Arterial Stiffness Is Associated With Left Ventricular Diastolic Function in Patients With Cardiovascular Risk Factors: Early Detection With the Use of Cardio-Ankle Vascular Index and Ultrasonic Strain Imaging

Ventricular Function and Cardio-Ankle Vascular Index in Patients With Pulmonary Artery Hypertension

Aim

This study aims to evaluate the left ventricle (LV) systolic and diastolic function in patients with idiopathic pulmonary arterial hypertension (IPAH) and its correlation with systemic arterial stiffness assessed by cardio-ankle vascular index (CAVI).

Patient and methods

We included 37 patients with IPAH and 20 healthy people matched by age. All patients were assessed: vital signs, 6-minute walk test, NT-proBNP level, the CAVI, the right ventricular (RV) and LV function parameters, including ejection time (ET), tissue speckle-tracking values - global longitudinal strain (GLS) and strain rate (SR).

Results

The groups were matched by age, gender, BMI, office SBP and DBP. Patients with IPAH had higher heart rate, NT-proBNP level and lower ferritin level, GFR (CKD-EPI), SaO2 than healthy people. The mean CAVIleft was higher in IPAH patients than in the control group- 8.7±1.1 vs 7.5±0.9, P=0.007. Healthy people had significantly less E/e' and lower IVRT. LVET and RVET were shorter in IPAH patients. Patients with IPAH had mean LVGLS -(-17.6±4.8%) and 35.1% of them were with LVGLS ≤16% compared to healthy people -(-21.8±1.4%) and 0%, respectively. LVSR was significant less in IPAH patients, but in the normal range. We found significant correlations of CAVI with age, history of syncope, bilirubin, uric acid, total cholesterol, cardiac output, cardiac index, RVET, LVET and E/A. Multiple linear regression confirmed the independent significance for age (β=0.083±0.023, CI 0.033-0.133) and RVET (β=-0.018±0.005, CI -0.029 to -0.008) only. The risk to have CAVI ≥8 increased in 5.8 times in IPAH patients with RVET <248 ms (P=0.046). CAVI did not correlate with LVGLS and LVSR.

Conclusion

Significant worse systolic and diastolic LV functions were stated in pulmonary hypertensive patients compared to the control group. No LV GLS, no LV SR had significant associations with arterial stiffness evaluated by CAVI.

Cardio-Vascular Interaction Evaluated by Speckle-Tracking Echocardiography and Cardio-Ankle Vascular Index in Hypertensive Patients

Hypertension increases arterial stiffness, leading to dysfunction and structural changes in the left atrium (LA) and left ventricle (LV). However, the effects of hypertension on the right atrium (RA) and the right ventricle are still not fully understood. The purpose of this study was to clarify whether there is an interaction not only in the left ventricular system but also in the right ventricular system in hypertensive patients with preserved LV ejection fraction. The current retrospective observational study included patients (n = 858) with some risk of metabolic abnormalities (hypertension, diabetes, and dyslipidemia) who had visited our hospital and undergone echocardiography between 2015 and 2018. Among them, we retrospectively studied 165 consecutive hypertensive patients with preserved LV ejection fraction who had echocardiography performed on the same day as a cardio-ankle vascular index (CAVI) in our hospital. The phasic function of both atria was evaluated by two-dimensional speckle-tracking echocardiography. CAVI was measured using Vasela 1500 (Fukuda Denshi^®). In the univariate analysis, CAVI was significantly correlated with LA and RA conduit function (LA conduit function, r = -0.448, p = 0.0001; RA conduit function, r = -0.231, p = 0.003). A multivariate regression analysis revealed that LA and RA conduit function was independently associated with CAVI (LA, t = -5.418, p = 0.0001; RA, t = -2.113, p = 0.036). CAVI showed a possibility that the association between heart and vessels are contained from not only LA phasic function but also RA phasic function in hypertensive patients.

Clinical Applications Measuring Arterial Stiffness: An Expert Consensus for the Application of Cardio-Ankle Vascular Index

BACKGROUND

The purpose of this document is to provide clinicians with guidance, using expert consensus, to help summarize evidence and offer practical recommendations.

METHODS

Expert Consensus Documents are intended to provide guidance for clinicians in areas in which there are no clinical practice guidelines, especially for new and evolving tests such as arterial stiffness measurements, until any formal guidelines are released.

RESULTS

This expert consensus document is intended as a source of information for decision-making and to guide clinician-patient discussions in various clinical scenarios.

CONCLUSIONS

The goal is to help clinicians and patients make a more informed decision together.

Evaluating Impact of Pulse Pressure on Indexes of Myocardial Work by Speckle-Tracking Echocardiography in Normotensive, Prehypertensive and Newly Diagnosed Hypertensive Patients

Background

The impact of pulse pressure (PP) on indexes of myocardial work (MWIs). This study aims to explore the potential association of high PP with myocardial work (MW).

Hypothesis

PP had an association with four indexes of MW in a mixed population of normotensive, prehypertensive and newly diagnosed hypertensive individuals.

Methods

The study was a single-center, cross-sectional, observational study. A total of 204 participants (66 normotensive, 35 prehypertensive and 103 newly diagnosed hypertensive individuals) were evaluated by speckle-tracking echocardiography (STE) and blood pressure measurement. According to the PP tertiles, the participants were divided into three groups: Group I (<44 mmHg, n=67), Group II (44–52 mmHg, n=68) and Group III (≥52 mmHg, n=69).

