Usefulness Of Pulse Wave Velocity Research Articles

Pulse wave velocity on the risk stratification of aortic aneurysm

Introduction. The maintenance of tissue perfusion during the cardiac cycle is essential in organs with high metabolic demand, which is guaranteed by the maintenance of the physical properties of the arterial wall. When altered, there are hemodynamic repercussions that can be quantified using new methods, such as pulse wave velocity (PWV). These changes can occur in aortic aneurysms (AA), which have a high mortality rate associated with their rupture, making risk stratification and early intervention essential. Objectives. Demonstrate the relationship between PWV in risk stratification in patients with AA. Methods. Original articles from the Scientific Electronic Library Online (Scielo), the Latin American and Caribbean Health Sciences System (Lilacs) and PubMed Central (PMC) databases were included, which addressed the risk stratification of AA with the use of PWV in the human population. Studies published more than five years ago and those that did not address AA risk stratification based on PWV were excluded. Results and Discussion. Three articles were selected. An increase in PWV was observed in patients with abdominal aortic aneurysms (AAA) when compared to the control group (12.3 m/s x 10.9 m/s, p<0.01). Furthermore, the use of PWV is recommended in the risk stratification of all patients with AAA. Finally, the prediction of the use of PWV in the growth of thoracic aortic aneurysm (TAA) stands out, as well as its increased sensitivity for females. Conclusions. PWV is an excellent marker for cardiovascular risk stratification in AA, easy to apply clinically and at low cost. However, some issues must be resolved for its application, such as the PWV value based on age and blood pressure variables.

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

Pulse wave velocity (PWV) is an important and well-established measure of arterialstiffness that is strongly associated with aging. Age-related alterations in the elastic properties and integrity ofarterial walls can lead to cardiovascular disease. PWV measurements play an important role in the earlydetection of these changes, as well as other cardiovascular disease risk factors, such as hypertension. Thisreview provides a comprehensive summary of the current knowledge of the effects of aging on arterial stiffness,as measured by PWV. This review highlights recent findings showing the applicability of PWV analysis forinvestigating heart failure, hypertension, and other cardiovascular diseases, as well as cerebrovascular diseasesand Alzheimer's disease. It also discusses the clinical implications of utilizing PWV to monitor treatmentoutcomes, various challenges in implementing PWV assessment in clinical practice, and the development ofnew technologies, including machine learning and artificial intelligence, which may improve the usefulness ofPWV measurements in the future. Measuring arterial stiffness through PWV remains an important technique to study aging, especiallyas the technology continues to evolve. There is a clear need to leverage PWV to identify interventions thatmitigate age-related increases in PWV, potentially improving CVD outcomes and promoting healthy vascularaging.

Global distributions of age- and sex-related arterial stiffness: systematic review and meta-analysis of 167 studies with 509,743 participants.

Arterial stiffening is central to the vascular ageing process and a powerful predictor and cause of diverse vascular pathologies and mortality. We investigated age and sex trajectories, regional differences, and global reference values of arterial stiffness as assessed by pulse wave velocity (PWV). Measurements of brachial-ankle or carotid-femoral PWV (baPWV or cfPWV) in generally healthy participants published in three electronic databases between database inception and August 24th, 2020 were included, either as individual participant-level or summary data received from collaborators (n=248,196) or by extraction from published reports (n=274,629). Quality was appraised using the Joanna Briggs Instrument. Variation in PWV was estimated using mixed-effects meta-regression and Generalized Additive Models for Location, Scale, and Shape. The search yielded 8920 studies, and 167 studies with 509,743 participants from 34 countries were included. PWV depended on age, sex, and country. Global age-standardised means were 12.5m/s (95% confidence interval: 12.1-12.8m/s) for baPWV and 7.45m/s (95% CI: 7.11-7.79m/s) for cfPWV. Males had higher global levels than females of 0.77m/s for baPWV (95% CI: 0.75-0.78m/s) and 0.35m/s for cfPWV (95% CI: 0.33-0.37m/s), but sex differences in baPWV diminished with advancing age. Compared to Europe, baPWV was substantially higher in the Asian region (+1.83m/s, P=0.0014), whereas cfPWV was higher in the African region (+0.41m/s, P<0.0001) and differed more by country (highest in Poland, Russia, Iceland, France, and China; lowest in Spain, Belgium, Canada, Finland, and Argentina). High vs. other country income was associated with lower baPWV (-0.55m/s, P=0.048) and cfPWV (-0.41m/s, P<0.0001). China and other Asian countries featured high PWV, which by known associations with central blood pressure and pulse pressure may partly explain higher Asian risk for intracerebral haemorrhage and small vessel stroke. Reference values provided may facilitate use of PWV as a marker of vascular ageing, for prediction of vascular risk and death, and for designing future therapeutic interventions. This study was supported by the excellence initiative VASCage funded by the Austrian Research Promotion Agency, by the National Science Foundation of China, and the Science and Technology Planning Project of Hunan Province. Detailed funding information is provided as part of the Acknowledgments after the main text.

