Measurement Of Aortic Pulse Wave Velocity Research Articles

Role of carotid-femoral (aortic) pulse wave velocity measurement in the evaluation of cardiovascular risk in children with idiopathic nephrotic syndrome

Introduction and objective: The study was aimed to evaluate carotid-femoral (aortic) pulse wave velocity (cfPWV) in children with idiopathic nephrotic syndrome. Materials and methods: A total of 48 children with idiopathic nephrotic syndrome were enrolled in the study, including 35 patients in acute phase and 32 in remission. In 19 patients, measurements were performed twice: in relapse and in remission. The control group consisted of 22 healthy children. In all children, cfPWV measurements were performed. Selected clinical, biochemical parameters and fetuin-A concentrations were determined. Results: The patients with idiopathic nephrotic syndrome had significantly higher cfPWV both in relapse and in remission, as compared to the control group. Fetuin-A levels were significantly lower in both phases of the disease than in the healthy controls. cfPWV in relapse positively correlated with body weight, body mass index, systolic, diastolic, mean and pulse pressure. cfPWV in remission positively correlated with body weight, residual proteinuria, and total and low-density lipoproteins cholesterol. Systolic blood pressure in relapse, body weight, and total cholesterol in remission were found to be independent risk factors for increased cfPWV. Total cholesterol in remission was an independent risk factor for an increase of cfPWV to height rate. Conclusions: Increased cfPWV in children with idiopathic nephrotic syndrome indicates the possibility of premature cardiovascular complications. Significant effects of the modifiable risk factors, such as arterial pressure, body weight and disturbances of lipid metabolism, on arterial stiffness may contribute to early diagnostic and therapeutic interventions to improve the prognosis in patients with idiopathic nephrotic syndrome. Measurements of cfPWV may be useful in the assessment of cardiovascular risk in children with idiopathic nephrotic syndrome.

Comparison of echocardiographic aortic stiffness index measurements and pulse wave velocity measurements in obese and overweight children.

Aortic/arterial stiffness is a reliable, independent predictor and a risk factor for cardiovascular mortality. Arterial stiffness is assessed by pulse wave velocity and echocardiography. The purpose of this study is to analyse aortic/arterial stiffness in patients using echocardiographic and pulse wave velocity techniques. The participants of this study consisted of 62 patients who presented to the Gazi University Pediatric Endocrinology and Pediatric Cardiology outpatient clinics, including 21 obese, 20 overweight, and 21 normal-weight patients. Echocardiography was performed on all patients, and echocardiographic measurements were compared to pulse wave velocity measurements. The mean (min-max) arterial strain measurements were 0.146 ± 0.0 (0.06-0.3) in the obese group and 0.106 ± 0.0 (0.05-0.18) in the overweight group. In comparison to the overweight group, the obese group had greater arterial strain measurements. The pulse wave velocity measurements in the obese and overweight groups were greater than those in the normal weight group (p > 0.05). Elastic modulus and aortic stiffness ß index values were shown to be positively correlated with pulse wave velocity measurements in the obese group (r = 0.56, r = 0.53, respectively; p = 0.008, p = 0.01, respectively). Systolic and diastolic blood pressure measurements were correlated with pulse wave velocity measurements in the obese group (r = 0.98, p = 0.0001, respectively). In our study, echocardiographic aortic measurements showing the vessel wall were correlated with pulse wave velocity measurements. Echocardiographic evaluation should be included in the routine follow-up of patients because pulse wave velocity measurement devices are not available in all centres, echocardiography is available in many centres, it is easily applicable, and it facilitates the follow-up of patients.

HEMODYNAMICS STRESS TEST USING FINGER-TO-TOE PULSE WAVE VELOCITY IN SUPINE AND SITTING POSITION IN END-STAGE KIDNEY DISEASE

Objective: Aortic pulse wave velocity (PWV), a measure of arterial stiffness can either be measured by the ratio of distance to pulse transit time or, estimated based on the pulse wave profile (ePWV). Aortic PWV measurements are performed in the supine position as there is no added hydrostatic pressure along the arterial path, and the recording of the arterial pressure waveform of the femoral arterial is easier to perform. However, finger-to-toe PWV (ftPWV), a surrogate for aortic PWV, can easily be performed in other positions, such as the sitting position, giving the opportunity to examine arterial wall properties in a dynamic manner. The aim of the study was to observe the impact of the position (supine vs sitting) on the ePWV and on the measured ftPWV in patients with end-stage kidney disease. Design and method: In a cross-sectional study involving adult hemodialysis patients, we performed vascular assessments in the supine and the sitting position within the first 2 hours of their hemodialysis session. The ePWV was obtained using the Mobil-O-Graph and ftPWV was obtained using the pOpmètre®. Three measures were taken with each device. Generalized estimated equations were then used to calculate the average of ePWV and ftPWV with respect to each position. Results: In 46 patients (17 females), the average age was 71±12 years and the blood pressure was 136±24 /77±15 mmHg. The ePWV was 10.8 m/s (IC95% :10.1-11.4 m/s) in the supine position and 10.7 m/s (IC95%: 10.0-11.3 m/s) in the sitting position. However, the ftPWV was 12.1 m/s (IC95%: 9.6-14.7 m/s) in the supine position but it increased to 22.0 m/s (IC95%: 15.0-29.0 m/s) in the sitting position. This increase of 9.8 m/s was highly significant (P = 0.006) even though the brachial blood pressure and the heart rate had barely changed. Conclusions: This study shows that finger-to-toe PWV increases in the sitting position, offering us the opportunity to explore this postural changes in PWV as a possible vascular stress test.

