Aortic Pulse Wave Velocity and Carotid-Femoral Pulse Wave Velocity: Similarities and Discrepancies

Arterial Stiffness and Adult Onset Vasculitis: A Systematic Review

Chronic inflammation represents the cornerstone of the raised cardiovascular (CV) risk in patients with inflammatory rheumatic diseases (IRD), including vasculitis. Standardized mortality ratios in these patients are higher as compared to the general population, and the excess of premature mortality is due to early atherosclerotic events. Thus, IRD patients need appropriate CV risk assessment and management according to this CV disease (CVD) burden. Adequate control of CV risk is still lacking in usual care, but early diagnosis of silent and subclinical CVD is crucial to improve the long-term prognosis of these patients. Increased arterial stiffness may provide a pathophysiological link between inflammation and increased cardiovascular risk. Several noninvasive methods are now available to estimate artery stiffness in the clinical setting, including pulse wave velocity assessment. The independent predictive value of arterial stiffness for cardiovascular events has been demonstrated in general as well as in selected populations, and reference values adjusted for age and blood pressure have been suggested. Thus, arterial stiffness is an interesting biomarker for cardiovascular risk stratification. This systematic review summarizes the additional value that PWV measurement can provide in the setting of vasculitis, with a focus in the different clinical stages and CV risk prevention. This systematic review is registered with registration number: Prospero CRD42021259603.

ECG Abnormalities and Arterial Stiffness by HIV Status among High-Risk Populations in Rakai, Uganda: A Pilot Study

Background

People living with HIV are at increased risk for cardiovascular disease (CVD). In sub-Saharan Africa, population-based data on major CVD events such as stroke and myocardial infarction are difficult to collect. The use of proxy measures could be a feasible way to better study CVD in such settings. This study aimed to determine the acceptance of incorporating ECG and arterial function measurements into a population-based cohort study and to assess the prevalence of ECG abnormalities and arterial stiffness.

Methods

A pilot study was conducted within the Rakai Community Cohort Study in Uganda on two high-risk CVD populations; one determined by age (35-49) and Framingham CVD risk scores and the other by age alone (50+). Data on ECG, arterial function, blood pressure, and HIV status were collected. The acceptability of incorporating ECG and arterial function measurements was established as an acceptance rate difference of no more than 5% to blood pressure measurements.

Results

A total of 118 participants were enrolled, 57 participants living with HIV and 61 HIV-negative participants. Both ECG measurements and arterial function were well accepted (2% difference). Left ventricular hypertrophy (LVH) and arterial stiffness (>10 m/s) were common in both participants living with HIV and HIV-negative participants across the two high-risk populations. Prevalence rates ranged from 30% to 53% for LVH and 25% to 58% for arterial stiffness. Arterial stiffness at the 11 m/s cutoff (p = 0.03) was found to be more common among participants living with HIV in the 35-49 population.

Conclusions

The incorporation of ECG and arterial function measurements into routine activities of a population-based cohort was acceptable and incorporating these proxy measures into cohort studies should be explored further. LVH and arterial stiffness were both common irrespective of HIV status with arterial stiffness potentially more common among people living with HIV.

Comparison of the Association Between Arterial Stiffness Indices and Heart Failure in Patients With High Cardiovascular Risk: A Retrospective Study

