Common carotid intima-media thickness and arterial stiffness: indicators of cardiovascular risk in high-risk patients. The SMART Study (Second Manifestations of ARTerial disease)

Carotid arterial wall characteristics are associated with incident ischemic stroke but not coronary heart disease in the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND PURPOSE

Ultrasound measurements of arterial stiffness are associated with atherosclerosis risk factors, but limited data exist on their association with incident cardiovascular events. We evaluated the association of carotid ultrasound-derived arterial stiffness measures with incident coronary heart disease (CHD) and ischemic stroke in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS

Carotid arterial strain and compliance, distensibility and stiffness indices, pressure-strain, and Young elastic moduli were measured in 10 407 individuals using ultrasound. Hazard ratios for incident CHD (myocardial infarction, fatal CHD, coronary revascularization) and stroke in minimally adjusted (age, sex, center, race) and fully adjusted models (minimally adjusted model+diabetes, height, weight, total cholesterol, high-density lipoprotein cholesterol, tobacco use, systolic blood pressure, antihypertensive medication use, and carotid intima-media thickness) were calculated.

RESULTS

The mean age was 55.3 years. Over a mean follow-up of 13.8 years, 1267 incident CHD and 383 ischemic stroke events occurred. After full adjustment for risk factors and carotid intima-media thickness, all arterial stiffness parameters (carotid arterial strain hazard ratio [HR], 1.14 [95% CI, 1.02-1.28]; arterial distensibility HR, 1.19 [1.02-1.39]; stiffness indices HR, 1.14 [1.04-1.25]; pressure-strain HR, 1.17 [1.06-1.28]; Young elastic moduli HR, 1.13 [1.03-1.24]), except arterial compliance (HR, 1.02 [0.90-1.16], were significantly associated with incident stroke but not with CHD.

CONCLUSIONS

After adjusting for cardiovascular risk factors, ultrasound measures of carotid arterial stiffness are associated with incident ischemic stroke but not incident CHD events despite that the 2 outcomes sharing similar risk factors.

CLINICAL TRIAL REGISTRATION

URL: www.clinicaltrials.gov. Unique identifier: NCT00005131.

Nonlinear mechanical behavior of the human common, external, and internal carotid arteries in vivo

BACKGROUND

The mechanical environment and properties of the carotid artery play an important role in the formation and progression of atherosclerosis in the carotid bifurcation. The purpose of this work was to measure and compare the range and variation of circumferential stress and tangent elastic moduli in the human common (CCA), external (ECA), and internal (ICA) carotid arteries over the cardiac cycle in vivo.

METHODS

Measurements were performed in the surgically exposed proximal cervical CCA, distal ECA, and distal ICA of normotensive patients (n = 16) undergoing carotid endarterectomy. All measurements were completed in vivo over the cardiac cycle in the repaired carotid bifurcation after the atherosclerotic plaque was successfully removed. B-mode Duplex ultrasonography was used for measurement of arterial diameter and wall thickness, and an angiocatheter placed in the CCA was used for concurrent measurement of blood pressure. A semiautomatic segmentation algorithm was used to track changes in arterial diameter and wall thickness in response to blood pressure. These measurements were then used to calculate the variation of circumferential (hoop) stresses, tangent elastic moduli (the slope of the stress-strain curve at specified stresses), and strain-induced stiffness of the arterial wall (stiffening in response to the increase of intraluminal blood pressure) for each patient.

RESULTS

The diameter and wall thickness of the segments (CCA, ECA, and ICA) of the carotid bifurcation were found to decrease and strain-induced stiffness to increase from proximal CCA to distal ECA and ICA. The circumferential stress from end-diastole (minimum pressure) to peak-systole (maximum pressure) varied nonlinearly from 25 ± 7 to 63 ± 23 kPa (CCA), from 22 ± 7 to 57 ± 19 kPa (ECA), and from 28 ± 8 to 67 ± 23 kPa (ICA). Tangent elastic moduli also varied nonlinearly from end-diastole to peak-systole as follows: from 0.40 ± 0.25 to 1.50 ± 2.05 MPa (CCA), from 0.49 ± 0.34 to 1.14 ± 0.52 MPa (ECA), and from 0.68 ± 0.31 to 1.51 ± 0.69 MPa (ICA). The strain-induced stiffness of CCA and ECA increased more than 3-fold and the stiffness of ICA increased more than 2.5-fold at peak-systole compared with end-diastole.

CONCLUSIONS

The in vivo mechanical behavior of the three segments of the carotid bifurcation was qualitatively similar, but quantitatively different. All three arteries--CCA, ECA and ICA--exhibited nonlinear variations of circumferential stress and tangent elastic moduli within the normal pressure range. The variability in the properties of the three segments of the carotid bifurcation indicates a need for development of carotid models that match the in vivo properties of the carotid segments. Finally, the observed nonlinear behavior of the artery points to the need for future vascular mechanical studies to evaluate the mechanical factors of the arterial wall over the entire cardiac cycle.

