Comparison of brachial-ankle pulse wave velocity in Japanese and Russians

[Possibilities of application of cardio-ankle vascular index in patients with cerebrovascular diseases]

This publication focuses on the feasibility of using the cardio-ankle vascular index (CAVI) in patients with cerebrovascular diseases. The authors consider the pathological conditions and risk factors of stroke associated with increased arterial stiffness, methods for its assessment, the advantages of using CAVI, the experience of using CAVI in patients with cardiovascular diseases, in particular, in neurological patients. The complexity of the application of CAVI in the Russian population, promising directions for determining the index in neurology as well as the importance of CAVI borderline indicators are shown. It is emphasized that stroke patients should be screened with a mandatory study of CAVI.

The cardio-ankle vascular index and ankle-brachial index in young russians

AIM

A noninvasive approach to assess atherosclerosis in young people is of great concern. The cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI) reflect the arterial conditions, although the CAVI has not fully been studied in Russian populations. This study aimed to determine the CAVI and ABI in young Russians, to compare these findings with those in their Japanese peers and to investigate the lifestyle correlates and genetic associations with the CAVI and ABI in the Russians.

METHODS

In addition to several atherosclerotic parameters and self-reported lifestyle factors, the CAVI and ABI levels were measured in 114 Russians (mean 21 years). Four gene polymorphisms, including cholesteryl ester transfer protein (CETP) Taq1B polymorphism, were typed in some of the subjects.

RESULTS

The Russians exhibited significantly higher CAVI levels compared to their Japanese counterparts (5.87 vs. 5.36; p＜0.05), while the ABI levels were similar between the two populations. In the Russians, the ABI was significantly correlated with the mean blood pressure (r=-0.26) and heart rate (r=-0.43), while the CAVI did not show such correlations. No significant associations existed between lifestyle-related factors and the CAVI or ABI levels. A lower ABI level was found in carriers with the T-allele of CETP Taq1B in the Russians.

CONCLUSIONS

The reference CAVI value can be specified for individual ethnic populations. Our findings suggest that Russians may develop atherosclerosis-related conditions at a younger age compared to Japanese subjects, although this must be verified in additional studies. The possible association between CETP polymorphisms and the ABI deserves further investigation.

Effects of metabolic syndrome on cardio-ankle vascular index in middle-aged and elderly Chinese

Metabolic syndrome is characterized by multiple risk factors and is associated with increased risk of diabetes and cardiovascular disease. The rapid change in the lifestyle and food habits of Chinese people has resulted in metabolic syndrome becoming one of the most widespread health challenges in China. Recently, the cardio-ankle vascular index (CAVI) was developed as a new parameter reflecting arterial stiffness and providing an index of vascular status. The purpose of this study was to investigate the effect of metabolic syndrome on CAVI. A total of 222 Chinese subjects aged 50-92 years participated in this study. We measured CAVI and examined blood samples to define metabolic syndrome according to the International Diabetes Federation criteria. CAVI in the subjects with abnormal waist circumference was significantly higher than that obtained in the normal subjects (P < 0.01). In the abnormal high-density lipoprotein cholesterol (HDL-C) group, CAVI was significantly increased (P < 0.01) compared to the normal HDL-C group. CAVI showed a positive correlation with waist circumference and increased significantly with the number of metabolic syndrome components. In conclusion, subjects with metabolic syndrome have a high CAVI that indicated arterial stiffness and is closely associated with an increase in the number of metabolic syndrome risk factors. Elevated abdominal obesity and low HDL-C are the main players affecting arterial stiffness in the middle-aged and elderly Chinese. These findings suggest that interaction of the individual components of metabolic syndrome plays a role in the relationship between metabolic syndrome and arterial stiffness.

Prognostic value of changes in arterial stiffness in men with coronary artery disease

Background

Men with coronary artery disease (CAD) have been shown to have enhanced arterial stiffness. Arterial function may change over time according to treatment, but the prognostic value of these changes has not been investigated.

Objectives

The aim of the present study was to assess whether an improvement in large artery rigidity in response to treatment, could predict a more favorable prognosis in a population of men with CAD.