PS-P15-6: PERIPHERAL OSTEOPONTIN MIGHT BE A POTENTIAL BIO-MARKER FOR PREDICTING ARTERIAL STIFFNESS IN ELDERLY CHINESE

Objective: Compare the efficiency of pulse wave velocity (PWV) and ankle-brachial Index (ABI) in diabetes patients and healthy participants. Investigate novel bio-markers for aging related arterial stiffness. JOURNAL/jhype/04.03/00004872-202301001-01307/figure1/v/2023-10-24T163949Z/r/image-jpeg Design and method: PWV, ABI, vascular cell adhesion molecule (VCAM), osteopontin (OPN) and glutathione peroxidase (GPX) were evaluated in elderly Chinese from March to June in 2019. Results: 86 participants were included in the study. There were 69 male participants (80.2%), the mean age is 87.2 ± 0.5 years, the mean BMI is 23.3 ± 0.5. Of the 86 participants, 34 were diagnosed with diabetes mellitus. Compared with non- diabetes mellitus participants, ABI levels declined in left limbs of diabetes mellitus (DM) patients (0.94 ± 0.04 vs 1.02 ± 0.03, P &lt; 0.05, separately). After adjusted by age, SBP, DBP, BMI, FPG, Cholesterol and HCT, serum OPN level was negatively correlated to both L- ABI and R- ABI (r = - 0.317, P = 0.028; r = - 0.362, P = 0.014, separately). Conclusions: Differential use of PWV and ABI should be considered in elderly with diabetes. Serum levels of OPN might be an independent bio-marker for predicting arterial stiffness in elderly Chinese.

CARDIOVASCULAR RISK RECLASSIFICATION BY PULSE WAVE VELOCITY IN BRAZILIAN HYPERTENSIVE PATIENTS

Objective: Objetive: The number of asymptomatic hypertensive patients who already have subclinical injuries in the early stages of hypertensive disease is high and, generally, they are not identified by the traditional evaluation model. The use of Pulse Wave Velocity (PWV) in addition to traditional cardiovascular risk factors can improve risk stratification. The present study intends to perform the reclassification of cardiovascular risk according to the median Pulse Wave Velocity (PWV) and correlate PWV with the intima-media thickness, with the left ventricular (LV) mass indexed and with microalbuminuria. Design and method: Design and method: Multicenter analytical cross-sectional study of patients undergoing measurement of central and peripheral blood pressure parameters between October/2018 and March/2019. Intima-media thickness (IMT) and presence of carotid plaque, left ventricular mass indexed and microalbuminuria were also evaluated. Fisher’s test was applied to verify the association of cardiovascular risk reclassification by median PWV. Spearman’s correlation was used to correlate PWV with intima-media thickness, presence or absence of carotid plaque, microalbuminuria and indexed left ventricular mass. A significance level of 5% was adopted. Results: Results: 126 patients were evaluated, with a mean age of 60.58 ± 10.51 years and 87 (69.95%) are women. When reclassified, there was an increase in the frequency of patients who moved from medium to high risk (p&lt;0.001). A weak and positive correlation was identified between PWV and LV mass indexed (r = 0.304, p &lt; 0.001) and with IMT (r = 0.30, p &lt; 0.001). Conclusions: Conclusions: The application of median PWV values is a simple and effective tool to reclassify intermediate-risk individuals to high-risk.