Results

In Group II and Group III, the proportion of males was higher than that in Group I (median 46 vs 30 (P=0.002)). With increasing PP, the three indexes of MW, namely, GWI, GCW and GWW, increased, and the differences among the three groups were statistically significant (P<0.001). PP was positively related to GWI, GCW and GWW and negatively correlated with GWE. After adjusting for E/e’, LVMI, LAVI and GLS, PP was still significantly correlated with the four MW indexes (both P<0.001).

Conclusion

PP had a strong association with four indexes of MW in a mixed population of normotensive, prehypertensive and newly diagnosed hypertensive individuals. The evaluation of PP and MWIs might be valuable for identifying very early diastolic impairment of the heart.

Effects of long-term air pollution exposure on ankle-brachial index and cardio-ankle vascular index: A longitudinal cohort study using data from the Electricity Generating Authority of Thailand study

BACKGROUND

Ankle-brachial index (ABI) and cardio-ankle vascular index (CAVI) are surrogate measures of atherosclerosis based on the functional performance of vessels, and are highly related to cardiovascular events. However, only a few longitudinal studies have been conducted on their associations with long-term air pollution exposure.

OBJECTIVE

This study aimed to examine whether long-term air pollution exposure is associated with ABI and CAVI in workers of the Electricity Generating Authority of Thailand (EGAT) in the Bangkok Metropolitan Region (BMR).

METHODS

This longitudinal study included 1261 participants (age range, 57-76 years as of 2007) of the EGAT study (2007-2017). ABI and CAVI were measured in 2007, 2012, and 2017. Annual mean concentrations of particulate matter ≤10 μm in diameter (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), ozone (O₃), and carbon monoxide (CO) were estimated by ordinary kriging using data from 22 background and 7 traffic monitoring stations in BMR between 2002 and 2017. Linear mixed-effects models were used to assess associations between air pollution (expressed as 1-year, 3-year, and 5-year average concentration) and ABI and CAVI (expressed as percent changes per interquartile range (IQR) increase in PM₁₀, O₃, NO₂, SO_2, and CO). We also applied the mixed-effect ordinal logistic models to calculate odds ratios (ORs) of having high or moderate CAVI per an IQR increase in air pollution.

RESULTS

After controlling for potential confounders, 1-year average CO was negatively associated with ABI, but not significantly (-0.48%, 95% CI: -1.03, 0.07). Three-year average NO₂ was positively associated with CAVI (6.67%, 95% CI: 0.21, 13.1). In contrast, 1-year average PM₁₀ was inversely associated with CAVI although the association was not significant. Although not significantly, 1-year average NO₂ and CO were positively associated with prevalence of high or moderate CAVI.

CONCLUSIONS

Although not statistically significant, long-term NO₂ and CO exposure was associated with ABI and CAVI in the participants of the EGAT study.

Switching Dipeptidyl Peptidase-4 Inhibitors to Tofogliflozin, a Selective Inhibitor of Sodium-Glucose Cotransporter 2 Improve Arterial Stiffness Evaluated by Cardio-Ankle Vascular Index in Patients with Type 2 Diabetes: A Pilot Study

BACKGROUND

We have found that anagliptin, a dipeptidyl peptidase-4 inhibitor (DPP-4) significantly ameliorates arterial stiffness in Type 2 Diabetes Mellitus (T2DM) patients compared with an equivalent hypoglycaemic agent, glimepiride. However, it remains unclear whether switching DPP-4 inhibitors to tofogliflozin, a selective inhibitor of Sodium-Glucose Cotransporter 2 (SGLT2) improves arterial stiffness in T2DM patients.

METHODS

Nineteen T2DM patients who had received DPP-4 inhibitors for at least 1 year were enrolled in this study. Clinical parameters and arterial stiffness evaluated by cardio-ankle vascular index (CAVI) were measured at baseline and after 6-months treatment with tofogliflozin.

RESULTS

At 6 months after switching to tofogliflozin, CAVI, waist circumference, body weight, body mass index, subcutaneous and visceral fat volume, white blood cell number, fasting plasma insulin, uric acid, aspartate transaminase (AST), γ-glutamyl transferase (GTP), and advanced glycation end products (AGEs) were significantly reduced, while red blood cell number, haemoglobin, and HbA1c values were increased. When stratified by median values of change in CAVI after switching to tofogliflozin (ΔCAVI), baseline serum levels of AGEs were significantly higher in the low ΔCAVI group (high responder) than in the high one (low responder). ΔAST and ΔGTP were positively correlated with ΔCAVI.

CONCLUSION

The present study suggests that switching DPP-4 inhibitors to tofogliflozin ameliorates arterial stiffness in T2DM patients partly via improvement of liver function. Baseline serum levels of AGEs may identify patients who improve arterial stiffness more after treatment with tofogliflozin.