Clinical characterization of symptomatic microangiopathic brain lesions

Background: Microangiopathic brain lesions can be separated in diffuse lesions – leukoaraiosis – and focal lesions – lacunes. Leukoaraiosis and lacunes are caused by common cerebrovascular risk factors, but whether they represent a common entity is not sufficiently investigated. The present study aimed to determine the clinical profiles associated with the extent of leukoaraiosis and lacunes. Methods: Sixty-four consecutive patients with acute microangiopathic stroke were studied. Leukoaraiosis and lacunes were stratified according to their MRI-based extent. Standardized clinical assessment included clinical syndromes, cerebrovascular risk factors, cognitive performance, retinal imaging, ultrasonography, blood, and urine parameters. Results: Different clinical profiles for leukoaraiosis and lacunes were found. Regarding leukoaraiosis, the cognitive scores (SISCO, mini mental score examination, mental examination) and the presence of hyperlipidemia decreased as the severity of leukoaraiosis increased. Univariate and multivariate analysis revealed that these cognitive score values as well as the presence of hyperlipidemia correlated significantly with no or only mild leukoaraiosis. Regarding lacunes, the percentage of migraine, previous stroke events, hydrocephalus, left ventricular hypertrophy, and a higher National Institutes of Health Stroke Scale increased as the number of lacunar lesions increased. Statistical analysis revealed that these parameters correlated not significantly with the number of lacunes. Conclusions: The findings suggests that leukoaraiosis and lacunes are different microangiopathic entities potentially requiering different treatment concepts.

Frequency and related factors of masked hypertension at a worksite in Korea

Objectives

Masked hypertension is associated with metabolic risks and increased risk of cardiovascular disease. The purpose of this study was to identify the frequency of and risk factors of masked hypertension in Korean workers.

Methods

The study was conducted among 121 employees at a hotel in Gyeongju, Korea, from December 2008 to February 2009. We measured blood pressure (BP) both in the clinic and using 24-hour ambulatory BP monitors for all subjects. Hypertension was defined independently by both methods, and subjects were classified into four groups: true normotension, masked hypertension, white coat hypertension, and sustained hypertension.

Results

The frequency of masked hypertension in our study group was 25.6%. Compared with true normotension, the factors related to masked hypertension were male gender (odds ratio [OR], 10.7; 95% confidence interval [CI], 1.41 to 81.09), aging one year (OR, 0.88; 95% CI, 0.78 to 0.99), clinic BP 120-129/80-84 mmHg (OR, 8.42; 95% CI, 1.51 to 46.82), clinic BP 130-139 / 85-89 mmHg (OR, 12.14; 95% CI, 1.80 to 81.85), smoking (OR, 5.51; 95% CI, 1.15 to 26.54), and increase of total cholesterol 1 mg / dL (OR, 1.05; 95% CI, 1.02 to 1.08). In males only, these factors were clinic BP 120-129 / 80-84 mmHg (OR, 15.07; 95% CI, 1.55 to 146.19), clinic BP 130-139 / 85-89 mmHg (OR, 17.16; 95% CI, 1.56 to 189.45), smoking (OR, 11.61; 95% CI, 1.52 to 88.62), and increase of total cholesterol 1 mg/dL (OR, 1.05; 95% CI, 1.01 to 1.09).

Conclusions

The frequency of masked hypertension was high in our study sample. Detection and management of masked hypertension, a known strong predictor of cardiovascular risk, could improve prognosis for at-risk populations.

Segmental analysis of carotid arterial strain using speckle-tracking

BACKGROUND

Increased arterial stiffness has been shown to be associated with aging and cardiovascular risk factors. Speckle-tracking algorithms are being used to measure myocardial strain. The aims of this study were to evaluate whether speckle-tracking could be used to measure carotid arterial strain (CAS) reproducibly in healthy volunteers and to determine if CAS was lesser in individuals with diabetes.

METHODS

Bilateral electrocardiographically gated ultrasound scans of the distal common carotid arteries (three cardiac cycles; 14-MHz linear probe; mean frame rate, 78.7 ± 8.9 frames/sec) were performed twice (2-4 days apart) on 10 healthy volunteers to test repeatability. Differences in CAS between healthy subjects (n = 20) and patients with diabetes (n = 21) were examined. Peak CAS was measured in each of six equal segments, and averages of all segments (i.e., the global average), of the three segments nearest the probe, and of the three segments farthest from the probe (i.e., the far wall average) were obtained.

RESULTS

Global CAS (intraclass correlation coefficient = 0.40) and far wall average (intraclass correlation coefficient = 0.63) had the greatest test-retest reliability. Global and far wall averaged CAS values were lower in patients with diabetes (4.29% [SE, 0.27%] and 4.30% [SE, 0.44%], respectively) than in controls (5.48% [SE, 0.29%], P = .001, and 5.58% [SE, 0.44%], P = .003, respectively). This difference persisted after adjustment for age, gender, race, and hemodynamic parameters.

CONCLUSIONS

Speckle-tracking to measure CAS is feasible and modestly reliable. Patients with diabetes had lower CAS obtained with speckle-tracking compared with healthy controls.

Short-term effect of atorvastatin on carotid artery elasticity: a pilot study

BACKGROUND AND PURPOSE

Few studies have examined the early effects of statins on carotid artery elasticity, a potential surrogate marker of cardiovascular risk. This study examined the short-term effects of atorvastatin 80 mg daily on carotid elasticity measured by high-resolution B-mode ultrasound.

METHODS

The study included 40 stroke-free and statin-naive subjects older than age 45 (mean age, 70±7 years; 55% men; 64% Caribbean-Hispanic). Outcome measures included carotid stiffness indices at 14 and 30 days after initiation of treatment. The systolic and diastolic diameters of the right common carotid artery were averaged from multiple B-mode imaging frames. Absolute and relative changes of strain [(systolic diameter-diastolic diameter)/diastolic diameter], stiffness (β) [ln (systolic/diastolic blood pressure)/strain], and distensibility (1/β adjusted for wall thickness) from baseline were compared by the repeated measures t test and were considered significant at α=0.05.

RESULTS

Baseline mean stiffness was 0.08 (95% confidence interval [CI], 0.06-0.10). It significantly decreased at day 30 to 0.05 (CI, 0.04-0.06; P<0.01). Mean baseline distensibility was 15.25 (CI, 13.18-17.32), increasing significantly at day 30 to 17.23 (CI, 14.01-20.45; P<0.05). An improvement in distensibility of ≥10% from baseline was observed in 29 (73%) subjects. Changes in stiffness and distensibility were maximal among subjects with baseline low-density lipoprotein levels<130 mg/dL.