Five years of cardio-ankle vascular index (CAVI) and CAVI0: how close are we to a pressure-independent index of arterial stiffness?

Pulse wave velocity, a common metric of arterial stiffness, is an established predictor for cardiovascular events and mortality. However, its intrinsic pressure-dependency complicates the discrimination of acute and chronic impacts of increased blood pressure on arterial stiffness. Cardio-ankle vascular index (CAVI) represented a significant step towards the development of a pressure-independent arterial stiffness metric. However, some potential limitations of CAVI might render this arterial stiffness metric less pressure-independent than originally thought. For this reason, we later introduced CAVI0. Nevertheless, advantages of one approach over the other are left debated. This review aims to shed light on the pressure (in)dependency of both CAVI and CAVI0. By critically reviewing results from studies reporting both CAVI and CAVI0 and using simple analytical methods, we show that CAVI0 may enhance the pressure-independent assessment of arterial stiffness, especially in the presence of large inter-individual differences in blood pressure.

P1553Differential association between vascular and chronological age with cardiovascular outcomes

Abstract Background/Introduction Increased pulse wave velocity (PWV), is a reliable marker of early vascular aging (EVA). However, the identification of individuals whose arteries are abnormally healthy in comparison to their age and cardiovascular (CV) risk profile might be of interest, to discover novel pathways of cardioprotection and provide preventive strategies for successful vascular aging. Purpose 1) to provide a novel calculation for vascular age and examine his determinants; 2) to test the hypothesis that individuals with the largest difference between chronological and vascular age (C-V age) show a lower rate of CV events than their counterparts, and may thus be defined as the supernormal vascular aging group (SUPERNOVA). Methods Vascular age was defined as predicted age based on classical CV risk factors and PWV. The best fitting model for vascular age was investigated in the multicenter, European, cross-sectional Reference Values for Arterial stiffness Collaboration Database (n=11406). Continuous variables were modelled as smoothing splines. Thereafter, the risk of fatal and non-fatal CV events associated with C-V age was examined in the longitudinal cohort of the Malmo Diet and Cancer Study (n=2663) using Cox proprotional hazard regression models. C-V age was examined as a continuous variable (natural splines) and as a 3 levels categorical variables based on the best grouping of the deciles of C-V age and corresponding to the EVA (&lt;3.0 years), normal vascular aging (3.0 to 8.8 years) and SUPERNOVA (&gt;8.8 years) respectively. Results In the Reference Values Cohort (age range 17–85 years, 52.4% men, 38.1% hypertensives, 3.9% diabetics, average PWV 7.8 m/s), the most significant predictor of vascular age (full model r2 0.598) was PWV. In the Malmo Diet and Cancer Study Cohort (age 61–89 years, 63.6% men, 64.0% hypertensives, 12.9% diabetics, PWV 11.5 m/s), during follow-up (6.6 years on average), 286 individuals developed a first cardiovascular event. In the Cox survival analysis, C-V age was significantly and inversely associated with CV events. Compare to normal vascular aging, participants with SUPERNOVA had lower risk for CV events [HR 0.51 (0.34–0.76)] whereas those with EVA had a higher risk [HR 2.71 (1.80–4.09)]. Instead, there was no significant association with all-cause mortality. Conclusions The use of PWV and CV risk factors may be useful to define early and supernormal vascular aging in particular, and to assess its clinical relevance towards the risk of cardiovascular disease and death.