Enhancement of Endothelial KCa Channel Activity as a Novel Strategy to Oppose Atherosclerosis

Atherosclerosis represents a major risk factor for cardiovascular disease and is associated with endothelial dysfunction (ED), which facilitates fatty plaque formation, impairs blood flow and increases arterial stiffness. A hallmark feature of ED is decreased bioavailability of nitric oxide (NO). We have previously reported that pharmacological activation of endothelial Ca2+‐activated K+ channels (KCa2.3 and KCa3.1) can oppose ED by enhancing endothelium‐dependent vasodilation.We hypothesized that improving endothelial function will mitigate the development and/or severity of atherosclerosis in Apoe knockout (Apoe‐/‐) mice. Administration of the KCa channel activator SKA‐31 was utilized to improve endothelial function in vivo.Experimentally, male, 8‐week old Apoe‐/‐ mice on a regular chow diet were administered one of three daily treatments for 16 weeks: SKA‐31 (10 mg/kg), the KCa3.1 channel blocker senicapoc (40 mg/kg), or drug vehicle alone. Pharmacological inhibition of KCa3.1 channels is reported to reduce atherosclerosis in Apoe‐/‐ mice and was utilized as a benchmark. Drugs were formulated in miglyol and condensed milk, which was readily ingested by the mice. Cardiac function and arterial pulse wave velocity (PWV) were assessed by echocardiography under isoflurane anesthesia. Atherosclerotic lesions in the aorta were visualized by Oil‐Red‐O staining and select tissue histology was carried out using H&E staining. Abdominal aortic contractility and relaxation were measured by wire myography in drug‐treated Apoe‐/‐ mice and age/sex‐matched wild‐type C57/BL6 mice.At the end of drug treatment, left ventricular (LV) ejection fraction, fractional shortening and LV posterior wall thickness were not different in Apoe‐/‐ mice treated with either SKA‐31 or senicapoc compared with vehicle. Measurements of aortic PWV showed no significant differences among the three groups, which indicated that neither drug treatment decreased aortic stiffness. Oil‐Red‐O staining of the thoracic aorta and aortic arch revealed fatty plaque formation in Apoe‐/‐ mice (i.e. 10‐12% of area) compared with WT controls (< 1%), however, neither SKA‐31 nor senicapoc treatments reduced plaque formation vs. vehicle. Phenylephrine (PE)‐evoked contraction of abdominal aortic rings appeared similar in WT and vehicle/drug treated Apoe‐/‐ mice, whereas endothelium‐dependent, acetylcholine‐induced relaxation of PE‐constricted aortic rings was enhanced in aortic rings from mice treated with SKA‐31 and senicapoc vs. vehicle. Although relaxation to the smooth muscle vasodilator sodium nitroprusside was augmented in Apoe‐/‐ mice compared with WT, this response was not altered by drug treatment.While both SKA‐31 and senicapoc improved aortic endothelial function, neither drug decreased plaque formation or aortic stiffness, perhaps due to the later onset of these events in the progression of atherosclerotic pathology. We will investigate this likelihood by feeding Apoe‐/‐ mice a high fat diet to accelerate the development of plaque formation and arterial stiffness to determine the effects of both drug treatments on these later stages of atherosclerosis.

Aortic Pulse Wave Velocity as Adjunct Risk Marker for Assessing Cardiovascular Disease Risk: Prospective Study.

Aortic pulse wave velocity is a noninvasive measure of aortic stiffness and arterial aging. Its current value in cardiovascular risk estimation practice is unknown. We aimed to establish whether aortic pulse wave velocity identified individuals with higher risk of incident major adverse cardiovascular events and improved performance of the American Heart Association/American College of Cardiology atherosclerotic cardiovascular disease risk score. This prospective analysis included 3837 Whitehall II cohort participants screened in 2008 to 2009, and followed for 11.7 years (mean=10.3, SD=1.81), without history of stroke, myocardial infarction, or coronary heart disease. Mean age of the sample was 65.0 years (SD=5.6), 2831 participants (73.8%) were male and mean atherosclerotic cardiovascular disease risk score was 13.8%. At the end of follow-up, 411 individuals (10.7%) had suffered a major cardiovascular event. Those in the highest aortic pulse wave velocity quartile were at high risk (hazard ratio, 2.99 [95% CI, 2.25-3.97]) and reached the threshold for statin medication (7.5% risk) after 5 years whereas others reached it after 10 years (difference P<0.001). The addition of aortic pulse wave velocity to the risk score improved the C statistic (0.68 versus 0.67, P=0.03) and net reclassification index (4.6%, P=0.04 and 11.3%, P=0.02). Our results show that aortic stiffness predicted major adverse cardiovascular events in a cohort of elderly individuals, improving the performance of a widely used cardiovascular disease risk estimator. Aortic pulse wave velocity measurement is scalable, radiation-free, and easy to perform. Further studies on its applicability in cardiovascular disease risk assessment in primary care settings are needed.

