elastic Modulus Research Articles

Effects of accumulated exercise on the stiffness and hemodynamics of the common carotid artery.

Purpose: This research aims to study and compare the effects of moderate-intensity continuous exercise and accumulated exercise with different number of bouts on common carotid arterial stiffness and hemodynamic variables. Methods: Thirty healthy male adults were recruited to complete four trials in a randomized crossover design: no-exercise (CON); continuous exercise (CE, 30-min cycling); accumulated exercise including two or three bouts with 10-min rest intervals (AE15, 2 × 15-min cycling; AE10, 3 × 10-min cycling). The intensity in all the exercise trials was set at 45%-55% heart rate reserve. Blood pressure, right common carotid artery center-line velocity, and arterial inner diameter waveforms were measured at baseline and immediately after exercise (0min), 10 min, and 20 min. Results: 1) The arterial stiffness index and pressure-strain elastic modulus of the CE and AE15 groups increased significantly at 0min, arterial diameters decreased in AE15 and AE10, and all indicators recovered at 10min. 2) The mean blood flow rate and carotid artery center-line velocity increased in all trials at 0min, and only the mean blood flow rate of AE10 did not recover at 10min. 3) At 0min, the blood pressure in all trials was found to be increased, and the wall shear stress and oscillatory shear index of AE10 were different from those in CE and AE15. At 20min, the blood pressure of AE10 significantly decreased, and the dynamic resistance, pulsatility index, and peripheral resistance of CE partially recovered. Conclusion: There is no significant difference in the acute effects of continuous exercise and accumulated exercise on the arterial stiffness and diameter of the carotid artery. Compared with continuous exercise, accumulated exercise with an increased number of bouts is more effective in increasing cerebral blood supply and blood pressure regulation, and its oscillatory shear index recovers faster. However, the improvement of blood flow resistance in continuous exercise was better than that in accumulated exercise.

The Effect of Age, Hypertension, and Overweight on Arterial Stiffness Assessed Using Carotid Wall Echo-Tracking in Childhood and Adolescence.

Arterial stiffness represents an independent predictor of the risk of subsequent cardiovascular events. Early identification of high-risk individuals is necessary for effective prevention and targeted interventions. Carotid wall echo-tracking is a modern method for an accurate evaluation of the structural and functional properties of carotid arteries. This study aimed to assess age and sex-specific reference values of the echo-tracking parameters of carotid stiffness in 400 healthy children and adolescents and to evaluate the potential early effect of elevated blood pressure and overweight in 69 overweight normotensives, 45 white coat hypertensives, and 44 essential hypertensives. Stiffness index β, pressure-strain elastic modulus (Ep), arterial compliance (AC), and pulse wave velocity β (PWV β) were evaluated using Aloka ProSound F75. Both white coat and essential hypertension were associated with impaired carotid wall properties with the greatest effect on Ep, followed by PWV β, index β, and AC. The excess weight showed a weaker effect on Ep and PWV β. This is the first study to compare the effects of white coat and essential hypertension on carotid arterial stiffness assessed using the echo-tracking technique in childhood and adolescence with direct application of pediatric reference values specific to age and sex.

Central and local arterial stiffness in White Europeans compared to age-, sex-, and BMI-matched South Asians.

Ethnicity impacts cardiovascular disease (CVD) risk, and South Asians demonstrate a higher risk than White Europeans. Arterial stiffness is known to contribute to CVD, and differences in arterial stiffness between ethnicities could explain the disparity in CVD risk. We compared central and local arterial stiffness between White Europeans and South Asians and investigated which factors are associated with arterial stiffness. Data were collected from cohorts of White Europeans (the Netherlands) and South Asians (India). We matched cohorts on individual level using age, sex, and body mass index (BMI). Arterial stiffness was measured with ARTSENS® Plus. Central stiffness was expressed as carotid-femoral pulse wave velocity (cf-PWV, m/s), and local carotid stiffness was quantified using the carotid stiffness index (Beta) and pressure-strain elastic modulus (Epsilon, kPa). We compared arterial stiffness between cohorts and used multivariable linear regression to identify factors related to stiffness. We included n = 121 participants per cohort (age 53±10 years, 55% male, BMI 24 kg/m2). Cf-PWV was lower in White Europeans compared to South Asians (6.8±1.9 vs. 8.2±1.8 m/s, p<0.001), but no differences were found for local stiffness parameters Beta (5.4±2.4 vs. 5.8±2.3, p = 0.17) and Epsilon (72±35 vs. 70±31 kPa, p = 0.56). Age (standardized β, 95% confidence interval: 0.28, 0.17-0.39), systolic blood pressure (0.32, 0.21-0.43), and South Asian ethnicity (0.46, 0.35-0.57) were associated with cf-PWV; associations were similar between cohorts (p>0.05 for interaction). Systolic blood pressure was associated with carotid stiffness in both cohorts, whereas age was associated to carotid stiffness only in South Asians and BMI only in White Europeans. Ethnicity is associated with central but not local arterial stiffness. Conversely, ethnicity seems to modify associations between CVD risk factors and local but not central arterial stiffness. This suggests that ethnicity interacts with arterial stiffness measures and the association of these measures with CVD risk factors.