AORTIC PULSE WAVE VELOCITY AS A POTENTIALLY USEFUL DIAGNOSTIC TOOL FOR SUSPECTED NEW HYPERTENSION IN ADULTS – PRELIMINARY RESULTS

Objective: Aortic pulse wave velocity (PWV) is a well-established marker of arterial stiffness (AS) and is an independent predictor of cardiovascular risk. However, to which extent this hemodynamic parameter could be used for the diagnosis of systemic arterial hypertension (AH) has not been consistently addressed, and this was the objective of our study. Design and method: A cross-sectional study including 54 consecutive apparently healthy adults, with elevated office blood pressure (BP) (new AH), free of any chronic medication or relevant clinical condition. Carotid-femoral PWV was measured to all participants with the Complior SP device, complying with the methodological recommendations, and 24 h ambulatory blood pressure monitoring (ABPM) was used to confirm the presence of AH. All participants were evaluated by the same experienced clinician. Results: The 54 participants had a mean age of 46 ± 11 years, was predominantly male (n = 48; 89%), with a mean body mass index of 27 ± 4 Kg/m2, mean office BP was 163 ± 13 mmHg for systolic BP and 95 ± 9 mmHg for diastolic BP, and mean heart rate of 75 ± 12 bpm. Mean total cholesterol was 184 ± 35 mg/dL, HDL-cholesterol was 53 ± 11 mg/dL and glycaemia was 86 ± 11 mg/dL. PWV was significantly correlated with age, BP and potassium levels. Abnormal ABPM was identified in 44 participants (86%). The predictive capacity of PWV for the diagnosis of new HT was checked in a ROC-curve analysis (figure), from which an AUC of 0.76 (IC: 0.61–0.92; p = .02) was observed. A cut-off of 9.5 m/s had a sensibility of 94%, with a positive predictive value of 90% for an abnormal ABPM and confirmation of HT.Conclusions: This study provides promising preliminary results on the potential use of PWV for clinical decision-making concerning the diagnosis of new AH in adults, with PWV expressing predominant hemodynamic changes that are predictive for the presence of HT in adults with a first abnormal office BP measurement.

The Use of Pulse Wave Velocity in Predicting Pre-Eclampsia in High-Risk Women

In this study, we evaluated the diagnostic utility of pulls wave velocity (PWV) alone or in combination with other diagnostic markers in predicting pre-eclampsia (PE) on high-risk women. Pregnant women at high risk for PE were recruited between 32 and 36 weeks of gestation period. This study is the first in Romanian and shows that PWV may be a potentially promising predictor of early-onset PE in women at high risk for PE. All these patients were treated and were instructed according to the ESC/ESH guidelines regarding hypertensive patients. Statistical analysis was performed using the Chi-square, a Mann-Whitney test, Pearson correlation, and linear regression tests.After we ran several test the main conclusions are that there is a positive correlation between the para-clinics data (creatinine, Esbach proteinuria) and the pulls wave velocity for aorta (PWVao). The risk for preeclampsia is increasing if the body mass index (BMI) of the patients is higher than the average value (BMI]26) or if the patient is a smoker.

Usefulness of pulse wave velocity as an indicator of atherosclerosis in subjects with impaired fasting glucose

Background: The prediabetic state with impaired fasting glucose level (IFG) is one of the risk factors for endothelial dysfunction leading to atherosclerosis. Pulse wave velocity is an effective index of arterial stiffness and is widely used for noninvasive assessment of atherosclerosis. Aims and Objectives: To assess the usefulness of pulse wave velocity (PWV) as an indicator of atherosclerosis in IFG. Also to compare PWV values in subjects with IFG and those with normal fasting glucose (NFG) levels and to correlate the PWV values with the fasting glucose levels. Materials and Methods: Two hundred male subjects were involved in the study. Group 1 comprised subjects with IFG (n = 100). Group 2 comprised subjects with NFG (n = 100). Both the groups were evaluated for physiological parameters-Blood pressure and brachial-ankle pulse wave velocity (ba-PWV) using PeriScope. The biochemical parameters such as fasting blood glucose, HbA1c, and lipid profile were also measured. Statistical analysis was done using SPSS-19 software. All parameters were compared using unpaired Student’s t-test. Pearson correlation analysis was done to establish the relationship between two variables. Results: Significant differences were found between the ba-PWV values in the IFG and NFG groups (1549.5 ± 60.5 cm/s vs 1351.7 ± 44.0 cm/s, p < 0.05). There was also significant positive correlation (r = 0.88) between ba-PWV value and fasting glucose level. The multiple regression analysis showed that IFG level is an independent risk factor for increased ba-PWV levels. Conclusion: Our study showed that ba-PWV can be used as an indicator to detect the early development of atherosclerosis in subjects with IFG levels.