CONCLUSIONS

Short-term treatment with high-dose atorvastatin was associated with improvement in the carotid elasticity metrics. Carotid artery elasticity measured by B-mode ultrasound is a simple noninvasive measure of arterial wall function and may be a useful surrogate end point in clinical trials targeting individuals at increased risk for atherosclerosis.

Longitudinal levels of apolipoproteins and antibodies against phosphorylcholine are independently associated with carotid artery atherosclerosis 5 years after rheumatoid arthritis onset--a prospective cohort study

OBJECTIVE

RA is associated with premature atherosclerosis. Here, we determined the associations of apolipoproteins and immunoglobulin M (IgM) antibodies against phosphorylcholine (anti-PC) with carotid artery atherosclerosis in a prospective cohort of patients with early RA.

METHODS

In all 114 patients, age 50.6 (11.2) years, 68.4% women, with recent RA (<12 months after symptoms onset) were included and assessed at 0, 3, 12, 24 and 60 months after RA diagnosis. At the same time points, apolipoproteins were determined by immunoturbidimetry, and IgM anti-PC by ELISA. Carotid intima-media thickness (cIMT) (common carotid) and occurrence of plaques (common, internal and external carotids) were the principal study outcomes, which were examined with high-resolution B-mode ultrasonography after 5 years of RA disease. Mixed linear modelling and generalized estimating equations (GEEs) were used for longitudinal statistical analyses.

RESULTS

Multivariate regression analyses showed that age, male gender, smoking (ever) and history of cardiovascular disease (CVD), hypertension or diabetes mellitus, but no other baseline variables, had independent associations with cIMT (P < 0.05). Plaque detection was positively associated with age and smoking (ever). After adjustment, a longitudinal approach demonstrated an independent negative prediction of cIMT by apoA1 (P = 0.047), but a positive by apoB/apoA1 ratio (P = 0.030). Higher levels of pro-atherogenic apolipoproteins over time, apoB and apoB/apoA1 ratio, and low anti-PC tertile were independently associated with enhanced detection of bilateral carotid plaque (P = 0.002, 0.026 and 0.000, respectively). Both baseline and longitudinal levels of inflammatory/disease-related factors failed to show significant associations with the study outcomes.

CONCLUSION

Apolipoproteins and anti-PC may have independent roles in subclinical atherosclerosis in patients with RA.

Multiscale entropy analysis of pulse wave velocity for assessing atherosclerosis in the aged and diabetic

This study proposed a dynamic pulse wave velocity (PWV)-based biomedical parameter in assessing the degree of atherosclerosis for the aged and diabetic populations. Totally, 91 subjects were recruited from a single medical institution between July 2009 and October 2010. The subjects were divided into four groups: young healthy adults (Group 1, n = 22), healthy upper middle-aged adults (Group 2, n = 28), type 2 diabetics with satisfactory blood sugar control (Group 3, n = 21), and unsatisfactory blood sugar control (Group 4, n = 20). A self-developed six-channel electrocardiography (ECG)-PWV-based equipment was used to acquire 1000 successive recordings of PWV(foot) values within 30 min. The data, thus, obtained were analyzed with multiscale entropy (MSE). Large-scale MSE index (MEI(LS)) was chosen as the assessment parameter. Not only did MEI(LS) successfully differentiate between subjects in Groups 1 and 2, but it also showed a significant difference between Groups 3 and 4. Compared with the conventional parameter of PWV(foot) and MEI on R-R interval [i.e., MEI(RRI)] in evaluating the degree of atherosclerotic change, the dynamic parameter, MEI(LS) (PWV), could better reflect the impact of age and blood sugar control on the progression of atherosclerosis.

Carotid atherosclerosis and progression of brain atrophy: the SMART-MR study

OBJECTIVE

Atherosclerosis has been implicated in the development of brain atrophy. However, support for this association comes from cross-sectional studies.

METHODS

Within the Second Manifestations of ARTerial disease-Magnetic Resonance (SMART-MR) study, a prospective cohort study among patients with symptomatic atherosclerotic disease (mean age ± standard deviation, 58 ± 10 years; 80% men), magnetic resonance imaging of the brain was performed in 1,232 patients at baseline (2001-2005) and in 663 patients at follow-up (2006-2009). Brain segmentation was used to quantify total brain volume, cortical gray matter volume, and ventricular volume as indicators of global, cortical, and subcortical atrophy. At baseline, measurements of carotid intima-media thickness (CIMT) and carotid stenosis were performed. Carotid stenosis was classified into groups 0 of 50%, 50 of 70% (moderate), and >70% (severe) and into unilateral or bilateral stenosis.

RESULTS

Cross-sectional regression analyses showed that both increased CIMT and carotid stenosis were associated with decreased relative total brain and cortical gray matter volume. Our prospective findings showed that after a mean follow-up of 3.9 years (range, 3.0-5.8 years), CIMT and moderate stenosis were not related to progression of brain atrophy. Only severe or bilateral carotid stenosis was related to progression of global atrophy (β [95% confidence interval (CI)], -0.52% [-0.84 to -0.20%], -0.94% [-1.45 to -0.43%]), cortical atrophy (β [95% CI], -0.75% [-1.37 to -0.13%], -1.34% [-2.32 to -0.35%]), and subcortical atrophy (β [95% CI], 0.06% [-0.02 to 0.16%], 0.13% [0.01 to 0.28%]).