Arterial Stiffness Assessed by Cardio-Ankle Vascular Index

Arterial stiffness is an age-related disorder. In the medial layer of arteries, mechanical fracture due to fatigue failure for the pulsatile wall strain causes medial degeneration vascular remodeling. The alteration of extracellular matrix composition and arterial geometry result in structural arterial stiffness. Calcium deposition and other factors such as advanced glycation end product-mediated collagen cross-linking aggravate the structural arterial stiffness. On the other hand, endothelial dysfunction is a cause of arterial stiffness. The biological molecular mechanisms relating to aging are known to involve the progression of arterial stiffness. Arterial stiffness further applies stress on large arteries and also microcirculation. Therefore, it is closely related to adverse outcomes in cardiovascular and cerebrovascular system. Cardio-ankle vascular index (CAVI) is a promising diagnostic tool for evaluating arterial stiffness. The principle is based on stiffness parameter β, which is an index intended to assess the distensibility of carotid artery. Stiffness parameter β is a two-dimensional technique obtained from changes of arterial diameter by pulse in one section. CAVI applied the stiffness parameter β to all of the arterial segments between heart and ankle using pulse wave velocity. CAVI has been commercially available for a decade and the clinical data of its effectiveness has accumulated. The characteristics of CAVI differ from other physiological tests of arterial stiffness due to the independency from blood pressure at the time of examination. This review describes the pathophysiology of arterial stiffness and CAVI. Molecular mechanisms will also be covered.

Cardio-Ankle Vascular Index as a Surrogate Marker of Early Atherosclerotic Cardiovascular Disease in Koreans with Type 2 Diabetes Mellitus

BACKGROUND

Carotid artery intima medial thickness (IMT), brachial-ankle pulse wave velocity (baPWV), and ankle-brachial index (ABI) are commonly used surrogate markers of subclinical atherosclerosis in patients with type 2 diabetes mellitus (T2DM). The cardio-ankle vascular index (CAVI) is a complement to the baPWV, which is affected by blood pressure. However, it is unclear which marker is the most sensitive predictor of atherosclerotic cardiovascular disease (ASCVD).

METHODS

This was a retrospective non-interventional study that enrolled 219 patients with T2DM. The correlations among IMT, ABI, and CAVI as well as the relationship of these tests to the 10-year ASCVD risk were also analyzed.

RESULTS

Among the 219 patients, 39 (17.8%) had ASCVD. In the non-ASCVD group, CAVI correlated significantly with IMT after adjusting for confounding variables, but ABI was not associated with CAVI or IMT. The analyses after dividing the non-ASCVD group into three subgroups according to the CAVI score (<8, ≥8 and <9, and ≥9) demonstrated the significant increase in the mean IMT, 10-year ASCVD risk and number of metabolic syndrome risk factors, and decrease in the mean ABI in the high-CAVI group. A high CAVI was an independent risk factor in the non-ASCVD group for both a high 10-year ASCVD risk (≥7.5%; odds ratio [OR], 2.42; P<0.001) and atherosclerosis (mean IMT ≥1 mm; OR, 1.53; P=0.007).

CONCLUSION

In Korean patients with T2DM without ASCVD, CAVI was the most sensitive of several surrogate markers for the detection of subclinical atherosclerosis.

Gender-specific association of metabolic syndrome and its components with arterial stiffness in the general Chinese population

OBJECTIVES

Metabolic syndrome (MS) is considered to be a cluster of interrelated risk factors for metabolism, which may increase arterial stiffness and cardiovascular morbidity. The cardio-ankle vascular index (CAVI) is a reliable indicator of arterial stiffness and early arteriosclerosis. The main objective of this study is to evaluate the gender-specific relationship between MS and CAVI in the general Chinese population.

METHODS

A total of 1,301 subjects aged 20 to 60 years participated in this study. CAVI was measured noninvasively using a Vasera VS-1000 device. Blood samples and waist circumference were examined to identify metabolic syndrome according to the criteria set forth in the 2009 Joint Scientific Statement.

RESULTS

The prevalence of MS in the study subjects was 17.4% (30.7% in males and 7.0% in females, P < 0.001). CAVI values were significantly higher in MS subjects than in non-MS subjects and increased linearly as the number of MS components increased in females, but not in males. Using multiple regression analysis, we found that BMI was correlated with CAVI in the overall population and in both genders, and that high-density lipoprotein cholesterol (HDL-C) was associated with CAVI in males, while the number of MS components was related to CAVI in females. CAVI values increased linearly with age in both genders (P-trend < 0.001 for both), and this correlation was stronger in males than in females.

CONCLUSIONS

There are gender-specific differences in the association of MS and CAVI. First, the effects of the number of MS components on CAVI are stronger in females than in males. Second, the effect of each MS component on arterial stiffness may differ in relation to gender. In addition, aging affects arterial stiffness more severely in males, and the increase in arterial stiffness tends to occur at a younger age in males than in females. Larger samples and longitudinal studies are needed to further confirm our results in the future.

Association of arteriosclerosis and/or atherosclerosis with hypertensive target organ damage in the community-dwelling elderly Chinese: the Northern Shanghai Study

Objective

Vascular abnormality includes two forms, arteriosclerosis (ARS) and atherosclerosis (ATS), which coexist in patients with cardiovascular (CV) diseases. However, whether their combination may lead to a worsening status in those patients remains unclear. We therefore aimed to investigate the association of ARS and/or ATS with hypertensive target organ damage (TOD).

Methods

From June 2014 to August 2015, a total of 1,599 community-dwelling elderly subjects (aged >65 years) from northern Shanghai were recruited. Vascular measurements, such as carotid–femoral pulse wave velocity (cf-PWV), ankle–brachial index (ABI) and carotid plaque, were conducted on each participant, and ARS was defined as cf-PWV >12 m/s, while ATS was defined as participants who have carotid plaque or ABI <0.9. Within the framework of comprehensive CV examinations, CV risk factors were assessed, and asymptomatic TOD was evaluated by measuring participants’ left ventricular mass index (LVMI), peak transmitral pulsed Doppler velocity/early diastolic tissue Doppler velocity (E/Ea), urinary albumin–creatinine rate (UACR) and estimated glomerular filtration rate (eGFR).