Usefulness of pulse wave velocity and plasma renin activity measurement for arterial hypertension phenotyping

Usefulness of pulse wave velocity and plasma renin activity measurement for arterial hypertension phenotyping

Abstract P183: Repeatability of Pulse Wave Velocity: The Atherosclerosis Risk in Communities (ARIC) Study

Background: Despite the growing use of pulse wave velocity (PWV), a measure of arterial stiffness that is predictive of cardiovascular disease and all-cause mortality, the repeatability of central, lower-extremity, and composite measures of PWV has not been examined. Objectives: Characterize the repeatability of PWV in a multi-center, population-based study of older adults. Methods: We included a subset of the ARIC visit 5 (2011-2013) participants (n=79; mean age 75.7 years; 46 females) from the following four United States communities: Forsyth County, NC; Jackson, MS; Minneapolis, MN; and Washington County, MD who underwent two standardized exams 4-8 weeks apart. At each exam, trained and certified technicians obtained two PWV measurements following a standardized protocol using the VP-1000 Plus system (Omron Co., Ltd., Kyoto, Japan). Measurements included carotid-femoral PWV (cfPWV), right brachial-ankle PWV (baPWV) and right femoral-ankle PWV (faPWV). We excluded participants with evidence of a major arrhythmia on a 12-lead electrocardiogram, aortic stenosis, body mass index &gt;40 kg/m 2 , and excluded PWV values &gt;3 standard deviations away from the mean. We used random-effects mixed models to parse the variance of the measures into their between-participant, between-visit, and within-visit components, then calculated the intra-class correlation coefficient (ICC) and estimated the number of replicates needed to achieve an ICC of 0.9 using the Spearman-Brown formula and the lower bound of the ICC 95% confidence interval (95% CI). We also calculated the minimal detectable change (MDC; 95% confidence) and minimal detectable difference (MDD). Results: Between-participant variation accounted for 69% to 84% of the total variation in cfPWV, baPWV and faPWV. The ICCs (95% CIs) were 0.70 (0.59, 0.81) for cfPWV, 0.84 (0.78, 0.90) for baPWV, and 0.69 (0.59, 0.79) for faPWV. The number of replicates to achieve an ICC of 0.90 was 6 for cfPWV and faPWV and 3 for baPWV. The overall means and standard deviations (SD) were 1,198.9 ± 269.6 cm/s for cfPWV, 1,742.0 ± 328.3 cm/s for baPWV, and 1,063.4 ± 189.4 cm/s for faPWV. The MDC between repeat measures within an individual was 411.0 cm/s for cfPWV, 370.6 cm/s for baPWV, and 301.4 cm/s for faPWV. The MDD for two independent samples of 100 per group was 139.3 cm/s for cfPWV, 172.3 cm/s for baPWV, and 100.4 cm/s for faPWV. Conclusion: The repeatability is excellent for baPWV and fair for cfPWV and faPWV. The MDC was approximately 1 SD for baPWV and 1.5 SDs for cfPWV and faPWV and the MDD for 100 per group was approximately 0.5 SD for cfPWV, baPWV and faPWV. Averaging replicates would reduce the effects of measurement variability. These results support the use of PWV in clinical and epidemiologic studies; however, to minimize potential bias, studies need to consider measurement variability in design development and in the analysis and interpretation of results.