Objective: Study findings of the relationship of each arterial stiffness index with incident heart failure (HF) are conflicting. We aimed to compare the association between the indices of arterial stiffness and the risk of HF. Methods: We analysed 3,034 patients from a prospective cohort that enrolled patients with high cardiovascular risk. They underwent brachial-ankle pulse wave velocity (baPWV), brachial pulse pressure (PP), carotid-femoral pulse wave velocity (cfPWV), and central PP measurements. Results: Over a median follow-up of 4.7 years (interquartile range, 3.4-5.8 years), 65 HF events occurred. The incidence rate of HF was 4.7 per 1,000 person-years [95% confidence interval (CI), 3.7-6.0]. There was no difference in baPWV in those with and without HF events (1,561 ± 401 and 1,520 ± 321 cm/s, respectively, P = 0.415); however, there was a significant difference in brachial PP (63.2 ± 16.9 vs. 52.3 ± 11.5 mmHg, P < 0.001), cfPWV (11.0 ± 3.1 vs. 9.4 ± 2.4 m/s, P < 0.001) and central PP (56.6 ± 19.9 vs. 42.9 ± 13.8 mmHg, P < 0.001). In the multivariable-adjusted model, brachial PP [hazards ratio (HR) per standard deviation unit (SDU), 1.48; 95% CI, 1.19-1.84, P < 0.001], cfPWV (HR per SDU, 1.29; 95% CI, 1.02-1.63, P = 0.032) and central PP (HR per SDU, 1.44; 95% CI, 1.17-1.78; P < 0.001) were associated with incident HF, but baPWV was not (HR per SDU, 0.83; 95% CI, 0.63-1.10; P = 0.198). In the receiver operating characteristic analysis, the area under the curve (AUC) of brachial PP (P < 0.001), cfPWV (P = 0.003) or central PP (P = 0.001) was larger than that of baPWV, and there was no difference in the AUCs of brachial PP, cfPWV and central PP. Conclusion: Among arterial stiffness indices, brachial PWV was less associated with the risk of heart failure, and brachial PP and measures representing central hemodynamics were highly associated with incident HF.

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.

Local Pulse Wave Velocity: Theory, Methods, Advancements, and Clinical Applications

Local pulse wave velocity (PWV) is evolving as one of the important determinants of arterial hemodynamics, localized vessel stiffening associated with several pathologies, and a host of other cardiovascular events. Although PWV was introduced over a century ago, only in recent decades, due to various technological advancements, has emphasis been directed toward its measurement from a single arterial section or from piecewise segments of a target arterial section. This emerging worldwide trend in the exploration of instrumental solutions for local PWV measurement has produced several invasive and noninvasive methods. As of yet, however, a univocal opinion on the ideal measurement method has not emerged. Neither have there been extensive comparative studies on the accuracy of the available methods. Recognizing this reality, makes apparent the need to establish guideline-recommended standards for the measurement methods and reference values, without which clinical application cannot be pursued. This paper enumerates all major local PWV measurement methods while pinpointing their salient methodological considerations and emphasizing the necessity of global standardization. Further, a summary of the advancements in measuring modalities and clinical applications is provided. Additionally, a detailed discussion on the minimally explored concept of incremental local PWV is presented along with suggestions of future research questions.

Pulse Wave Velocity in Atherosclerosis

Early detection of subclinical atherosclerosis is important to reduce patients' cardiovascular risk. However, current diagnostic strategy focusing on traditional risk factors or using risk scoring is not satisfactory. Non-invasive imaging tools also have limitations such as cost, time, radiation hazard, renal toxicity, and requirement for specialized techniques or instruments. There is a close interaction between arterial stiffness and atherosclerosis. Increased luminal pressure and shear stress by arterial stiffening causes endothelial dysfunction, accelerates the formation of atheroma, and stimulates excessive collagen production and deposition in the arterial wall, leading to the progression of atherosclerosis. Pulse wave velocity (PWV), the most widely used measure of arterial stiffness, has emerged as a useful tool for the diagnosis and risk stratification of cardiovascular disease (CVD). The measurement of PWV is simple, non-invasive, and reproducible. There have been many clinical studies and meta-analyses showing the association between PWV and coronary/cerebral/carotid atherosclerosis. More importantly, longitudinal studies have shown that PWV is a significant risk factor for future CVD independent of well-known cardiovascular risk factors. The measurement of PWV may be a useful tool to select subjects at high risk of developing subclinical atherosclerosis or CVD especially in mass screening.

