Pulse Wave Velocities Derived From Cuff Ambulatory Pulse Wave Analysis

Evaluation of Arterial Stiffness Parameters Measurement With Noninvasive Methods-A Systematic Review

Objective: Arterial stiffness, as determined by pulse wave velocity (PWV), is a recognized marker of cardiovascular risk. Noninvasive technologies have enabled easier and more accessible assessments of PWV. The current gold standard for measuring carotid-femoral PWV (cfPWV)-a reliable indicator of arterial stiffness-utilizes applanation tonometry devices, as recommended by the Artery Society Guidelines. The objective of this study was to compare the performance of various noninvasive arterial stiffness measurement methods, specifically the Mobil-O-Graph and SphygmoCor/SphygmoCor XCEL, and evaluate their alignment with the Artery Society Guidelines for accuracy and reliability. Methods: A comprehensive search was conducted in the PubMed and Scopus databases to identify studies that compared and validated noninvasive PWV measurements, focusing on their repeatability. The search covered studies from inception through March 31, 2024. A total of 2092 papers were identified. Following the selection process, 21 studies met the inclusion criteria. Additionally, 2 more studies, not retrieved by the initial search but deemed relevant from other databases, were included. The included studies focused on populations with chronic diseases who were hemodynamically stable. Studies involving participants in specific conditions, such as pregnancy, hemodynamic shock, or undergoing stress tests, were excluded from the analysis. Results: Several devices have been developed and validated for the noninvasive measurement of arterial stiffness, utilizing applanation tonometry (e.g., SphygmoCor, SphygmoCor XCEL) and cuff-based oscillometry (e.g., Arteriograph, Mobil-O-Graph). The analyses reviewed included studies using both invasive and noninvasive devices. A notable finding was the relative heterogeneity of study populations across different research, with variations in sample size, BMI, sex proportions, and age groups often falling short of guideline recommendations. In most of the included validation studies, the sample sizes were smaller than the minimum recommended by guidelines. Moreover, factors such as BMI, sex distribution, and age group sizes were inconsistent with established standards. Despite these limitations, validation studies comparing invasive and noninvasive methods consistently highlighted the superiority of cfPWV assessment devices. Applanation tonometry devices demonstrated smaller discrepancies in PWV measurements and better overall agreement with invasive methods than oscillometry-based devices. Three studies comparing the SphygmoCor XCEL with the standard SphygmoCor showed an excellent level of agreement, with one study confirming the SphygmoCor XCEL's superior adherence to validation criteria. Oscillometric devices showed a stronger reliance on algorithmic adjustments based on factors such as age and systolic blood pressure. This dependence likely contributes to the underestimation of PWV, particularly in populations with chronic diseases or other conditions promoting arterial stiffness. Despite this, oscillometric devices demonstrated lower PWV variability in short-term repeatability assessments. Conclusions: More research on a larger population should be performed in order to introduce noninvasive devices into daily medical practice.

Associations of Cardiovascular Health Metrics in Childhood and Adolescence With Arterial Health Indicators in Adolescence: The PANIC Study

BACKGROUND

Our aim was to assess the relationships of cardiovascular health metrics, cardiorespiratory fitness, lean mass, and fat percentage with arterial structure and function from childhood to adolescence.

METHODS AND RESULTS

Five hundred four children aged 6 to 9 years were examined in the PANIC (Physical Activity and Nutrition in Children) study at baseline, 2 and 8 years later. The associations of adjusted American Heart Association cardiovascular health metrics (smoking status, body mass index-SD score, moderate-to-vigorous physical activity, diet quality, plasma total cholesterol, systolic blood pressure, plasma glucose categorized into poor, intermediate, and ideal), the American Heart Association cardiovascular health score, cardiorespiratory fitness measured by maximal oxygen uptake in a bicycle exercise test, lean mass and fat percentage with carotid intima-media thickness (cIMT) and pulse wave velocity (PWV) were analyzed cross-sectionally and longitudinally in 277 participants at age 15 to 17 years. Higher American Heart Association cardiovascular health score at baseline was associated with lower PWV at 8-year follow-up (ß, -0.19 [95% CI, -0.32 to -0.05]). Higher body mass index-SD score and systolic blood pressure were associated with higher cIMT (ß, 0.18 [95% CI, 0.05-0.31]); and (ß, 0.13 [95% CI, 0.00-0.25]; respectively) and PWV (ß, 0.20 [95% CI, 0.07-0.34]) and (ß, 0.13 [95% CI, 0.00-0.26]; respectively) at 8-year follow-up. Higher moderate-to-vigorous physical activity was associated with higher cIMT (ß, 0.25 [95% CI, 0.07-0.43]); yet lower PWV (ß, -0.25 [95% CI, -0.44 to -0.06]) at 8-year follow-up. Better cardiorespiratory fitness (ß, 0.29 [95% CI, 0.08-0.51]) and higher lean mass (ß, 0.51 [95% CI, 0.03-0.98]) were associated with higher cIMT after accounting for American Heart Association cardiovascular health score at 8-year follow-up.

CONCLUSIONS

While our results suggest that higher cardiometabolic risk factors in childhood may exert unfavorable effects on arterial health during adolescence, we demonstrated the complexity of relationships between cardiovascular health metrics and arterial health indicators in childhood and adolescence. We found different associations of cardiovascular health metrics with cIMT and PWV in childhood and adolescence, calling for caution when interpreting the results of various cardiovascular risk factors with measures of arterial health, particularly in youth.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01803776.

Correlation between estimated pulse wave velocity values from two equations in healthy and under cardiovascular risk populations

INTRODUCTION

Equations can calculate pulse wave velocity (ePWV) from blood pressure values (BP) and age. The ePWV predicts cardiovascular events beyond carotid-femoral PWV. We aimed to evaluate the correlation between four different equations to calculate ePWV.

METHODS

The ePWV was estimated utilizing mean BP (MBP) from office BP (MBPOBP) or 24-hour ambulatory BP (MBP24-hBP). We separated the whole sample into two groups: individuals with risk factors and healthy individuals. The e-PWV was calculated as follows: [Formula: see text] [Formula: see text] We calculated the concordance correlation coefficient (Pc) between e1-PWVOBP vs e2-PWVOBP, e1-PWV24-hBP vs e2-PWV24-hBP, and mean values of e1-PWVOBP, e2-PWVOBP, e1-PWV24-hBP and e2-PWV24-hBP. The multilevel regression model determined how much the ePWVs are influenced by age and MBP values.

RESULTS

We analyzed data from 1541 individuals; 1374 ones with risk factors and 167 healthy ones. The values are presented for the entire sample, for risk-factor patients and for healthy individuals respectively. The correlation between e1-PWVOBP with e2-PWVOBP and e1-PWV24-hBP with e2-PWV24-hBP was almost perfect. The Pc for e1-PWVOBP vs e2-PWVOBP was 0.996 (0.995-0.996), 0.996 (0.995-0.996), and 0.994 (0.992-0.995); furthermore, it was 0.994 (0.993-0.995), 0.994 (0.994-0.995), 0.987 (0.983-0.990) to the e1-PWV24-hBP vs e2-PWV24-hBP. There were no significant differences between mean values (m/s) for e1-PWVOBP vs e2-PWVOBP 8.98±1.9 vs 8.97±1.8; p = 0.88, 9.14±1.8 vs 9.13±1.8; p = 0.88, and 7.57±1.3 vs 7.65±1.3; p = 0.5; mean values are also similar for e1-PWV24-hBP vs e2-PWV24-hBP, 8.36±1.7 vs 8.46±1.6; p = 0.09, 8.50±1.7 vs 8.58±1.7; p = 0.21 and 7.26±1.3 vs 7.39±1.2; p = 0.34. The multiple linear regression showed that age, MBP, and age2 predicted more than 99.5% of all four e-PWV.