Association of Aortic Pulse Wave Velocity with the Severity of Coronary Artery Disease in Patients with Non-ST-Segment Elevation Myocardial Infarction

Background: Noninvasive assessment of arterial stiffness with aortic pulse wave velocity (PWV) may serve as a useful adjunct to the cardiovascular risk stratification and risk management. The aim of this study was to evaluate the association between aortic PWV and severity of coronary artery disease (CAD) in patients with non-STsegment elevation myocardial infarction (NSTEMI). Methods: This cross sectional analytical study was conducted over 100 NSTEMI patients who were purposively selected and agreed to do coronary angiogram during index hospital admission. PWV was assessed noninvasively using the SphygmoCor® system on the day before coronary angiogram (CAG). Study subjects were divided into two groups on the basis of PWV. In group I: PWV was ≤10 m/sec and in group II: PWV was &gt; 10 m/sec. Fifty patients in each group. Angiographic severity of CAD was assessed by vessel score, Friesinger score and Leaman score. Results: Vessel score 2 and 3 were significantly (p&lt;0.05) higher in group II and vessel score 0 and 1 were significantly (p&lt;0.05) higher in group I. The mean PWV in the group with normal angiographic results was 8.21±1.8 m/sec, and in patients with single-vessel disease it was 9.88±2.02 m/sec. In those with double and triple vessel disease the mean PWV was found 11.95±2.61 m/sec and 14.37±2.96 m/sec respectively. There was a significant difference of the mean value of PWV among the vessel involvement group (p=0.001). Normal and low Friesinger score were significantly (p&lt;0.05) higher in group I patients. Intermediate and high Friesinger score were significantly (p&lt;0.05) higher in group II patients. Increased PWV was significantly associated with the presence and severity of CAD in NSTEMI. This association showed a positive linear relation between the values of PWV and vessel score (r=0.65, p=0.01), Friesinger score (r=0.61, p=0.01), and Leaman score (r=0.36, p=0.01). Conclusion: From this study it may be stated that arterial stiffness, as measured by the aortic PWV, is an independent predictor of the presence and extent of CAD. Measurements of aortic PWV in NSTEMI can detect high risk patients requiring an early invasive strategy over a delayed invasive strategy. Bangladesh Heart Journal 2021; 36(1) : 38-46

A Novel Methodology for Semi-automatic Measurement of Arterial Stiffness by Doppler Ultrasound: Clinical Feasibility and Reproducibility

The conventional manual approach to measurement of aortic pulse wave velocity (PWV) by Doppler ultrasonography is time consuming and operator dependent. Here we report a new semi-automated methodology for more efficient and objective measurement of aortic PWV and results of tests of its clinical feasibility and reproducibility. Carotid–femoral pulse wave velocity (cfPWV) was measured in 50 patients with suspected coronary artery disease (aged 59.2 ± 10.0 y, 36 males) by three independent observers, including two experienced sonographers and one cardiologist without ultrasonographic experience. The cfPWV measured by the semi-automatic method (cfPWVA) was compared with reference values obtained by averaging measurements by two experienced sonographers using the conventional standard manual method (cfPWVM). Measurements of cfPWVA were feasible in all 50 patients and exhibited excellent agreement with averaged cfPWVM from the two experienced sonographers, with an intraclass correlation coefficient (ICC) of 0.915 (95% confidence interval: 0.876–0.942). The inexperienced observer-measured cfPWVA did not differ from the cfPWVM measured by the two experienced sonographers (8.04 ± 1.29 vs. 8.14 ± 1.32 m/s, p > 0.05), with a high consistency by ICC of 0.877 (0.793–0.928). Bland–Altman plots further illustrated the good agreement between the two methods and good intra- and inter-observer reproducibility. Time consumption for cfPWV measurement using the new method was significantly less than that for the manual method (122 ± 35 s vs. 455 ± 105 s, p < 0.0001), saving about 73% of the time. This new semi-automatic methodology for aortic PWV measurement not only has an accuracy similar to that of the conventional standard manual method but is also highly feasible and time saving. It may provide a reliable, simple and reproducible approach to arterial stiffness evaluation in clinical settings.

Does Pulse Wave Velocity Increase Over Time in Hemodialysis Patients?