Normalization of Flow-mediated Dilation to Brachial Artery Material Property: A Feasibility Study.

Endothelial reactivity (ER) is widely measured using flow-mediated dilation (FMD) of brachial artery. Conventional measurement of FMD is influenced by factors such as input shear stress, arterial transmural pressure, diameter and thereby arterial material properties (ε). Thus, for a reliable interpretation of FMD, it has to be normalized with respect to the above confounding factors. Normalization of FMD with shear stress at the time of measurement has been reported to reduce measurement variability. However, its widespread usage among the research community is limited. In this work, we examine the feasibility of normalizing the brachial FMD index (FMD%) to ε : extrema (εp), baseline (εb) and extrema change (∆ε) post-ischemia using its inter-day variability against FMD. In-vivo measurements were performed on 10 participants for 2 consecutive days and simultaneous pressure-diameter cycles were collected to estimate the material properties during reactive hyperemia (RH). The box-whisker plot reveals differences in the mean and deviation of FMD to FMD|εb. A significant value for repeatability (ICC ≥ 0.6) was obtained for normalized FMD (FMD|εb) for specific stiffness index (β), pressure-strain elastic modulus (Ep), and local pulse wave velocity (PWV) as compared to FMD. Hence, normalization of FMD% to arterial ε can potentially improve the measurement reliability of ER assessment.Clinical Relevance- This pilot study demonstrates the feasibility of brachial artery stiffness assessment during FMD and its potential use for normalizing the standard FMD measurement.

Central Arterial Dynamic Evaluation from Peripheral Blood Pressure Waveforms Using CycleGAN: An In Silico Approach.

Arterial stiffness is a major condition related to many cardiovascular diseases. Traditional approaches in the assessment of arterial stiffness supported by machine learning techniques are limited to the pulse wave velocity (PWV) estimation based on pressure signals from the peripheral arteries. Nevertheless, arterial stiffness can be assessed based on the pressure-strain relationship by analyzing its hysteresis loop. In this work, the capacity of deep learning models based on generative adversarial networks (GANs) to transfer pressure signals from the peripheral arterial region to pressure and area signals located in the central arterial region is explored. The studied signals are from a public and validated virtual database. Compared to other works in which the assessment of arterial stiffness was performed via PWV, in the present work the pressure-strain hysteresis loop is reconstructed and evaluated in terms of classical machine learning metrics and clinical parameters. Least-square GAN (LSGAN) and Wasserstein GAN with gradient penalty (WGAN-GP) adversarial losses are compared, yielding better results with LSGAN. LSGAN mean ± standard deviation of error for pressure and area pulse waveforms are 0.8 ± 0.4 mmHg and 0.1 ± 0.1 cm2, respectively. Regarding the pressure-strain elastic modulus, it is achieved a mean absolute percentage error of 6.5 ± 5.1%. GAN-based deep learning models can recover the pressure-strain loop of central arteries while observing pressure signals from peripheral arteries.

The Value of RBP4 in Assessing Coronary Artery Elasticity in Patients with Coronary Heart Disease and Type 2 Diabetes Mellitus.

Existing research has shown that retinol binding protein (RBP4) has an impairing effect on arterial elasticity and induces insulin resistance, but the clinical value of RBP4 in patients with coronary heart disease (CHD) combined with type 2 diabetes mellitus (T2DM) has not been investigated. This study sought to compare the complexity of coronary artery lesions and coronary artery elasticity between patients with CHD combined with T2DM and those with CHD without T2DM, analyze the risk factors affecting coronary artery elasticity, and investigate the value of RBP4 in assessing coronary artery elasticity in patients with CHD and T2DM. A total of 130 patients with confirmed CHD were consecutively enrolled, including 38 patients with CHD combined with T2DM and 92 patients with CHD without T2DM. Basic clinical data, laboratory findings, coronary angiography and intravascular ultrasound (IVUS) imaging data, and Gensini scores and coronary artery elasticity parameters were calculated in both groups. Elasticity parameters included: stiffness parameter ( ), pressure-strain elastic modulus ( ), distensibility coefficient (DC), and compliance coefficient (CC). Multiple linear regression equations were established with elasticity parameters as dependent variables to explore the factors influencing coronary artery elasticity parameters in patients within the two groups. Compared with patients in the CHD without T2DM group, patients in the CHD combined with T2DM group had higher RBP4 levels, Gensini scores, and values, and lower DC and CC values. Linear regression analysis showed that Gensini score increased with higher and values and decreased with higher DC and CC values. In all patients in the CHD and CHD combined with T2DM groups, RBP4 was an independent risk factor for values after correction for confounders by multiple linear regression analysis, whereas in patients in the CHD without T2DM group, the effect of RBP4 on values was not statistically different. RBP4 was an independent risk factor of coronary artery elasticity in CHD patients with T2DM and in overall CHD patients, but it did not affect coronary artery elasticity in CHD patients without T2DM.