INTERPRETATION

In a study of patients with atherosclerotic disease with 4 years of follow-up, only severe or bilateral carotid stenosis, and not moderate carotid stenosis and increased CIMT, were associated with progression of brain atrophy.

Telmisartan improves morphologic and functional changes in both left ventricular myocardium and carotid arterial wall in patients with hypertension: assessment by tissue Doppler imaging and carotid ultrasonography

OBJECTIVE

The aim of the present study was to clarify the beneficial effects of telmisartan on the morphologic and functional changes in left ventricular (LV) myocardium and carotid arterial wall in patients with hypertension (HT) using tissue Doppler imaging and carotid ultrasonography.

METHODS

Telmisartan (20-40 mg daily) was administered to 35 previously untreated patients with HT. Conventional and pulsed tissue Doppler echocardiography were performed after medication had been continued for 1-2 months with normal values for blood pressure (BP) (phase I) and for 12 months (phase II). Subclinical atherosclerosis also was determined by measuring the intima-media thickness (IMT) and stiffness β of the left and right common carotid arteries using B- and M-mode ultrasonography.

RESULTS

In the phase II, the LV mass index and isovolumic relaxation time were lower, the peak systolic and early diastolic mitral annular motion velocities were greater compared to the phase I. The stiffness β and mean IMT were lower in the phase II than in the phase I. On multivariate regression analyses, age, BP, and LV diastolic variables emerged as stronger predictors of carotid arterial IMT and stiffness β.

CONCLUSIONS

The 1-year use of telmisartan improved LV hypertrophy, regional LV myocardial contraction and relaxation, and carotid atherosclerosis in patients with HT. Our results support cardio- and arterioprotective benefits from continuous long-term telmisartan monotherapy, and combined analysis of tissue Doppler imaging and carotid ultrasonography may be a useful tool for understanding ventriculoarterial coupling in patients with HT.

Effect of vascular risk factors on increase in carotid and femoral intima-media thickness. Identification of a risk scale

BACKGROUND

The well established correlation between intima-media thickness (IMT) and the risk of cardiovascular and cerebrovascular events and death is usually measured in subjects with multiple vascular risk factors, which makes it difficult, after application of the usual analysis-of-variance linear combination of effects model, to establish whether each cardiovascular risk factor has, per se, an effect on IMT.

METHOD AND RESULTS

In this study we investigated five "pure" groups of patients (865), i.e. each presenting only one of the following risk factors: hypertension, obesity, overweight, smoking, hypercholesterolaemia and a control group of 37 healthy subjects. We measured, both as discrete and as continuous variables, the following indices: intima-media thickening of the common carotid artery (IMT(C)) and of the common femoral artery (IMT(F)) and the ankle-brachial index (ABI). Descriptive statistics were used to analyse the prevalence of pathological values for the three indices in the different groups. Subsequently the entire group of 902 subjects was included in a correlation analysis in which the Pearson correlation coefficient for each pair of variables was computed. In order to assign the risk factors a continuous ranking, and obtain a more general idea of the correlation structure, principal component analysis (PCA) was used. The scores obtained from PCA made it possible to build a scale of severity of the vascular risk factors considered. All the risk factors considered were demonstrated to strongly affect the studied indices. Overweight was shown to be the least important risk factor with regard to intima-media thickening, followed by smoking, hypercholesterolaemia, hypertension and finally obesity, which emerged as the greatest risk factor.

CONCLUSIONS

The strong correlation between the indices made it possible to compute a composite general score, which provides an univocal risk estimation at single-patient level. IMT(F) was demonstrated to be the most sensitive descriptor. The construction of this risk scale has implications for preventive treatment and the frequency of instrumental examinations, allowing clear quantitative definition of the extent of the damage.

Imaging of atherosclerosis

It is now well recognized that the atherosclerotic plaques responsible for thrombus formation are not necessarily those that impinge most on the lumen of the vessel. Nevertheless, clinical investigations for atherosclerosis still focus on quantifying the degree of stenosis caused by plaques. Many of the features associated with a high-risk plaque, including a thin fibrous cap, large necrotic core, macrophage infiltration, neovascularization, and intraplaque hemorrhage, can now be probed by novel imaging techniques. Each technique has its own strengths and drawbacks. In this article, we review the various imaging modalities used for the evaluation and quantification of atherosclerosis.

A Virtual Instrument for Automated Measurement of Arterial Compliance

Measurement of arterial distensibility is very important in cardiovascular diagnosis for early detection of coronary heart disease and possible prediction of future cardiac events. Conventionally, B-mode ultrasound imaging systems have been used along with expensive vessel wall tracking systems for estimation of arterial distension and calculation of various estimates of compliance. We present a simple instrument for noninvasive in vivo evaluation of arterial compliance using a single element ultrasound transducer. The measurement methodology is initially validated using a proof of concept pilot experiment using a commercial ultrasound pulser-receiver. A prototype system is then developed around a PXI chassis using LABVIEW software. The virtual instrument employs a dynamic threshold algorithm to identify the artery walls and then utilizes a correlation based tracking technique to estimate arterial distension. The end-diastolic echo signals are averaged to reduce error in the automated diameter measurement process. The instrument allows automated measurement of the various measures of arterial compliance with minimal operator intervention. The performance of the virtual instrument was first analyzed using simulated data sets to establish the maximum measurement accuracy achievable under different input signal to noise ratio (SNR) levels. The system could measure distension with accuracy better than 10 μm for positive SNR. The measurement error in diameter was less than 1%. The system was then thoroughly evaluated by the experiments conducted on phantom models of the carotid artery and the accuracy and resolution were found to meet the requirements of the application. Measurements performed on human volunteers indicate that the instrument can measure arterial distension with a precision better than 5%. The end-diastolic arterial diameter can be measured with a precision better than 2% and an accuracy of 1%. The measurement system could lead to the development of small, portable, and inexpensive equipment for estimation of arterial compliance suitable in mass screening of “at risk” patients. The automated compliance measurement algorithm implemented in the instrument requires minimal operator input. The instrument could pave the way for dedicated systems for arterial compliance evaluation targeted at the general medical practitioner who has little or no expertise in vascular ultrasonography.