Objectives: Arterial stiffness, measured by pulse wave velocity (PWV), is reported to be increased in hemodialysis (HD) patients and increases cardiovascular mortality. Previous studies have reported an association between extracellular water (ECW) and PWV. We wished to review whether PWV increases over time and whether this is associated with ECW. Methods: We reviewed repeat aortic PWV measurements using an oscillograph method along with corresponding ECW measured by multifrequency bioimpedance in HD patients a minimum of 5 years apart. Results: Twenty-four patients (16 [66.7%] male and 11 [45.8%] diabetic, mean age 61.7 ± 15.2 years) had PWV and ECW initially measured after 46 (26–124) months of HD and then after 112 (97–202) months. Overall, there was no change in PWV or ECW (9.4 ± 2.2 vs. 8.1 ± 2.5 cm/s; 14.7 ± 2.5 vs. 15.2 ± 2.9 L, respectively), whereas the ECW/total body water ratio increased (0.399 ± 0.015 vs. 0.408 ± 0.021, p < 0.05). We found no association between changes in PWV and ECW (r = −0.05, p = 0.84), whereas there was an association with the change in peri-dialytic systolic blood pressure (SBP) (r = 0.59, p = 0.007). Conclusion: In our small observational study, there was no overall change in PWV, after 5 years of HD, with PWV increasing in 50% and falling in 50%. Changes in PWV were not associated with changes in ECW but were associated with changes in peri-dialytic SBP. Our study demonstrates that PWV does not increase in all HD patients with time, and interventional studies are required to determine whether targeted blood pressure control reduces PWV in HD patients.

Inductive Plethysmography for aortic Pulse Wave Velocity.

Aortic stiffening is a process that is linked to cardiovascular risk factor increase. Then, aortic stiffness evaluation is considered as a good index of the evolution of pathophysiological situations, including myocardial infarction, heart failure, atherosclerosis or stroke. Today, pulse wave velocity (PWV) measurement is considered as the gold standard for evaluation of arterial stiffness. However, most of the current measurement techniques of PWV consider the time for the blood pressure pulse to propagate through a combined length of arteries and give access to arterial PWV. Therefore, none of the available techniques focuses only on the aorta. In the present context of smart clothes development, Inductive Plethsymography (IP) can be an interesting alternative for aortic PWV measure, since it has recently been shown that combination of thoracic and abdominal IP recordings can give cardiac information. We therefore investigate the potential of IP for aortic PWV measurement. In this preliminary study, a comparative analysis of PWV estimated from IP and PWV evaluated from the arm has been carried out on 11 healthy volunteers. Results show a significant linear correlation between both measures (r = 0.86, p<0.001), promising for future investigations on pathological populations.

Changes in aortic pulse wave velocity in peritoneal dialysis do not mirror changes in extracellular water measured by bioimpedance.

Pulse wave velocity is a measurement of arterial stiffness and associated with increased cardiovascular mortality. Previous reports in peritoneal dialysis have linked increased pulse wave velocity with an expansion in extracellular water. As cardiovascular mortality is increased in peritoneal dialysis patient, we wished to determine whether changes in pulse wave velocity mirrored changes in extracellular water. We repeated aortic pulse wave velocity and bioimpedance-derived extracellular water measurements in peritoneal dialysis patients attending for assessment of peritoneal membrane function. Sixty-six patients, 41 males (62.1%), mean age of 66.2 ± 13.9 years, median duration of peritoneal dialysis treatment (14.3 (3.1-31.9) months) had repeated measurement 6.4 (5.8-10.2) months apart, with no significant change in aortic pulse wave velocity (10.1 ± 3.2 to 9.9 ± 2.8 m/s). In univariate analysis, the initial aortic pulse wave velocity was associated with extracellular water (r = 0.26, p = 0.034) and serum N-terminal pro brain-type natriuretic peptide (r = 0.25, p = 0.04), and on follow-up, aortic pulse wave velocity with N-terminal pro brain-type natriuretic peptide (r = 0.31, p = 0.01). Aortic pulse wave velocity increased in 50% of patients, and these patients had greater serum C-reactive protein 3(2-10) versus 2(1-4) mg/L, and ferritin (778(444-1099) versus 585(313-811), p < 0.05), but there were no differences in either absolute or adjusted extracellular water. Both log C-reactive protein (odds ratio 4.7 (95% confidence limits 1.3-17.1), p = 0.019) and prescription of calcium channel blockers (odds ratio 4.9 (95% confidence limits 1.2-19.1), p = 0.024) were independently associated with an increase in aortic pulse wave velocity. We did not find an independent association between a change in aortic pulse wave velocity and extracellular water, suggesting that changes in aortic stiffness in peritoneal dialysis patients are more complex than simply following changes in extracellular water.

Variability of MRI Aortic Stiffness Measurements in a Multicenter Clinical Trial Setting: Intraobserver, Interobserver, and Intracenter Variability of Pulse Wave Velocity and Aortic Strain Measurement.