Pulse Wave Velocity in Atherosclerosis

Early detection of subclinical atherosclerosis is important to reduce patients' cardiovascular risk. However, current diagnostic strategy focusing on traditional risk factors or using risk scoring is not satisfactory. Non-invasive imaging tools also have limitations such as cost, time, radiation hazard, renal toxicity, and requirement for specialized techniques or instruments. There is a close interaction between arterial stiffness and atherosclerosis. Increased luminal pressure and shear stress by arterial stiffening causes endothelial dysfunction, accelerates the formation of atheroma, and stimulates excessive collagen production and deposition in the arterial wall, leading to the progression of atherosclerosis. Pulse wave velocity (PWV), the most widely used measure of arterial stiffness, has emerged as a useful tool for the diagnosis and risk stratification of cardiovascular disease (CVD). The measurement of PWV is simple, non-invasive, and reproducible. There have been many clinical studies and meta-analyses showing the association between PWV and coronary/cerebral/carotid atherosclerosis. More importantly, longitudinal studies have shown that PWV is a significant risk factor for future CVD independent of well-known cardiovascular risk factors. The measurement of PWV may be a useful tool to select subjects at high risk of developing subclinical atherosclerosis or CVD especially in mass screening.

The importance of accurate measurement of aortic stiffness in patients with chronic kidney disease and end-stage renal disease

Cardiovascular (CV) disease is the leading cause of death in chronic kidney disease (CKD) and end-stage renal disease (ESRD). A key driver in this pathology is increased aortic stiffness, which is a strong, independent predictor of CV mortality in this population. Aortic stiffening is a potentially modifiable biomarker of CV dysfunction and in risk stratification for patients with CKD and ESRD. Previous work has suggested that therapeutic modification of aortic stiffness may ameliorate CV mortality. Nevertheless, future clinical implementation relies on the ability to accurately and reliably quantify stiffness in renal disease. Pulse wave velocity (PWV) is an indirect measure of stiffness and is the accepted standard for non-invasive assessment of aortic stiffness. It has typically been measured using techniques such as applanation tonometry, which is easy to use but hindered by issues such as the inability to visualize the aorta. Advances in cardiac magnetic resonance imaging now allow direct measurement of stiffness, using aortic distensibility, in addition to PWV. These techniques allow measurement of aortic stiffness locally and are obtainable as part of a comprehensive, multiparametric CV assessment. The evidence cannot yet provide a definitive answer regarding which technique or parameter can be considered superior. This review discusses the advantages and limitations of non-invasive methods that have been used to assess aortic stiffness, the key studies that have assessed aortic stiffness in patients with renal disease and why these tools should be standardized for use in clinical trial work.

Improved pressure contour analysis for estimating cardiac stroke volume using pulse wave velocity measurement

BACKGROUND

Pressure contour analysis is commonly used to estimate cardiac performance for patients suffering from cardiovascular dysfunction in the intensive care unit. However, the existing techniques for continuous estimation of stroke volume (SV) from pressure measurement can be unreliable during hemodynamic instability, which is inevitable for patients requiring significant treatment. For this reason, pressure contour methods must be improved to capture changes in vascular properties and thus provide accurate conversion from pressure to flow.

METHODS

This paper presents a novel pressure contour method utilizing pulse wave velocity (PWV) measurement to capture vascular properties. A three-element Windkessel model combined with the reservoir-wave concept are used to decompose the pressure contour into components related to storage and flow. The model parameters are identified beat-to-beat from the water-hammer equation using measured PWV, wave component of the pressure, and an estimate of subject-specific aortic dimension. SV is then calculated by converting pressure to flow using identified model parameters. The accuracy of this novel method is investigated using data from porcine experiments (N = 4 Pietrain pigs, 20-24.5 kg), where hemodynamic properties were significantly altered using dobutamine, fluid administration, and mechanical ventilation. In the experiment, left ventricular volume was measured using admittance catheter, and aortic pressure waveforms were measured at two locations, the aortic arch and abdominal aorta.

RESULTS

Bland-Altman analysis comparing gold-standard SV measured by the admittance catheter and estimated SV from the novel method showed average limits of agreement of ±26% across significant hemodynamic alterations. This result shows the method is capable of estimating clinically acceptable absolute SV values according to Critchely and Critchely.

CONCLUSION

The novel pressure contour method presented can accurately estimate and track SV even when hemodynamic properties are significantly altered. Integrating PWV measurements into pressure contour analysis improves identification of beat-to-beat changes in Windkessel model parameters, and thus, provides accurate estimate of blood flow from measured pressure contour. The method has great potential for overcoming weaknesses associated with current pressure contour methods for estimating SV.

