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BACKGROUND: Systemic arterial compliance and venous capacitance are typically impaired in patients with heart failure with preserved ejection fraction (HFpEF), contributing to hemodynamic congestion with stress. Sodium-glucose cotransporter-2 inhibitors reduce hemodynamic congestion and improve clinical outcomes in patients with HFpEF, but the mechanisms remain unclear. This study tested the hypothesis that Dapagliflozin would improve systemic arterial compliance and venous capacitance during exercise in patients with HFpEF. METHODS: In this secondary analysis from the CAMEO-DAPA trial (Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction Trial), 37 patients with HFpEF (mean age 68 ± 9 years, women 65%) underwent invasive hemodynamic exercise testing with simultaneous echocardiography at baseline and following treatment for 24 weeks with Dapagliflozin or placebo. Radial artery pressure (BP) was measured continuously using a fluid-filled catheter with transformation to aortic pressure, central hemodynamics were measured using high-fidelity micromanometers, and stressed blood volume was estimated from hemodynamic indices fit to a comprehensive cardiovascular model. RESULTS: There was no statistically significant effect of Dapagliflozin on resting BP, but Dapagliflozin reduced systolic BP during peak exercise (estimated treatment difference [ETD], -18.8 mm Hg [95% CI, -33.9 to -3.7] P=0.016). Reduction in BP was related to improved exertional total arterial compliance (ETD, 0.06 mL/mm Hg/m2 [95% CI, 0.003--0.11] P=0.039) and aortic root characteristic impedance (ETD, -2.6 mm Hg/mL*sec [95% CI: -5.1 to -0.03] P=0.048), with no significant effect on systemic vascular resistance. Dapagliflozin reduced estimated stressed blood volume at rest and during peak exercise (ETD, -292 mm Hg [95% CI, -530 to -53] P=0.018), and improved venous capacitance evidenced by a decline in ratio of estimated stressed blood volume to total blood volume (ETD, -7.3% [95% CI, -13.3 to -1.3] P=0.020). Each of these effects of Dapagliflozin at peak exercise were also observed during matched 20W exercise intensity. Improvements in total arterial compliance and estimated stressed blood volume were correlated with decreases in body weight, and reduction in systolic BP with treatment was correlated with the change in estimated stressed blood volume during exercise (r=0.40, P=0.019). Decreases in BP were correlated with reduction in pulmonary capillary wedge pressure during exercise (r=0.56, P<0.001). CONCLUSIONS: In patients with HFpEF, treatment with Dapagliflozin improved systemic arterial compliance and venous capacitance during exercise, while reducing aortic characteristic impedance, suggesting a reduction in arterial wall stiffness. These vascular effects may partially explain the clinical benefits with sodium-glucose cotransporter-2 inhibitors in HFpEF. [ABSTRACT FROM AUTHOR]

Background: As key regulators of gene expression, microRNAs affect many cardiovascular mechanisms and have been associated with several cardiovascular diseases. In this study, we aimed to investigate the relation of whole blood microRNAs with several quantitative measurements of vascular function, and explore their biological role through an integrative microRNA-gene expression analysis. Methods: Peripheral whole blood microRNA expression was assessed through RNA-Seq in 2606 participants (45.8% men, mean age: 53.93, age range: 30 to 95 years) from the Rhineland Study, an ongoing population-based cohort study in Bonn, Germany. Weighted gene co-expression network analysis was used to cluster microRNAs with highly correlated expression levels into 14 modules. Through linear regression models, we investigated the association between each module's expression and quantitative markers of vascular health, including pulse wave velocity, total arterial compliance index, cardiac index, stroke index, systemic vascular resistance index, reactive skin hyperemia and white matter hyperintensity burden. For each module associated with at least one trait, one or more hub-microRNAs driving the association were defined. Hub-microRNAs were further characterized through mapping to putative target genes followed by gene ontology pathway analysis. Results: Four modules, represented by hub-microRNAs miR-320 family, miR-378 family, miR-3605-3p, miR-6747-3p, miR-6786-3p, and miR-330-5p, were associated with total arterial compliance index. Importantly, the miR-320 family module was also associated with white matter hyperintensity burden, an effect partially mediated through arterial compliance. Furthermore, hub-microRNA miR-192-5p was related to cardiac index. Functional analysis corroborated the relevance of the identified microRNAs for vascular function by revealing, among others, enrichment for pathways involved in blood vessel morphogenesis and development, angiogenesis, telomere organization and maintenance, and insulin secretion. Conclusions: We identified several microRNAs robustly associated with cardiovascular function, especially arterial compliance and cardiac output. Moreover, our results highlight miR-320 as a regulator of cerebrovascular damage, partly through modulation of vascular function. As many of these microRNAs were involved in biological processes related to vasculature development and aging, our results contribute to the understanding of vascular physiology and provide putative targets for cardiovascular disease prevention. [ABSTRACT FROM AUTHOR]

Arterial compliance (AC) plays a crucial role in vascular aging and cardiovascular disease. The ability to continuously estimate aortic AC or its surrogate, pulse pressure (PP), through wearable devices is highly desirable, given its strong association with daily activities. While the single-site photoplethysmography (PPG)-derived arterial stiffness indices show reasonable correlations with AC, they are susceptible to noise interference, limiting their practical use. To overcome this challenge, our study introduces a noise-resistant indicator of AC: Katz's fractal dimension (KFD) of PPG signals. We showed that KFD integrated the signal complexity arising from compliance changes across a cardiac cycle and vascular structural complexity, thereby decreasing its dependence on individual characteristic points. To assess its capability inmeasuring AC,we conducted a comprehensive evaluation using both in silico studies with 4374 virtual human data and real-world measurements. In the virtual human studies, KFD demonstrated a strong correlation with AC (r = 0.75), which only experienced a slight decrease to 0.66 at a signal-to-noise ratio of 15dB, surpassing the best PPG-morphology-derived AC measure (r = 0.41) under the same noise condition. In addition, we observed that KFD's sensitivity to AC varied based on the individual's hemodynamic status,whichmay further enhance the accuracy of AC estimations. These in silico findings were supported by real-world measurements encompassing diverse health conditions. In conclusion, our study suggests that PPGderived KFD has the potential to continuously and reliably monitor arterial compliance, enabling unobtrusive and wearable assessment of cardiovascular health. [ABSTRACT FROM AUTHOR]

The concept of self-predictability plays a key role for the analysis of the self-driven dynamics of physiological processes displaying richness of oscillatory rhythms. While time domain measures of self-predictability, as well as time-varying and local extensions, have already been proposed and largely applied in different contexts, they still lack a clear spectral description, which would be significantly useful for the interpretation of the frequency-specific content of the investigated processes. Herein, we propose a novel approach to characterize the linear self-predictability (LSP) of Gaussian processes in the frequency domain. The LSP spectral functions are related to the peaks of the power spectral density (PSD) of the investigated process, which is represented as the sum of different oscillatory components with specific frequency through the method of spectral decomposition. Remarkably, each of the LSP profiles is linked to a specific oscillation of the process, and it returns frequency-specific measures when integrated along spectral bands of physiological interest, as well as a time domain self-predictability measure with a clear meaning in the field of information theory, corresponding to the well-known information storage, when integrated along the whole frequency axis. The proposed measure is first illustrated in a theoretical simulation, showing that it clearly reflects the degree and frequency-specific location of predictability patterns of the analyzed process in both time and frequency domains. Then, it is applied to beat-to-beat time series of arterial compliance obtained in young healthy subjects. The results evidence that the spectral decomposition strategy applied to both the PSD and the spectral LSP of compliance identifies physiological responses to postural stress of low and high frequency oscillations of the process which cannot be traced in the time domain only, highlighting the importance of computing frequency-specific measures of self-predictability in any oscillatory physiologic process.