To assess intraobserver, interobserver, and scan-rescan variability of MRI aortic stiffness measurements in a multicenter trial setting. This study was a retrospective analysis of prospectively collected data in a multicenter prospective clinical trial (clinicaltrials.gov ID NCT01870739). Forty-five adult patients (31 men; mean age, 58 years ± 12 [standard deviation]; 15 patients per center; three centers) with arterial hypertension underwent standardized 3-T baseline MRI assessments between June and September 2014. Aortic strain was calculated from maximum and minimum aortic area measurements repeated three times by three readers at three aortic levels on three retrospectively gated axial gradient-echo (GRE) data sets. Pulse wave velocity (PWV) was assessed three times by five readers as Δx/Δt: Δx was measured on a parasagittal GRE image of the aortic arch, and Δt was extracted from ascending and descending aortic velocity curves created on three axial phase-contrast acquisitions. Intraobserver, interobserver, and scan-rescan variability was calculated using percentage coefficient of variation (COV). Aortic strain variability was lowest at the level of the distal descending aorta (DDA) with median COVs of 1.6% for intraobserver variability, 4.0% for interobserver variability, and 10.3% for scan-rescan variability. It was highest at the ascending aorta (AA) with COVs of 3.6% for intraobserver variability, 10.7% for interobserver variability, and 19.8% for scan-rescan variability. Variability of PWV was low: 0.7% for intraobserver variability, 1.5% for interobserver variability, and 8.1% for scan-rescan variability. Low variability can be achieved for aortic strain and PWV measurements in a multicenter trial setting using standardized MRI protocols. Although COV was lower when measuring aortic strain at DDA compared with AA, variability was acceptable at both anatomic locations.Supplemental material is available for this article.© RSNA, 2020.

Group delay method for MRI aortic pulse wave velocity measurements in clinical protocols with low temporal resolution: Validation in a heterogeneous cohort

BackgroundMRI assessment of aortic pulse wave velocity (PWV) helps predict the risk of vascular events, but the recommended phase contrast sampling rate is faster than what is utilized in most clinical sequences. There are many existing MRI databases obtained for assessment of cardiac output using lower temporal frequency sampling where information might be obtained about aortic stiffness (PWV). In this work, we sought to evaluate whether the Group Delay (GD) method can generate a reproducible measure of stiffness and describe expected age-related stiffening of the aortic arch using lower sampling rates in standard clinical sequences. MethodsPhase contrast (PC) MRI was obtained on the ascending and descending aortic arch in a heterogeneous adult cohort (n = 23; 9 women) spanning over a wide range of ages (ages 24–89, mean 49.4 ± 18.4). Data was collected with standard cardiac MRI protocols for cardiac output evaluation (repetition time = 7.8 ms, views-per-segment = 4, encoding velocity = 200 cm/s). Pulse wave transit times (TT) were computed using the GD method, two other validated automated approaches (cross correlation TT Algorithm by Gaddum and Segment by Medviso), and the manual tangent method. Pressure waveforms from tonometry and flow waveforms from PC MRI were used to assess wave reflections. ResultsGroup Delay and TT-Algorithm showed significant and high retest reproducibility (r = 0.86 for both) as well as high PWV correlation with age (r = 0.93, P-value < 0.00005 and r = 0.96, P-value < 0.00005 respectively) and with each other (r = 0.94, P-value < 0.00001, RMSE = 0.94 m/s). Arbitrary altering of the image acquisition trigger in the GD method introduced error of 10%–13%, but the TT-algorithm error range was 11%–25%. ConclusionGroup Delay enables reproducible assessment of transit time to derive PWV from low temporal resolution clinical cardiac MRI sequences that can also identify age-related stiffening.