Results

Although LVMI, E/Ea and eGFR were significantly different among subjects with or without ARS and/or ATS (P<0.02), in full adjustment model, only E/Ea showed the independent and significant difference (P=0.023). Moreover, E/Ea was significantly different between participants with ARS or ATS and those without ARS or ATS (P=0.045), while there was no significant difference between participants with ARS and ATS and those without ARS or ATS (P=0.28). Similar results were obtained in the multivariate logistic regression of left ventricular diastolic dysfunction (LVDD). With similar adjustment, LVDD was significantly associated with ATS (P=0.01) but not with ARS (P=0.99).

Conclusion

In the community-dwelling elderly Chinese, among hypertensive TOD, LVDD was significantly associated with ATS but not with ARS. The proportion of patients with LVDD was not significantly different despite the presence of both ATS and ARS, when compared to patients with ATS alone.

Arterial Stiffness Is Significantly Associated With Left Ventricular Diastolic Dysfunction in Patients With Cardiovascular Disease

Left ventricular (LV) diastolic dysfunction is considered the main cause of heart failure with preserved ejection fraction (HFpEF). There have been few reports on the correlation between LV diastolic dysfunction and arterial stiffness in patients with clinical cardiovascular disease.This cross-sectional study enrolled 100 patients (67 men, 33 women; mean age, 70 years). All participants were diagnosed with cardiovascular disease. A total of 89 (89%) patients had coronary artery disease or HF. Patients with reduced EF and valvular disease were excluded. Arterial stiffness was assessed by the cardio-ankle vascular index (CAVI), and LV diastolic dysfunction was estimated using echocardiography. The patients were divided into two groups based on the median value of CAVI. In all patients the ratio of early diastolic transmitral flow velocity to early diastolic mitral annular velocity (E/e') was significantly higher in the high CAVI group than in the low CAVI group (15.5 ± 6.4 versus 12.5 ± 2.9, P = 0.003). In the HF subgroup, E/e' was also significantly higher in the high CAVI group than in the low CAVI group (17.2 ± 5.9 versus 13.0 ± 3.1, P = 0.026). In univariate regression analysis, CAVI was significantly associated with E/e' in all patients (β = 0.28, P = 0.004) and in HF patients (β = 0.4, P = 0.028). Also in multivariate analysis, CAVI remained as an independent predictive factor of E/e' (β = 0.252, P = 0.037).A high CAVI was independently associated with LV diastolic dysfunction in patients with clinical cardiovascular disease. These results suggested that arterial stiffness contributed to the development of LV diastolic dysfunction.

Challenges for 'diastology': contributions from Japanese researchers

Diastology is a study to treat diastole of the heart. Transmitral flow and pulmonary venous flow velocities recorded by pulsed Doppler echocardiography provide more important information about left ventricular (LV) diastolic dysfunction [left atrial (LA)-LV coupling] than cardiac catheterization in clinical practice; however, these waveforms are influenced by loading conditions, particularly preload. The early diastolic mitral annular and LV wall motion indices measured by tissue Doppler echocardiography can evaluate LV relaxation abnormality and filling pressure by being relatively preload independent. In addition, the role of concomitant systolic longitudinal dysfunction is well characterized in asymptomatic patients and in patients with heart failure and preserved ejection fraction. Two-dimensional speckle tracking echocardiography is an angle-independent method, and has the potential to evaluate the contraction and relaxation abnormalities in the longitudinal, circumferential, and radial directions of the LV myocardium as well as LV torsion/untwisting and, moreover, deformation of the LA myocardium and large arterial wall. As a result, this new technique can facilitate the early detection of impaired LA-LV-arterial coupling in patients before occurrence of overt heart failure symptoms.

Endothelial progenitor cells as markers of severity in hypertrophic cardiomyopathy

AIMS

Endothelial progenitor cells (EPCs) are bone marrow-derived cells that are mobilized into the circulation to migrate and differentiate into mature endothelial cells contributing to post-natal physiological and pathological neovascularization. In this study, we evaluated circulating EPCs in patients with hypertrophic cardiomyopathy (HCM) and examined a potential association with clinical parameters of the disease.

METHODS AND RESULTS

We included 40 HCM patients and 23 healthy individuals. Using flow cytometry we measured EPCs in peripheral blood as two subpopulations of CD45-/CD34+/VEGFR2+ and CD45-/CD34+/CD133+ cells. Circulating CD45-/CD34+/VEGFR2+ cells were significantly increased in HCM patients in comparison with the controls (0.000238 ± 0.0003136 vs. 0.000057 ± 0.0001316, respectively, P = 0.002). However, there was no significant difference in the number of circulating CD45-/CD34+/CD133+ cells (0.003079 ± 0.0033288 vs. 0.002065 ± 0.0022173, respectively, P = 0.153). The CD45-/CD34+/VEGFR2+ subpopulation revealed a moderate correlation with LV mass index (r = 0.35, P = 0.026), while both EPC subpopulation levels showed strong positive correlations with th E/e' ratio (r = 0.423, P = 0.007 for CD45-/CD34+/VEGFR2+ and r = 0.572, P < 0.001 for CD45-/CD34+/CD133+).

CONCLUSION

HCM patients showed an increased mobilization of EPCs compared with healthy individuals that correlated with diastolic dysfunction. Our findings may open up new dimensions in the pathophysiology, prognostication, and treatment of HCM.