Genetically determined serum levels of mannose-binding lectin correlate negatively with common carotid intima-media thickness in systemic lupus erythematosus

OBJECTIVE

Patients with systemic lupus erythematosus (SLE) have excess cardiovascular morbidity and mortality due to accelerated atherosclerosis that cannot be attributed to traditional cardiovascular risk factors alone. Variant alleles of the mannose-binding lectin gene (MBL2) causing low serum concentrations of functional mannose-binding lectin (MBL) are associated with SLE and development of atherosclerosis. Recent studies show that these variant alleles are associated with increased risk of arterial thrombosis and cardiovascular disease in patients with SLE. Intima-media thickness of the common carotid artery (ccIMT) is a validated noninvasive anatomic measure of subclinical atherosclerosis. In a cross-sectional study we examined the relation among ccIMT, MBL2 genotypes, and serum concentrations of MBL.

METHODS

The MBL2 extended genotypes (YA/YA, YA/XA, XA/XA, YA/YO, XA/YO, YO/YO) and serum concentrations of MBL were determined in 41 outpatients with SLE. ccIMT was measured by means of ultrasonography. Traditional and nontraditional cardiovascular risk modifiers were assessed and controlled for.

RESULTS

Using nonparametric Mann-Whitney tests we found a significant difference in ccIMT between low-expressing (XA/XA+YA/YO+XA/YO+YO/YO) and high-expressing (YA/YA+YA/XA) MBL2 genotypes (p = 0.034). The difference in ccIMT remained significant in multivariable analysis adjusting for traditional and nontraditional cardiovascular risk modifiers (p = 0.049). ccIMT was negatively correlated to serum concentrations of MBL (Spearman rho = -0.33, p = 0.037). This relation also remained significant in multivariable analysis (p = 0.042).

CONCLUSION

In this group of SLE patients, MBL2 low-expressing genotypes and low serum levels of MBL were correlated with ccIMT, independent of the effects of traditional and nontraditional cardiovascular risk modifiers.

Common Carotid Artery Intima-media Thickness is not Increased but Distensibility is Reduced in Normotensive Patients with Type 2 Diabetes compared with Control Subjects

This study evaluated carotid artery parameters in normotensive patients with type 2 diabetes compared with non-diabetic control subjects. Using a high-resolution B-mode ultrasound scanner, common carotid artery intima-media thickness (IMT) and carotid tree atheroma thickness were measured in 82 patients with type 2 diabetes and 41 controls. The distensibility of the common carotid artery was calculated using the Reneman equation. Distensibility was significantly decreased and atheroma thickness was significantly increased in the diabetes group. There was no significant difference in IMT between the two groups. Stepwise linear regression analysis revealed an association between common carotid artery distensibility and post-ischaemic dilatation of the brachial artery (a measure of endothelial function), body mass index and diabetes duration in patients with type 2 diabetes. In conclusion, common carotid artery IMT in normotensive patients with type 2 diabetes is comparable to that of control subjects, whereas atheroma thickness is higher and arterial stiffness more pronounced in those with type 2 diabetes, indicating the existence of atherosclerotic changes in normotensive type 2 diabetes patients.

Interleukin-18 gene polymorphism and markers of subclinical atherosclerosis. The Cardiovascular Risk in Young Finns Study

BACKGROUND AND AIM

Interleukin-18 (IL-18) is a pro-atherosclerotic cytokine. We wanted to evaluate whether IL-18 gene polymorphism associates independently of risk factors, with early subclinical markers of atherosclerosis (intima-media thickness (IMT), coronary artery compliance (CAC), and flow-mediated dilatation (FMD)) in a population of young healthy Caucasian adults.

METHODS

This study was based on the on-going Cardiovascular Risk in Young Finns Study consisting of 2260 young adults, mean age being 31.7 (range 24-39 years) (1247 women and 1013 men).

RESULTS

Five studied tagSNPs formed six major haplotypes, which accounted for 99.9% of all variation of the IL-18 gene. According to adjusted analysis of variance, the IL-18 gene polymorphism did not associate with subclinical atherosclerosis in the whole study population. However, one major haplotype associated differently among men and women with IMT (P = 0.011). Male carriers of a major CCTgT haplotype (n = 441) seemed to have a lower IMT when compared to the non-carriers (-0.016 mm, 95% confidence interval (CI) -0.028 to -0.004, P = 0.014). Among women no significant associations were observed.

CONCLUSIONS

Among all study subjects, the polymorphism of the IL-18 gene is not associated with subclinical markers of atherosclerosis. However, among men one major IL-18 haplotype seemed to associate with substantially lower IMT values.

Association of Indian Diabetes Risk Score with arterial stiffness in Asian Indian nondiabetic subjects: the Chennai Urban Rural Epidemiology Study (CURES-84)

OBJECTIVE

In this study, we aim to determine the association of Indian Diabetes Risk Score (IDRS) with augmentation index (AI), a preclinical marker of early atherosclerotic changes.

METHODS

Subjects without known diabetes (n = 1985) were randomly selected from the Chennai Urban Rural Epidemiology Study, an ongoing population-based study on a representative population (aged >or=20 years) of Chennai, the largest city in Southern India. Augmentation index was measured using the Sphygmocor apparatus (Sphygmocor BPAS-1; PWV Medical, Sydney, Australia). Serum lipids were measured in an overnight fasting sample along with other biochemical parameters. Indian Diabetes Risk Score includes four parameters: age, abdominal obesity, family history of type 2 diabetes, and physical activity.