P200 Arterial stiffness in patients with mild-to-moderate renal impairment

Abstract Background Arterial damage in chronic kidney disease (CKD) is characterized by aortic stiffness. This is seen in elderly patients with advanced CKD. The association between arterial stiffness and early CKD is not well established. Objective: We aimed to study arterial stiffness using pulse wave velocity (PWV) among patients with chronic kidney disease (CKD) stage 2 to 4 and normal renal function in younger-age population. Design and Method: Patients with confirmed CKD stage 2 to 4 were recruited from various clinics from Universiti Teknologi MARA Medical Center, Sungai Buloh, Malaysia from 1st August 2015 until 31st January 2018. Sociodemographic and anthropometric indices were recorded on recruitment. Each patient underwent carotid-femoral (aortic) PWV measurement to determine arterial stiffness. PWV is determined using a one-probe device (SphygmoSore XCEL). Results: 87 patients with CKD stage 2–4 and 87 control patients were recruited. The mean age was 47 ± 5.4 years. CKD patients had a higher mean PWV (7.8 m/s ± 1.7) than healthy controls (5.6 m/s ± 1.0) (p &amp;lt; 0.001, 95% CI –2.59, –1.77). There was significant difference of mean PWV between control (5.6 m/s ± 1.0) and CKD stage 2 (7.6 m/s ± 1.5) (p &amp;lt; 0.001, 95% CI –2.40, –1.49). Our results showed a stepwise increase in PWV from control subjects, CKD stage 2 through stage 4 (p &amp;lt; 0.001). The mean difference of PWV between CKD stage 2 (7.6 m/s, ± 1.5) and stage 4 (9.0 m/s, ± 0.8) was 1.43 (p &amp;lt; 0.001, 95% CI –2.50, -0.35). There was significant difference of mean PWV between diabetes mellitus (DM) (8.2 m/s ± 1.8) and non-DM (7.3 m/s ± 1.3) patients with CKD stage 2–4 (p = 0.022, 95% CI –1.50, –0.12). Mutiple linear regression analysis showed only age (β = 0.078, p = 0.014), mean arterial pressure (MAP) (β = 0.031, p = 0.007) and diuretics usage as the combination antihypertensive medication (β = 0.839, p = 0.018) were independently associated with PWV (r2 = 0.249, p &amp;lt; 0.001). Conclusions: This study shows that arterial stiffness as assessed by PWV occurs early in CKD patient and increased arterial stiffness occurs in parallel with decline of glomerular filtration rate in patients with mild-to-moderate CKD of younger age population.

P1830 Single-beat aortic arch pulse wave velocity by dual-gate simultaneous Doppler technique: a novel method for arterial stiffness evaluation

Abstract Background Guidelines recommend increased aortic stiffness as a negative prognostic factor to be considered in primary and secondary prevention. Pulse wave velocity (PWV) is a frequently employed surrogate marker of aortic stiffness. Carotid-femoral PWV is the most common index in research and clinical practice, but recently several velocity-encoded magnetic resonance imaging (MRI) techniques have been used for the evaluation of regional aortic arch PWV, where the stiffness seems to be particularly relevant from a prognostic point of view. Purposes. We developed a new ultrasound method for the assessment of aortic arch PWV, using a single-beat dual-gate simultaneous pulsed wave Doppler tracing. The aim of the study is to evaluate the feasibility of this new technique in a group of healthy volunteers. Methods We examined 126 healthy volunteers (81 females, 45 males, mean age 42 + 15 years, range 13-83 years) using a commercially available machine equipped with simultaneous dual-gate pulsed Doppler. Using the suprasternal approach, the first sample volume was placed in ascending aorta and the second one in descending aorta. The distance between the two sites was directly measured with a curvilinear tracing in the middle of the vessel, following the shape of the aortic arch. PWV was calculated as the ratio of distance (in millimiters) and the transit time (in milliseconds) measured using the "foot-to-foot" method. The results are then easily transformed, simplifying in the commonly unit of meters/second. Results Feasibility was 99%; in one case it was not possible to measure accurately the aortic arch PWV due to unfavorable suprasternal acustic window. The procedure time was very fast, requiring 2 + 1 minutes. Intraobserver and interobserver variability were 7% and 9% respectively. Aortic arch PWV, as expected, showed a strong correlation with age in males as well as in females (r= 0.71 and r = 0.60 respectively, p &amp;lt; 0.001 for both); there was also a significant correlation with body mass index (r = 0.31; p &amp;lt; 0.001). Aortic arch PWV values ranged from 3.1 to 8.5 m/s, showing a substantial overlap with normal values reported in MRI studies. Conclusions The direct measurement of aortic arch PWV is feasible and reproducible with ultrasound, using the novel single-beat dual-gate simultaneous pulsed wave Doppler tracing. This technique could be implemented in a standard echo examination, that is much more available than MRI studies. Further studies are needed to evaluate if Doppler-derived aortic arch PWV could provide additional prognostic information. Abstract P1830 Figure. Aortic Arch PWV

A novel methodology for rat aortic pulse wave velocity assessment by Doppler ultrasound: validation against invasive measurements.