Methods

A total of 161 men with CAD (mean age 56.8 ± 10.9 years) being treated with conventional therapy underwent brachial-ankle pulse wave velocity (PWVba) measurements at baseline and after six months. Follow-up period was 3.5 years. End-points were major adverse cardiac events (MACE): acute myocardial infarction, unstable angina, coronary intervention, or cardiac death.

Results

During the three-year follow-up period (since initial six-month follow-up), 30 patients experienced MACE. After six-month follow-up, PWVba had not improved (ΔPWVba ≥ 0%, relative to baseline) in 85 (52.8%) of 161 men (Group 1), whereas it had improved (ΔPWVba < 0%) in the remaining 76 men (47.2%) (Group 2). During follow-up, we noticed 24 cardiovascular events in Group 1 and six events in Group 2 (P < 0.001). Cox proportional hazards analyses demonstrated that independent of conventional risk factor changes, absence of PWVba decrease was a predictor of MACE (RR 3.99; 95% CI:1.81–8.78; P = 0.004). The sensitivity of ΔPWVba was 80% and its specificity was 54%.

Conclusions

This study demonstrates that an improvement in arterial stiffness may be obtained after six months of conventional therapy and clearly identifies patients who have a more favorable prognosis.

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.

Tissue Doppler echocardiography for predicting arterial stiffness assessed by cardio-ankle vascular index

It has been reported that left ventricular (LV) diastolic functional parameters assessed by conventional Doppler echocardiography, which measures blood flow velocities in cardiac cavity, correlate with arterial stiffness assessed by the cardio-ankle vascular index (CAVI) and are markers for increased risk of cardiovascular events. Recently, tissue Doppler echocardiography, which measures velocities of regional cardiac wall, has been widely used for assessment of LV diastolic function because of more accuracy than conventional Doppler echocardiography. However, there are no data regarding the ability of tissue Doppler echocardiography for predicting increased arterial stiffness. We investigated the correlation of LV diastolic functional parameters from tissue Doppler echocardiography to CAVI in order to clarify the ability of tissue Doppler echocardiography for predicting increased arterial stiffness in patients with cardiovascular risk factors. Enrolled in the study were 70 patients (69 +/- 8 years) who had no overt heart disease, but had at least one of hypertension, diabetes, and dyslipidemia. The peak early diastolic mitral annular velocity (E') was measured as an index of LV diastolic function using tissue Doppler echocardiography. The E' was correlated with CAVI (r = -0.518, p < 0.001). The optimal cut-off point for the detection of abnormal CAVI (> or = 8.81) was 5.6 cm/s for E' (sensitivity 71%, specificity 71%). The decrease in E' correlated with both LV diastolic dysfunction and increased arterial stiffness. Therefore, the LV diastolic dysfunction assessed by tissue Doppler echocardiography may be useful for predicting increased arterial stiffness and cardiovascular events in the patients with risk factors.

Impact of Type A Behavior on Brachial-Ankle Pulse Wave Velocity in Japanese

Pulse wave velocity (PWV) is the velocity of a pulse wave traveling a given distance between 2 sites in the arterial system, and is a well-known indicator of arteriosclerosis. Brachial-ankle PWV (baPWV) is a parameter more simple to obtain, compared with the conventional PWV, and is an easy and effective means of evaluating arteriosclerosis. BaPWV can be obtained by only wrapping the four extremities with blood pressure cuffs, and it can be easily used to screen a large number of subjects. Type A behavior has been confirmed as an independent risk factor for the development of coronary heart disease. To examine the relationship between Type A behavior and arteriosclerosis, 307 normal Japanese subjects were classified into either a Type A group (n = 90) or a non-Type A group (n = 217) by using Maeda's Type A Scale. BaPWV was evaluated using a PWV diagnosis device. The baPWV in the Type A group was significantly higher than that obtained in the non-Type A group. The baPWV showed a positive correlation with age both in the Type A group and in the non-Type A group; however, the straight-line regression slope of baPWV versus age in the Type A group was significantly larger than that in the non-Type A group. Therefore, our results suggest that arteriosclerosis might be promoted earlier in subjects expressing the Type A behavior pattern. Type A behavior pattern is confirmed as a risk factor for arteriosclerosis, and may increase the risk of the cardiovascular disease related to arteriosclerosis.