Prevalence of Obesity and Metabolic Changes After Kidney Transplantation: Hungarian Pediatric Cohort Study

BackgroundCardiovascular mortality rate in patients with end-stage renal disease is 3 magnitudes higher than in the general population; it remains 10-fold higher after successful renal transplantation (Tx). Among others, obesity and hypertension can exert deleterious effects on vascular structure and function after Tx. Successful kidney transplantation may induce excessive weight gain in part because of the effects of steroid treatment. MethodsThe purpose of this study was to evaluate the presence of obesity in Tx children, their obesity-related metabolic disturbances, and to assess their blood pressure and arterial stiffness in relation to obesity. Forty-one transplant children (age, 15.7 [3.5] years; 28 males) were studied. Body composition was assessed by body mass index (BMI), waist circumference, skin-fold measurements, and multifrequence bioimpedance analysis. Glucose metabolism, blood pressure, and arterial stiffness (with the use of pulse wave velocity) were studied. Age- and sex-dependent parameters were expressed as standard deviation scores (SDS). ResultsThe prevalence of overweight (BMI >85%) increased from 3.2% to 24.4% at 49 months (3–183) (median, range); the BMI SDS increased from −0.27 (0.79) to 0.67 (1.35) after Tx. There was a close correlation between BMI SDS and the percentage of body fat and body fat mass in the Tx group (r = 0.80; r = 0.94, P = .0001). Children with disturbed glycemic control (n = 14) had higher percentage of body fat and higher blood pressure compared with those with normal glucose metabolism (P < .05). There was no difference in pulse wave velocity between the lean and obese patients. ConclusionsThe prevalence of overweight or obese patients in the Hungarian pediatric renal cohort is low at transplantation and rises subsequently. Overweight is associated with disturbed glycemic control and increased blood pressure; however, these disturbances are not yet reflected by stiffening of the arteries. Strategies are needed to prevent obesity, its impact on hypertension, and cardiovascular disease in pediatric transplantation.

The use of pulse wave velocity in predicting pre-eclampsia in high-risk women

In this study, we evaluated the diagnostic utility of pulse wave velocity (PWV) alone or in combination with other diagnostic markers in predicting pre-eclampsia (PE) in high-risk women. Pregnant women at high risk for PE were recruited between 22 and 26 weeks of gestation and were assessed for (a) PWV, (b) serum levels of the placental soluble fms-like tyrosine kinase 1 (sFlt-1) protein and uric acid and (c) 24-h urinary protein and calcium excretion. Sensitivities and specificities were derived from receiver operating characteristic curves. Of 118 women recruited, 11 and 10 women developed early-onset PE (<34 weeks) and late-onset PE (≥34 weeks), respectively. Of the five diagnostic markers tested, PWV showed the highest detection rate for all cases (21) of PE (81%) and for early-onset PE (82%) at a fixed 10% false-positive rate (FPR), and when combined with sFlt-1, these figures increased to 90% and 92%, respectively. Despite the reduced ability of PWV to predict late-onset PE (detection rate 20%), the combination of PWV with sFlt-1 achieved a detection rate of 50% at a fixed 10% FPR. A suggested cutoff value of 9 m/s for PWV resulted in optimal sensitivity (91%) and specificity (86%) for predicting early-onset PE. This study is the first to show that PWV may be a potentially promising predictor of early-onset PE in women at high risk for PE. The combination of PWV with sFlt-1 may further improve the screening efficacy for predicting PE.

Pulse wave velocity as a diagnostic Index: The pitfalls of tethering versus stiffening of the arterial wall

Pulse wave velocity (PWV) is often used as a clinical index of aging, vascular disease, or age related hypertension. This practice is based on the assumption that a higher wave speed indicates vascular stiffening. This assumption is well grounded in the physics of pulsatile flow of an incompressible fluid where it is fully established that a pulse wave travels faster in a tube of stiffer wall, the wave speed becoming infinite in the mathematical limit of a rigid wall. However, in this paper we point out that the physical principal of higher pulse wave velocity in a stiffer tube is strictly valid only when the wall is free from outside constraints, which in the physiological setting is present in the form of tethering of the vessel wall. The use of PWV as an index of arterial stiffening may thus lose its validity if tethering is involved. A solution of the problem of vessel wall mechanics as they arise from the physiological pulsatile flow problem is presented for the purpose of resolving this issue. The vessel wall is considered to have finite thickness with or without tethering and with a range of mechanical properties ranging from viscoelastic to stiff. The results show that, indeed, while the wave speed becomes infinite in the mathematical limit of a rigid free wall, the opposite actually happens if the vessel wall is tethered. Here the wave speed actually diminishes as the degree of tethering increases. This dichotomy in the effects of tethering versus stiffening of the arterial wall may clearly lead to error in the interpretation of PWV as an index of vessel wall stiffness. In particular, a normal value of PWV may lead to the conclusion that vessel wall stiffening is absent while this value may in fact have been lowered by tethering. In other words, the diagnostic test may lead to a false negative diagnosis. Our results indicate that the reason for which PWV is lower in a tethered wall compared with that in a free wall of the same stiffness is that the radial movements of the wall are greatly reduced by tethering. More precisely, the results show that PWV depends strongly on the ratio of radial to axial displacements and that this ratio is much lower in a tethered wall than it is in a free wall of the same stiffness.