CONCLUSION

Our data presents a nearly perfect correlation between the values of two equations to calculate the estimated PWV, whether utilizing office or ambulatory blood pressure.

Feasibility of Arteriograph 24 for evaluation of 24-hour pulse wave velocity and central blood pressure in patients with type 2 diabetes and non-diabetic controls

The objective of this study was to assess the feasibility of the Arteriograph 24 device to measure 24-hour PWV and central systolic blood pressure (cSBP) in patients with type 2 diabetes (T2DM) and non-diabetic controls and compare daytime and nighttime characteristics in the two groups. Twenty-four-hour PWV and cSBP was measured in 58 patients with T2DM (mean age: 66 ± 9 years, 50% women, mean duration of T2DM: 7.8 ± 1.5 years) and 62 age- and sex-matched controls. Seventy percent of participants (71% T2DM patients and 69% controls) had sufficient readings to generate an acceptable 24-hour report (≥14 day and ≥7 night readings). Lower nocturnal than daytime PWV and cSBP were observed in both groups. Nocturnal PWV and cSBP dipping were attenuated in T2DM patients compared to controls (PWV: -0.3 ± 0.9 vs. -0.7 ± 0.9 m/s, P  = 0.04, cSBP: -8 ± 14 vs. -18 ± 18 mmHg, P  < 0.01). No group differences in PWV or cSBP were observed during daytime (T2D vs. controls, PWV: 9.2 ± 1.1 vs. 9.2 ± 1.3 m/s, P  = 0.99, cSBP: 133 ± 19 vs. 137 ± 25 mmHg, P  = 0.42) or nighttime (PWV: 8.9 ± 1.3 vs. 8.4 ± 1.3 m/s, P  = 0.14, cSBP 124 ± 20 vs. 118 ± 27 mmHg, P  = 0.26). The study findings indicate that the nocturnal dipping of PWV and cSBP is attenuated in T2DM patients. The significant number of missing measurements raises concerns regarding the clinical utility of the Arteriograph 24 device.

Update on the Use of Pulse Wave Velocity to Measure Age-Related Vascular Changes

PURPOSE OF REVIEW

Pulse wave velocity (PWV) is an important and well-established measure of arterial stiffness that is strongly associated with aging. Age-related alterations in the elastic properties and integrity of arterial walls can lead to cardiovascular disease. PWV measurements play an important role in the early detection of these changes, as well as other cardiovascular disease risk factors, such as hypertension. This review provides a comprehensive summary of the current knowledge of the effects of aging on arterial stiffness, as measured by PWV.

RECENT FINDINGS

This review highlights recent findings showing the applicability of PWV analysis for investigating heart failure, hypertension, and other cardiovascular diseases, as well as cerebrovascular diseases and Alzheimer's disease. It also discusses the clinical implications of utilizing PWV to monitor treatment outcomes, various challenges in implementing PWV assessment in clinical practice, and the development of new technologies, including machine learning and artificial intelligence, which may improve the usefulness of PWV measurements in the future. Measuring arterial stiffness through PWV remains an important technique to study aging, especially as the technology continues to evolve. There is a clear need to leverage PWV to identify interventions that mitigate age-related increases in PWV, potentially improving CVD outcomes and promoting healthy vascular aging.

Deterioration of Kidney Function Is Affected by Central Arterial Stiffness in Late Life

Cardiovascular diseases affect kidney function. The aim of this study was to investigate the possible associations between hemodynamic parameters and change in kidney function in individuals aged 75 years and older. Data on hemodynamics and blood and urine samples were collected at baseline and during one-year visits. Hemodynamics were split into two groups based on median values. Changes in the estimated glomerular filtration rate (eGFR) were investigated between low and high groups for each hemodynamic parameter using analysis of variance. Changes in the albumin-creatinine ratio (ACR) were examined as binary outcomes (large increase vs. stable) using logistic regression. The population consisted of 252 participants. Participants in the high central systolic blood pressure (cSBP) group had a greater decline in eGFR than participants in the low cSBP group (-6.3% vs. -2.7%, p = 0.006). Participants in the high aortic pulse wave velocity (aPWV) group had a greater decline in eGFR than those in the low aPWV group (-6.8% vs. -2.5%, p = 0.001). Other hemodynamic parameters were not associated with eGFR changes. Hemodynamics were not associated with changes in the ACR; aPWV and cSBP appear to be predictors for eGFR decline in older age; monitoring and treatment of elevated stiffness might be helpful in order to prevent kidney function decline.

2024 Recommendations for Validation of Noninvasive Arterial Pulse Wave Velocity Measurement Devices

BACKGROUND

Arterial stiffness, as measured by arterial pulse wave velocity (PWV), is an established biomarker for cardiovascular risk and target-organ damage in individuals with hypertension. With the emergence of new devices for assessing PWV, it has become evident that some of these devices yield results that display significant discrepancies compared with previous devices. This discrepancy underscores the importance of comprehensive validation procedures and the need for international recommendations.

METHODS

A stepwise approach utilizing the modified Delphi technique, with the involvement of key scientific societies dedicated to arterial stiffness research worldwide, was adopted to formulate, through a multidisciplinary vision, a shared approach to the validation of noninvasive arterial PWV measurement devices.

RESULTS

A set of recommendations has been developed, which aim to provide guidance to clinicians, researchers, and device manufacturers regarding the validation of new PWV measurement devices. The intention behind these recommendations is to ensure that the validation process can be conducted in a rigorous and consistent manner and to promote standardization and harmonization among PWV devices, thereby facilitating their widespread adoption in clinical practice.

CONCLUSIONS

It is hoped that these recommendations will encourage both users and developers of PWV measurement devices to critically evaluate and validate their technologies, ultimately leading to improved consistency and comparability of results. This, in turn, will enhance the clinical utility of PWV as a valuable tool for assessing arterial stiffness and informing cardiovascular risk stratification and management in individuals with hypertension.

Value of estimating pulse wave velocity compared to SCORE in cardiovascular risk stratification in community pharmacies

OBJECTIVES

Arterial stiffness is considered to be an intermediate marker with independent prognostic value. The objective of this study is to assess whether the estimation of arterial stiffness can improve CV risk stratification compared to SCORE in patients at community pharmacies.

METHODS

Observational prospective epidemiological study in which consecutive individuals entering a participating Community Pharmacy are offered a voluntary measurement of blood pressure and estimation of pulse wave velocity by oscillometry (AGEDIO, IEM®) to stratify their CV risk according to SCORE compared to the use of arterial stiffness.

RESULTS

After nine months of recruitment, data from 923 patients (570 women, 353 men) were collected. 16/122 (13.1%) patients under 40 years and 72/364 (19.8%) over 65 years of age presented pathological stiffness and could be classified as high-risk, even though being out of the age-range of SCORE. Of the 437 (47.3%) patients who were susceptible to calculating SCORE, 42/437 patients (9.6%) presented pathological arterial stiffness. Cholesterol values were available in 281 patients (64.3%). Among them, according to SCORE, only 6 (2.1%) fell into the high-risk category.

CONCLUSIONS

More than half of the subjects who randomly enter a community pharmacy had ages that make it impossible to calculate the CV risk by SCORE. Among them, arterial damage was detected in 18.1%. Of the other half, 9.6% presented arterial damage and, therefore, high CV risk, when SCORE only detected it in 2.1%. Therefore, estimating arterial stiffness in community pharmacies markedly improves detection of high CV risk compared to SCORE.