Effect of Gluten-Free Diet on Aortic Elasticity in Children with Celiac Disease

Background: Celiac disease is a hereditary digestive disease in children associated with an autoimmune disorder of the small intestine. This study aimed to study aortic stiffness in children with celiac disease compared with controls and assess the effects of a gluten-free diet on aortic stiffness parameters. Methods: This case-control study was conducted on 114 children with celiac disease and 57 healthy volunteers. Children with celiac disease comprised three groups: Gluten-free diet (GFD)-responsive, GFD-nonresponsive, and newly diagnosed. Systolic and diastolic diameters of the ascending aorta were recorded by M-mode echocardiography. Data were analyzed using SPSS 20. Study data had free distribution and nonparametric tests were applied for the analysis. The tests were Mann-Whitney U and Kruskal-Wallis with P value &lt; 0.05as the significance level. Results: Aortic strain (11.15 ± 7.47 vs. 13.78 ± 6.95, P = 0.002) and aortic distensibility (6.98 ± 5.03 vs. 8.33 ± 5.13, P = 0.037) were lower in celiac disease (CD) while pressure strain elastic modulus (410.60 ± 247.45 vs. 330.71 ± 216.94, P = 0.012) and aortic strain β index (1.79 ± 0.62 vs. 1.44 ± 0.51, P &lt; 0.001) were higher. The aortic strain significantly differed between control and response to GFD (P = 0.026), control and new diagnosis (P &lt; 0.001), response to GFD and new diagnosis (P = 0.003), and no response to GFD and new diagnosis (P &lt; 0.001) groups. The aortic strain β index differed significantly between control and response to GFD (P ≤ 0.001), control and new diagnosis (P &lt; 0.001), response to GFD and no response to GFD (P = 0.035), response to GFD and new diagnosis (P = 0.002), and no response to GFD and new diagnosis (P &lt; 0.001) groups. Aortic distensibility significantly differed between control and new diagnosis (P &lt; 0.001), response to GFD and new diagnosis (P = 0.037), and no response to GFD and new diagnosis (P = 0.021) groups. Pressure strain elastic modulus significantly differed between control and new diagnosis (P &lt; 0.001), response to GFD and new diagnosis (P = 0.037), and no response to GFD and new diagnosis (P = 0.021) groups. Conclusions: The present study concluded that the elasticity parameters will change due to celiac disease. Gluten-free diet had no significant effect on aortic stiffing measures except the ASβ index.

Assessment of aortic elasticity parameters in obese and overweight children.

Aortic elasticity is a predictor and recognized factor for future cardiovascular events in children. The aim of the study was to evaluate the aortic stiffness in obese and overweight children compared to healthy ones. The study evaluated 98 sex matched children aged 4 to 16 years that were equally distributed in asymptomatic obese or overweight and healthy children groups. All the participants were free of any heart diseases. Arterial stiffness indices were determined using two-dimensional echocardiography. The mean ages in the obese and healthy children were 10.40±2.50 years and 10.06±1.53 years, respectively. Aortic strain was significantly higher in obese children (20.70±5.04%), compared to healthy (7.06±3.77%) and overweight children (18.59±8.08%, p < 0.001). Aortic distensibility (AD) was significantly higher in obese children (0.010±0.005 cm < sup > 2 < /sup > dyn-1x10-6), compared to healthy (0.0036±0.004 cm < sup > 2 < /sup > dyn-1x10 < sup > -6 < /sup > ) and overweight children (0.009±0.005 cm < sup > 2 < /sup > dyn-1x10 < sup > -6 < /sup > , p < 0.001). Aortic strain beta (ASβ) index, was significantly higher in healthy children (9.26±6.17). Pressure-strain elastic modulus (PSEM) was significantly higher in healthy children (7.52±4.76 kPa). Systolic blood pressure increased with body mass index (BMI) significantly (p < 0.001) but diastolic blood pressure did not change (p=0.143). BMI had significant effect on arterial stiffness (AS) (β=0.732, p < 0.001), AD (β=0.636, p < 0.001), ASβ index (β=-0.573, p < 0.001) and PSEM (β=-0.578, p < 0.001). Age had significant effect on systolic diameter of the aorta (β=0.340, p < 0.001) and diastolic diameter of the aorta (β=0.407, p < 0.001). We concluded that aortic strain and aortic distensibility increased in obese children when aortic strain beta index and PSEM decreased. This result suggests that, as atrial stiffness is a predictor for future heart diseases, dietary treatment for children with overweight or obese status is important.