AimWe investigated the association between levels of leisure-time physical activity and vascular stiffness in a longitudinal observational study from a representative Swedish population.MethodA total of 2816 randomly selected individuals were examined at visit 1 (2002-2005, Men = 1400). After a mean follow-up of 9.7 ± 1.4 years, a representative sample of 1327 of the original participants were re-examined at visit 2. After excluding subjects with hypertension at baseline, 761 participants were included in the longitudinal analyses. Leisure-time physical (LTPA) activity was self-reported and dichotomized as high or low (level 3, 4 and level 1, 2, respectively). Large Arterial Elasticity Index (LAEI) and Small Arterial Elasticity Index (SAEI) were measured using the HDI/Pulse Wave™ CR2000. Multivariable general linear models were used to investigate the differences in changes SAEI and LAEI based on LTPA levels.ResultsAt visit 1, and after adjustment for possible confounders, participants in the high LTPA group had better small artery elasticity (SAEI) (SAEI in low-level LTPA: 7.89 ± 0.11, SAEI in high-level LTPA: 8.32 ± 0.15, ΔSAEI: 0.42, CI: 0.07-0.78; p = 0.020). SAEI decreased between the two assessments (Visit 1: SAEI 8.01 ± 3.37 ml/mmHg; Δ SAEI: 1.4, CI 1.2-1.6, p

The heterogeneity of progression of abdominal aortic aneurysms (AAAs) is not well understood. This study investigates which geometrical and mechanical factors, determined using time-resolved 3D ultrasound (3D + t US), correlate with increased growth of the aneurysm. The AAA diameter, volume, wall curvature, distensibility, and compliance in the maximal diameter region were determined automatically from 3D + t echograms of 167 patients. Due to limitations in the field-of-view and visibility of aortic pulsation, measurements of the volume, compliance of a 60 mm long region and the distensibility were possible for 78, 67, and 122 patients, respectively. Validation of the geometrical parameters with CT showed high similarity, with a median similarity index of 0.92 and root-mean-square error (RMSE) of diameters of 3.5 mm. Investigation of Spearman correlation between parameters showed that the elasticity of the aneurysms decreases slightly with diameter (p = 0.034) and decreases significantly with mean arterial pressure (p < 0.0001). The growth of a AAA is significantly related to its diameter, volume, compliance, and surface curvature (p < 0.002). Investigation of a linear growth model showed that compliance is the best predictor for upcoming AAA growth (RMSE 1.70 mm/year). To conclude, mechanical and geometrical parameters of the maximally dilated region of AAAs can automatically and accurately be determined from 3D + t echograms. With this, a prediction can be made about the upcoming AAA growth. This is a step towards more patient-specific characterization of AAAs, leading to better predictability of the progression of the disease and, eventually, improved clinical decision making about the treatment of AAAs. [ABSTRACT FROM AUTHOR]

ObjectivesThe radial artery pulse waveform is a continuous measure of pressure throughout the cardiac cycle, and thus can provide more information than just systolic and diastolic blood pressures. New indices based on a Windkessel model of the waveform, PTC1 and PTC2, are related to arterial compliance and add information for prediction of incident cardiovascular disease (coronary heart disease, stroke, myocardial infarction) but their association with heart failure is unknown.MethodsAmong 6229 adults (mean age 62 years) from four race/ethnic groups who were initially free of clinical cardiovascular disease and heart failure in 2000-2002, we evaluated the associations of baseline PTC1 and PTC2 with incident heart failure.ResultsMean ± standard deviation PTC1 and PTC2 were 394 ± 334 and 94 ± 46 ms, respectively. During a median of 15.7 years follow-up, there were 357 heart failure events (148 with reduced, 150 with preserved, and 59 with unknown ejection fraction). After adjustment for traditional risk factors, the hazard ratio for heart failure per 1 standard deviation higher PTC2 was 0.73 (95% confidence interval: 0.63--0.85). Higher PTC2 was also significantly associated with lower risk of heart failure with reduced ejection fraction (hazard ratio = 0.67; 95% confidence interval: 0.56--0.80). There was no evidence of a significant association between PTC2 and heart failure with preserved ejection fraction or between PTC1 and heart failure.ConclusionThe PTC2 measure of the radial artery pulse waveform may represent a novel phenotype related to heart failure, especially heart failure with reduced ejection fraction.

This paper presents the feasibility of automated and accurate in vivo measurements of vascular parameters using an ultrasound sensor. The continuous and non-invasive monitoring of certain parameters, such as pulse wave velocity (PWV), blood pressure (BP), arterial compliance (AC), and stiffness index (SI), is crucial for assessing cardiovascular disorders during surgeries and follow-up procedures. Traditional methods, including cuff-based or invasive catheter techniques, serve as the gold standard for measuring BP, which is then manually used to calculate AC and SI through imaging algorithms. In this context, the Continuous and Non-Invasive Vascular Stiffness and Arterial Compliance Screener (CaNVAS) is developed to provide continuous and non-invasive measurements of these parameters using an ultrasound sensor. By driving 5 MHz (ranging from 2.2 to 10 MHz) acoustic waves through the arterial walls, capturing the reflected echoes, and employing pre-processing techniques, the frequency shift is utilized to calculate PWV. It is observed that PWV measured by CaNVAS correlates exponentially with BP values obtained from the sphygmomanometer (BPMR-120), enabling the computation of instantaneous BP values. The proposed device is validated through measurements conducted on 250 subjects under pre- and post-exercise conditions, demonstrating an accuracy of 95% and an average coefficient of variation of 12.5%. This validates the reliability and precision of CaNVAS in assessing vascular parameters. [ABSTRACT FROM AUTHOR]

Purpose: Acute (immediate) or regular (mid- or long-term) stretching increases arterial compliance and reduces arterial stiffness. Stretching is widely known to induce arterial functional factor changes, but it is unclear whether stretching alters arterial structural factors. Ultrasound shear wave elastography can quantify the distribution of tissue elastic properties as an index of arterial structural factors. This study thus aimed to examine the effects of acute cervical stretching on arterial wall tissue elastic properties. Methods: Seventeen healthy young adults participated in two different trials for 15 min in random order on separate days: a resting and sitting trial (CON) and a supervised cervical stretching trial (CS). In CS, subjects performed 10 different stretches. At each site, the stretch was held for 30 s followed by a 10-s relaxation period. In CON, subjects rested on a chair for 15 min. Results: After the experiment, carotid arterial compliance, assessed by combined ultrasound imaging and applanation tonometry, was significantly increased in CS, but not in CON. However, there was no significant change in tissue elasticity properties of the arterial wall in either trial, as assessed by ultrasound shear wave elastography. Conclusion: Acute cervical stretching significantly increased carotid artery compliance in young participants, but did not reduce elastic tissue properties (i.e., arterial structural factors) of the carotid artery wall. These results strongly suggest that changes in structural factors have little relation to stretching-induced acute increases in arterial compliance. [ABSTRACT FROM AUTHOR]

Abstract Although neurohormones and Renin‐Angiotensin‐Aldosterone‐System (RAAS) components are important predictors of cardiovascular mortality (CVM), their importance for predicting outcomes in patients with/without RAAS‐blockers and different degrees of arterial stiffness is less understood. We therefore analyzed long‐term data from the Ludwigshafen Risk and Cardiovascular Health (LURIC) study in 3316 patients subdivided according to pulse pressure (PP) and RAAS‐blocker use. Patients on RAAS‐inhibition had higher renin and noradrenaline, lower aldosterone and aldosterone/renin quotient (ARQ). Renin and noradrenaline significantly predicted CVM in patients without RAAS‐blocker (HR = 1.17, 1.15) and in patients receiving angiotensin‐converting‐enzyme (ACE) inhibitors (HR = 1.17, 1.29), whereas aldosterone predicted CVM only in patients receiving ACE‐inhibitors (HR = 1.13). CVM was predicted independently from PP by renin, noradrenaline and angiotensin II. Independently from RAAS inhibition renin decreased and ARQs increased with rising PP. Furthermore, noradrenaline increased with PP, but only without ACE‐inhibition. The HR for CVM in the ACE‐inhibitor group were 1.29, 1.28, 1.29 for renin in the first, second and third PP quartiles and 1.22, and 1.19 for aldosterone in the second and fourth quartile. Furthermore, we showed that noradrenaline predicts CVM in all PP quartiles in patients with ACE‐inhibition. In the RAAS‐blocker‐free group, the HR for renin for CVM were 1.36 and 1.18 in the third and fourth PP quartiles, but neither aldosterone nor noradrenaline were predictive for CVM within the PP quartiles. Renin and noradrenaline are strong predictors of CVM regardless of RAAS blockade, whereas aldosterone is predictive only in the ACE‐inhibitor group. Catecholamines but not renin are associated with rising PP.