Cardio-ankle vascular index predicts for the incidence of cardiovascular events in obese patients: a multicenter prospective cohort study (Japan Obesity and Metabolic Syndrome Study: JOMS)

OBJECTIVE

The cardio-ankle vascular index (CAVI) is an index of arterial stiffness less dependent on blood pressure and an indicator suitable for assessing the arterial dysfunction. However, it remains unclear whether CAVI can predict the outcome of cardiovascular diseases (CVD) in obese patients.

METHODS

A total of 425 obese Japanese outpatients (189 men and 236 women, mean age: 51.5 years) were enrolled in a multicenter prospective cohort Japan, the Japan Obesity and Metabolic Syndrome Study (JOMS). Primary analysis regarding measurements of cardiovascular risk factors including CAVI and the occurrence of macrovascular complications was based on following the participants over a 5-year period.

RESULTS

Of the eligible patients, 300 (78%) were followed into the fifth year. During the study period, 15 coronary heart disease, 7 stroke, and 6 arteriosclerosis obliterans events occurred. All events occurred in 28 patients, and CVD incidence rate was 15.8 per 1000 person-years. In the analysis of adjusted models for traditional risk factors, CAVI was a significant factor for the incidence of events. In addition, high CAVI and low HDL-cholesterol were significant factors for the incidence of events in Cox stepwise multivariate analysis when age- and sex-adjusted (CAVI [per 1]: HR = 1.44 [1.02-2.02], p = 0.037; HDL-cholesterol [per 1 mmol/L]: HR = 0.20 [0.06-0.69], p = 0.011). In addition, CAVI added value to atherosclerotic cardiovascular disease risk score in predicting the development of CVD.

CONCLUSION

This study demonstrates for the first time that CAVI is an effective predictor of CVD events in obese patients.

Serum uric acid is associated with cardiac diastolic dysfunction among women with preserved ejection fraction

Serum uric acid (SUA) is associated with the severity and prognosis of systolic heart failure. We investigated the potential association between SUA and cardiac diastolic dysfunction among total of 744 cardiac patients (202 women and 542 men) who had preserved left ventricular ejection fraction. Presence of diastolic dysfunction was assessed by echocardiographic data, plasma B-type natriuretic peptide concentration, and left ventricular hypertrophy. Univariate analysis showed that the prevalence of diastolic dysfunction increased with increasing SUA value in women, but not in men. When sex-nonspecific SUA quartiles were used, multivariate logistic regression analysis, among female patients who were not taking uric acid lowering medication, showed that the third (SUA, 5.7-6.4 mg) and the fourth (SUA, ≥6.5 mg/dl) SUA quartiles were associated with diastolic dysfunction with an odds ratio of 3.25 (P < 0.05) and 8.06 (P < 0.001), respectively, when compared with the first SUA quartile (≤4.7 mg/dl). When sex-specific SUA quartiles were used among these population, multivariate logistic regression analysis showed that the fourth SUA quartile (≥5.7 mg/dl) was associated with diastolic dysfunction with an odds ratio of 5.34 (P < 0.05) when compared with the first SUA quartile (≤4.1 mg/dl). By contrast, the relationship between SUA and diastolic dysfunction was not significant in men, irrespective of which of the sex-nonspecific or sex-specific SUA quartiles were used. These data indicated that among cardiac patients with preserved ejection fraction, SUA was significantly associated with diastolic dysfunction in women but not in men.

Elevated arterial stiffness and diastolic dysfunction in subclinical hypothyroidism

BACKGROUND

Thyroid hormone is associated with arterial stiffness and left ventricular diastolic function in hypothyroid disease. The relationship of thyroid hormone level to cardio-ankle vascular index (CAVI) and left ventricular diastolic function, however, remains unclear in subjects with subclinical hypothyroidism.

METHODS AND RESULTS

We conducted a cross-sectional study of 83 patients with untreated subclinical hypothyroidism and compared them with 83 randomly selected controls from health check-ups. Log N-terminal prohormone of brain natriuretic peptide (NT-proBNP), C-reactive protein (CRP), and arterial stiffness were measured. In addition, we measured early diastolic mitral annular velocity (E') in 43 participants with subclinical hypothyroidism and in 40 controls. When compared with the control group, patients with subclinical hypothyroidism had higher logNT-proBNP (1.9±0.5 vs. 1.7±0.3pg/ml, P<0.05), CRP (0.22±0.04 vs. 0.09±0.06mg/dl, P<0.05), and CAVI (8.8±1.7 vs. 7.8±1.4, P<0.001) and lower E' (5.8±1.7 vs. 7.5±2.1cm/s, P<0.001). CAVI was significantly associated with logNT-proBNP, CRP and E' in the subclinical hypothyroidism group.

CONCLUSIONS

High logNT-proBNP was associated with a raised CAVI in patients with subclinical hypothyroidism. Subclinical hypothyroidism may be a risk factor for cardiovascular events related to arterial stiffening and left ventricular diastolic dysfunction.

Effects of amlodipine and candesartan on arterial stiffness estimated by cardio-ankle vascular index in patients with essential hypertension: A 24-week study

BACKGROUND

Aortic stiffness assessed by brachio-ankle pulse wave velocity (baPWV) can be used to predict cardiovascular events. However, baPWV is dependent on blood pressure. Antihypertensive drugs have been reported to reduce baPWV; but it is difficult to determine if this effect is associated with lowered blood pressure or reduced arterial stiffness.