RESULTS

Arterial stiffness values increased with an increase in IDRS. Subjects with IDRS >or=60 had significantly higher AI (24.6 +/- 7.2; p < .001) compared to subjects with an IDRS of 30-60 (16.4 +/- 5.5; p < .001) and with IDRS <30 (13.3 +/- 4.5), and the p for trend was statistically significant (<.001). Pearson correlation analysis in the total population revealed that AI was significantly correlated with age (p < .001), systolic and diastolic blood pressure (p < .001), IDRS (p < .001), glycated hemoglobin A1c (A1C) (p < .001), serum cholesterol (p < .001), serum triglycerides (p < .001), high-density lipoprotein (HDL) cholesterol (p < .001), low-density lipoprotein cholesterol (p < .001), and non-HDL cholesterol (p < .001). In linear regression analysis, IDRS showed a significant association with AI even after adjusting for blood pressure, smoking, insulin resistance, A1C, cholesterol, and triglycerides (beta = 6.388; p < .001).

CONCLUSION

This study shows that, in addition to identifying unknown diabetes, IDRS also helps to identify those with arterial stiffness.

Relationship between serum homocysteine and other parameters in renal transplant patients

INTRODUCTION

Hyperhomocysteinemia frequently occurs after renal transplantation. We therefore assessed whether serum homocysteine (Hcy) concentrations were correlated with clinical, paraclinical, and arterial Doppler parameters among renal transplant patients.

METHODS

A cross-sectional study was performed on 47 patients (30 males, 17 females) who received unrelated living donor renal transplants.

RESULTS

The mean serum Hcy concentration was 21.7 +/- 8.4 micromol/L (range = 5.8-48 micromol/L); 37 patients (79%) showed hyperhomocysteinemia (Hcy >or= 15 micromol/L). Serum Hcy was strongly related to body mass index (BMI; r = .43, P = .002), cyclosporine trough level (r = .44, P = .005), and serum creatinine concentration (r = .32, P = .028), but not to age, transplant duration, or sex. Multivariate analysis showed that only BMI (P = .003) and cyclosporine trough level (P = .0037) were independent predictors of serum Hcy concentrations. Hyperhomocysteinemia was more prevalent among patients taking mycophenolate mofetil (MMF) than azathioprine (86% vs 50%; P = 0.017). The hyperhomocysteinemia and normohomocysteinemia groups did not differ significantly in mean carotid intima-media thickness (IMT; 0.78 +/- 0.348 vs 0.77 +/- 0.419 mm, P = .97) or mean intrarenal resistive index (RI) (0.7 +/- 0.06 vs 0.7 +/- 0.06, P = .85). The two groups also did not differ in sex prevalence, diabetes, C-reactive protein >or= 5 mg/L, or mean low-density lipoprotein, high-density lipoprotein, and mean arterial pressure (MAP) values.

CONCLUSION

Serum Hcy correlated with higher cyclosporine trough levels and obesity. Hyperhomocysteinemia was more common among patients taking MMF than azathioprine, but had no effect on intrarenal RI or carotid IMT.

Relationships between Obesity, Cardiorespiratory Fitness, and Cardiovascular Function

Background. Obesity and low cardiorespiratory fitness (CRF) have been shown to independently increase the risk of CVD mortality. The aim of this study was to investigate the relationship between CRF, body fatness and markers of arterial function. Method and Results. Obese (9 male, 18 female; BMI 35.3 ± 0.9 kg·m(-2)) and lean (8 male, 18 female; BMI 22.5 ± 0.3 kg·m(-2)) volunteers were assessed for body composition (DXA), cardiorespiratory fitness (predicted V˙O2max), blood pressure (BP), endothelial vasodilatator function (FMD), and arterial compliance (AC) (via radial artery tonometry). The obese group had more whole body fat and abdominal fat (43.5 ± 1.2% versus 27.2 ± 1.6%; P < .001 and 48.6 ± 0.9% versus 28.9 ± 1.8%; P < .001, resp.), and lower FMD (3.2 ± 0.4% versus 5.7 ± 0.7%; P < .01) than the lean subjects, but there was no difference in AC. AC in large arteries was positively associated with CRF (R = 0.5; P < .01) but not with fatness. Conclusion. These results indicate distinct influences of obesity and CRF on blood vessel health. FMD was impaired with obesity, which may contribute to arterial and metabolic dysfunction. Low CRF was associated with reduced elasticity in large arteries, which could result in augmentation of aortic afterload.

Double role of mannose-binding lectin in relation to carotid intima-media thickness in patients with rheumatoid arthritis

BACKGROUND

Patients with rheumatoid arthritis (RA) have increased risk of atherosclerosis and cardiovascular disease (CVD) that cannot be explained by excess of traditional risk factors. Several studies indicate that mannose-binding lectin (MBL) may modify the development of atherosclerosis; both high and low serum levels of MBL are reported to be associated with CVD. Intima-media thickness of the common carotid artery (ccIMT) is a validated non-invasive anatomic measure of subclinical CVD. We examined the relation between ccIMT and MBL in 114 RA patients.

METHODS

In a cross-sectional study MBL2 genotypes and serum concentrations of MBL were assessed; ccIMT was determined by means of ultrasonography; traditional and RA related cardiovascular risk modifiers were measured.

RESULTS

The median ccIMT was 0.67 mm. The investigated MBL2 genotypes were not significantly associated with ccIMT. Using a general linear model, ccIMT was not linearly associated with serum MBL but was highly associated with the quadratic term of serum MBL (MBL(2)) (P=0.001) reflecting a U-shaped relation. MBL(2) was also significantly associated with ccIMT in a multivariable analysis adjusting for traditional and RA related cardiovascular risk modifiers (P=0.025).