Arterial compliance is an important cardiovascular parameter. It can be measured by several techniques. Most of them are invasive. In this article, we investigated and confirmed the relevance of using a non‐invasive method, peripheral electrical impedance to estimate compliance. We considered a study population composed by a healthy group of 82 volunteers, and a diseases group of 59 volunteers. We determined arterial compliance values for all subjects and studied them as a function of health status, gender, age, blood pressure, blood volume, and baseline impedance Z0. Experimental results showed that arterial compliance is significantly lower in cardiac (1.7 ± 1.0), or diabetic (1.5 ± 1) patients compared to healthy subjects, 2.6 ± 1.1 ml/mmHg (p < 0.001). The comparison of arterial compliance values estimated by peripheral bioimpedance and by echocardiography showed acceptable precision with a mean absolute error = 0.1 and a mean percentage error = 8.51%. Arterial compliance is a potentially useful hemodynamic parameter that could be successfully used to detect several diseases and as a predictor of future heart disease. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

BackgroundArterial stiffening and peripheral wave reflections have been considered the major determinants of raised pulse pressure (PP) and isolated systolic hypertension, but the importance of cardiac contractility and ventricular ejection dynamics is also recognised.MethodsWe examined the contributions of arterial compliance and ventricular contractility to variations in aortic flow and increased central (cPP) and peripheral (pPP) pulse pressure, and PP amplification (PPa) in normotensive subjects during pharmacological modulation of physiology, in hypertensive subjects, and in silico using a cardiovascular model accounting for ventricular–aortic coupling. Reflections at the aortic root and from downstream vessels were quantified using emission and reflection coefficients, respectively.ResultscPP was strongly associated with contractility and compliance, whereas pPP and PPa were strongly associated with contractility. Increased contractility by inotropic stimulation increased peak aortic flow (323.9 ± 52.8 vs. 389.1 ± 65.1 ml/s), and the rate of increase (3193.6 ± 793.0 vs. 4848.3 ± 450.4 ml/s2) in aortic flow, leading to larger cPP (36.1 ± 8.8 vs. 59.0 ± 10.8 mmHg), pPP (56.9 ± 13.1 vs. 93.0 ± 17.0 mmHg) and PPa (20.8 ± 4.8 vs. 34.0 ± 7.3 mmHg). Increased compliance by vasodilation decreased cPP (62.2 ± 20.2 vs. 45.2 ± 17.8 mmHg) without altering dP/dt, pPP or PPa. The emission coefficient changed with increasing cPP, but the reflection coefficient did not. These results agreed with in silico data obtained by independently changing contractility/compliance over the range observed in vivo.ConclusionsVentricular contractility plays a key role in raising and amplifying PP, by altering aortic flow wave morphology.

Purpose: Acute (immediate) or regular (mid- or long-term) stretching increases arterial compliance and reduces arterial stiffness. Stretching is widely known to induce arterial functional factor changes, but it is unclear whether stretching alters arterial structural factors. Ultrasound shear wave elastography can quantify the distribution of tissue elastic properties as an index of arterial structural factors. This study thus aimed to examine the effects of acute cervical stretching on arterial wall tissue elastic properties.Methods: Seventeen healthy young adults participated in two different trials for 15 min in random order on separate days: a resting and sitting trial (CON) and a supervised cervical stretching trial (CS). In CS, subjects performed 10 different stretches. At each site, the stretch was held for 30 s followed by a 10-s relaxation period. In CON, subjects rested on a chair for 15 min.Results: After the experiment, carotid arterial compliance, assessed by combined ultrasound imaging and applanation tonometry, was significantly increased in CS, but not in CON. However, there was no significant change in tissue elasticity properties of the arterial wall in either trial, as assessed by ultrasound shear wave elastography.Conclusion: Acute cervical stretching significantly increased carotid artery compliance in young participants, but did not reduce elastic tissue properties (i.e., arterial structural factors) of the carotid artery wall. These results strongly suggest that changes in structural factors have little relation to stretching-induced acute increases in arterial compliance.

Abstract Although it has been suggested that increased arterial stiffness is linked to exaggerated blood pressure (BP) from brief moderate exercise, it is not clear whether this occurs in older adults with and without hypertension. This study investigates whether the immediate post‐exercise systolic BP following brief moderate exercise is associated with arterial stiffness in older females with different BP status. This cross‐sectional study included 191 older females aged 60–80 years without known cardiovascular disease (CVD). Arterial stiffness was determined by aortic pulse wave velocity (aPWV). Systolic BP was measured before and immediately following a 3‐min moderate walking test (stage 1 Bruce protocol). Specific quartile‐based thresholds were used to define an exaggerated immediate post‐exercise systolic BP for hypertensive and normotensive older females (quartile 4 as an exaggerated response). Traditional CVD risk factors were assessed (covariates). Older females from the highest quartile of immediate post‐exercise absolute systolic BP showed higher aPWV compared to their peers from the lowest quartile (β = .22 m/s, p = .018). The quartile‐based threshold to define the exaggerated post‐exercise systolic BP was higher in hypertensive than in normotensive older females (174 vs. 172 mmHg). In summary, exaggerated immediate post‐exercise systolic BP following a brief moderate exercise is associated with higher arterial stiffness in older females with different BP status.

Although neurohormones and Renin‐Angiotensin‐Aldosterone‐System (RAAS) components are important predictors of cardiovascular mortality (CVM), their importance for predicting outcomes in patients with/without RAAS‐blockers and different degrees of arterial stiffness is less understood. We therefore analyzed long‐term data from the Ludwigshafen Risk and Cardiovascular Health (LURIC) study in 3316 patients subdivided according to pulse pressure (PP) and RAAS‐blocker use. Patients on RAAS‐inhibition had higher renin and noradrenaline, lower aldosterone and aldosterone/renin quotient (ARQ). Renin and noradrenaline significantly predicted CVM in patients without RAAS‐blocker (HR = 1.17, 1.15) and in patients receiving angiotensin‐converting‐enzyme (ACE) inhibitors (HR = 1.17, 1.29), whereas aldosterone predicted CVM only in patients receiving ACE‐inhibitors (HR = 1.13). CVM was predicted independently from PP by renin, noradrenaline and angiotensin II. Independently from RAAS inhibition renin decreased and ARQs increased with rising PP. Furthermore, noradrenaline increased with PP, but only without ACE‐inhibition. The HR for CVM in the ACE‐inhibitor group were 1.29, 1.28, 1.29 for renin in the first, second and third PP quartiles and 1.22, and 1.19 for aldosterone in the second and fourth quartile. Furthermore, we showed that noradrenaline predicts CVM in all PP quartiles in patients with ACE‐inhibition. In the RAAS‐blocker‐free group, the HR for renin for CVM were 1.36 and 1.18 in the third and fourth PP quartiles, but neither aldosterone nor noradrenaline were predictive for CVM within the PP quartiles. Renin and noradrenaline are strong predictors of CVM regardless of RAAS blockade, whereas aldosterone is predictive only in the ACE‐inhibitor group. Catecholamines but not renin are associated with rising PP. [ABSTRACT FROM AUTHOR]