Leisure-Time Physical Activity Has a More Favourable Impact on Carotid Artery Stiffness Than Vigorous Physical Activity in Hypertensive Human Beings.

Aim. To assess the effect of leisure time versus vigorous long-term dynamic physical activity (PA) on carotid stiffness in normotensive versus hypertensive subjects. Methods. The study was conducted on 120 leisure-time exercisers and 120 competitive athletes. One hundred and twenty sedentary subjects served as controls. In addition, participants were classified according to whether their systolic blood pressure was ≥130 mmHg (hypertensives, n = 120) or normal (normotensives, n = 240) according to the ACC/AHA 2017 definition. Carotid artery stiffness was assessed with an echo-tracking ultrasound system, using the pressure-strain elastic modulus (EP) and one-point pulse wave velocity (PWVβ) as parameters of stiffness. Results. The effect of the two levels of PA differed in the normotensives and the hypertensives. Among the normotensives, there was an ongoing, graded reduction in EP and PWVβ from the sedentary subjects to the athletes. By contrast, among the hypertensives, the lowest levels of EP and PWVβ were found among the leisure-time PA participants. EP and PWVβ did not differ between the hypertensive sedentary subjects and the athletes. A significant interaction was found between PA and BP status on EP (p = 0.03) and a borderline interaction on PWVβ (p = 0.06). In multiple regression analyses, PA was a negative predictor of EP (p = 0.001) and PWVβ (p = 0.0001). The strength of the association was weakened after the inclusion of heart rate in the models (p = 0.04 and 0.007, respectively). Conclusions. These data indicate that in people with hypertension, leisure-time PA has beneficial effects on carotid artery stiffness, whereas high-intensity chronic PA provides no benefit to vascular functions.

COMMON CAROTID ARTERY ELASTICITY, INTIMA-DIAMETER RATIO, AND TENSILE STRESS IN PEDIATRIC PATIENTS WITH PRIMARY HYPERTENSION

Objective: Elevated blood pressure (BP) lead to increased thickness of arterial wall and increased diameter of arteries, are risk factors of cardiovascular sequelae in adult populations. Intima-diameter ratio (IDR) and tensile stress (TS) may reflect arterial wall-remodeling to elevated BP. The aim was to evaluate common carotid artery elasticity, IDR, and TS in children with primary hypertension (PH). Design and method: 50 untreated patients with PH and we evaluated: common carotid artery(CCA) intima-media thickness (cIMT) and elasticity(E-tracking - ET), central BP and aortic elasticity (aPWV,AIx75HR), office BP and ABPM, and clinical, and biochemical data. IDR (cIMT/minimal diameter of CCA[D]) and TS (MAP∗D/cIMT) were calculated in all the subjects. Results: Patients with PH compared to CG were characterized by significantly higher peripheral, central office and ambulatory BP, BMI Z-score, uric acid, triglycerides, lower HDL-cholesterol and higher aPWV. PH patients had thicker cIMT and larger CCA D. The groups did not differ in parameters of CCA elasticity: beta stiffness index, CCA pulse wave velocity(PWVbeta) and pressure-strain elasticity modulus(Ep) and in IDR(0.08 ± 0.01vs.0.08 ± 0.02,p = 0.479) and TS(584.9 ± 135.5mmHg vs.529.7 ± 84.2,p = 0.095). We found correlations between cIMT(Z-score) and triglycerides, peripheral SBP Z-score, and ABPM MAP 24 h Z-score. CCA D correlated with BMI Z-score, uric acid and HDL-cholesterol, 24 h systolic blood pressure load(SBPL), Central systolic blood pressure(AoSBP) and peripheral diastolic BP Z-score. We found significant correlations between TS and uric acid, 24 h diastolic blood pressure load, and peripheral systolic and diastolic blood pressure Z-scores. There was no association between IDR and BP except for a weak correlation between IDR and SBPL. In PH patients, there was a strong correlation between cIMT and CCA D(r = 0.790,p &lt; 0.001). Conclusions: In children with PH, structural changes and decreased elasticity primarily affect the aorta and to a lesser extent the muscular arteries. In children with PH, both CCA wall thickness and internal diameter are associated with BP, and are significantly higher in children with PH. The changes observed in the carotid artery are probably adaptive in nature, not associated with impaired arterial function, thus intima-diameter ratio or tensile stress measurement does not appear to contribute additional information in this group of patients.