There is still lack of a simple, accurate, and noninvasive method for rat aortic pulse wave velocity (PWV) measurement, especially the transit distance cannot be accurately measured. Thus, we aimed to derive an equation for aortic transit distance as a function of the nose-to-rump length (L) and to test the hypothesis that aortic PWV measured by new equation combined with Doppler ultrasound (the "equation method") may have stronger correlation with invasive measurements than traditional "body surface method." Two-hundred male Sprague-Dawley (SD) rats (age ranged 5-24 wk) were included in protocol 1, and the aortic transit distances were measured postmortem. In protocol 2, heart-femoral PWV and carotid-femoral PWV were measured by equation method (hfPWVE, cfPWVE) and also by traditional body surface method (hfPWVS, cfPWVS) in another 30 young and 28 old rats. These measurements were then validated against invasively measured hfPWVI and cfPWVI from the same animal. Protocol 1 showed that the heart-femoral transit distance could be calculated by 0.6086 × L - 1.6523, and the carotid-femoral transit distance by 0.4614 × L + 1.8335. In protocol 2, in young rats, the Pearson r between hfPWVE, cfPWVE, hfPWVS, and cfPWVS and their corresponding invasive measurement were 0.8962, 0.8509, 0.8387, and 0.7828, respectively (all P < 0.0001). In the old group, the results were 0.8718, 0.7999, 0.8330, and 0.7112, respectively (all P < 0.0001). The hfPWVE and cfPWVE showed better agreement with hfPWVI and cfPWVI and lower intra- and interobserver variability compared with hfPWVS and cfPWVS in both groups. These findings demonstrate that this novel methodology provides a simple and reliable method for rat noninvasive aortic PWV measurement.NEW & NOTEWORTHY First, when measuring aortic PWV in SD rat models, the heart-femoral transit distance can be estimated by 0.6086 × L - 1.6523, and the carotid-femoral distance transit distance can be estimated by 0.4614 × L + 1.8335, where L (in mm) is nose-to-rump length. Second, this novel methodology for aortic PWV measurement was validated with a closer correlation with the invasive measurements than traditional approach in young and old rats. Third, this study provides a simple and reliable method for rat noninvasive aortic PWV measurement.

Two years of maintenance hemodialysis has a pronounced effect on arterial stiffness progression.

The change of aortic stiffness, but not the particular baseline value, plays a crucial role in estimating the patient risk with end-stage renal disease. Therefore, we aimed to analyze the evolution of central and peripheral arterial stiffness in hemodialysis population without previous cardiovascular events during a 2-year follow-up. 60 hemodialysis patients (mean age 57.61 ± 13.01years) were prospectively interviewed, and they underwent blood tests, chest X-ray for aortic calcification evaluation and pulse wave velocity (PWV) measurements at the baseline, after 6months and after 2years of observation period. We found significant progression of aortic PWV (12.73 vs. 14.24m/s, p = 0.032) and regression of brachial PWV (11.53 vs. 8.85m/s, p < 0.001). CRP increase influenced evolution of aortic PWV (β = 0.331, p = 0.031, R2 = 0.599). Higher β2-microglobulin values was related to the progression of aortic PWV (β = 0.219, p = 0.022, R2 = 0.568). Mean arterial blood pressure had influence only on the short-term arterial stiffness evolution. Patients on maintenance hemodialysis experience pronounced changes of arterial stiffness during the 2-year follow-up period. The progression of aortic stiffness is related to inflammatory response and particularly is influenced by β2-microglobulin concentration and aortic calcification.

MRI-derived aortic characteristics after pregnancy: The AMBITYON study.

Pregnancy and pregnancy complications have been associated with increased arterial stiffness even at young age. In this study we assessed the impact of parity on CMR-derived aortic characteristics as early markers of atherosclerosis and arterial stiffness in healthy women between 25 and 35 years. We studied 68 women who participated in the AMBITYON study, a prospective population-based cohort study for assessment of atherosclerotic burden by MRI and traditional CVD risk factors in healthy, young adults. Of these women, 40 (58.8%) were nulliparous, 13 (19.1%) were primiparous and 15 (22.1%) were multiparous. Descending thoracic aortic wall thickness (AWT) and pulse wave velocity (PWV) were measured using 3.0T CMR. AWT measurements were similar between nulliparous women and primi- or multiparous women (1.6 mm ± 0.2 mm vs. 1.6 mm ± 0.2 mm; p = 0.79). Correction for age and systolic blood pressure did not change these results. Applying percentile based cut-off values showed a non-significant increase in AWT in parous women. PWV measurements did not differ between nulliparous women and parous women (4.5 m/s ± 0.7 m/s vs. 4.5 m/s ± 0.8 m/s; p = 0.78). Correction for age and systolic blood pressure did not influence these results. Using percentile based cut-off values, showed an increasing likelihood of higher PWV-values in parous women, although not statistically significant. Direct measurement of aortic AWT and PWV by CMR showed no difference between nulliparous and parous women, probably indicating limited effect of pregnancy on arterial stiffness and early markers of atherosclerosis. Netherlands Trial Register (NTR) number: 4742.

Effects of endurance training and intense resistance training on arterial stiffness assessed by pulse wave velocity in elite athletes