Abstract While regular exercise exposure is considered the most effective therapy to reduce arterial stiffness, the effect of acute exercise training on arterial stiffness in adults with different blood pressure (BP) levels remains unclear. The authors aimed to investigate the effects of acute aerobic exercise on arterial stiffness in male with different BP levels. This cross‐sectional study utilized data for 1200 males aged 20–49 years from the Kailuan study cohort who participated in the fifth National Fitness Monitoring project. A total of 940 participants (621 in the non‐hypertensive group and 319 in the hypertensive group) aged 36.82 ± 7.76 who completed a twice‐quantitative cycle ergometer exercise and measure of brachial‐ankle pulse wave velocity (baPWV) at both the baseline and immediately after exercise were included in this study. The baPWV was decreased after acute aerobic exercise in the non‐hypertension and hypertension groups (Δ 40.29 [95% confidence interval [CI], −47.72 to −32.86] vs. Δ20.45 [95% CI, −31.32 to −9.58] cm/s). Participants without hypertension showed a greater decrease in baPWV (Δ 19.84 [95% CI, −33.83 to −5.84] cm/s) than participants with hypertension. Aerobic exercise had an acute positive effect on arterial stiffness. This study provides evidence of a greater reduction in arterial stiffness in individuals without hypertension than in those with hypertension.

BackgroundBody fat percentage were positively correlated with arterial stiffness, but the acute change in arterial stiffness after aerobic exercise in individuals with different body fat percentages remains unclear. This study was aimed to determine the effect of acute aerobic exercise on arterial stiffness in individuals with different body fat percentages.MethodsIndividuals who both participated in the seventh survey of the Kailuan study and the fifth iteration of National Physical Fitness Monitoring were enrolled in our study. All participants underwent measurement of brachial–ankle pulse wave velocity, blood pressure, and heart rate before and after a two-stage load test on cycle ergometry. Additionally, the generalized linear model was established to analyse between-group differences of the change in brachial–ankle pulse wave velocity before and after exercise for individuals with different body fat percentages.ResultsThe participants (N = 940, 36.8 ± 7.7years old, all male) were divided into: Q1 10.0–19.3%, Q2 19.3–23.3%, Q3 23.3–27.1% and Q4 27.1–37.7% by body fat percentage quartile. Overall, after exercise, brachial–ankle pulse wave velocity decreased significantly (before, 1,375.1 ± 209.1; after, 1,341.5 ± 208.0cm/s; p < 0.01). After adjusting for confounding factors, the generalized linear model showed that the β values and 95% confidence interval (CI) of Q1, Q2 and Q3 groups were −38.1 (95% CI: −57.3, −19.0), −8.5 (95% CI: −25.8, 3.7),−3.7 (95% CI: −20.5, 13.0), respectively, when compared with Q4. For an increase in body fat percentage by one standard deviation (5.8%), β = 14.5 (95% CI: 7.3, 21.6). Similar results were obtained in sensitivity analyses.ConclusionsAcute aerobic exercise had a positive effect on the arterial stiffness of adults with different body fat percentages. Compared with individuals with high body fat percentages, the arterial stiffness of people with low body fat percentages had significant reduction after exercise.

Arterial stiffness is a reliable independent predictor of cardiovascular events. Exercise training might enhance arterial compliance through improved metabolic health status. Different modes of exercise may have different effects on arterial stiffness. However, the interactions among different modes of exercise on endothelial senescence, the development of arterial vascular stiffness, and the associated molecular mechanisms are not completely understood. In this narrative review, we evaluate the current evidence focusing on the effects of various exercise modes on arterial stiffness and vascular health, and the known underlying physiological mechanisms are discussed as well. Here, we discuss the most recent evidence of aerobic exercise, high-intensity interval training (HIIT), and resistance exercise (RE) on arterial stiffness and endothelial senescence in physiological and cellular studies. Indeed, aerobic, HIIT, and progression RE-induced arterial compliance may reduce arterial stiffness by effectively promoting nitric oxide (NO) bioavailability and reducing endothelial senescence. However, the transient increase in inflammation and sympathetic activation may contribute to the temporary elevation in arterial stiffness following whole-body high-intensity acute resistance exercise. [ABSTRACT FROM AUTHOR]

Arterial compliance (AC) decrease with aging is accelerated by factors associated with the progression of atherosclerotic process, including obesity. Prevalence of obesity increases not only in adult population but also in children and adolescents. The results of studies characterizing the effect of obesity on AC (often indirectly estimated by pulse wave velocity (PWV)) are contradictory. Considering the limitations of previously applied methods and the need to interpret AC values in the context of potential confounders or during various physiological states, the aim of this study was to compare AC of control and obese adolescents during four different physiological states: supine rest, head-up tilt (HUT), supine recovery and mental arithmetic (MA). AC was assessed by the method based on two-element Windkessel model as the ratio of a time constant t characterizing diastolic blood pressure decay and total peripheral resistance (TPR). In total, fifty healthy and normotensive subjects (40 females, 10 males, age 17.5 years (SD=1.1 years)) were examined - 25 obese and 25 age- and sex-matched control subjects. We observed significantly increased AC values during all phases in obese group. An increase in AC was also preserved after controlling for blood pressure influence. These results were confirmed using PWV based AC estimation. Interestingly, AC decreased similarly during stress phases (HUT, MA) in both groups. Lastly, TPR was decreased throughout the study protocol in obese subjects. In conclusion, AC is increased in young obese subjects consistently during various physiological states. Furthermore, changes of physiological states evoke similar response of AC in both groups indicating preserved autonomic control of elastic arteries. A decreased TPR in obese subjects points towards the influence of different maturation state of the arterial tree and/or changes in vasomotion possibly counterbalancing acceleration of atherosclerosis process. [ABSTRACT FROM AUTHOR]

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This paper presents the feasibility of automated and accurate in vivo measurements of vascular parameters using an ultrasound sensor. The continuous and non-invasive monitoring of certain parameters, such as pulse wave velocity (PWV), blood pressure (BP), arterial compliance (AC), and stiffness index (SI), is crucial for assessing cardiovascular disorders during surgeries and follow-up procedures. Traditional methods, including cuff-based or invasive catheter techniques, serve as the gold standard for measuring BP, which is then manually used to calculate AC and SI through imaging algorithms. In this context, the Continuous and Non-Invasive Vascular Stiffness and Arterial Compliance Screener (CaNVAS) is developed to provide continuous and non-invasive measurements of these parameters using an ultrasound sensor. By driving 5 MHz (ranging from 2.2 to 10 MHz) acoustic waves through the arterial walls, capturing the reflected echoes, and employing pre-processing techniques, the frequency shift is utilized to calculate PWV. It is observed that PWV measured by CaNVAS correlates exponentially with BP values obtained from the sphygmomanometer (BPMR-120), enabling the computation of instantaneous BP values. The proposed device is validated through measurements conducted on 250 subjects under pre- and post-exercise conditions, demonstrating an accuracy of 95% and an average coefficient of variation of 12.5%. This validates the reliability and precision of CaNVAS in assessing vascular parameters.