Relationship between carotid artery stiffness and total serum homocysteine in coronary slow flow phenomenon: a high-resolution echo-tracking study

Coronary slow flow phenomenon (CSFP) is not uncommon in conventional coronary angiography. A disorder of serum homocysteine (tHcy) metabolism may play a role in the pathogenesis of slow coronary flow. Moreover, elevated tHcy concentration is closely associated with atherosclerosis. We aimed to evaluate the relationship between carotid artery stiffness and serum tHcy levels in patients with CSFP. This was a case-control study. The study population comprised 146 patients with newly diagnosed stable angina, including 73 patients with CSFP and 73 patients with normal coronary flow. All participants underwent conventional coronary angiography, carotid ultrasonography, and biochemical examination. The carotid artery stiffness parameters of β index (β), pressure-strain elastic modulus (Ep), and local pulse wave velocity (PWV) in the CSFP group were significantly higher than those in the control group (β: 10.75±2.16 vs. 9.02±2.11, P=0.007; Ep: 147.41±41.22 vs. 116.21±39.21, P=0.004; PWV: 7.45±1.23 vs. 6.16±1.20, P=0.003), However, arterial compliance (AC) was lower in the CSFP group than the control group (0.52±0.11 vs. 0.69±0.24, P=0.008). The mean thrombolysis in myocardial infarction (TIMI) frame count and the tHcy concentration in the CSFP group were significantly higher than those in the control group (48.60±1.30 vs. 24.50±3.80, P=0.001; 19.95±4.00 vs. 9.12±2.72, P=0.009). The tHcy concentration was positively correlated with β (R value =0.494, P<0.0001), Ep (R value =0.469, P<0.0001), and PWV (R value =0.436, P<0.0001), but negatively correlated with AC (R value =-0.230, P=0.022). The predictors of CSFP were tHcy concentration, left PWV, right PWV, left β index, and right β index. Among them, the left β index and right β index were the best indictors for predicting CSFP. The cutoff values of left β index, right β index, left PWV, and right PWV were 9.3, 9.3, 6.7, and 6.6, respectively. Our data showed that serum tHcy levels were elevated in patients with CSFP compared with the control group. Carotid artery stiffness parameters were correlated with tHcy. The best predictors of CSFP were left β index and right β index. These findings may contribute to a better understanding of systemic vascular disorders in patients with coronary slow flow, rather than simply attributing such disorders to a single and isolated lesion of the epicardial coronary artery.

Cardiovascular risk assessment in children and adolescents with congenital solitary kidneys.

Patients with solitary kidneys (SKs) are at risk of hypertension (HT) and associated end‐organ damage. The authors aimed to evaluate whether children with congenital SKs (CSKs) have higher office, ambulatory, or central blood pressure (BP), increased arterial stiffness or left ventricular mass index, or any risk for arrhythmia. With this purpose, patients with CSK and healthy controls being followed up between January 2018 and June 2019 were enrolled in the study. Demographic, biochemical, and office blood pressure (BP) data were recorded. Then, ambulatory blood pressure monitoring (ABPM) and measurements of central BP (cBP), pulse wave velocity (PWV), and augmentation index (AIx@75) were obtained. Ventricular repolarization parameters were acquired by 12‐lead electrocardiography. Left ventricular mass index (LVMI) and abdominal aortic stiffness parameters including strain, pressure strain elastic modulus (Ep), and normalized Ep (Ep*) were calculated with echocardiographic measurements. Finally, 36 children with CSK and 36 healthy controls were included. Serum creatinine, uric acid, total cholesterol levels, ABPM parameters, cBP levels, and PWV values were significantly higher, and eGFR levels were significantly lower in the CSK group. VR parameters, abdominal aortic stiffness indices, and LVMI were similar between the groups. CSK increased the risk of HT in ABPM (HTABPM) by 6 times. PWV was significantly correlated with Ep and Ep* in cases with CSK. Determination of cBP and PWV along with 24‐hour ABPM would be a useful tool in children with CSK.

Assessment of Carotid Arterial Stiffness in Community Settings With ARTSENS®.