Diagnosis of cardiovascular disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular disease (CVD) and cardiovascular death. Identifying and monitoring cardiovascular complications and hypertension is important for managing patients with CKD or kidney failure and transplant recipients. Biomarkers of myocardial ischaemia, such as troponins and electrocardiography (ECG), have limited utility for diagnosing cardiac ischaemia in patients with advanced CKD. Dobutamine stress echocardiography, myocardial perfusion scintigraphy and dipyridamole stress testing can be used to detect coronary disease in these patients. Left ventricular hypertrophy and left ventricular dysfunction can be detected and monitored using various techniques with differing complexity and cost, including ECG, echocardiography, nuclear magnetic resonance, CT and myocardial scintigraphy. Atrial fibrillation and other major arrhythmias are common in all stages of CKD, and ambulatory heart rhythm monitoring enables precise time profiling of these disorders. Screening for cerebrovascular disease is only indicated in asymptomatic patients with autosomal dominant polycystic kidney disease. Standardized blood pressure is recommended for hypertension diagnosis and treatment monitoring and can be complemented by ambulatory blood pressure monitoring. Judicious use of these diagnostic techniques may assist clinicians in detecting the whole range of cardiovascular alterations in patients with CKD and enable timely treatment of CVD in this high-risk population.

Arteriosclerosis Assessment Based on Single-Point Fingertip Pulse Monitoring Using a Wearable Iontronic Sensor

Arteriosclerosis, which appears as a hardened and narrowed artery with plaque buildup, is the primary cause of various cardiovascular diseases such as stroke. Arteriosclerosis is often evaluated by clinically measuring the pulse wave velocity (PWV) using a two-point approach that requires bulky medical equipment and a skilled operator. Although wearable photoplethysmographic sensors for PWV monitoring are developed in recent years, likewise, this technique is often based on two-point measurement, and the signal can easily be interfered with by natural light. Herein, a single-point strategy is reported based on stable fingertip pulse monitoring using a flexible iontronic pressure sensor for heart-fingertip PWV (hfPWV) measurement. The iontronic sensor exhibits a high pressure-resolution on the order of 0.1 Pa over a wide linearity range, allowing the capture of characteristic peaks of fingertip pulse waves. The forward and reflected waves of the pulse are extracted and the time difference between the two waves is computed for hfPWV measurement using Hiroshi's method. Furthermore, a hfPWV-based model is established for arteriosclerosis evaluation with an accuracy comparable to that of existing clinical criteria, and the validity of the model is verified clinically. The work provides a reliable technique that can be used in wearable arteriosclerosis assessment systems.

Impact of arterial location, pressure wave indicators, and measurement devices on arterial form factor and mean and central arterial pressure

Mean arterial pressure (MAP) is often estimated from cuff systolic (S) and diastolic (D) blood pressure (BP) using a fixed arterial form factor (FF, usually 0.33). If MAP is measured directly, a true FF can be calculated: FF = [MAP-DBP]/[SBP-DBP]. Because waveform shapes vary, true FF should also vary and MAP accuracy will be affected. We studied factors affecting FF using radial tonography (SphygmoCor, n = 376) or brachial oscillometry (Mobil-O-Graph, n = 157) and to compare devices, 101 pairs were matched precisely for SBP and DBP. SphygmoCor brachioradial FF correlated strongly with central FF (r2 = 0.75), central augmentation index (cAI, r2 = 0.39), and inversely with pulse pressure amplification (PPA) ratio (r2 = 0.44) [all p < 0.000]; brachioradial FF was lower than central (c) FF (0.34 vs. 0.44, 95% CI's [0.23,0.46] and [0.34,0.54], p < 0.000). On forward stepwise regression, brachioradial FF correlated with PPA ratio, age, heart rate, and cAI (multiple-r2 0.63, p < 0.000). With Mobil-O-Graph: brachial FF was fixed, lower than the corresponding cFF [mean(SD)] 0.46(0.00098) vs. 0.57(0.048), p < 0.000], and uncorrelated with clinical characteristics; MAP and cSBP were higher than SphygmoCor by 6.3 and 2.2 mmHg (p < 0.005) at the midpoint with systematic negative biases. We conclude that FF derived from radial tonometry (SphygmoCor) varies with pulse wave morphology within and between individuals and by measurement site, age, and heart rate. With oscillometry (Mobil-O-Graph), brachial FF was fixed and high and unrelated to other clinical variables; MAP and cSBP were higher than tonometry, with systematic negative biases.

Aortic pulse wave comparison between controls and triathletes in baseline conditions and in response to acute maximum exercise

To determine the effects of intense training on aortic pulse wave variables and hemodynamic parameters at baseline and at recovery from maximal exercise testing (MaxET) in triathletes compared with sedentary individuals. In this prospective and experimental study, 21 triathletes and 21 sedentary individuals were recruited and evaluated prior and two minutes after the MaxET using the Mobil-O-Graph®, which estimates the aortic pulse wave from the brachial artery pressure. The augmentation index (AIx@75) was lower in triathletes after the MaxET compared to control group (16.34 ± 5.95 vs. 23.5 ± 8.53%, p = 0.001), while the pulse wave velocity (PWV) was similar between groups. The heart rate was significantly lower at baseline and after MaxET in triathletes group (55.70 ± 8.95 bpm 91.49 ± 11.39 bpm) compared with control group (62.11 ± 6.70 bpm; 102.08 ± 10.85 bpm). The stroke volume was significantly higher at baseline (96.08 ± 13.96 ml; 86.17 ± 11.24 ml) and after MaxET in triathletes group (69.15 ± 6.51 ml, 58.38 ± 6.99 ml) compared with control group. Triathetes show lower value of AIx@75 after MaxET in comparison with the control group. AIx@75, in addition to being an indirect measure of arterial stiffness, is also a measure of left ventricular afterload. Thus, the lower AIx@75 in triathletes may be due to their lower left ventricular afterload, lower myocardial oxygen demand, and greater coronary perfusion than sedentary individuals. The hemodynamic changes observed in triathletes at rest and during an acute exercise bout are distinctive characteristics of aerobic physical training.

Filtering-induced changes of pulse transmit time across different ages: a neglected concern in photoplethysmography-based cuffless blood pressure measurement

Background: Pulse transit time (PTT) is a key parameter in cuffless blood pressure measurement based on photoplethysmography (PPG) signals. In wearable PPG sensors, raw PPG signals are filtered, which can change the timing of PPG waveform feature points, leading to inaccurate PTT estimation. There is a lack of comprehensive investigation of filtering-induced PTT changes in subjects with different ages. Objective: This study aimed to quantitatively investigate the effects of aging and PTT definition on the infinite impulse response (IIR) filtering-induced PTT changes. Methods: One hundred healthy subjects in five different ranges of age (i.e., 20-29, 30-39, 40-49, 50-59, and over 60 years old, 20 subjects in each) were recruited. Electrocardiogram (ECG) and PPG signals were recorded simultaneously for 120 s. PTT was calculated from the R wave of ECG and PPG waveform features. Eight PTT definitions were developed from different PPG waveform feature points. The raw PPG signals were preprocessed then further low-pass filtered. The difference between PTTs derived from preprocessed and filtered PPG signals, and the relative difference, were calculated and compared among five age groups and eight PTT definitions using the analysis of variance (ANOVA) or Scheirer-Ray-Hare test with post hoc analysis. Linear regression analysis was used to investigate the relationship between age and filtering-induced PTT changes. Results: Filtering-induced PTT difference and the relative difference were significantly influenced by age and PTT definition (p < 0.001 for both). Aging effect on filtering-induced PTT changes was consecutive with a monotonous trend under all PTT definitions. The age groups with maximum and minimum filtering-induced PTT changes depended on the definition. In all subjects, the PTT defined by maximum peak of PPG had the minimum filtering-induced PTT changes (mean: 16.16 ms and 5.65% for PTT difference and relative difference). The changes of PTT defined by maximum first PPG derivative had the strongest linear relationship with age (R-squared: 0.47 and 0.46 for PTT difference relative difference). Conclusion: The filtering-induced PTT changes are significantly influenced by age and PTT definition. These factors deserve further consideration to improve the accuracy of PPG-based cuffless blood pressure measurement using wearable sensors.