Purpose: Augmentation Index (AIx) is used clinically for monitoring both wave reflections and arterial stiffness, which when increased is a risk factor of cardiovascular mortality and morbidity. We hypothesize that AIx is not solely related to vascular stiffness as described by arterial compliance and other hemodynamic parameters since AIx underestimates wave reflections. Methods: Aortic pressure and flow datasets (n = 42) from mongrel dogs were obtained from our experiments and Mendeley Data under various conditions. Arterial compliances based on the Windkessel model (Ct), the stroke volume (SV) to pulse pressure (PP) ratio (Cv = SV/PP), and at inflection pressure point (CPi) were computed. Other relevant hemodynamic factors are also computed. Results: AIx was poorly associated with arterial stiffness calculated from Ct (r = 0.299, p = 0.058) or CPi (r = 0.203, p = 0.203), even when adjusted for heart rates. Ct and Cv were monotonically associated. Alterations in inflection pressure (Pi) did not follow the changes in pulse pressure (PP) (r = 0.475, p = 0.002), and Pi was quantitatively similar to systolic pressure (r = 0.940, p < 0.001). Conclusion: AIx is neither linearly correlated with arterial stiffness, nor with arterial compliance and several cardiac and arterial parameters have to be considered when AIx is calculated. [ABSTRACT FROM AUTHOR]

Reports have indicated that high-intensity resistance training (RT) increases or does not change arterial stiffness. Meanwhile, higher stature has been suggested to have a protective effect on cardiovascular disease and arterial stiffness. Stature could explain the disagreement in the reported effects of RT on arterial stiffness. This study was aimed at investigating whether stature is related to RT-induced change in arterial stiffness. Thirty-six young Japanese men were assigned to the control (n = 15) and training groups (n = 21). RT programme consisted of supervised bicep curls 3 days per week for 4 weeks (5 sets of 10 repetitions at 75% of 1-repetition maximum). Arterial compliance (AC) and β-stiffness index (via combination of ultrasound and carotid pressure waveforms) were measured in all participants. To verify the effect of stature on RT-induced change in arterial stiffness, the training group was divided into tertiles of stature: lower, middle, and higher stature groups (each group, n = 7). RT significantly decreased AC and increased β-stiffness index in only the lower stature group (both, P < 0.05). Moreover, stature was positively associated with decreased AC and negatively associated with increased β-stiffness index, even after adjusting for confounders including changes in relative strength, pulse pressure, and arterial distension (P < 0.05). The present results suggest that short stature contributes to the increase in arterial stiffness induced by RT in young Japanese men. The present findings suggest that stature should be taken into consideration when designing/engaging in RT programme, due to potential implications for cardiovascular health. Participants were divided into 3 groups according to tertiles of statures, and arterial stiffness of lower stature group (range of stature: 161.0–169.8 cm) increased after resistance training in young Japanese men, but not middle and higher stature group. Stature was negatively associated with the changed arterial stiffness by resistance training. This study suggests that short stature contributes to the elevation in arterial stiffness elicited by resistance training. [ABSTRACT FROM AUTHOR]

As we age, remodeling takes place in our body, and while some changes can be attributed to the mere aging process, others can be attributed to an early pathological process of subclinical changes typical in atherosclerosis. Aging is an imminent part of life and is a risk factor for atherosclerosis and cerebrovascular disorders in both sexes. Once established, cerebrovascular diseases are strong contributors in worldwide morbidity and mortality scales, and stroke is the worldwide leading cause of mortality and disability in adults. Cerebrovascular disorders in Croatia are the second leading cause of mortality and the first in adult disability. In this article, we attempt to present all the changes of aging in the common carotid artery thus distinguishing them from a pathological processes. [ABSTRACT FROM AUTHOR]

Although it has been suggested that increased arterial stiffness is linked to exaggerated blood pressure (BP) from brief moderate exercise, it is not clear whether this occurs in older adults with and without hypertension. This study investigates whether the immediate post‐exercise systolic BP following brief moderate exercise is associated with arterial stiffness in older females with different BP status. This cross‐sectional study included 191 older females aged 60–80 years without known cardiovascular disease (CVD). Arterial stiffness was determined by aortic pulse wave velocity (aPWV). Systolic BP was measured before and immediately following a 3‐min moderate walking test (stage 1 Bruce protocol). Specific quartile‐based thresholds were used to define an exaggerated immediate post‐exercise systolic BP for hypertensive and normotensive older females (quartile 4 as an exaggerated response). Traditional CVD risk factors were assessed (covariates). Older females from the highest quartile of immediate post‐exercise absolute systolic BP showed higher aPWV compared to their peers from the lowest quartile (β =.22 m/s, p =.018). The quartile‐based threshold to define the exaggerated post‐exercise systolic BP was higher in hypertensive than in normotensive older females (174 vs. 172 mmHg). In summary, exaggerated immediate post‐exercise systolic BP following a brief moderate exercise is associated with higher arterial stiffness in older females with different BP status. [ABSTRACT FROM AUTHOR]

From the recordings, we obtained beat-specific waveforms and PTC1 and PTC2 using methods as in Brumback et al.,[1] with a minor adjustment due to the 250 Hz sampling rate at the fifth exam (online Supplemental Figure). We created one PTC1 and one PTC2 for each participant using the median PTC1 and median PTC2 from all beat-specific waveforms from the 60-second recording. Keywords: arterial compliance; pulse waveform; Windkessel model EN arterial compliance pulse waveform Windkessel model 141 143 3 04/12/23 20230401 NES 230401 Several approaches have assessed arterial compliance in population studies, but few compliance measures have been rigorously evaluated for reproducibility. [Extracted from the article]

Studies in the gravid rat model revealed a key role for the corpus luteal hormone, relaxin, in the maternal circulatory changes of early pregnancy epitomized by profound systemic vasodilation and increased arterial compliance. To determine whether the corpus luteum may play a similar role in human pregnancy, women who conceived by in vitro fertilization were studied. Implementation of artificial (programmed) cycles for embryo transfers, which precluded the formation of a corpus luteum, was associated with notable attenuation of the gestational rise in cardiac output and fall in carotid-femoral pulse wave velocity (reflecting impairment of arterial dilation and increased compliance, respectively) and deficiencies in other cardiovascular changes normally observed during the first trimester. Cardiac output and carotid-femoral pulse wave velocity were restored after the first trimester of pregnancy, consistent with rescue by placental vasodilators, such as placental growth factor. In addition, a potential role of corpus luteal factors in reducing the risk of developing preeclampsia was hypothesized. In most single and multiple center, prospective and retrospective cohort (and registry) studies, the risk of developing preeclampsia and preeclampsia with severe features was increased specifically in women undergoing autologous frozen embryo transfer in artificial cycles without the formation of a corpus luteum relative to natural, modified natural, stimulated, or controlled ovarian stimulation cycles and spontaneous pregnancies-all associated with the formation of at least 1 corpus luteum. Taken together, these observational studies are sufficiently compelling to warrant randomized clinical trials comparing preeclampsia risk in autologous frozen embryo transfer in natural vs artificial cycles. Impaired endometrial function because of suboptimal hormonal administration is an alternative but not mutually exclusive explanation for increased preeclampsia risk in autologous frozen embryo transfer in artificial cycles. Potential mechanisms by which the corpus luteum may reduce the risk of developing preeclampsia and whether autologous frozen embryo transfer in artificial cycles is associated with increased risk of preterm preeclampsia, term preeclampsia, or both are discussed. Last, suggestions for future investigations are noted. [ABSTRACT FROM AUTHOR]

While regular exercise exposure is considered the most effective therapy to reduce arterial stiffness, the effect of acute exercise training on arterial stiffness in adults with different blood pressure (BP) levels remains unclear. The authors aimed to investigate the effects of acute aerobic exercise on arterial stiffness in male with different BP levels. This cross‐sectional study utilized data for 1200 males aged 20–49 years from the Kailuan study cohort who participated in the fifth National Fitness Monitoring project. A total of 940 participants (621 in the non‐hypertensive group and 319 in the hypertensive group) aged 36.82 ± 7.76 who completed a twice‐quantitative cycle ergometer exercise and measure of brachial‐ankle pulse wave velocity (baPWV) at both the baseline and immediately after exercise were included in this study. The baPWV was decreased after acute aerobic exercise in the non‐hypertension and hypertension groups (Δ 40.29 [95% confidence interval [CI], −47.72 to −32.86] vs. Δ20.45 [95% CI, −31.32 to −9.58] cm/s). Participants without hypertension showed a greater decrease in baPWV (Δ 19.84 [95% CI, −33.83 to −5.84] cm/s) than participants with hypertension. Aerobic exercise had an acute positive effect on arterial stiffness. This study provides evidence of a greater reduction in arterial stiffness in individuals without hypertension than in those with hypertension. [ABSTRACT FROM AUTHOR]

