The effects of experimental, meteorological, and physiological factors on short-term repeated pulse wave velocity measurements, and measurement difficulties: A randomized crossover study with two devices

Establishing Reference Values for Pulse Wave Velocity in Young People

BACKGROUND

Aortic pulse wave velocity (PWV) is an indicator of vascular aging and has proven to be effective in adult cardiovascular risk assessment. To use it in young people to identify those who may be at increased cardiovascular disease risk, reference values need to be determined. The Youth Vascular Consortium is a large, international database which was established to investigate vascular aging in youth. Using data from the Youth Vascular Consortium, this study aimed to develop reference values for aortic PWV in healthy young people.

METHODS

This is a retrospective, multicenter study. Data on demographics, anthropometric, biochemical, and vascular aging measures from participants aged 1 year to 40 years were harmonized. Generalized additive models were used to derive percentile curves for PWV and predicted percentiles at years of age were reported by sex, continent, and device.

RESULTS

Data from 19 930 participants (mean age=17 years, 51% female, 71% European), classified as healthy based on blood pressure, body mass index, serum glucose, and cholesterol levels, were included to construct the reference values. Six devices were used to assess aortic PWV (29% SphygmoCor). Device-specific percentile curves for aortic PWV were constructed, and an increasing trend was identified for both sexes with age.

CONCLUSIONS

This study provided reference values for aortic PWV assessed with 6 devices for healthy young people by age and sex. These percentiles may be applied clinically to identify youth with impaired vascular aging and, thus, those who may be at risk of developing overt cardiovascular disease in the future.

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.

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.

Prediabetes, Non-Dipping Profile and Hypertension—A Recipe for Increased Arterial Stiffness

Background: Pulse wave velocity (PWV) is a known predictor of target organ damage, cardiovascular disease and overall mortality. The aim of this study was to compare the PWV values in subjects with prediabetes, a non-dipper profile and arterial hypertension with their values in healthy subjects. Methods: A total of 301 subjects, aged 40–70 years, without diabetes mellitus were included in this cross-sectional study (150 with prediabetes). They underwent a 24 h ambulatory blood pressure monitoring (ABPM). Subjects were divided into three hypertension groups (A = healthy, B = controlled hypertension, C = uncontrolled hypertension). Dipping status was determined according to ABPM results, and PWV was measured by an oscillometric device. Prediabetes was defined as having 2 separate fasting plasma glucose (FPG) measurements between 5.6 and 6.9 mmol/L. Results: The highest PWV values were found in group C (9.60 ± 1.34 vs. 8.46 ± 1.01 in group B vs. 7.79 ± 1.10 in group A; p < 0.001), in subjects with prediabetes (8.98 ± 1.31 m/s vs. 8.26 ± 1.22 m/s; p < 0.001) and in prediabetic non-dippers among age groups (p = 0.05). In the multivariate regression model age, blood pressure, nocturnal indices and FPG were shown as independent predictors of PWV values. Conclusion: Significantly higher PWV values were found in subjects with prediabetes and non-dipping profiles in all three examined hypertension groups.

Long-Term Adverse Effects of Mild COVID-19 Disease on Arterial Stiffness, and Systemic and Central Hemodynamics: A Pre-Post Study

COVID-19-associated vascular disease complications are primarily associated with endothelial dysfunction; however, the consequences of disease on vascular structure and function, particularly in the long term (>7 weeks post-infection), remain unexplored. Individual pre- and post-infection changes in arterial stiffness as well as central and systemic hemodynamic parameters were measured in patients diagnosed with mild COVID-19. As part of in-laboratory observational studies, baseline measurements were taken up to two years before, whereas the post-infection measurements were made 2-3 months after the onset of COVID-19. We used the same measurement protocol throughout the study as well as linear and mixed-effects regression models to analyze the data. Patients (N = 32) were predominantly healthy and young (mean age ± SD: 36.6 ± 12.6). We found that various parameters of arterial stiffness and central hemodynamics-cfPWV, AIx@HR75, and cDBP as well as DBP and MAP-responded to a mild COVID-19 disease. The magnitude of these responses was dependent on the time since the onset of COVID-19 as well as age (pregression_models ≤ 0.013). In fact, mixed-effects models predicted a clinically significant progression of vascular impairment within the period of 2-3 months following infection (change in cfPWV by +1.4 m/s, +15% in AIx@HR75, approximately +8 mmHg in DBP, cDBP, and MAP). The results point toward the existence of a widespread and long-lasting pathological process in the vasculature following mild COVID-19 disease, with heterogeneous individual responses, some of which may be triggered by an autoimmune response to COVID-19.

What Is the Smallest Change in Pulse Wave Velocity Measurements That Can Be Attributed to Clinical Changes in Arterial Stiffness with Certainty: A Randomized Cross-Over Study

Pulse wave velocity (PWV), a direct measure of arterial stiffness, is a promising biomarker of cardiovascular risk and a cardiovascular surrogate outcome. The resolution for detecting its smallest clinically significant change is dependent on the expected reproducibility, but there is currently no consensus on this. We estimated the PWV reproducibility in a range of intra-subject values that were observed over a 2 week period in a broad range of participants and under clinically relevant experimental conditions (two observers, morning/afternoon sessions, and number of visits) using SphygmoCor and Arteriograph devices. Each participant was recorded 12 times with each device over three visits, one week apart, and two morning and two afternoon recordings were taken per visit. The factors affecting reproducibility and the discrepancies between the consecutive PWV measurements for each device were also examined using multilevel mixed-effect models. We show that current PWV estimation guidance recommending 2 + 1 measurements is suboptimal because the PWV range was outside of the 1 m/s threshold for most of the participants, which is proposed as a minimal clinically important difference. The best reproducibility was yielded with median of four measurements and a 1.1 m/s threshold. Although PWV reproducibility and repeatability are frequently used interchangeably in studies, we demonstrated that despite their relative measures of variability (e.g., coefficient of variation) being comparable, their ranges revealed a clinically significant difference between them. We also found that different physiological variables were predictors of the discrepancy between the consecutive measurements made by the two devices, which is likely due to their distinct modes of operation. The evidence base for PWV reproducibility is limited, and more research is needed to deepen our understanding of the variation in arterial stiffness over time, as well as fluctuations within a population group and in an intervention setting.