OBJECTIVES

The primary end point of this study was to assess whether antihypertensive drugs reduce arterial stiffness as estimated by cardio-ankle vascular index (CAVI). The secondary end point was to compare the effects of 2 widely used drugs, the calcium-channel blocker amlodipine and the angiotensin II receptor blocker candesartan, on arterial stiffness.

METHODS

Between October 2005 and September 2006, consecutive Japanese outpatients with essential hypertension (EHT) (defined as using antihypertensive drugs at screening, systolic blood pressure [SBP] > 140 mm Hg, or diastolic BP [DBP] >90 mm Hg) were assigned to treatment for 24 weeks with either amlodipine (5-10 mg/d) or candesartan (8-12 mg/d). Arterial stiffness was evaluated with CAVI before and after 24 weeks of treatment. Relative change in arterial stiffness from baseline was also compared. The evaluator was blinded to treatment.

RESULTS

Twenty patients (11 men, 9 women; mean [SD] age, 62 [10] years) were included in the study. There were no significant differences in clinical characteristics between the 2 groups. At baseline, mean (SD) CAVI was not significantly different in the amlodipine group compared with the candesartan group (8.93 [0.93] vs 8.46 [1.34], respectively). During the 24-week treatment period, mean SBP and DBP decreased significantly in both the amlodipine (14/10 mm Hg; P = 0.006 and P = 0.005) and the candesartan groups (13/11 mm Hg; P = 0.033 and P = 0.005). Amlodipine was associated with a significant change in CAVI from baseline (8.93 [0.93] vs 8.60 [1.50]; P = 0.017), whereas candesartan was not (8.46 [1.34] vs 8.81 [1.20]). The percentage change in CAVI was significantly different in the amlodipine group compared with the candesartan group (-7.14 [8.83] vs 5.85 [16.0], respectively; P = 0.038). After 24 weeks of treatment, the CAVI of the amlodipine group was still numerically larger than baseline CAVI of the candesartan group, although the difference was not statistically significant. Furthermore, there was no significant difference in absolute CAVI between the 2 groups after 24 weeks, but the relative change from baseline was significant in favor of amlodipine. Logistic regression analysis revealed that amlodipine improved CAVI independent of its antihypertensive effect.

CONCLUSION

These data suggest that amlodipine and candesartan had different effects on aortic stiffness estimated by CAVI, despite similar effects on brachial blood pressure after 24 weeks of treatment in these Japanese patients with EHT.

Fibulin-5 null mice with decreased arterial compliance maintain normal systolic left ventricular function, but not diastolic function during maturation

Abstract The large arteries serve as compliant vessels that store energy during systole and return it during diastole. This function is made possible by the elastic fibers in the arterial wall that are assembled during late embryonic and early postnatal development from various proteins, including fibulin-5. Mice and humans with insufficient amounts of fibulin-5 have reduced arterial compliance as adults. Reduced compliance of the large arteries is correlated with hypertension, reduced cardiac function, and an increased risk of death from cardiac and cardiovascular disease. The goal of this study was to quantify arterial compliance, blood pressure, and left ventricular (LV) function from early postnatal development to young adulthood in fibulin-5 null (Fbln5-/-) mice to determine the effects of reduced arterial compliance during this critical period of elastic fiber assembly. We find that ascending aorta compliance is reduced as early as postnatal day (P) 7 and carotid artery compliance is reduced by P21 in Fbln5-/- mice. We did not find significant increases in systolic blood pressure by P60, but pulse pressures are increased by P21 in Fbln5-/- mice. LV systolic function, as measured by ejection fraction and fractional shortening, is unaffected in Fbln5-/- mice. However, LV diastolic function, as measured by tissue Doppler imaging, is compromised at all ages in Fbln5-/- mice. We propose that Fbln5-/- mice represent a suitable model for further studies to determine mechanistic relationships between arterial compliance and LV diastolic function.

Relationship between coronary artery stenosis and cardio-ankle vascular index (CAVI) in patients undergoing cardiovascular surgery

BACKGROUND

The cardio-ankle vascular index (CAVI) was developed as an indicator of arterial wall stiffness, and it is less influenced by blood pressure (BP). We investigated the relationship between the CAVI and coronary artery disease (CAD), and evaluated the effects of rapid changes in BP induced by anesthetics on CAVI.

MATERIALS AND METHODS

We measured the CAVI in 76 patients before and after the administration of anesthetics for elective cardiovascular surgery. The patients were assigned to groups with or without CAD (0VD). The CAD group was then divided into 3 subgroups based on the number of stenotic vessels (1VD, 2VD, and 3VD). We compared the CAVI between CAD and 0VD, and changes in BP during the induction of anesthesia. All data were analyzed using Stat View 5.0 software.

RESULTS

Systolic BP significantly decreased from 145 ± 21 to 107 ± 20 mmHg, whereas CAVI was not altered after the administration of intravenous anesthetics. Changes in BP and in pre-anesthetic CAVI (pre-CAVI) did not correlate. The pre- and post-anesthetic values for the CAVI (post-CAVI) in the 0VD and CAD groups were 8.34 ± 1.01 and 8.44 ± 1.39, and 9.95 ± 1.22 and 10.12 ± 1.56, respectively. Both values were higher in the CAD, than in the 0VD group (P < 0.05).

CONCLUSION

The CAVI is independent of BP and reproducible regardless of the induction of anesthesia and is significantly higher in patients with CAD. The CAVI might be able to predict atherosclerosis and coronary artery stenosis in patients undergoing cardiovascular surgery.