Abstract Aim We investigated the association between levels of leisure-time physical activity and vascular stiffness in a longitudinal observational study from a representative Swedish population. Method A total of 2816 randomly selected individuals were examined at visit 1 (2002–2005, Men = 1400). After a mean follow-up of 9.7 ± 1.4 years, a representative sample of 1327 of the original participants were re-examined at visit 2. After excluding subjects with hypertension at baseline, 761 participants were included in the longitudinal analyses. Leisure-time physical (LTPA) activity was self-reported and dichotomized as high or low (level 3, 4 and level 1, 2, respectively). Large Arterial Elasticity Index (LAEI) and Small Arterial Elasticity Index (SAEI) were measured using the HDI/Pulse Wave™ CR2000. Multivariable general linear models were used to investigate the differences in changes SAEI and LAEI based on LTPA levels. Results At visit 1, and after adjustment for possible confounders, participants in the high LTPA group had better small artery elasticity (SAEI) (SAEI in low-level LTPA: 7.89 ± 0.11, SAEI in high-level LTPA: 8.32 ± 0.15, ΔSAEI: 0.42, CI: 0.07–0.78; p = 0.020). SAEI decreased between the two assessments (Visit 1: SAEI 8.01 ± 3.37 ml/mmHg; Δ SAEI: 1.4, CI 1.2–1.6, p

Background: Endothelial dysfunction is associated with increased risk of cardiovascular disease (CVD). Currently available noninvasive methods of measuring endothelial function have limitations. We tested a novel device that provides an automated measurement of the difference between baseline and post-ischemic, hyperemia-induced, brachial arterial compliance, a phenomenon known to be endothelium-dependent. The association between the calculated index, Flow-mediated Compliance Response (FCR), and established CVD risk indices was determined. Methods: Adults with CVD risk factors or known coronary artery disease (CAD) were enrolled. Framingham Risk Score (FRS) was calculated and presence of metabolic syndrome (MetSyn) was assessed. Carotid artery plaques were identified by ultrasound. Cardiorespiratory fitness was assessed by 6-minute walk test (6MWT). FCR was measured using the device. Results: Among 135 participants, mean age 49.3 +/- 17.9 years, characteristics included: 48% female, 7% smokers, 7% CAD, 10% type 2 diabetes, 34% MetSyn, and 38% with carotid plaque. Those with MetSyn had 24% lower FCR than those without (p

Objective: The capacity of discriminating between normal and impaired dynamic cerebral autoregulation (dCA), based on spontaneous fluctuations in arterial blood pressure (ABP) and cerebral blood flow (CBF), has considerable clinical relevance. This study aimed to quantify the separate contributions of vascular resistance and compliance as parameters that could reflect myogenic and metabolic mechanisms to dCA. Methods: Forty-five subjects were studied under normo and hypercapnic conditions induced by breathing a mixture of 5% carbon dioxide in air. Dynamic cerebrovascular resistance and compliance models with ABP as input and CBFV as output were fitted using Genetic Algorithms to identify parameter values for each subject, and respiratory condition. Results: The efficiency of dCA was assessed from the model's generated CBFV response to an ABP step change, corresponding to an autoregulation index of 5.56 ± 1.57 in normocapnia and 2.38 ± 1.73 in hypercapnia, with an area under the ROC curve (AUC) of 0.9 between both conditions. Vascular compliance increased from 0.75 ± 0.7 ml/mmHg in normocapnia to 5.82 ± 12.0 ml/mmHg during hypercapnia, with an AUC of 0.88. Conclusion: Further work is needed to validate this approach in clinical applications where individualised model parameters could provide relevant diagnostic and prognostic information about dCA impairment. [ABSTRACT FROM AUTHOR]

Background: Chronic endurance exercise training elicits desirable physiological adaptations in the cardiovascular system. The volume of exercise training required to generate healthy adaptations is unclear. This study assessed the effects of differing exercise training levels on arterial stiffness, compliance, and autonomic function. Methods: Eighty healthy adults (38.5 ± 9.7 years; 44% female) defined as endurance-trained (ET, n = 29), normally active (NA, n = 27), or inactive (IN, n = 24) participated. Cardiovascular markers, including hemodynamics, large arterial compliance and small arterial compliance (LAC and SAC), carotid-femoral pulse wave velocity (PWV), and spontaneous baroreceptor sensitivity (BRS) were assessed. Results: ET showed significantly greater LAC values (21.4 ± 6.5) than NA (16.9 ± 2.5; p = 0.002) and IN (14.7 ± 3.2 mL × mm Hg × 10; p = 0.028). Values for SAC and BRS were significantly higher in ET than IN (p < 0.001 and p = 0.028, respectively), but not NA. Compared to IN, PWV values for ET and NA were significantly lower (p < 0.003). After adjusting for covariates (age, sex, and SBP), significant associations with cardiovascular fitness status were noted for all markers but BRS. Conclusion: Endurance exercise increases LAC likely due to high-volume training; however, lower volumes of physical activity may be sufficient to positively benefit vascular health overall. [ABSTRACT FROM AUTHOR]

Background: Physiologically, the aorta is less stiff than peripheral conductive arteries, creating an arterial stiffness gradient, protecting microcirculation from high pulsatile pressure. However, the pharmacological manipulation of arterial stiffness gradient has not been thoroughly investigated. We hypothesized that acute administration of nitroglycerin (NTG) may alter the arterial stiffness gradient through a more significant effect on the regional stiffness of medium-sized muscular arteries, as measured by pulse wave velocity (PWV). The aim of this study was to examine the differential impact of NTG on regional stiffness, and arterial stiffness gradient as measured by the aortic-brachial PWV ratio (AB-PWV ratio) and aortic-femoral PWV ratio (AF-PWV ratio). Methods: In 93 subjects (age: 61 years, men: 67%, chronic kidney disease [CKD]: 41%), aortic, brachial, and femoral stiffnesses were determined by cf-PWV, carotid-radial (cr-PWV), and femoral-dorsalis pedis artery (fp-PWV) PWVs, respectively. The measurements were repeated 5 min after the sublingual administration of NTG (0.4 mg). The AB-PWV and AF-PWV ratios were obtained by dividing cf-PWV by cr-PWV or fp-PWV, respectively. The central pulse wave profile was determined by radial artery tonometry through the generalized transfer function. Results: At baseline, cf-PWV, cr-PWV, and fp-PWV were 12.12 ± 3.36, 9.51 ± 1.81, and 9.71 ± 1.89 m/s, respectively. After the administration of NTG, there was a significant reduction in cr-PWV of 0.86 ± 1.27 m/s (p < 0.001) and fp-PWV of 1.12 ± 1.74 m/s (p < 0.001), without any significant changes in cf-PWV (p = 0.928), leading to a significant increase in the AB-PWV ratio (1.30 ± 0.39 vs. 1.42 ± 0.46; p = 0.001) and AF-PWV ratio (1.38 ± 0.47 vs. 1.56 ± 0.53; p = 0.001). There was a significant correlation between changes in the AF-PWV ratio and changes in the timing of wave reflection (r = 0.289; p = 0.042) and the amplitude of the heart rate-adjusted augmented pressure (r = − 0.467; p < 0.001). Conclusion: This study shows that acute administration of NTG reduces PWV of muscular arteries (brachial and femoral) without modifying aortic PWV. This results in an unfavorable profile of AB-PWV and AF-PWV ratios, which could lead to higher pulse pressure transmission into the microcirculation. [ABSTRACT FROM AUTHOR]