Taking the pulse of a sick kidney: Arterial stiffness in glomerulonephritis

Arterial stiffness is an increasingly recognized independent predictor of cardiovascular morbidity. Vessel volume and wall texture are the main determinants of pulse wave velocity (PWV), the most commonly used indicator of arterial elasticity. Hence, measurements of PWV will be affected by the site of measurement and the overall dimensions of the vascular tree as well as by alterations of vascular morphology. In children, methodological heterogeneity and the lack of pediatric reference values complicate the interpretation of PWV. Arterial elasticity is altered in numerous clinical conditions such as vasculitis, end-stage renal disease, and diabetes. Novel evidence suggests that acute postinfectious glomerulonephritis, but not pyelonephritis, is also associated with increased arterial stiffness, the persistence of which may predict the emergence of chronic kidney disease. We review the potential mechanisms underlying the link between acute and chronic kidney disease and impaired arterial elasticity. These might include activation of the renin-angiotensin system, sympathetic hyperactivation, and a subclinical state of inflammation. In view of the excessive cardiovascular comorbidity associated with kidney disease, the increasing evidence of the prognostic relevance of arterial stiffness should encourage further research investigating the usefulness of PWV as a biomarker in acute and chronic kidney disorders.

Chest Pulse-Wave Velocity: A Novel Approach to Assess Arterial Stiffness

Pulse-wave velocity (PWV) is considered as the gold-standard method to assess arterial stiffness, an independent predictor of cardiovascular morbidity and mortality. Current available devices that measure PWV need to be operated by skilled medical staff, thus, reducing the potential use of PWV in the ambulatory setting. In this paper, we present a new technique allowing continuous, unsupervised measurements of pulse transit times (PTT) in central arteries by means of a chest sensor. This technique relies on measuring the propagation time of pressure pulses from their genesis in the left ventricle to their later arrival at the cutaneous vasculature on the sternum. Combined thoracic impedance cardiography and phonocardiography are used to detect the opening of the aortic valve, from which a pre-ejection period (PEP) value is estimated. Multichannel reflective photoplethysmography at the sternum is used to detect the distal pulse-arrival time (PAT). A PTT value is then calculated as PTT = PAT - PEP. After optimizing the parameters of the chest PTT calculation algorithm on a nine-subject cohort, a prospective validation study involving 31 normo- and hypertensive subjects was performed. 1/chest PTT correlated very well with the COMPLIOR carotid to femoral PWV (r = 0.88, p < 10 (-9)). Finally, an empirical method to map chest PTT values onto chest PWV values is explored.

Pulse Wave Velocity and Digital Volume Pulse as Indirect Estimators of Blood Pressure: Pilot Study on Healthy Volunteers