Low length-for-age Z-score within 1 month after birth predicts hyperdynamic circulation at the age of 21 years in rural Malawi

Low birth weight predisposes to the development of hypertension in middle- and high-income countries. We examined the relation of early life length-for-age score (Z-score) on cardiovascular function in young adults in Malawi, a low-income country. Capture of supine, seated, and standing brachial pulse waveforms (Mobil-O-Graph) were performed in 223 females and 152 males (mean age 21 years), and analyzed according to the length-for-age Z-score tertiles during the first month of life. Plasma LDL cholesterol in young adulthood was slightly lower in the lowest versus highest tertile. Otherwise, blood hemoglobin and plasma chemistry were similar in all tertiles. Irrespective of posture, blood pressure, forward and backward wave amplitudes, and pulse wave velocity were corresponding in all tertiles. In the three postures, the lowest tertile presented with 4.5% lower systemic vascular resistance than the highest tertile (p = 0.005), and 4.4% and 5.5% higher cardiac output than the middle and highest tertiles, respectively (p < 0.01). Left cardiac work was 6.8% and 6.9% higher in the lowest tertile than in the middle and highest tertiles, respectively (p < 0.01). To conclude, in a low-income environment, low length-for-age Z-score after birth predicted hyperdynamic circulation at 21 years of age without changes in blood pressure and metabolic variables.

Arterial stiffness and augmentation index are associated with balance function in young adults

OBJECTIVE

Arterial stiffness and pulsatile central hemodynamics have been shown to affect various aspects of physical function, such as exercise capacity, gait speed, and motor control. The aim of this study was to examine the potential association between arterial stiffness and balance function in healthy younger men and women.

METHODS

112 participants (age = 21 ± 4 years, n = 78 women) underwent measures of arterial stiffness, pulsatile central hemodynamics, balance function and physical fitness in this cross-sectional study. Postural sway was measured in triplicate while participants stood on a foam surface with their eyes closed for 20 s. The average total center of pressure path length from the three trials was used for analysis. Measures of vascular function were estimated using an oscillometric blood pressure device while at rest and included pulse wave velocity (PWV), augmentation index (AIx), and pulse pressure amplification. Measures of physical fitness used as covariates in statistical models included handgrip strength determined from a handgrip dynamometer, lower-body flexibility assessed using a sit-and-reach test, estimated maximal aerobic capacity (VO₂max) using heart rate and a step test, and body fat percentage measured from air displacement plethysmography.

RESULTS

The results from linear regression indicated that after considering sex, mean arterial pressure, body fat, estimated VO₂max, handgrip strength, and sit-and-reach, PWV (β = 0.44, p < 0.05) and AIx (β = - 0.25, p < 0.01) were significant predictors of postural sway, explaining 10.2% of the variance.

CONCLUSION

Vascular function is associated with balance function in young adults independent of physical fitness. Increased arterial stiffness may negatively influence balance, while wave reflections may be protective for balance.

Twenty-Four-Hour Central Hemodynamic Load in Adults With and Without a History of COVID-19

BACKGROUND

Although hypertension is a risk factor for severe Coronavirus Disease 2019 (COVID-19) illness, little is known about the effects of COVID-19 on blood pressure (BP). Central BP measures taken over a 24-hour period using ambulatory blood pressure monitoring (ABPM) adds prognostic value in assessing cardiovascular disease (CVD) risk compared with brachial BP measures from a single time point. We assessed CVD risk between adults with and without a history of COVID-19 via appraisal of 24-hour brachial and central hemodynamic load from ABPM.

METHODS

Cross-sectional analysis was performed on 32 adults who tested positive for COVID-19 (29 ± 13 years, 22 females) and 43 controls (28 ± 12 years, 26 females). Measures of 24-hour hemodynamic load included brachial and central systolic and diastolic BP, pulse pressure, augmentation index (AIx), pulse wave velocity (PWV), nocturnal BP dipping, the ambulatory arterial stiffness index (AASI), and the blood pressure variability ratio (BPVR).

RESULTS

Participants who tested positive for COVID-19 experienced 6 ± 4 COVID-19 symptoms, were studied 122 ± 123 days after testing positive, and had mild-to-moderate COVID-19 illness. The results from independent samples t-tests showed no significant differences in 24-hour, daytime, or nighttime measures of central or peripheral hemodynamic load across those with and without a history of COVID-19 (P > 0.05 for all).

CONCLUSIONS

No differences in 24-hour brachial or central ABPM measures were detected between adults recovering from mild-to-moderate COVID-19 and controls without a history of COVID-19. Adults recovering from mild-to-moderate COVID-19 do not have increased 24-hour central hemodynamic load.

Estimation of carotid-femoral pulse wave velocity from finger photoplethysmography signal

Objective. This project compared a new method to estimate the carotid-femoral pulse wave velocity (cf-PWV) to the gold-standard cf-PWV technique.Approach. The cf-PWV was estimated from the pulse transit time (FPS-PTT) calculated by processing the finger photoplethysmographic signal of Finapres (FPS) and subject's height only (brief mode) as well as along with other variables (age, heart rate, arterial pressure, weight; complete mode). Doppler ultrasound cf-PWVs and FPS-PTTs were measured in 90 participants equally divided into 3 groups (18-30; 31-59; 60-79 years). Predictions were performed using multiple linear regressions (MLR) and with the best regression model identified by using MATLAB Regression Learner App. A validation set approach (60 training datasets, 30 testing datasets; VSA) and leave-one-out cross-validation (LOOCV) were used.Main results. With MLR, the discrepancies were: 0.01 ± 1.21 m s^-1(VSA) and 0.001 ± 1.11 m s^-1(LOOCV) in brief mode; -0.02 ± 0.83 m s^-1(VSA) and 0.001 ± 0.84 m s^-1(LOOCV) in complete mode. Using a linear support vector machine model (SVM) in brief mode, the discrepancies were: 0.01 ± 1.19 m s^-1(VSA) and -0.01 ± 1.06 m s^-1(LOOCV). Using an Exponential Gaussian process regression model (GPR) in complete mode, the discrepancies were: -0.03 ± 0.79 m s^-1(VSA) and 0.01 ± 0.75 m s^-1(LOOCV).Significance. The cf-PWV can be estimated by processing the FPS-PTT and subjects' height only, but the inclusion of other variables improves the prediction performance. Predictions through MLR qualify as acceptable in both brief and complete modes. Predictions via linear SVM in brief mode improve but still qualify as acceptable. Interestingly, predictions through Exponential GPR in complete mode improve and qualify as excellent.

Pulse Wave Velocity for Risk Stratification of Patients with Aortic Aneurysm

Background: Patients with an aortic aneurysm are at high cardiovascular risk. Pulse wave velocity (PWV) is used as a parameter for risk stratification but may be affected by aortic disease (AoD). This study aimed to investigate the dependence of PWV on treated or untreated AoD and to identify modifiable factors of PWV. Methods: The measurement of PWV with the Mobil-O-Graph was performed fully automatically in a collective of 381 patients (75.6% male and 24.4% female). Of all patients, 53.8% had nonaortic atherosclerotic vascular disease (AVD), 28.9% had treated AoD, and 17.3% had untreated AoD. Results: There was a statistically significant effect of age (R2 = 0.838) and current systolic blood pressure (SBP) on PWV (page corrected < 0.05). After correction for age, no statistically significant difference was found between the PWV of men and women, patients with different body weights or degrees of chronic kidney disease, diabetics and nondiabetics, and smokers and nonsmokers. Comparison between patients with nonaortic AVD and treated or untreated AoD revealed no statistically significant differences (PWVnonaortic AVD 10.0 ± 1.8 m/s, PWVtreated AoD 10.0 ± 1.5 m/s, PWVuntreated AoD 9.8 ± 1.6 m/s; page corrected > 0.05). Conclusions: PWV determined with the Mobil-O-Graph correlated with age and current SBP. Neither aortic disease versus nonaortic AVD, its treatment, nor other cardiovascular risk factors had a significant effect on PWV. Successful blood pressure control is crucial to avoid high PWV and thus an increase in cardiovascular events.