Objective: We investigate the field feasibility of carotid stiffness measurement using ARTSENS® Touch and report the first community-level data from India. Method: In an analytical cross-sectional survey among 1074 adults, we measured specific stiffness index (n}{}beta n), pressure-strain elastic modulus (n}{}text{E}_{text {p}}n), arterial compliance (AC), and one-point pulse wave velocity (PWVn}{}_{beta }n) from the left common carotid artery. Data for established risk factors (waist circumference, blood pressure, plasma glucose, triglycerides, and HDL-C) were also collected. The association of carotid stiffness with age, gender, hypertension/diabetes, smoking, and clustering of risk factors was studied. Results: Measurements were repeatable with a relative difference (RD) between consecutive readings of < 5% for blood pressure and < 15% for n}{}sim 80n% of arterial diameter values. The average RDs for n}{}beta n, n}{}text{E}_{text {p}}n, AC, and PWVn}{}_{beta }n, were 20.51%, 22.31%, 25.10%, and 14.13%, respectively. Typical range for stiffness indices among females and males were n}{}beta n: 8.12 ± 3.59 vs 6.51 ± 2.78, n}{}text{E}_{text {p}}n: 113.24 ± 56.12 kPa vs 92.33 ± 40.65 kPa, PWVn}{}_{beta }n: 6.32 ± 1.38 ms−1 vs 5.81 ± 1.16 ms−1, and AC: 0.54 ± 0.36 mm2 kPa−1 vs 0.72 ± 0.38 mm2 kPa−1. Mean n}{}beta n, n}{}text{E}_{text {p}}n, and PWVn}{}_{beta }n increased (and mean AC decreased) across decades of age; the trend persisted even after excluding hypertensives and subjects with diabetes. The odds ratio of presence of multiple risk factors for n}{}text{E}_{text {p}} ge93.71n kPa and/or PWVn}{}_{beta } ge6.56n ms−1 was ≥ 2.12 or above in males. In females, it was just above 2.00 for n}{}text{E}_{text {p}} ge91.21n kPa and/or PWVn}{}_{beta } ge5.10n ms−1 and increased to ≥ 3.33 for n}{}text{E}_{text {p}} ge143.50n kPa and ≥ 3.25 for PWVn}{}_{beta } ge7.31n ms−1. Conclusion: The study demonstrated the feasibility of carotid stiffness measurement in a community setting. A positive association between the risk factors and carotid artery stiffness provides evidence for the device’s use in resource-constrained settings. Clinical Impact: The device paves the way for epidemiological and clinical studies that are essential for establishing population-level nomograms for wide-spread use of carotid stiffness in clinical practice and field screening of ‘at-risk’ subjects.

Aortic adventitial thickness as a marker of aortic atherosclerosis, vascular stiffness, and vessel remodeling in systemic lupus erythematosus.

There is limited human imaging data on the association of adventitial thickness (AT) with arterial disease. Systemic lupus erythematosus (SLE) is a prototypical disease model for studying markers of premature arterial disease. To determine if increased aortic AT is associated with aortic atherosclerosis [increased intima media thickness (IMT) or plaques], stiffness [increased pressure-strain elastic modulus (PSEM)], and vessel remodeling. In total, 70 SLE patients and 26 age- and sex-matched controls underwent transesophageal echocardiography (TEE). Two-dimensional guided M-mode images were obtained to assess AT, IMT, and plaques, and PSEM at the proximal, mid, and distal thoracic aorta. Images were interpreted by 3 observers unaware of the subjects' clinical data and each other's measurements. Abnormal aortic AT, IMT, and PSEM were defined as > 2SD above the overall mean values in controls and corresponded to > 1 mm, > 1 mm, and > 10.6 Pascal units, respectively. Plaques were defined as focal-protruding IMT > 50% of the surrounding vessel wall. Abnormal aortic AT, atherosclerosis, and abnormal stiffness were more frequent in SLE patients than in controls (all p ≤ 0.02). In SLE patients, abnormal AT combined with atherosclerosis was associated with larger aortic end-diastolic diameters than in controls (p ≤ 0.05). In SLE patients, aortic AT was greater in patients with atherosclerosis and in those with abnormal stiffness than in patients without these abnormalities (all p ≤ 0.02). In patients with abnormal AT, the degree of aortic stiffness was similar to those with atherosclerosis (p = 0.22). In patients with SLE, increased aortic AT is associated with aortic atherosclerosis, abnormal stiffness, and eccentric vessel remodeling. Key Points • In patients with SLE, abnormal aortic adventitial thickness is associated with aortic atherosclerosis, abnormal stiffness, and eccentric vessel remodeling. • In patients with SLE, aortic adventitial thickening may contribute to the extent of aortic atherosclerosis, abnormal aortic stiffness, and vessel remodeling. • To our knowledge, this is the first human imaging study to characterize the aortic adventitial layer and delineate its association with aortic disease.