Chlorthalidone Plus Amiloride Reduces the Central Systolic Blood Pressure in Stage 1 Hypertension Patients

BACKGROUND

Hypertension reduction strategies use blood pressure in the brachial artery as the primary endpoint. Individuals who achieve the target blood pressure reduction with antihypertensive treatment have residual cardiovascular risk attributed to the difference in pressure between the aorta and brachial artery. Antihypertensive treatment affects the intrinsic properties of the vascular wall and arterial stiffness markers and consequently the central pressure. Recent publications stress the importance of adequate control of the central compared to peripheral blood pressure. Related clinical implications suggest that individuals with normal peripheral but high central blood pressure should not receive antihypertensive drugs that act on the central pressure. Therefore, they are at greater cardiovascular risk. The aim of the study was to evaluate the effect of treatment with a thiazide diuretic versus losartan on the central blood pressure in stage 1 hypertensive patients.

METHODS

Twenty-five patients were randomized to the chlorthalidone 25 mg/amiloride 5 mg group (q.d.) and 25 patients received losartan 50 mg (b.i.d). The central systolic blood pressure (CSBP) and augmentation index (AIx 75) were assessed using applanation tonometry. The paired t-test was used to compare the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), CSBP and AIx 75 between the thiazide and losartan groups at baseline and after 6 months of treatment.

RESULTS

Significant reductions in CSBP (123.3 ± 14.2 vs. 113.4 ± 111.4, P = 0.0103) and AIx 75 (87.7 ± 9.6 vs. 83.8 ± 8.9, P = 0.0289) were observed after 6 months of drug treatment with chlorthalidone 25 mg/amiloride 5 mg (q.d.). The administration of losartan 50 mg (b.i.d) did not reduce the CSBP and there were insignificant changes in the AIx 75.

CONCLUSIONS

Six-month treatment of chlorthalidone/amiloride but not losartan reduces the CSBP and AIx 75 in adults with stage 1 hypertension.

Novel Methods for Pulse Wave Velocity Measurement

The great incidence of cardiovascular (CV) diseases in the world spurs the search for new solutions to enable an early detection of pathological processes and provides more precise diagnosis based in multi-parameters assessment. The pulse wave velocity (PWV) is considered one of the most important clinical parameters for evaluate the CV risk, vascular adaptation, and therapeutic efficacy. Several studies were dedicated to find the relationship between PWV measurement and pathological status in different diseases, and proved the relevance of this parameter. The commercial devices dedicate to PWV estimation make a regional assessment (measured between two vessels), however a local measurement is more precise evaluation of artery condition, taking into account the differences in the structure of arteries. Moreover, the current devices present some limitations due to the contact nature. Emerging trends in CV monitoring are moving away from more invasive technologies to non-invasive and non-contact solutions. The great challenge is to explore the new instrumental solutions that allow the PWV assessment with fewer approximations for an accurately evaluation and relatively inexpensive techniques in order to be used in the clinical routine.

Inverse Relationship between Cardio-Ankle Vascular Index and Body Mass Index in Healthy Children

OBJECTIVE

To establish reference scores for cardio-ankle vascular index (CAVI), a noninvasive measure of vascular function, which reflects the stiffness of arteries, in healthy children, to test for racial and ethnic differences, and to compare CAVI scores between overweight and normal weight children.

STUDY DESIGN

Subjects included 292 children aged 10-18 years: 100 non-Hispanic whites, 89 non-Hispanic blacks, and 103 Hispanics. Subjects were grouped as normal weight (body mass index [BMI] <85th percentile for age) and overweight (BMI >85th percentile for age). Blood pressure (BP) and CAVI scores were measured in all subjects.

RESULTS

After controlling for age, sex, and BMI, normal weight black males had a higher CAVI score (indicating stiffer arteries) in comparison with Hispanic males and white males (5.53 ± 0.15 vs 5.13 ± 0.15 vs 5.02 ± 0.15, P = .04). BMI had an inverse association on the CAVI score (r = -0.335, P < .0001). In multivariable analysis, BMI and average CAVI scores were significant predictors of each other (R(2) = 0.37, P < .0001, R(2) = 0.21, P < .0001). There was no significant correlation between CAVI scores and resting BP values, confirming that CAVI scores were independent of concurrent BP values.