Accuracy Difference of Noninvasive Blood Pressure Measurements by Sex and Height

IMPORTANCE

Women are at higher risk of cardiovascular events than men with similar blood pressure (BP). Whether this discrepancy in risk is associated with the accuracy of brachial cuff BP measurements is unknown.

OBJECTIVES

To examine the difference in brachial cuff BP accuracy in men and women compared with invasively measured aortic BP and to evaluate whether noninvasive central BP estimation varies with sex.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study enrolled 500 participants without severe aortic stenosis or atrial fibrillation from January 1 to December 31, 2019, who were undergoing nonurgent coronary angiography at a tertiary care academic hospital.

EXPOSURES

Simultaneous measurements of invasive aortic BP and noninvasive BP.

MAIN OUTCOMES AND MEASURES

Sex differences in accuracy were determined by calculating the mean difference between the noninvasive measurements (brachial and noninvasive central BP) and the invasive aortic BP (reference). Linear regression and mediation analyses were performed to identify mediators between sex and brachial cuff accuracy.

RESULTS

This study included 500 participants (145 female [29%] and 355 male [71%]; 471 [94%] White; mean [SD] age, 66 [10] years). Baseline characteristics were similar for both sexes apart from body habitus. Despite similar brachial cuff systolic BP (SBP) (mean [SD], 124.5 [17.7] mm Hg in women vs 124.4 [16.4] in men; P = .97), invasive aortic SBP was higher in women (mean [SD], 130.9 [21.7] in women vs 124.7 [20.1] mm Hg in men; P < .001). The brachial cuff was relatively accurate compared with invasive aortic SBP estimation in men (mean [SD] difference, -0.3 [11.7] mm Hg) but not in women (mean [SD] difference, -6.5 [12.1] mm Hg). Noninvasive central SBP (calibrated for mean and diastolic BP) was more accurate in women (mean [SD] difference, 0.6 [15.3] mm Hg) than in men (mean [SD] difference, 8.3 [14.2] mm Hg). This association of sex with accuracy was mostly mediated by height (3.4 mm Hg; 95% CI, 1.1-5.6 mm Hg; 55% mediation).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, women had higher true aortic SBP than men with similar brachial cuff SBP, an association that was mostly mediated by a shorter stature. This difference in BP measurement may lead to unrecognized undertreatment of women and could partly explain why women are at greater risk for cardiovascular diseases for a given brachial cuff BP than men. These findings may justify the need to study sex-specific BP targets or integration of sex-specific parameters in BP estimation algorithms.

Clinical Applications Measuring Arterial Stiffness: An Expert Consensus for the Application of Cardio-Ankle Vascular Index

BACKGROUND

The purpose of this document is to provide clinicians with guidance, using expert consensus, to help summarize evidence and offer practical recommendations.

METHODS

Expert Consensus Documents are intended to provide guidance for clinicians in areas in which there are no clinical practice guidelines, especially for new and evolving tests such as arterial stiffness measurements, until any formal guidelines are released.

RESULTS

This expert consensus document is intended as a source of information for decision-making and to guide clinician-patient discussions in various clinical scenarios.

CONCLUSIONS

The goal is to help clinicians and patients make a more informed decision together.

Utility of estimated pulse wave velocity for assessing vascular stiffness: comparison of methods

Background: Pulse wave velocity independently predicts cardiovascular risk. Easy to use single cuff oscillometric methods are utilized in clinical practice to estimate pulse wave velocity. We applied the approach in master athletes to assess possible beneficial effects of lifelong exercise on vascular health. Furthermore, we compared single cuff measurements with a two-cuff method in another cohort.

Methods: We obtained single cuff upper arm oscillometric measurements thrice in 129 master athletes aged 35 to 86 years and estimated pulse wave velocity using the ArcSolver algorithm. We applied the same method in 24 healthy persons aged 24 to 55 years participating in a head down tilt bedrest study. In the latter group, we also obtained direct pulse wave velocity measurements using a thigh cuff.

Results: Estimated pulse velocity very highly correlated with age (R² = 0.90) in master athletes. Estimated pulse wave velocity values were located on the same regression line like values obtained in participants of the head down tilt bed rest study. The modest correlation between estimated and measured PWV (r² 0.40; p<0.05) was attenuated after adjusting for age; the mean difference between pulse wave velocity measurements was 1 m/s.

Conclusion: Estimated pulse wave velocity mainly reflects the entered age rather than true vascular properties and, therefore, failed detecting beneficial effects of life long exercise.

Funding: The AGBRESA-Study was funded by the German Aerospace Center (DLR), the European Space Agency (ESA, contract number 4000113871/15/NL/PG) and the National Aeronautics and Space Administration (NASA, contract number 80JSC018P0078). FH received funding by the DLR and the German Federal Ministry of Economy and Technology, BMWi (50WB1816). SM, JT and JJ were supported by the Austrian Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology, BMK (SPACE4ALL Project, FFG No. 866761).

Arterial Stiffness in Aortic Stenosis and the Impact of Aortic Valve Replacement

The most common cause for interventional valve treatment is aortic stenosis. A cardinal symptom of aortic stenosis is heart failure due to the increased load exerted on the left ventricle. However, the left ventricular load is not solely determined based on the degree of aortic stenosis but is also impacted by arterial stiffness. The combined load can be determined by valvulo-arterial impedance (Zva), which is associated with poor outcome in aortic stenosis. We recently demonstrated low measures of systemic arterial stiffness in patients with aortic stenosis, and that arterial stiffness was increased after surgical aortic valve replacement. The results indicated a masked arterial stiffness in aortic stenosis when using methods incorporating peripheral arterial segments. Available studies using several different methods to assess arterial stiffness in relatively small aortic stenosis cohorts examined before and after either surgical or transcatheter aortic valve replacement/intervention have generated contradictory results. In this commentary, we present a detailed literature review to explore how different methods and measures of arterial stiffness in aortic stenosis capture or not, a masked arterial stiffness in aortic stenosis and possible reasons for the observed results. Future studies validating a non-invasive reproducible method to assess arterial stiffness in aortic stenosis patients could potentially lead to an implementation in pre-interventional risk assessment for aortic stenosis.

Posture-Related Differences in Cardiovascular Function Between Young Men and Women: Study of Noninvasive Hemodynamics in Rural Malawi

Background

Cardiovascular risk is higher in men than in women, but little information exists about sex‐related differences in cardiovascular function from low‐income countries. We compared hemodynamics between sexes in rural Malawi in a cohort followed up since their birth.

Methods and Results

Supine, seated, and standing hemodynamics were recorded from 251 women and 168 men (mean age, 21 years; body mass index, 21 kg/m²) using oscillometric brachial waveform analyses (Mobil‐O‐Graph). The results were adjusted for estimated glomerular filtration rate, and plasma potassium, lipids, and glucose. Men had higher brachial and aortic systolic blood pressure and stroke index regardless of posture (P<0.001), and higher upright but similar supine diastolic blood pressure than women. Regardless of posture, heart rate was lower in men (P<0.001), whereas cardiac index did not differ between sexes. Women presented with lower supine and standing systemic vascular resistance index (P<0.001), whereas supine‐to‐standing increase in vascular resistance (P=0.012) and decrease in cardiac index (P=0.010) were higher in women. Supine left cardiac work index was similar in both sexes, whereas standing and seated left cardiac work index was higher in men than in women (P<0.001).