New Comprehensive Reference Values for Arterial Vascular Parameters in Children

Noninvasive measurements of vascular parameters can be used for the detection and risk stratification of cardiovascular diseases. Most vascular parameters are influenced by age and body size, but pediatric reference values are scarce and limited to a few parameters. The aim of this study was to develop pediatric reference values and Z score equations for a comprehensive set of vascular parameters. A total of 292 healthy subjects aged 0 to 18years were prospectively recruited. Stiffness index β, pressure-strain elastic modulus, common carotid intima-media thickness, brachial flow-mediated dilation, radial augmentation index, central and right arm peripheral artery pulse-wave velocities, and pulse-wave velocity ratio were assessed. Normalization for age and anthropometric variables was performed using parametric multivariate regression modeling. Z scores were assessed for heteroscedasticity, residual association with age and body size, and distribution. Multivariate regression models with various combinations of height, weight, and age were used to obtain Z scores that were independent of age and body size. There was no residual association between Z scores and body size, age, or body mass index. There was no significant departure from the normal distribution. The authors present reference values and Z score equations for a comprehensive set of vascular parameters during childhood. Further studies are necessary to assess their usefulness in detecting the vascular signs of subclinical atherosclerosis and chronic diseases, including congenital heart disease.

Similar Effects of Acute Resistance Exercise on Carotid Stiffness in Males and Females.

Sex differences exist in vascular responses to blood pressure perturbations, such as resistance exercise. Increases in aortic stiffness following acute resistance exercise appear different between sexes, with attenuated increases in females vs. males. Whether sex differences exist in carotid stiffness, following resistance exercise is unknown. This study sought to examine sex differences in carotid stiffness, aortic stiffness, and hemodynamics following acute resistance exercise. Thirty-five participants (18 male) completed 3 sets of 10 repetitions of maximal isokinetic knee extension/flexion. Aortic stiffness and hemodynamics were estimated using an automated oscillometric blood pressure monitor at baseline, 5- and 30-min post-exercise. Carotid stiffness was assessed by β-stiffness index, pressure-strain elastic modulus and arterial compliance using ultrasonography. Resistance exercise increased aortic stiffness, mean and systolic pressure at 5-min (p<0.01), and pressure-strain elastic modulus at 5-min in both sexes (p<0.05). Arterial compliance decreased at 5- and 30-min post exercise in both sexes (p<0.01). No interaction effects were detected in carotid stiffness, aortic stiffness, and hemodynamics, indicating similar vascular responses between sexes. Our findings indicate that the large arteries appear to stiffen similarly following resistance exercise in males and females when presented with similar blood pressure responses.

Assessment of Aortic Elasticity and the Doppler Tissue Echocardiography in Thalassemia Major Children

AbstractCardiovascular diseases are the most common illness that needs special medical care in thalassemia particularly in children and adolescents. We aimed to compare aortic stiffness in thalassemia major and healthy children. The study included 65 asymptomatic thalassemia major 6 to 19-year–old children without known history of heart disease and 65 age- and sex-matched healthy controls. Arterial stiffness indices determined using two-dimensional (2D) and Doppler echocardiography. Data were analyzed by SPSS 20.0 with 0.05 as significant error. From the study, results showed that systolic (p = 0.009) and diastolic (p &lt; 0.001) blood pressures were higher in controls. Left ventricular mass index (LVMI) was higher in patients (p &lt; 0.001). Aortic stiffness index (p &lt; 0.001), pulse pressure (p &lt; 0.001), and pressure strain elastic modulus (p &lt; 0.001) were higher in patients, while aortic strain (p &lt; 0.002) and aortic distensibility (p &lt; 0.001) were lower significantly. Aortic stiffness index was correlated with diastole aorta (p = 0.005), systole aorta (p &lt; 0.001), and LVMI (p &lt; 0.001). Strain was correlated with diastole aorta (p &lt; 0.001). Pulse pressure was correlated with systolic blood pressure (p &lt; 0.001), diastolic blood pressure (p = 0.002) significantly. Aortic distensibility was correlated with systolic blood pressure (p = 0.039) and diastole aorta (p &lt; 0.001) significantly. The pressure strain elastic modulus was correlated only with diastole aorta (p = 0.029). Concluded, aortic stiffness index, pulse pressure, and pressure strain elastic modulus were higher in thalassemia children, while aortic strain and aortic distensibility were lower. This increase may result in reduction of mechanical efficiency of the heart. Therefore, assessment of aortic elastic properties as nontraditional cardiovascular risk factors may contribute to the identification of cardiovascular risks in children with thalassemia

Carotid arterial stiffness is increased and related to left ventricular function in patients with hypertrophic cardiomyopathy.