CONCLUSION

In RA patients, a quadratic U-shaped relation between serum MBL and ccIMT was observed independently of the effects of traditional and RA related risk factors for CVD. These results provide further support to the notion that both high and low levels of MBL may be associated with CVD.

The risk of the metabolic syndrome on carotid thickness and stiffness: sex and age specific effects

BACKGROUND AND PURPOSE

The metabolic syndrome (MS) is associated with a high risk for cardiovascular disease. Intima-media thickness (IMT) and stiffness reflect structure and functional alterations in arteries. We investigated the relationship of MS on IMT and stiffness and also dissected its gender and age specific effect.

METHODS

Carotid segment-specific IMT and stiffness were obtained in 1245 stroke- and myocardial infarction free volunteers between the ages of 15 and 87. The MS was defined according to the National Cholesterol Education Program Adult Treatment Panel III with Asian modification.

RESULTS

The prevalence of MS was 22.2% in our study population. The MS was associated with increased IMT in the common carotid artery (CCA IMT) and stiffness modalities (including Ep, beta, and PWV), but was not associated with bifurcation and internal carotid artery IMT. The relationship of MS on atherosclerosis was more prominent in women than in men. Only women revealed a significant interaction between MS and age for CCA IMT (p=0.013), which was more pronounced in young women (< or = 45 years) than in elderly. Comparing the risk components between young and elderly women in regard to MS, high triglycerides were more common in the affected young women (p=0.007).

CONCLUSIONS

MS is associated with a risk for increased CCA IMT and stiffness, and this relationship is particularly pronounced in women. Age can modify the MS impact on atherosclerosis. Young women with MS who often have high triglycerides experience the highest risk to associate with atherosclerosis. Young MS women who are easily overlooked for atherosclerotic diseases need more detailed assessment for atherosclerosis to prevent premature cardiovascular disease.

The high prevalence of subclinical atherosclerosis in patients with ankylosing spondylitis without clinically evident cardiovascular disease

We conducted the present study to determine whether subclinical macrovascular atherosclerotic disease was present in patients with ankylosing spondylitis (AS) without clinical history of cardiovascular disease. We also sought to establish whether demographic or clinical features of the disease may influence the development of subclinical atherosclerotic disease in a series of patients with AS seen at a community hospital. We recruited 64 patients who fulfilled the modified New York diagnostic criteria for AS from Hospital Xeral-Calde, Lugo, Spain. We excluded patients seen during the recruitment period who had cardiovascular disease or renal insufficiency. We also studied 64 matched controls. Carotid artery intima-media thickness (IMT) and carotid plaques were measured in the right common carotid artery. The study was performed using high-resolution B-mode ultrasound.Patients with AS exhibited greater carotid IMT than did matched controls (mean +/- SD, 0.74 +/- 0.21 mm vs. 0.67 +/- 0.14 mm; p = 0.01; differences of means, 0.077; 95% confidence interval, 0.016-0.139). Carotid plaques were more commonly observed in patients with AS than in controls (19 [29.7%] vs. 6 [9.4%], respectively; p = 0.03). The best predictors for carotid plaques in patients with AS were erythrocyte sedimentation rate (ESR) at time of disease diagnosis (odds ratio [OR], 1.18; 95% confidence intervals [CI], 1.04-1.33; p = 0.01) and duration of disease (OR, 1.39; 95% CI, 1.01-1.92; p = 0.05). In contrast, there was no significant correlation between carotid IMT and either ESR or C-reactive protein in this study. Results of the present study show that patients with AS without clinically evident cardiovascular disease have a high prevalence of subclinical macrovascular disease in the form of increased carotid IMT and carotid plaques compared to matched controls.

Cerebrovascular disease in diabetes mellitus: the role of carotid intima-media thickness

BACKGROUND AND PURPOSE

Cerebrovascular disease in diabetes appears to be less considered than coronary and peripheral disease, the reason being the intrinsic difficulty in finding available diagnostic tools for its early identification. Among these, carotid artery intima-media thickness (cIMT) represents the simplest measurable parameter for pre-atherosclerotic lesions in extra-cranic arteries.

METHODS

The role of cIMT as a surrogate marker of cerebral atherosclerosis and predictor of stroke, its relationship to microangiopathy and chronic inflammation, along with its role as an outcome parameter in anti-hyperglycemic therapeutical intervention trials in type 2 and 1 diabetes mellitus are discussed in this paper.

RESULTS AND CONCLUSIONS

Carotid IMT is increased in diabetes. It is an independent predictor of stroke, in particular of the ischemic subtype, and of stroke recurrence in diabetic, as well as in non-diabetic populations. A possible role of cIMT as a predictor of microangiopathy has also been suggested, but it needs further investigation. A weak association with chronic inflammation has been demonstrated in diabetic patients. Carotid IMT has been successfully employed as an outcome parameter for several anti-hyperglycemic therapeutic trials. However data on cIMT as a predictor of cerebrovascular disease are scarce in diabetic patients, particularly in type 1 diabetes, and more studies are needed to define the risk of cerebrovascular disease in diabetic patients.

Low bone mineral density is related to atherosclerosis in postmenopausal Moroccan women

BACKGROUND

Some studies have implicated several possible metabolic linkages between osteoporosis and vascular calcification, including estrogen deficiency, vitamin D excess, vitamin K deficiency and lipid oxidation products. Nevertheless, it remains unclear whether osteoporosis and atherosclerosis are related to each other or are independent processes, both related to aging. The aim of this cross-sectional study was to evaluate the correlation between arterial thickening and bone status in a sample of apparently healthy Moroccan women.