Conclusions

In young Malawian adults, men had higher systolic blood pressure, systemic vascular resistance, and upright cardiac workload, whereas women presented with higher posture‐related changes in systemic vascular resistance and cardiac output. These findings show systematic sex‐related differences in cardiovascular function in a cohort from a low‐income country with high exposure to prenatal and postnatal malnutrition and infectious diseases.

Effects of a Low-Salt and High-Potassium Diet on Arterial Stiffness and Left Ventricular Function in Indigenous Papuans

Background

A sodium‐restricted diet represents a potential non‐pharmacological strategy for improving blood pressure, arterial stiffness, and left ventricular (LV) diastolic function. We investigated age‐related differences in LV structure and function and the relationship between LV function and central hemodynamics in an indigenous Papuan population, who maintain a traditional lifestyle, including a low‐salt and high‐potassium diet.

Methods and Results

We measured LV dimensions, transmitral blood flow, and mitral annular tissue velocities through echocardiography and Doppler imaging. Blood pressure and brachial‐ankle pulse wave velocity were measured using an automatic device (Omron). Central blood pressure and wave reflection parameters were estimated via oscillometry (Mobil‐O‐Graph, using European calibrations). A total of 82 native Papuans (median age, 42 years; 38 women; no blood pressure treatment) were enrolled. Age‐related difference in brachial systolic pressure was modest but significant, and brachial‐ankle pulse wave velocity significantly increased with age; however, LV mass index remained unchanged. LV ejection fraction and global longitudinal strain were preserved; mitral A‐wave velocity and average E/e´ increased; and e´ and E/A decreased with age. Brachial‐ankle pulse wave velocity and spot urine Na/K were positively and independently correlated with E/e´. Age and heart rate were inversely associated with E/A. In conclusion, LV systolic function was preserved; however, LV diastolic function decreased with age in Papuans. Moreover, age‐related arterial stiffening, but not wave reflections, was inversely related to LV diastolic function.

Conclusions

Our results suggest that arterial and LV stiffness may not be altered by sodium restriction. Longitudinal studies are warranted to elucidate the effects of diet on arterial and LV function.

Comparing oscillometric and tonometric methods to assess pulse wave velocity: a population-based study

BACKGROUND

Oscillometric pulse wave velocity (o-PWV) represents an attractive, non invasive and non operator-dependent method to estimate arterial stiffness. Tonometric carotid-femoral measurements (cf-PWV),are considered the gold-standard for non-invasive aortic stiffness assessment. To date, no studies in the general population comparing the two methods have been performed.

METHODS AND RESULTS

1162 subjects were analysed. O-PWV and cf-PWV showed a mean difference of -0.31 m/sec(p ≤ 0.001). No significant differences between cf-PWV and o-PWVs were observed in patients without cardiovascular risk factors. The Bland and Altman analysis showed a moderate agreement between 24 h-o-PWV and cf-PWV (mean difference -0.99, LoA 4.23 to -6.22m/s). O-PWVs underestimate and overestimate arterial stiffness under and over 50 years respectively(p ≤ 0.001). Systolic blood pressure (SBP) and age differently impact cf-PWV and in office o-PWV variability (r2 0.35 and 0.88 respectively). In younger subjects a strong relationship between o-PWV and SBP reducing as age increases was found. Analysing the impact of age, an opposite trend was noticed.

CONCLUSIONS

Oscillometric PWV estimates provide reliable values in the general population. An o-PWV tendency to underestimate arterial stiffness in younger subjects and in subjects with diseases known to increase arterial stiffness and to overestimate it with increasing age was found, even if scarcely relevant in clinical perspective. Overall the present findings underline an acceptable and satisfactory agreement between oscillometric and tonometric methods for the PWV assessment. KEY MESSAGES Oscillometric and tonometric PWV estimates showed a good and satisfactory agreement in the general population, above all in subjects without cardiovascular risk factors or a documented vascular damage. In comparison with tonometric values, oscillometric PWV estimates showed, however, the tendency to underestimate arterial stiffness in younger subjects and to overestimate it with increasing age, while diverging when diseases known to increase arterial stiffness are present. The magnitude of differences in PWV estimates between tonometric and oscillometric methods found in the general population appears most likely not to be significant in everyday clinical practice.

Arterial Stiffness Assessment Using the Arteriograph in Patients with Moderate-Severe OSA and Metabolic Syndrome-A Pilot Study

BACKGROUND

Both obstructive sleep apnea (OSA) and metabolic syndrome (MS) promote arterial stiffening. As a basis for this study, we presumed that arterial stiffness could be assessed using the Arteriograph (TensioMed, Budapest, Hungary) to detect early modifications induced by continuous positive airway therapy (CPAP) in reversing this detrimental vascular remodeling. Arterial stiffness is increasingly acknowledged as a major cardiovascular risk factor and a marker of subclinical hypertension-mediated organ damage. The aim of this pilot study was to evaluate the arterial stiffness changes in patients with moderate-severe OSA and MS after short-term CPAP use.

METHODS

We performed a prospective study that included patients with moderate-severe OSA and MS who had not undergone previous CPAP therapy. All subjects underwent clinical examination and arterial stiffness assessment using the oscillometric technique with Arteriograph (TensioMed, Budapest, Hungary) detection before and after 8-week CPAP therapy.

RESULTS

39 patients with moderate-severe OSA were included. Eight weeks of CPAP therapy significantly improved central systolic blood pressure (Δ = -11.4 mmHg, p = 0.009), aortic pulse wave velocity (aoPWV: Δ = -0.66 m/s, p = 0.03), and aortic augmentation index (aoAix: Δ = -8.25%, p = 0.01) only in patients who used the device for a minimum of 4 h/night (n = 20).

CONCLUSIONS

Arterial stiffness was improved only among CPAP adherent patients and could be detected using the Arteriograph (TensioMed, Budapest, Hungary), which involves a noninvasive procedure that is easy to implement for the clinical evaluation of arterial stiffness.

Inaccuracy of brachial blood pressure and its potential impact on treatment and aortic blood pressure estimation

OBJECTIVE

Although brachial cuff SBP is universally used to guide hypertension management, it can differ significantly from intraarterial SBP. We examine the potential impacts of cuff-to-intraarterial brachial SBP (bSBP) mismatch on hypertension treatment and accuracy towards central SBP.

METHODS

In 303 individuals, cuff bSBP (CUFF-bSBP) and central SBP were measured using a Mobil-o-Graph simultaneously to intraarterial bSBP (IA-bSBP) and aortic SBP. According to the difference between CUFF-bSBP and IA-bSBP, we identified three phenotypes: Underestimation (CUFF-bSBP < IA-bSBP by >10 mmHg); No Mismatch (CUFF-bSBP within 10 mmHg of IA-bSBP); Overestimation (CUFF-bSBP > IA-bSBP by >10 mmHg) phenotypes. Risk of overtreatment and undertreatment, and accuracy (ARTERY society criteria: mean difference ≤5 ± 8 mmHg) were determined. A multiple linear regression model was used to assess variables associated with the bSBP difference.

RESULTS

Underestimation (n = 142), No Mismatch (n = 136) and Overestimation (n = 25) phenotypes had relatively similar characteristics and CUFF-bSBP (124 ± 17, 122 ± 14, 127 ± 19 mmHg, P = 0.19) but different aortic SBP (133 ± 21, 120 ± 16, 112 ± 18 mmHg, P < 0.001). In the underestimation phenotype, 59% were at risk of undertreatment (14% in No Mismatch), whereas 50% in the Overestimation phenotype were at risk of overtreatment (17% in No Mismatch). CUFF-bSBP accurately estimated aortic SBP only in the No Mismatch Group (mean difference 1.6 ± 8.2 mmHg) whereas central BP never met the accuracy criteria. Male sex, higher height and active smoking were associated with lesser underestimation of bSBP difference.