CONCLUSIONS

Significant differences in vascular function exist among ethnic groups of children. Overweight children had lower CAVI scores, suggestive of vascular adaptation to obesity in early life. CAVI, by providing a noninvasive measure of vascular health, may help identify children at increased risk for cardiovascular disease.

Comparison of the Complior Analyse device with Sphygmocor and Complior SP for pulse wave velocity and central pressure assessment

BACKGROUND

The Complior device (Alam Medical, France) was used in epidemiological studies which established pulse wave velocity (PWV) as a cardiovascular risk marker. Central pressure is related, but complementary to PWV and also associated to cardiovascular outcomes. The new Complior Analyse measures both PWV and central blood pressure during the same acquisition. The aim of this study was to compare PWV values from Complior Analyse with the previous Complior SP (PWVcs) and with Sphygmocor (PWVscr; AtCor, Australia), and to compare central systolic pressure from Complior Analyse and Sphygmocor.

METHOD

Peripheral and central pressures and PWV were measured with the three devices in 112 patients. PWV measurements from Complior Analyse were analysed using two foot-detection algorithms (PWVca_it and PWVca_cs). Both radial (ao-SBPscr) and carotid (car-SBPscr) approaches from Sphygmocor were compared to carotid Complior Analyse measurements (car-SBPca). The same distance and same calibrating pressures were used for all devices.

RESULTS

PWVca_it was strongly correlated to PWVscr (R(2) = 0.93, P < 0.001) with a difference of 0.0 ± 0.7  m/s. PWVca_cs was also correlated to PWVcs (R(2) = 0.90, P < 0.001) with a difference of 0.1 ± 0.7  m/s. Central systolic pressures were strongly correlated. The difference between car-SBPca and ao-SBPscr was 3.1 ± 4.2  mmHg (P < 0.001), statistically equivalent to the difference between car-SBPscr and ao-SBPscr (3.9 ± 5.8  mmHg, P < 0.001), whilst the difference between car-SBPca and car-SBPscr was negligible (-0.7 ± 5.6  mmHg, P = NS).

CONCLUSION

The new Complior Analyse device provides equivalent results for PWV and central pressure values to the Sphygmocor and Complior SP. It reaches Association for the Advancement of Medical Instrumentation standard for central blood pressure and grades as excellent for PWV on the Artery Society criteria. It can be interchanged with existing devices.

Percentiles for central blood pressure and pulse wave velocity in children and adolescents recorded with an oscillometric device

OBJECTIVE

In adults with arterial hypertension, measuring arterial stiffness by pulse wave velocity (PWV) can determine the extent of cardiovascular subclinical organ damage. PWV has independent predictive value for cardiovascular events, but there are currently no recommendations for measuring PWV in children. In addition, central systolic blood pressure (cSBP) strongly reflects vascular changes. The aim of this study was to establish percentiles for cSBP and PWV in children and adolescents to evaluate and classify altered vascular function in youths.

METHODS AND RESULTS

We measured PWV and cSBP with an oscillometric device with inbuilt ARCSolver-algorithm (estimated by using the brachial waveform) and calculated smoothed reference percentiles for 1445 children and young adults (49.5% female; 13.41 ± 2.80 years, range 8-22 years; PWV 4.67 ± 0.34 m/s; cSBP 100.7 ± 8.9 mmHg) using the LMS-method based on age and height. PWV and cSBP increased with age and height, but slightly differently for girls and boys, possibly reflecting different growth patterns. Between 8 and 21 years, PWV increased from 4.29 ± 0.32 to 4.98 ± 0.33 m/s in girls and from 4.27 ± 0.18 to 5.22 ± 0.46 m/s in boys. While girls showed a minor increase in cSBP (91.2 ± 7.5 to 109.1 ± 8.6 mmHg), the cSBP in boys ranged from 90.0 ± 5.8 to 110.5 ± 9.6 mmHg with a more pronounced increase between 14 and 17 years.