LCAT cholesterol esterification is associated with the increase of ApoE/ApoA-I ratio during atherosclerosis progression in rabbit

Apolipoprotein A-I and Apolipoprotein E promote different steps of reverse cholesterol transport, including lecithin-cholesterol acyltransferase stimulation. Our aim was to study the changes in the levels of Apolipoprotein A-I, Apolipoprotein E, and lecithin-cholesterol acyltransferase activity during atherosclerosis progression in rabbits. Quantitative echocardiographic parameters were analyzed in order to evaluate, for the first time, whether atherosclerosis progression in rabbit is associated to apolipoproteins changes and alteration of indices of cardiac function, such as systolic strain and strain rate of the left ventricle. Atherosclerosis was induced by feeding rabbits for 8 weeks with 2 % cholesterol diet. The HDL levels of cholesterol and cholesteryl esters were measured by HPLC. The lecithin-cholesterol acyltransferase activity was evaluated both ex vivo, as cholesteryl esters/cholesterol molar ratio, and in vitro. Apolipoproteins levels were analyzed by ELISA. The HDL levels of cholesterol and cholesteryl esters increased, during treatment, up to 3.7- and 2.5-fold, respectively, compared to control animals. The lecithin-cholesterol acyltransferase activity in vitro was halved after 4 weeks. During cholesterol treatment, Apolipoprotein A-I level significantly decreased, whereas Apolipoprotein E concentration markedly increased. The molar ratio Apolipoprotein E/Apolipoprotein A-I was negatively correlated with the enzyme activity, and positively correlated with both increases in the intima-media thickness of common carotid wall and cardiac dysfunction signs, such as systolic strain and strain rate of the left ventricle.

Arterial stiffness contributes to coronary artery disease risk prediction beyond the traditional risk score (RAMA-EGAT score)

Objectives

The traditional risk score (RAMA-EGAT) has been shown to be an accurate scoring system for predicting coronary artery disease (CAD). Arterial stiffness measured by the cardio–ankle vascular index (CAVI) is known to be a marker of atherosclerotic burden. A study was undertaken to determine whether CAVI improves the prediction of CAD beyond the RAMA-EGAT score.

Design

Cross-sectional study.

Patients

Patients with a moderate to high risk for CAD by the RAMA-EGAT score were enrolled between November 2005 and March 2006. 64-slice multidetector CT coronary angiography was used to evaluate the coronary artery calcium score and coronary stenosis. Arterial stiffness was assessed by CAVI.

Results

1391 patients of median age 59 years (range 31–88) were enrolled in the study, 635 (45.7%) men and 756 (54.3%) women. Of the 1391 patients, 346 (24.87%) had coronary stenosis. There was a correlation between CAVI and the prevalence of coronary stenosis after adjusting for traditional CAD risk factors (OR 3.29). In addition, adding CAVI into the RAMA-EGAT score (modified RAMA-EGAT score) improved the prediction of CAD incidence, increasing C-statistics from 0.72 to 0.85 and resulting in a net reclassification improvement of 27.7% (p<0.0001).

Conclusion

CAVI is an independent risk predictor for CAD. The addition of CAVI to the RAMA-EGAT score significantly improves the diagnostic yield of CAD.

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.

Head-to-head comparison of the cardio-ankle vascular index between patients with acute coronary syndrome and stable angina pectoris

We aimed to evaluate whether there was a difference in the arterial stiffness assessed by the cardio-ankle vascular index (CAVI) between patients with acute coronary syndrome (ACS) and those with stable angina pectoris (SAP). A total of 199 consecutive patients, 79 with ACS and 120 with SAP, who underwent emergency or elective coronary revascularization were enrolled. The CAVI was measured within 2 days after the procedures, and was compared between the ACS and SAP patients. As parameters related to arteriosclerosis, carotid intima-media thickness (IMT) and number of stenotic coronary vessels were also evaluated. Although IMT was significantly greater in SAP patients (2.1±1.1 vs. 2.4±0.9; P=0.022), CAVI was significantly higher in ACS patients (10.0±1.7 vs. 9.3±1.3; P=0.0012). After an adjustment for the clinical parameters with a significant difference between the two patient groups, CAVI remained significantly higher in ACS patients than in SAP patients (odds ratio 1.92, 95% confidence interval 1.30-3.02; P=0.0023). A multiple linear regression analysis revealed that age (β=0.44; P<0.0001) and ACS (β=0.3; P<0.0001) were the independent determinants of CAVI. A significant decrease in CAVI was observed at 6 months of follow-up as compared with the acute phase in 18 patients with ACS (10.9±1.6 vs. 10.0±1.5; P=0.019). In conclusion, CAVI was significantly and independently higher in patients with ACS than in those with SAP, which might result from a transient increase in the CAVI caused by acute myocardial ischemia.