CONCLUSION

The brachial cuff lacks accuracy towards intraarterial BP in a significant proportion of patients, potentially leading to increased risks of BP mismanagement and inaccurate determination of central BP. This illustrates the need to improve the accuracy of cuff-based BP monitors.

Association between Objectively Measured Physical Activity and Arterial Stiffness in Children with Congenital Heart Disease

BACKGROUND

The association between physical activity (PA) and arterial stiffness is particularly important in children with congenital heart disease (CHD) who are at risk for arterial stiffening. The aim of this study was to examine the association between objectively measured PA and arterial stiffness in children and adolescents with CHD.

METHODS

In 387 children and adolescents with various CHD (12.2 ± 3.3 years; 162 girls) moderate-to-vigorous PA (MVPA) was assessed with the "Garmin vivofit jr." for 7 consecutive days. Arterial stiffness parameters including pulse wave velocity (PWV) and central systolic blood pressure (cSBP) were non-invasively assessed by oscillometric measurement via Mobil-O-Graph®.

RESULTS

MVPA was not associated with PWV (ß = -0.025, p = 0.446) and cSBP (ß = -0.020, p = 0.552) in children with CHD after adjusting for age, sex, BMI z-score, peripheral systolic blood pressure, heart rate and hypertensive agents. Children with CHD were remarkably active with 80% of the study population reaching the WHO recommendation of average 60 min of MVPA per day. Arterial stiffness did not differ between low-active and high-active CHD group after adjusting for age, sex, BMI z-score, peripheral systolic blood pressure, heart rate and hypertensive agents (PWV: F = 0.530, p = 0.467; cSBP: F = 0.843, p = 0.359).

CONCLUSION

In this active cohort, no association between PA and arterial stiffness was found. Longer exposure to the respective risk factors of physical inactivity might be necessary to determine an impact of PA on the vascular system.

Arterial Stiffness and Cardiovascular Risk in Hypertension

Arterial stiffness, a leading marker of risk in hypertension, can be measured at material or structural levels, with the latter combining effects of the geometry and composition of the wall, including intramural organization. Numerous studies have shown that structural stiffness predicts outcomes in models that adjust for conventional risk factors. Elastic arteries, nearer to the heart, are most sensitive to effects of blood pressure and age, major determinants of stiffness. Stiffness is usually considered as an index of vascular aging, wherein individuals excessively affected by risk factor exposure represent early vascular aging, whereas those resistant to risk factors represent supernormal vascular aging. Stiffness affects the function of the brain and kidneys by increasing pulsatile loads within their microvascular beds, and the heart by increasing left ventricular systolic load; excessive pressure pulsatility also decreases diastolic pressure, necessary for coronary perfusion. Stiffness promotes inward remodeling of small arteries, which increases resistance, blood pressure, and in turn, central artery stiffness, thus creating an insidious feedback loop. Chronic antihypertensive treatments can reduce stiffness beyond passive reductions due to decreased blood pressure. Preventive drugs, such as lipid-lowering drugs and antidiabetic drugs, have additional effects on stiffness, independent of pressure. Newer anti-inflammatory drugs also have blood pressure independent effects. Reduction of stiffness is expected to confer benefit beyond the lowering of pressure, although this hypothesis is not yet proven. We summarize different steps for making arterial stiffness measurement a keystone in hypertension management and cardiovascular prevention as a whole.

Effect of Intensive Blood Pressure Control on Aortic Stiffness in the SPRINT-HEART

[Figure: see text].

Age dependence of brachial cuff-based ambulatory PWV in end-stage kidney disease patients undergoing long-term peritoneal dialysis

BACKGROUND

The newly introduced device Mobil-O-Graph (IEM, Stolberg, Germany) combines brachial cuff oscillometry and pulse wave analysis, enabling the determination of pulse wave velocity (PWV) via complex mathematic algorithms during 24-h ambulatory blood pressure monitoring (ABPM). However, the determinants of oscillometric PWV in the end-stage kidney disease (ESKD) population remain poorly understood.

METHODS

In this study, 81 ESKD patients undergoing long-term peritoneal dialysis underwent 24-h ABPM with the Mobil-O-Graph device. The association of 24-h oscillometric PWV with several demographic, clinical and haemodynamic parameters was explored using linear regression analysis.

RESULTS

In univariate analysis, among 21 risk factors, 24-h PWV exhibited a positive relationship with age, body mass index, overhydration assessed via bioimpedance spectroscopy, diabetic status, history of dyslipidaemia and coronary heart disease, and it had a negative relationship with female sex and 24-h heart rate. In stepwise multivariate analysis, age (β: 0.883), 24-h systolic blood pressure (BP) (β: 0.217) and 24-h heart rate (β: -0.083) were the only three factors that remained as independent determinants of 24-h PWV (adjusted R ² = 0.929). These associations were not modified when all 21 risk factors were analysed conjointly or when the model included only variables shown to be significant in univariate comparisons.

CONCLUSION

The present study shows that age together with simultaneously assessed oscillometric BP and heart rate are the major determinants of Mobil-O-Graph-derived PWV, explaining >90% of the total variation of this marker. This age dependence of oscillometric PWV limits the validity of this marker to detect the premature vascular ageing, a unique characteristic of vascular remodelling in ESKD.

Improvement of Arterial Stiffness One Month after Bariatric Surgery and Potential Mechanisms

Arterial stiffness (AS) is an independent predictor of cardiovascular risk. We aimed to analyze changes (Δ) in AS 1-month post-bariatric surgery (BS) and search for possible pathophysiological mechanisms. Patients with severe obesity (43% hypertensives) were prospectively evaluated before and 1-month post-BS, with AS assessed by pulse-wave velocity (PWV), augmentation index (AIx@75) and pulse pressure (PP). Ambulatory 24 h blood pressure (BP), anthropometric data, renin-angiotensin-aldosterone system (RAAS) components and several adipokines and inflammatory markers were also analyzed. Overall reduction in body weight was mean (interquartile range (IQR)) = 11.0% (9.6–13.1). A decrease in PWV, AIx@75 and PP was observed 1-month post-BS (all, p < 0.01). There were also significant Δ in BP, RAAS components, adipokines and inflammatory biomarkers. Multiple linear regression adjusted models showed that Δaldosterone was an independent variable (B coeff.95%CI) for final PWV (B = −0.003, −0.005 to 0.000; p = 0.022). Angiotensin-converting enzyme (ACE)/ACE2 and ACE were independent variables for final AIx@75 (B = 0.036, 0.005 to 0.066; p = 0.024) and PP (B = 0.010, 0.003 to 0.017; p = 0.01), respectively. There was no correlation between ΔAS and anthropometric changes nor with Δ of adipokines or inflammatory markers except high-sensitivity C-reactive protein (hs-CRP). Patients with PWV below median decreased PWV (mean, 95%CI = −0.18, −0.25 to −0.10; p < 0.001) and both AIx@75 and PP at 1-month, but not those with PWV above median. In conclusion, there is an improvement in AS 1-month post-BS that correlates with ΔBP and Δrenin-angiotensin-aldosterone components. The benefit is reduced in those with higher PWV.

Low muscle strength and increased arterial stiffness go hand in hand

Low handgrip strength and increased arterial stiffness are both associated with poor health outcomes, but evidence on the relationship between handgrip strength and arterial stiffness is limited. In this cross-sectional analysis of combined baseline datasets from the LipidCardio and Berlin Aging Study II cohorts we aimed to examine whether handgrip strength (HGS) is associated with arterial stiffness. 1511 participants with a median age of 68.56 (IQR 63.13–73.08) years were included. Arterial stiffness was assessed by aortal pulse wave velocity (PWV) with the Mobil-O-Graph device. Handgrip strength was assessed with a handheld dynamometer.