CONCLUSION

These percentiles for PWV and cSBP can help define arterial stiffness in youths and contribute to risk stratification for cardiovascular disease. For example, in children with prehypertension or isolated systolic hypertension, PWV and cSBP can provide additional information about the function of the vascular system, thereby strengthening intervention strategies.

Relationship between aortic pulse wave velocity, selected proinflammatory cytokines, and vascular calcification parameters in peritoneal dialysis patients

INTRODUCTION

Vascular calcification and arterial stiffening are cardiovascular risk factors among chronic kidney disease patients. Elevated aortic pulse wave velocity (AoPWV) is an independent predictor of increased cardiovascular morbidity and mortality.

OBJECTIVES

The aim of the study was to analyze the relationships between inflammatory and vascular calcification parameters and arterial wall stiffness in chronic kidney disease (CKD) patients treated by peritoneal dialysis.

PATIENTS AND METHODS

The study included 57 patients (27 women and 30 men) aged from 19 to 75 years (mean age 53 ± 13), treated by peritoneal dialysis during 4-100 months (mean 30.4 months). The concentrations of albumin, lipids, interleukin-6 (IL-6), IL-18, high-sensitive C-reactive protein, transforming growth factor-β1 (TGF-β1), osteocalcin, osteoprotegerin (OPG), fibroblast growth factor 23, fetuin A, parathyroid hormone (iPTH), total calcium (Ca), and phosphates (Pi) were measured. AoPWV was performed using a tonometric method, common carotid artery intima-media thickness (CCA-IMT) by ultrasonography evaluation, and calcium scoring (CaSc) with multirow spiral computed tomography (MSCT).

RESULTS

In univariate analysis, AoPWV correlated negatively with osteocalcin (R = -0.37; P = 0.005) and positively with OPG (R = 0.41; P = 0.002). Additionally, AoPWV was significantly positively associated with inflammatory parameters: IL-6 (R = 0.35; P = 0.009), TGF-β1 (R = 0.27; P = 0.047), and white blood cell (WBC) count (R = 0.33; P = 0.01). There were also positive correlations between AoPWV and imaging data: CCA-IMT (R = 0.32; P = 0.02) and CaSc (R = 0.38; P = 0.004). AoPWV did not correlate with calcium, phosphate, Ca × Pi index, or iPTH concentration. After multiple adjustments, osteocalcin was the only significant predictor of AoPWV. In logistic regression adjusted for age, hypertension, and mean arterial pressure at AoPWV evaluation, only osteocalcin was significantly associated with high (above median) AoPWV values [odds ratio 0.96 (0.92-0.99) per unit increase in osteocalcin].

CONCLUSION

OPG concentration and some inflammatory markers (WBC count, IL-6, TGF-β1) influenced the severity of arterial wall stiffness in CKD patients. Measurement of osteocalcin seems to be the best predictor of AoPWV.

Pulmonary artery pulse wave velocity in idiopathic pulmonary arterial hypertension

BACKGROUND

Idiopathic pulmonary artery (PA) hypertension (IPAH) is associated with severe PA remodelling. Although the resulting increase in pulse wave velocity (PWV) might be of major pathophysiological relevance, little is known about PA-PWV in IPAH. The aim of this study was to characterize PA-PWV and its predictors in patients with IPAH.

METHODS

We studied 26 consecutive patients with incident IPAH aged 55.0 (45.0-66.0) years (62% female) and 10 control subjects without pulmonary hypertension. PA-PWV was measured invasively; PA wall thickness and diameter were assessed using intravascular and transthoracic ultrasonography.

RESULTS

PA-PWV was higher in IPAH than in control subjects (10.0 [7.5-14.0] m/s vs 3.5 [1.9-4.0] m/s; P < 0.001) as was also PA diameter and PA wall thickness. In IPAH patients, in univariate analysis PA-PWV was greater in men than in women and in patients with body mass index (BMI) < 25 kg/m(2) than with BMI ≥ 25 kg/m(2) and correlated positively with symptomatic disease duration, mean PA pressure, pulmonary vascular resistance, creatinine level, and negatively with low-density lipoprotein (LDL) cholesterol and triglyceride level but not with PA diameter or PA wall thickness. In multiple regression analysis mean PA pressure, LDL cholesterol level and BMI < 25 kg/m(2) were the main predictors of PA-PWV in IPAH patients (R(2) = 77%; P < 0.001).