Arterial compliance is an important cardiovascular parameter characterizing mechanical and structural properties of arteries and significantly influencing ventricular-arterial coupling. Decreased arterial compliance is associated with several physiological states and pathological processes. Furthermore, arterial compliance is influenced by other cardiovascular parameters even at short time scales. Today, there are numerous noninvasive methods of estimation arterial compliance in vivo introducing some level of confusion about selection of the best method for particular application and measurement setting. In this review, the most common noninvasive methods of arterial compliance estimation are summarized, discussed and categorized. Finally, interpretation of estimated arterial compliance in the context of other possible confounders is discussed. [ABSTRACT FROM AUTHOR]

Arterial compliance (C) is a complex parameter influencing ventricular-arterial coupling depending on structural (arterial wall remodeling) and functional (blood pressure, smooth muscles tone) changes. Based on Windkessel model, C can be calculated as the ratio of a time constant Tau characterizing diastolic blood pressure decay and total peripheral resistance (TPR). The aim of this study was to assess changes of C in the context of systolic arterial pressure (SAP) perturbations during four physiological states (supine rest, head-up tilt, supine recovery, mental arithmetic). In order to compare pressure independent changes of C a new index of C120 was proposed predicting C value at 120 mm Hg of SAP. Eighty-one healthy young subjects (48 f, average age 18.6 years) were examined. Hemodynamic parameters were measured beat-to-beat using volume-clamp photoplethysmographic method and impedance cardiography. We observed that C was strongly related to SAP values on the beat-to-beat time scale. Interestingly, C120 decreased significantly during stress phases. In conclusion, potential changes of SAP should be considered when measuring C. Arterial compliance changes in the opposite direction to TPR pointing towards influence of vascular tone changes on its value. [ABSTRACT FROM AUTHOR]

There is no clear understanding about the effect of intensive physical load on arterial stiffness and related biomarkers. The aim of this study was to evaluate the effect of half-marathon running on arterial stiffness and blood biomarkers during post-competitive recovery period in competitive and recreational male athletes. Eleven high-level long-distance runners (27.1 ± 4.8 yrs) and seven recreational athletes (34.3 ± 6.1 yrs), who participated in a half-marathon run were examined. Blood biomarkers and arterial stiffness (SphygmoCor 7.1) were measured at baseline and at 18 to 22 hours after the competition. There were no statistically significant changes between the groups in augmentation index (AIx, AIx@75) or pulse wave velocities at carotid-femoral segment (cfPWV) during recovery period. Between-group comparison did not reveal significant differences in blood pressure and arterial stiffness values at baseline and during recovery period. The change of cfPWV (difference between cfPWV at baseline and cfPWV during post-competitive recovery period) was significantly dependent on race time and sports level of the athlete (high-level or recreational). A significant increase was found in hsCRP, creatine kinase and LDH activity during the post-race period in both groups. No significant changes were found in oxidative stress markers in the groups after the race except for higher diene conjugates level in recreational athletes in comparison with the high-level group during recovery period. Our study results showed that half-marathon competition did not cause any significant changes in arterial stiffness parameters during the recovery period. However, the change in cfPWV was independently associated with half-marathon race time and the athlete's level of training revealing a mild increase of arterial stiffness in high-level athletes and athletes with a faster race time. [ABSTRACT FROM AUTHOR]

BackgroundEndothelial function by flow-mediated dilatation assesses early markers of atherosclerotic progression. Greater amounts of physical activity and physical fitness in children are associated with cardiovascular health benefits. We aimed to explore factors, influencing endothelial function and arterial compliance in a cohort of healthy school children.MethodsThe 94 participants (41 girls, 53 boys) in the study were young, healthy children from a German school cohort. Anthropometric data, body composition and blood pressure were assessed. Blood was drawn (8 h overnight fast), assessing total cholesterol, high density lipoprotein and low density lipoprotein and triglycerides. Endothelial function was diagnosed by flow-mediated dilatation with ultrasonography (ALOKA/Hitachi, Prosound alpha 6). Tracking gates were set on the intima in B-mode. The waveform of diameter changes over the cardiac cycle was displayed in real time using the FMD-mode of the eTRACKING system. Changes in arterial diameter at baseline, ischaemia and vasodilatation were measured. A symptom limited pulmonary exercise test on a bicycle ergometer was performed to test cardiorespiratory fitness. Physical activity was assessed using GT3x accelerometers (Actigraph, USA), over 4 days (including 1 week-end day), with a minimum wear-time duration of 10 h.ResultsThe median age was 12.2 years (11.8–12.8). Children were normal weight, blood lipid profiles (cholesterol, high-density lipoprotein, low-density lipoprotein, triglyceride) were in normal range. Baseline measurements during the diagnostics of endothelial function revealed higher arterial compliance of the brachial artery in boys. Boys' cardiorespiratory fitness was higher than compared to girls. Boys met the recommendations of 60 min moderate to vigorous activity, whereas girls were significantly less active and did not meet current recommendations. More time spent in sedentary activity was the main predictor for lower arterial compliance (adjusted for age and sex), accounting for 14% of the variance. No significant model revealed, analyzing the influencing factors such as anthropometric data, blood lipids, physical activity and fitness on endothelial function.ConclusionThis is the first study on endothelial function in association to objectively measured physical activity and cardiorespiratory fitness in healthy school children in Germany. The study highlights the importance of reducing time spent being sedentary to maintain endothelial health.

Abstract Background and aims Sauna bathing and aerobic exercise have each been shown to affect cardiovascular function. However, direct comparisons between standalone sauna bathing and a combination of exercise and sauna on vascular indices remain limited. Therefore, we conducted a cross‐over study using matched durations to explore the hemodynamic changes of sauna exposure when compared to a combination of aerobic exercise and sauna exposure. Methods Participants (N = 72) with at least one cardiovascular risk factor underwent, on two separate occasions: (a) a 30‐minute sauna at 75°C (SAUNA) and (b) the combination of a 15‐minute cycling exercise at 75% maximum heart rate followed by 15‐minute sauna exposure (EX+SAUNA). Relative changes to arterial stiffness (PWV), augmentation index (Alx), brachial systolic and diastolic blood pressure (SBP and DBP), central SBP (cSBP), mean arterial pressure (MAP), and heart rate (HR) were compared PRE‐POST and pre‐ to 30‐minutes post‐intervention (PRE‐POST30). Results Baseline SBP and DBP were 143 (SD 18) mmHg and 86 (SD 10) mmHg, respectively. From PRE‐POST, SAUNA had lower DBP (mean difference [95% CI] 2.5 [1.0, 4.1], P = .002) and MAP (2.5 [0.6, 4.3], P = .01). However, EX+SAUNA had lower SBP (−2.7 [−4.8, −0.5], P = .02), DBP (−1.8 [−3.3, −0.4], P = .01), and MAP (−2.0 [−3.5, −0.5], P = .009) PRE‐POST30. There were no statistically significant differences between SAUNA and EX+SAUNA for other measured parameters. Conclusion This study demonstrated that when matched for duration, EX+SAUNA and SAUNA elicit comparable acute hemodynamic alterations in middle‐aged participants with cardiovascular risk factors. The sauna is a suitable option for acute blood pressure reductions in those who are unable to perform aerobic exercise, and may be a viable lifestyle treatment option to improve blood pressure control.