The mean HGS was 39.05 ± 9.07 kg in men and 26.20 ± 7.47 kg in women. According to multivariable linear regression analysis per 5 kg decrease in handgrip strength there was a mean increase in PWV of 0.08 m/s after adjustment for the confounders age, sex, coronary artery disease, systolic blood pressure, body mass index, cohort, and smoking. Thus, there was evidence that low handgrip strength and increased arterial stiffness go hand in hand. Arterial stiffness can possibly create the missing link between low handgrip strength and increased cardiovascular morbidity and mortality. Causality and direction of causality remain to be determined.

Would Oscillometry be Able to Solve the Dilemma of Blood Pressure Independent Pulse Wave Velocity - A Novel Approach Based on Long-Term Pulse Wave Analysis?

The utility of pulse wave velocity (PWV) as a surrogate parameter of arterial vessel damage (AVD) beyond the traditional brachial blood pressure (BP) measurement may be questioned as changes in BP are often accompanied by the corresponding changes in PWV. We sought to establish a new way for BP-independent estimation of AVD with PWV. We retrospectively analyzed data from 507 subjects with at least one available 24 h ambulatory BP- and pulse wave analysis, performed with Mobil-O-Graph (I.E.M., Stolberg, Germany). Individual relationship between eaPWV and central systolic BP (cSBP) was analyzed for every 24 h recording. The analysis revealed linear relation between eaPWV and cSBP in all subjects, which is described by equation eaPWV = a^∗cSBP + b. We termed “a” as PWVslope and “b” as PWVbaseline. All available demographic parameters and clinical data were correlated with eaPWV, PWVslope and PWVbaseline. 108 subjects had repeated 24 h recordings. Mean age was 60.7 years and 48.7% were female. 92.5% had hypertension, 22.9% were smoker, 20.5% had diabetes mellitus and 29.6% eGFR < 60 ml/min/1,73 m². Direct correlation was observed between age, SBP and eaPWV, while diastolic BP (DBP) and eGFR correlated inversely with eaPWV. PWVbaseline correlated directly with age and inversely with DBP, while PWVslope didn’t correlate with any inputted parameter. Using simple mathematical approach by plotting eaPWV and cSBP values obtained during ABPM, it is possible to visualize unique course of individual PWV related to BP. Using PWVslope and PWVbaseline as novel parameters could be a feasible way to approach BP-independent PWV, though their clinical relevance should be tested in future studies. Our data underline the importance of BP-independent expression of PWV, when we use it as a clinical surrogate parameter for the vascular damage.

Twenty-four-hour ambulatory central blood pressure in adolescents and young adults: association with peripheral blood pressure and preclinical organ damage

OBJECTIVES

To investigate the relationship of 24-h ambulatory central blood pressure (ABP) with preclinical organ damage in youth.

METHODS

Individuals aged 10-25 years referred for suspected hypertension and healthy volunteers had simultaneous 24-h peripheral and central ABP monitoring (Mobil-O-Graph 24 h PWA). Central BP was calculated using two different calibration methods (c1 using oscillometric systolic/diastolic ABP; c2 using mean arterial/diastolic ABP). Their association with preclinical organ damage [left ventricular mass index (LVMI), carotid intima-media thickness (IMT), 24-h pulse wave velocity (PWV)] was investigated.

RESULTS

A total of 136 participants were analyzed (age 17.9 ± 4.7 years, 54% adolescents, 77% males, 34% with elevated ABP). Twenty-four-hour peripheral systolic ABP (pSBP) was higher than c1 systolic ABP (c1SBP) by 14.1 ± 3.7 mmHg, but lower than c2SBP by 6.5 ± 7.6 mmHg (all P < 0.01). c2SBP quartiles provided better stratification of preclinical organ damage than pSBP. Both c1SBP/c2SBP were significantly associated with LVMI (r = 0.35/0.33) and IMT (r = 0.23/0.42; all P < 0.01; primary endpoint). These associations were stronger for c2SBP compared with those of pSBP in adolescents but not in adults. PWV was more closely associated with pSBP than c2SBP (r = 0.94/0.83, P < 0.01). LVMI variation was best determined by c2SBP in adolescents and pSBP in adults; IMT by c2SBP and PWV by pSBP in both subgroups.

CONCLUSION

These findings suggest that in young individuals, the calibration method for 24-h central ABP plays a major role in determining its association with preclinical organ damage. In adolescents, 24-h central ABP appears to be more strongly associated with early cardiac and carotid damage than peripheral BP.

Monitoring of vital bio-signs by analysis of speckle patterns in a fabric-integrated multimode optical fiber sensor

Continuous noninvasive measurement of vital bio-signs, such as cardiovascular parameters, is an important tool in evaluation of the patient's physiological condition and health monitoring. Based on new enabling technologies, continuous monitoring of heart and respiration rate, pulse wave velocity and blood pressure have been investigated, advanced and reflected in numerous papers published in recent years. In this paper, we introduce a new technique for noninvasive sensing of vital bio-signs based on a multimode optical fiber sensor that can be integrated into a fabric. The sensor consists of a laser, optical fiber, video camera and computer. Its operation is based on tracking of point-wise intensity variations on speckle patterns caused by interference of the light modes within the fiber subjected to deformation. The paper contains theoretical analysis and experimental validation of the proposed scheme. The main goal is to advance a simple low-cost sensor embedded in a cloth fabric to track changes in the cardiovascular condition of the wearer.

Large-Artery Stiffness in Health and Disease: JACC State-of-the-Art Review

A healthy aorta exerts a powerful cushioning function, which limits arterial pulsatility and protects the microvasculature from potentially harmful fluctuations in pressure and blood flow. Large-artery (aortic) stiffening, which occurs with aging and various pathologic states, impairs this cushioning function, and has important consequences on cardiovascular health, including isolated systolic hypertension, excessive penetration of pulsatile energy into the microvasculature of target organs that operate at low vascular resistance, and abnormal ventricular-arterial interactions that promote left ventricular remodeling, dysfunction, and failure. Large-artery stiffness independently predicts cardiovascular risk and represents a high-priority therapeutic target to ameliorate the global burden of cardiovascular disease. This paper provides an overview of key physiologic and biophysical principles related to arterial stiffness, the impact of aortic stiffening on target organs, noninvasive methods for the measurement of arterial stiffness, mechanisms leading to aortic stiffening, therapeutic approaches to reduce it, and clinical applications of arterial stiffness measurements.

How to Measure Arterial Stiffness in Humans

Despite the wide recognition of larger artery stiffness as a highly clinically relevant and independent prognostic biomarker, it has yet be incorporated into routine clinical practice and to take a more prominent position in clinical guidelines. An important reason may be the plethora of methods and devices claiming to measure arterial stiffness in humans. This brief review provides a concise overview of methods in use, indicating strengths and weaknesses. We classified and graded methods, highly weighing their scrutiny and purity in quantifying arterial stiffness, rather than focusing on their ease of application or the level at which methods have demonstrated their prognostic and diagnostic potential.

Uses of Arterial Stiffness in Clinical Practice

As far back as the ancient Egyptians and Greeks, physicians have observed and interpreted the arterial pulse to diagnose disease. In the last 20 years, advances in modern engineering have rendered quantitative pulse wave analysis widely available, reliable, and reproducible. To date, measurement of arterial stiffness has remained almost exclusively a research activity. However, ongoing technological improvements coupled with already strong and growing evidence of clinical value should facilitate integration of arterial stiffness measures into clinical practice in the near future. This brief review will highlight clinical areas where arterial stiffness measures are likely to be the most informative in clinical practice.