There have been contradictory reports regarding resistance exercise and arterial stiffness. We examined the effects of long-term endurance training and intense resistance training on central hemodynamics, compared with healthy sedentary control (SED). We hypothesized that young adults participating in endurance sports would have decreased arterial stiffness, whereas those in intense resistance sports would have increased arterial stiffness. One hundred and thirty participants, 20–30 years; 46 intense resistance trained athletes (IRT) (weight-lifters), 42 endurance trained athletes (ET) (long distance runners) and 42 sedentary individuals (SED) were investigated by tonometry-pulse wave analysis, aortic pulse wave velocity (aPWV) and ambulatory blood pressure measurement (ABPM). Data were expressed as mean (SD). Differences were tested by analysis of variance, covariance and multiple linear regressions after adjustment for confounding variables. There were no differences among groups regarding age, height, serum glycaemia, cholesterol and triglycerides levels and ABPM. Weight, BMI and waist size were higher in IRT group than ET. Resting heart rate and augmentation index were lower in trained participants than sedentary. Brachial and central blood pressures were lower in ET than IRT. aPWV was significantly lower in endurance trained (5.58 ± 1.00 m/s) and higher in IRT (7.06 ± 0.87 m/s) and SED (7.18 ± 1.06 m/s). After multiple regression analysis, diastolic blood pressure (DBP) remained the only hemodynamic parameter correlated to the aPWV whatever the group. We find that aPWV is influenced by exercise modalities. DBP is an important determinant of aPWV in young.

Ethnic Difference in Proximal Aortic Stiffness: An Observation From the Dallas Heart Study

ObjectivesThis study aims to compare ethnic difference in proximal aortic pulse wave velocity (PWV) and characteristic impedance (Zc). BackgroundIncreased aortic stiffness is an independent predictor of target organ damage, incident hypertension, and all-cause mortality. However, previous studies have not directly assessed proximal aortic function in Blacks, the ethnic population with disproportionately high risk for incident hypertension and target organ complications. MethodsWe evaluated the multiethnic, population-based DHS (Dallas Heart Study) participants (N = 2,544, 54.2% women, 49.7% Black) who underwent cardiac magnetic resonance at 1.5-T. Aortic stiffness and Zc were determined from aortic arch PWV and lumen area measurements. Linear regression was used to evaluate ethnic differences in proximal aortic wall stiffness using aortic arch PWV and Zc as dependent variables with and without adjustment for traditional cardiovascular risk factors. Because cardiac output was significantly higher in Blacks compared to Whites and Hispanics, additional comparisons of PWV and Zc were performed after adjustment for cardiac output and peripheral vascular resistance. ResultsCompared with Whites, both Blacks and Hispanics had higher levels of aortic arch PWV (4.25, 95% confidence interval [CI]: 4.15 to 4.35 m/s, vs. 4.72, 95% CI: 4.64 to 4.81 m/s, vs. 4.48, 95% CI: 4.33 to 4.63 m/s, respectively, both p < 0.05 vs. White), and Zc (64.9, 95% CI: 63.3 to 66.6 dyne·s/cm5, vs. 75.6, 95% CI: 74.0 to 77.2 dyne·s/cm5, vs. 70.1, 95% CI: 67.6 to 72.8 dyne·s/cm5, respectively, both p < 0.01 vs. White) after adjustment for age, age squared, sex, body mass index, height, mean arterial blood pressure, antihypertensive treatment, heart rate, total cholesterol, diabetes mellitus, and smoking. Compared with Hispanics, Blacks also had higher level of both PWV and Zc (both p < 0.01). Ethnic differences in PWV and Zc persisted after adjustment for cardiac output and peripheral vascular resistance. ConclusionsIn a multiethnic population-based-sample, Blacks and Hispanics had higher proximal aortic stiffness compared with Whites independent of blood pressure and relevant risk factors.

Noninvasive measurement of regional pulse wave velocity in human ascending aorta with ultrasound imaging: an in-vivo feasibility study.

Accurate and noninvasive techniques for measurement of local/regional pulse wave velocity (PWV), instead of global PWV, is desired for quantifying localized arterial stiffness and improving cardiovascular disease assessment. This study aimed at investigating the feasibility of regional PWV measurement in human ascending aorta in vivo using an ultrasound-based technique. Proximal ascending aortas of 76 healthy patients (23-71 years) were scanned with transthoracic echocardiography in parasternal long-axis view, and ultrasound radiofrequency data were acquired in a high temporal resolution (∼404 Hz). The PWV was derived from the determination of arrival times and identification of travel distances. Both PWVs in early systolic phase (PWVsf; pulse wave velocity measured using the systolic foot as characteristic time point) and late systolic phase (PWVdn; pulse wave velocity measured using the dicrotic notch as characteristic time point) were obtained. The PWVsf and PWVdn were 4.58 ± 1.38 and 6.51 ± 1.90 m/s, respectively, and both were correlated with age (r = 0.30, P = 0.02 and r = 0.71, P < 0.0001). The measurements were reproducible, and PWVdn showed significant correlation with aortic diameter (r = 0.53, P < 0.0001), relative distension (r = -0.44, P = 0.0002), and local PWV derived from Bramwell-Hill equation (r = 35, P = 0.004). The PWV difference (PWVdn - PWVsf) reflected aortic stiffness change within cardiac cycle from early systole to late systole and was also correlated with age (r = 0.50, P < 0.0001). The feasibility of ascending aortic PWV measurement using ultrasound imaging was illustrated in vivo, suggesting the potential of the technique in characterization of regional aortic stiffness and assessment of aortic diseases.