Highly purified eicosapentaenoic acid reduces cardio-ankle vascular index in association with decreased serum amyloid A-LDL in metabolic syndrome

A recent clinical trial revealed that highly purified eicosapentaenoic acid (EPA), an n-3 polyunsaturated fatty acid, reduces the incidence of cardiovascular diseases. However, the detailed mechanism underlying the anti-atherogenic effect of EPA is still poorly understood. In this study, we examined the effect of EPA on cardio-ankle vascular index (CAVI), a new index of arterial stiffness that is less influenced by blood pressure (BP), as well as on serum amyloid A-low-density lipoprotein (SAA-LDL), an oxidized LDL (oxLDL), in the metabolic syndrome. Ninety-two obese Japanese subjects with metabolic syndromes were randomly divided into two groups (n=46): the EPA-treated group (1.8 g administered daily for 3 months) and the control group. Measurements were taken to assess the changes in glucose-lipid metabolism, SAA-LDL, C-reactive protein (CRP), leptin, adiponectin and pulse wave velocity (PWV), and CAVI. EPA treatment significantly reduced the levels of immunoreactive insulin, triglycerides, SAA-LDL, CRP, PWV and CAVI and increased the levels of adiponectin relative to the control group for 3 months (P<0.05). Stepwise multivariate linear regression analysis revealed that the only significant determinant for a decrease in CAVI by EPA is a reduction in SAA-LDL (P<0.05). Moreover, the EPA-induced reduction of SAA-LDL was only significantly correlated with a decrease in total cholesterol and an increase in adiponectin (P<0.05). This study is the first demonstration that EPA improves arterial stiffness and is less influenced by BP, possibly through the suppression of SAA-LDL, thereby leading to a reduction in the frequency of cardiovascular disease development in metabolic syndrome.

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.

Association of new arterial stiffness parameter, the cardio-ankle vascular index, with left ventricular diastolic function

AIM

Pulse wave velocity has been used as an index of aortic stiffness. Recently, the cardio-ankle vascular index (CAVI), which reflects the stiffness of the aorta independently of blood pressure, has been developed. In this study, we analyzed the relationship between CAVI and left ventricular (LV) diastolic dysfunction.

METHODS

A total of 119 patients were referred for echocardiography to evaluate ventricular function. Patients with reduced systolic function were excluded. Patients were divided on the basis of normal or reduced LV diastolic function determined by echocardiography. CAVI was measured using an automatic waveform analyzer.

RESULTS

CAVI was significantly higher in patients with reduced LV diastolic function than those with normal LV diastolic function (9.0+/-1.1 and 8.5+/-1.1, p=0.009). Multiple linear regression analysis revealed that CAVI was independently associated with the ratio of peak early diastolic velocity to peak atrial diastolic velocity and left atrial diameter. When patients were classified on the basis of CAVI quartiles, multiple logistic regression analysis demonstrated that the highest quartile of CAVI showed an increased odds ratio for the presence of LV diastolic dysfunction.

CONCLUSION

The present study revealed that an increased CAVI was independently associated with LV diastolic dysfunction in patients with preserved systolic function.

Evaluation of the cardio-ankle vascular index, a new indicator of arterial stiffness independent of blood pressure, in obesity and metabolic syndrome

Aortic stiffness is predictive of cardiovascular diseases (CVD) and mortality in lifestyle-related diseases. The cardio-ankle vascular index (CAVI), a new index of arterial stiffness, was recently developed by measuring of pulse wave velocity (PWV) and blood pressure (BP). CAVI is adjusted for BP based on stiffness parameter beta and is less influenced by BP, suggesting its superiority over brachial-ankle PWV (baPWV). However, there are currently no reports on the usefulness of CAVI as an atherogenic index in obesity and metabolic syndrome (MS). Among the 325 obese Japanese outpatients enrolled in the multi-centered Japan Obesity and Metabolic Syndrome Study, 216 patients (67%) met the criteria of MS according to the modified National Cholesterol Education Program-Adult Treatment Panel III. CAVI values were significantly higher in MS than in non-MS patients, whereas there was no significant difference in body mass index, total cholesterol, and low-density lipoprotein-cholesterol between both groups. CAVI values were weakly correlated with BP but closely correlated with the severity of MS and MS-related parameters such as hypoadiponectinemia, relative to baPWV. Furthermore, weight-reduction therapy through diet and exercise over a 3-month period significantly decreased CAVI values in parallel with increasing adiponectin. This study demonstrates for the first time that CAVI is a good indicator of arterial stiffness. It is closely correlated with the severity of MS and CVD risks in obesity and independent of BP, and is thus superior to baPWV. Therefore, the determination of arterial stiffness by CAVI may be useful for evaluating and managing the CVD risks of MS patients.

Relationship of cardio-ankle vascular index (CAVI) to carotid and coronary arteriosclerosis

BACKGROUND

The cardio-ankle vascular index (CAVI) has been recently reported as a new index of aortic stiffness, which is less influenced by blood pressure than pulse wave velocity (PWV). The present study investigated the relationship between the levels of CAVI and carotid and coronary arteriosclerosis.

METHODS AND RESULTS

The 443 consecutive patients who underwent CAVI, carotid sonography, and coronary angiography in hospital were examined. Intima-media thickness (IMT) and carotid plaque were evaluated by ultrasonography. The severity of coronary artery disease (CAD) was evaluated by coronary angiography and the subjects were divided into 4 groups (0, no significant organic stenosis: 1, 1-vessel disease: 2, 2-vessel disease: 3, 3-vessel disease). Univariate analyses showed that both CAVI and brachial-ankle PWV (baPWV) were associated with IMT and the presence of carotid plaque. Multiple stepwise regression analyses revealed that CAVI (p=0.0427), but not baPWV, was associated with the IMT. Both CAVI (p<0.0001) and baPWV (p=0.0140) were significantly associated with the severity of CAD. Multiple logistic analyses revealed that CAVI (p=0.0342), but not baPWV (p=0.8027), was associated with the presence of multivessel disease.

CONCLUSION

High CAVI implies progression of carotid and coronary arteriosclerosis. CAVI may be more closely linked with arteriosclerosis than baPWV.