To assess the carotid mechanical properties in patients with hypertrophic cardiomyopathy and the relation between arterial stiffness and left ventricular function in this setting. We have prospectively enrolled 71 patients (52 ± 16 years, 34 men) with hypertrophic cardiomyopathy, divided into two groups depending on the presence (46 patients) or absence (25 patients) of cardiovascular risk factors associated with increased arterial stiffness. Twenty-five normal subjects similar by age and gender with hypertrophic cardiomyopathy patients without risk factors formed the control group. A comprehensive echocardiography was performed in all subjects. Carotid arterial stiffness index (β index), pressure-strain elastic modulus, arterial compliance, and pulse wave velocity were also obtained using an echo-tracking system. β index, pulse wave velocity, and pressure-strain elastic modulus were significantly higher in hypertrophic cardiomyopathy patients without risk factors compared to controls. After linear regression analysis, the increase in carotid β index was independently correlated with the presence of hypertrophic cardiomyopathy [beta = 0.49, 95% confidence interval (CI) = 1.04-3.02; P < 0.001]. In the entire hypertrophic cardiomyopathy population arterial stiffness parameters correlated with age, gender, hypertension degree, presence of hypercholesterolaemia, and the E/e' ratio. In multivariable analysis, β index (beta = 0.36, 95% CI = 0.32-1.25; P = 0.001), global left ventricular longitudinal strain, and the presence of left ventricular outflow tract obstruction were independently correlated with the E/e' ratio. In patients with hypertrophic cardiomyopathy arterial stiffness is increased independently of age or presence of cardiovascular risk factors. Carotid artery stiffness is independently related to left ventricular filling pressure, increased arterial stiffness representing a possible marker of a more severe phenotype.

Carotid Artery Stiffness Accurately Predicts White Matter Hyperintensity Volume 20 Years Later: A Secondary Analysis of the Atherosclerosis Risk in the Community Study.

Arterial stiffness is a biomarker of cerebrovascular disease and dementia risk. Studies have shown an association between carotid artery stiffness and increased white matter hyperintensity volume and, as a result, reduced total brain volume on MR imaging, but none have had prolonged follow-up to fully evaluate the slow change seen in white matter hyperintensity volume and total brain volume with time. Our objective was to determine whether common carotid artery stiffness on sonography accurately predicts white matter hyperintensity volume and total brain volume on MR imaging more than 20 years later. We performed a secondary analysis of the Atherosclerosis Risk in the Community study to compare 5 measurements of carotid artery stiffness, including strain, distensibility, compliance, Stiffness index, and pressure-strain elastic modulus, with the white matter hyperintensity volume and total brain volume on a follow-up MR imaging using linear regression. We included 1402 patients enrolled in the Atherosclerosis Risk in the Community study. There was a significant relationship between increasing carotid artery stiffness and both higher white matter hyperintensity volume and lower total brain volume on MR imaging, measured at a mean of 21.5 years later. In multivariable linear regression models, the carotid strain, distensibility, Stiffness index, and pressure-strain elastic modulus were associated with white matter hyperintensity volume. Only compliance was associated with total brain volume in the multivariate models. Sonography measurements of carotid artery stiffness are predictive of white matter hyperintensity volume and total brain volume on MR imaging more than 20 years later. The association is more robust for white matter hyperintensity volume than total brain volume. These findings support the role of arterial stiffness as a method for identifying patients at risk of developing white matter hyperintensity volume and as a potential mechanism leading to small-artery disease of the brain.

Non-invasive assessment of aortic stiffness and blood pressure in young Turner syndrome patients.

Background Females with Turner syndrome (TS) carry an elevated risk of aortic dissection. The objective of the study was to assess the biophysical properties of the aorta and ambulatory blood pressure (BP) in females with TS and compare these findings to those in healthy female age-matched controls. Methods This was a prospective cohort study including subjects aged 8-25 years. Utilizing two-dimensional (2D) echocardiography and Doppler, proximal aortic dimensions were measured and biophysical properties of the aorta were calculated including pulse wave velocity (PWV), arterial pressure-strain elastic modulus and stiffness index. Resting BP was measured and ambulatory blood pressure monitoring (ABPM) was performed. Results Of 23 TS patients and 46 controls (median age 16.3 years), aortic annulus, sinus of Valsalva and sinotubular (ST) junction diameters, as well as left ventricular (LV) mass, were significantly greater in TS patients compared with controls when scaled for height2.7, but not for body surface area (BSA), although ascending aorta diameter was greater when scaled for both. Median PWV was faster in TS patients compared to controls (451 vs. 360 cm/s) while arterial pressure-strain elastic modulus and stiffness index were similar. Resting BP was abnormal in seven out of 22 patients and ABPM was abnormal in 16 out of 21 patients. Conclusions Young patients with TS had dilated proximal aortas when scaled for height2.7 and stiffer aortas when compared with healthy female age-matched controls. Moreover, resting BP underdiagnosed pre-hypertension and hypertension compared to ABPM. These findings are consistent with the presence of a primary aortopathy in TS.