Arterial compliance (AC) plays a crucial role in vascular aging and cardiovascular disease. The ability to continuously estimate aortic AC or its surrogate, pulse pressure (PP), through wearable devices is highly desirable, given its strong association with daily activities. While the single-site photoplethysmography (PPG)-derived arterial stiffness indices show reasonable correlations with AC, they are susceptible to noise interference, limiting their practical use. To overcome this challenge, our study introduces a noise-resistant indicator of AC: Katz's fractal dimension (KFD) of PPG signals. We showed that KFD integrated the signal complexity arising from compliance changes across a cardiac cycle and vascular structural complexity, thereby decreasing its dependence on individual characteristic points. To assess its capability in measuring AC, we conducted a comprehensive evaluation using both in silico studies with 4374 virtual human data and real-world measurements. In the virtual human studies, KFD demonstrated a strong correlation with AC ( r = 0.75), which only experienced a slight decrease to 0.66 at a signal-to-noise ratio of 15dB, surpassing the best PPG-morphology-derived AC measure ( r = 0.41) under the same noise condition. In addition, we observed that KFD's sensitivity to AC varied based on the individual's hemodynamic status, which may further enhance the accuracy of AC estimations. These in silico findings were supported by real-world measurements encompassing diverse health conditions. In conclusion, our study suggests that PPG-derived KFD has the potential to continuously and reliably monitor arterial compliance, enabling unobtrusive and wearable assessment of cardiovascular health., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xing, Hong, Alastruey, Long, Liu and Dong.)

• The vibrational method can measure arterial volume at maximum compliance. • The vibrational and volume-clamp method were simultaneously implemented. • We simultaneously measured changes in arterial blood pressure and compliance. • We introduced different methodological innovations in our custom made device. • Arterial pressure waveform could be measured without interruptions for recalibration. The arterial–blood-pressure (ABP) waveform can be monitored by the volume-clamp method. The photoplethysmography (PPG) signal is measured and clamped at maximum arterial compliance (PPGcmax) by controlling the external pressure (EP) with a cuff. PPGcmax is determined by the volume-oscillometric method though ABP measurement is regularly interrupted. To overcome this drawback, the vibrational method superimposes high-frequency vibrations on EP and measures the PPG response to estimate the "vibrational" compliance (Cv) and the PPGcmax. This method, though, has never been validated or implemented simultaneously with the volume-clamp method because the control has always been unstable. We implemented a custom-made device with a novel control system, monitoring stability and adapting the gain at high frequencies, plus lower-amplitude EP vibrations. We compared, in eleven volunteers, the EP at PPGcmax determined by the volume-oscillometric and the vibrational methods. Both exhibited a good linear correlation (r 2 >0.92) and Bland-Altman agreement (95% confidence interval <15 mmHg). Moreover, in three volunteers, the vibrational and volume-clamp methods were implemented together while experimentally changing the ABP and/or Cv without manifesting control-system instability. Cv measured with the vibrational method could be used by the volume-clamp method to measure the ABP waveform without any interruptions due to changes in arterial compliance. [ABSTRACT FROM AUTHOR]

Background: Endovascular treatment of aortic aneurysm is associated with an increase in pulse wave velocity (PWV) after surgery. However, the effect of different types of endovascular devices on PWV at different sites of the thoracic aorta remains unclear. Objectives: The purposes of this study were (1) to investigate the changes in PWV after endovascular treatment of thoracic aortic aneurysm; (2) to evaluate whether there is a difference in the changes in PWV at different treatment sites; and (3) to evaluate the effect of treatment length on changes in PWV. Methods: From July 2008 to July 2021, 276 patients underwent endovascular treatment of the true thoracic aortic aneurysm. Of these patients, 183 patients who underwent preoperative and postoperative PWV measurement within 1 year of surgery were included in the study. The treatment length index was calculated by treatment length divided by the height of the patients. Results: Five different types of endovascular devices were used (Najuta, Kawasumi Laboratories, Inc., Tokyo, Japan; TAG, W.L. Gore & Associates, Inc., AZ, USA; Relay, Bolton Medical, Inc., FL, USA; Talent/Valiant, Medtronic, MN, USA; and Zenith, Cook Medical, IN, USA). There was no significant change in PWV in patients receiving Najuta (Before: 2,040 ± 346.8 cm/s vs. After: 2,084 ± 390.5 cm/s, p = 0.14). However, a significant increase was observed in other devices: TAG (Before: 2,090 ± 485.9 cm/s vs. After: 2,300 ± 512.1 cm/s, p = 0.025), Relay (Before: 2,102 ± 465.3 cm/s vs. After: 2,206 ± 444.4 cm/s, p = 0.004), Valiant (Before: 1,696 ± 330.2 cm/s vs. After: 2,186 ± 378.7 cm/s, p < 0.001), and Zenith (Before: 2,084 ± 431.7 cm/s vs. After: 2,321 ± 500.6 cm/s, p < 0.001). There was a significant increase in PWV in patients treated from aortic arch (Before: 2,006 ± 333.7 cm/s vs. After: 2,132 ± 423.7 cm/s, p < 0.001) and patients treated from descending thoracic aorta (Before: 2,116 ± 460.9 cm/s vs. After: 2,292 ± 460.9 cm/s, p < 0.001). Multivariate analysis showed that treatment site was not an independent factor associated with changes in PWV. However, Najuta (Coef −219.43, 95% CI −322.684 to −116.176, p < 0.001) and treatment index (Coef 147.57, 95% CI 24.826 to 270.312, p = 0.019) were independent factors associated with changes in PWV. Conclusion: Najuta did not show a significant increase in PWV, while other commercially available devices showed a significant increase. The treatment site did not have a different effect on PWV. However, the treatment length was an independent factor associated with an increase in PWV. [ABSTRACT FROM AUTHOR]

Arterial smooth muscle cells (ASMCs), the predominant cell type within the arterial wall, detect and respond to external mechanical forces. These forces can be derived from blood flow (i.e. pressure and stretch) or from the supporting extracellular matrix (i.e. stiffness and topography). The healthy arterial wall is elastic, allowing the artery to change shape in response to changes in blood pressure, a property known as arterial compliance. As we age, the mechanical forces applied to ASMCs change; blood pressure and arterial wall rigidity increase and result in a reduction in arterial compliance. These changes in mechanical environment enhance ASMC contractility and promote disease-associated changes in ASMC phenotype. For mechanical stimuli to programme ASMCs, forces must influence the cell's load-bearing apparatus, the cytoskeleton. Comprised of an interconnected network of actin filaments, microtubules and intermediate filaments, each cytoskeletal component has distinct mechanical properties that enable ASMCs to respond to changes within the mechanical environment whilst maintaining cell integrity. In this review, we discuss how mechanically driven cytoskeletal reorganisation programmes ASMC function and phenotypic switching. [ABSTRACT FROM AUTHOR]

Degenerative aortic valve stenosis is the most common primary valve disease and a significant cause of cardiovascular morbidity and mortality. In an era when new techniques for the management of aortic stenosis are gaining ground, the understanding of this disease is more important than ever to optimize treatment. So far, the focus has been placed on the assessment of the valve itself. However, the role that the arterial system plays in the pathogenesis and natural history of the disease needs to be further elucidated. Arteriosclerosis, when it coexists with a stenotic valve, augments the load posed on the left ventricle contributing to greater impairment of cardiovascular function. Arterial stiffness, a well-established predictor for cardiovascular disease and all-cause mortality, could play a role in the prognosis and quality of life of this population. Several studies using a variety of indices to assess arterial stiffness have tried to address the potential utility of arterial function assessment in the case of aortic stenosis. Importantly, reliable data identify a prognostic role of arterial biomarkers in aortic stenosis and stress their possible use to optimize timing and method of treatment. This review aims at summarizing the existing knowledge on the interplay between the heart and the vessels in the presence of degenerative aortic stenosis, prior, upon and after interventional management. Further, it discusses the evidence supporting the potential clinical application of arterial biomarkers for the assessment of progression, severity, management and prognosis of aortic stenosis. [Display omitted] • The interplay between AVS and functional arterial alteration is a significant element of the pathophysiology of AVS. • The correlation of pressure-dependent functional indices with the presence and severity of AVS is not well established. • Arterial stiffness increases after surgical and transcatheter procedures to treat AVS. • Arterial biomarkers exhibit a prognostic role for patients with AVS prior to and after treatment interventions. [ABSTRACT FROM AUTHOR]