CONCLUSIONS

PA-PWV is increased in IPAH patients. High PA pressure, low LDL cholesterol level, and BMI < 25 kg/m(2) explain most of its variability in this group.

Pulse wave velocity and the non-invasive methods used to assess it: Complior, SphygmoCor, Arteriograph and Vicorder

Pulse wave velocity (PWV) is a known indicator of arterial stiffness and cardiovascular risk. We critically evaluated the evidence supporting the four main non-invasive devices available to assess it: Complior, SphygmoCor, Arteriograph and Vicorder. PubMed and Medline databases (1960-2011) were searched to identify studies reporting carotid-femoral PWV in humans using one or more of the four devices. Of the 183 articles retrieved, 43 met inclusion criteria. The Arteriograph device demonstrated least variance but had poor agreement with the other devices. Undisputable reference values for PWV need to be established and internationally agreed, and a standardized method for superficial distance measurement generated to reduce variability. Further studies comparing all four devices with invasive assessment are necessary.

Validated methods for assessment of subclinical atherosclerosis in rheumatology

Rheumatoid arthritis, as well as other types of arthritides and connective tissue diseases, is associated with accelerated atherosclerosis, and increased cardiovascular morbidity and mortality. The early signs of cardiovascular disease therefore need to be recognized in patients with these conditions so that effective cardiovascular protection can be introduced. This Review provides an overview of validated techniques that are currently available to determine subclinical atherosclerosis in patients with rheumatic conditions. Techniques for early assessment of endothelial dysfunction include brachial artery flow-mediated vasodilation and laser Doppler flowmetry. Coronary circulation can be assessed by measuring coronary flow reserve using CT, MRI or PET based techniques. The standard indicators of arterial stiffness are pulse-wave velocity and the augmentation index. Carotid atherosclerosis is determined by the common carotid intima-media thickness (ccIMT) measurement or by the assessment of plaques and plaque areas. The combination of ccIMT with plaque assessment is likely to increase the predictive value of this approach. The potential use of a multimarker approach to increase the diagnostic and prognostic value of these clinical assessments is also discussed.

Noninvasive determination of carotid-femoral pulse wave velocity depends critically on assessment of travel distance: a comparison with invasive measurement

OBJECTIVES

European Society of Hypertension guidelines recommend use of carotid- femoral pulse wave velocity (cfPWV) as a favored measure of aortic stiffness. However, there is no consensus on the measurement of distance travelled by the pulse wave along the aorta to the femoral artery. The aim of our study was to compare cfPWV, calculated with commonly used noninvasive methods for travel distance assessment, against aortic PWV measured invasively.

METHODS

One hundred and thirty-five patients had aortic PWV measured invasively during cardiac catheterization, from the delay in wave foot and distance travelled as the catheter was withdrawn from the ascending aorta to the aortic bifurcation. On the following day, noninvasive cfPWV was assessed, using the SphygmoCor system, relating the delay between carotid and femoral wavefoot to travel distance, estimated with five different methods on body surface.

RESULTS

Mean travel times were in good agreement [(travel time) TTinvasive was 63 ms, TTnoninvasive was 59.3 ms, Spearman's R: 0.8, P < 0.00001]. Mean PWVinvasive was 8.5 m/s. CfPWV, as assessed noninvasively, depended largely on the method used for travel distance estimation: 11.5, 9.9, 8.7, 11.9, and 9.6 m/s, using direct carotid-femoral distance, carotid-femoral minus carotid-suprasternal notch distances, suprasternal notch-femoral minus carotid-suprasternal notch distances, suprasternal notch-femoral plus carotid-suprasternal notch distances, and suprasternal notch-symphysis distance, respectively. There was acceptable correspondence between PWVinvasive and cfPWVnoninvasive (Spearman's R: 0.73-0.77, P < 0.0001).

CONCLUSION

For noninvasive assessment of cfPWV, estimation of pulse wave travel distance is critical. Best agreement with invasive measurements was found for the method of subtracting carotid-suprasternal notch distance from suprasternal notch-femoral distance.