The purpose of the study was to asses the potential use of pulse wave velocity (PWV) and digital volume pulse (DVP) as estimators of systolic (SBP) and diastolic (DPB) blood pressure. Single and multiple correlation studies were conducted, including biometric parameters and risk factors. Brachial-ankle PWV (baPWV) and DVP signals were obtained from a Pulse Trace PWV and Pulse Trace PCA (pulse contour analysis), respectively. The DVP (obtained by photoplethysmography), allowed stiffness (SI) and reflection indexes (RI) to be derived. The first study on 47 healthy volunteers showed that both SBP and DPB correlated significantly both with baPWV and SI. Multiple regression models of the baPWV and the waist-to-hip ratio (WHR) allowed SBP and DBP to be modeled with r = 0.838 and r = 0.673, respectively. SI results also employed WHR and modeled SBP and DBP with r = 0.852 and r = 0.663, respectively. RI did not correlate either with SBP or DBP. In order to avoid the use of ultrasound techniques to measure PWV, we then developed a custom-built system to measure PWV by photoplethysmography and validated it against the Pulse Trace. With the same equipment we conducted a second pilot study with ten healthy volunteers. The best SBP multiple regression model for SBP achieved r = 0.997 by considering the heart-finger PWV (hfPWV measured between R-wave and index finger), WHR and heart rate. Only WHR was significant in the DBP model. Our findings suggest that the hfPWV photoplethysmography signal could be a reliable estimator of approximate SBP and could be used, for example, to monitor cardiac patients during physical exercise sessions in cardiac rehabilitation.

Reproducibility of Regional Pulse Wave Velocity in Healthy Subjects

Background/AimsDespite the clinical importance and widespread use of pulse wave velocity (PWV), there are no standards for pulse sensors or for system requirements to ensure accurate pulse wave measurement. We assessed the reproducibility of PWV values using a newly developed PWV measurement system.MethodsThe system used in this study was the PP-1000, which simultaneously provides regional PWV values from arteries at four different sites (carotid, femoral, radial, and dorsalis pedis). Seventeen healthy male subjects without any cardiovascular disease participated in this study. Two observers performed two consecutive measurements in the same subject in random order. To evaluate the reproducibility of the system, two sets of analyses (within-observer and between-observer) were performed.ResultsThe means±SD of PWV for the aorta, arm, and leg were 7.0±1.48, 8.43±1.14, and 8.09±0.98 m/s as measured by observer A and 6.76±1.00, 7.97±0.80, and 7.97±0.72 m/s by observer B, respectively. Between-observer differences for the aorta, arm, and leg were 0.14±0.62, 0.18±0.84, and 0.07±0.86 m/s, respectively, and the correlation coefficients were high, especially for aortic PWV (r=0.93). All the measurements showed significant correlation coefficients, ranging from 0.94 to 0.99.ConclusionsThe PWV measurement system used in this study provides accurate analysis results with high reproducibility. It is necessary to provide an accurate algorithm for the detection of additional features such as flow wave, reflection wave, and dicrotic notch from a pulse waveform.

Preeclampsia More Than 1 Disease

In this issue of Hypertension , Rasmussen and Irgens provide strong support for the relationship of preeclampsia and intrauterine growth restriction (IUGR). They also provide data that support but also some that argue against the concept that the pregnancy complication, preeclampsia, may be more than one disease.1 In previous studies these authors demonstrated that women who have had a growth-restricted infant without preeclampsia are more likely to have preeclampsia in a subsequent pregnancy.2 Those data and similar findings in the current study support pathological findings indicating the similarity of IUGR and preeclampsia.3 In preeclampsia, IUGR and interestingly also in about one third of cases of preterm birth,4 the maternal myometrial and decidual vessels perfusing the placental site do not undergo the normal remodeling of pregnancy. In normal pregnancy trophoblastic invasion is associated with a greatly increased diameter and removal of vascular smooth muscle from the wall of these vessels. This results in large diameter, flaccid, unresponsive tubes that greatly increase placental perfusion. These changes are not present in pregnancies complicated by IUGR, preeclampsia, and some with preterm births. Implicit in the current study is the concept that preterm birth as well as IUGR is related to subsequent preeclampsia. Although preterm birth is not assessed directly, the effect of low birth weight (IUGR and preterm birth) was greater than the effect of IUGR alone. In a far smaller study our group was able to more directly support the relationship of preterm birth and preeclampsia, as women with early onset preeclampsia were more likely to have preterm birth in a subsequent nonpreeclamptic pregnancy.5 The current study extends the prior observation of the relationship of IUGR and preeclampsia but also raises other interesting points. In this larger study the authors were …