METHODS

Seventy-two postmenopausal women were studied. All patients were without secondary causes that might affect bone density. Bone status was assessed by bone mineral density (BMD) in lumbar spine and all femoral sites. Arterial wall thickening was assessed by intima-media thickness (IMT) in carotid artery (CA) and femoral artery (FA). Prevalent plaques were categorized into four groups ranging from low echogenicity to high echogenicity.

RESULTS

The mean age was 59.2 +/- 8.3 years. 84.7% had at least one plaque. By Spearman Rank correlation, CA IMT was negatively correlated to Femoral total BMD (r = -0.33), Femoral neck BMD (r = -0.23), Ward triangle BMD (r = -0.30) and Trochanter BMD (r = -0.28) while there was no association with lumbar BMD. In multiple regression analysis, CA IMT emerged as an independent factor significantly associated with all femoral sites BMD after adjusting of confounding factors. FA IMT failed to be significantly associated with both Femoral and Lumbar BMD. No significant differences between echogenic, predominantly echogenic, predominantly echolucent and echolucent plaques groups were found concerning lumbar BMD and all femoral sites BMD CONCLUSION: Our results demonstrate a negative correlation between bone mineral density (BMD) qnd carotid intima-media thickness (IMT) in postmenopausal women, independently of confounding factors. We suggest that bone status should be evaluated in patients with vascular disease to assess whether preventive or therapeutic intervention is necessarry.

Gadofosveset-enhanced MR angiography of carotid arteries: does steady-state imaging improve accuracy of first-pass imaging? Comparison with selective digital subtraction angiography

PURPOSE

To evaluate the diagnostic accuracy of gadofosveset-enhanced magnetic resonance (MR) angiography in the assessment of carotid artery stenosis, with digital subtraction angiography (DSA) as the reference standard, and to determine the value of reading first-pass, steady-state, and "combined" (first-pass plus steady-state) MR angiograms.

MATERIALS AND METHODS

This study was approved by the local ethics committee, and all subjects gave written informed consent. MR angiography and DSA were performed in 84 patients (56 men, 28 women; age range, 61-76 years) with carotid artery stenosis at Doppler ultrasonography. Three readers reviewed the first-pass, steady-state, and combined MR data sets, and one independent observer evaluated the DSA images to assess stenosis degree, plaque morphology and ulceration, stenosis length, and tandem lesions. Interobserver agreement regarding MR angiographic findings was analyzed by using intraclass correlation and Cohen kappa coefficients. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated by using the McNemar test to determine possible significant differences (P < .05).

RESULTS

Interobserver agreement regarding all MR angiogram readings was substantial. For grading stenosis, sensitivity, specificity, PPV, and NPV were, respectively, 90%, 92%, 91%, and 91% for first-pass imaging; 95% each for steady-state imaging; and 96%, 99%, 99%, and 97% for combined imaging. For evaluation of plaque morphology, respective values were 84%, 86%, 88%, and 82% for first-pass imaging; 98%, 97%, 98%, and 97% for steady-state imaging; and 98%, 100%, 100%, and 97% for combined imaging. Differences between the first-pass, steady-state, and combined image readings for assessment of stenosis degree and plaque morphology were significant (P < .001).

CONCLUSION

Gadofosveset-enhanced MR angiography is a promising technique for imaging carotid artery stenosis. Steady-state image reading is superior to first-pass image reading, but the combined reading protocol is more accurate.

Relation of common carotid intima-media thickness with left ventricular mass caused by shared risk factors for hypertrophy

BACKGROUND

It is unclear whether the relationship between common carotid intima-media thickness (cCIMT) and left ventricular mass (LVM) is due to shared risk factors for atherosclerosis or for hypertrophy.

METHODS

In 525 hypertensive subjects at high cardiovascular risk, the relation of cCIMT to LVM and established vascular risk factors was studied.

RESULTS

CCIMT was positively related to LVM. In a multivariable model including age, gender, height, weight, and LVM, a 1-g increase in LVM related to an increase in cCIMT of 1.6 microm (95% confidence interval, 0.8-2.4). After adjustment for atherosclerotic risk factors, notably previous stroke or transient ischemic attack, peripheral arterial disease, lipid-lowering medication, albuminuria and current smoking, the relation remained unchanged. In contrast, addition of systolic and diastolic blood pressure and hypertension treatment attenuated Beta for the relation between cCIMT and LVM with 19% to 1.3 microm (95% confidence interval, 0.2-2.2).

CONCLUSION

The relationship between cCIMT and LVM may be due to risk factors for hypertrophy rather than for atherosclerotic factors in a considerable proportion of patients.

Assessment of subclinical atherosclerosis and cardiovascular risk

Conventional cardiac risk factors do not fully explain the incidence of coronary artery disease and coronary events. Risk stratification and therapy based solely on these conventional risk factors may exclude a population who would otherwise benefit from lifestyle and risk factor modification. Recent efforts to improve our ability to recognize individuals and populations at increased risk of coronary events have focused on the noninvasive imaging of atherosclerosis, both in coronary and extracoronary arterial beds, or the identification of "non-traditional" serum markers. We review the complimentary role of these newer methods of risk stratification in the context of conventional risk factor evaluation.

Long-term effects of angiotensin II receptor blockade with valsartan on carotid arterial stiffness and hemodynamic alterations in patients with essential hypertension

Increased arterial stiffness and intima media thickness (IMT) in the common carotid artery (CCA) are related to cardiovascular risk in essential hypertension. Angiotensin II plays an important role in structural and functional changes in the vasculature. In this study, we evaluated the long-term effect of the angiotensin II receptor blocker, valsartan, on IMT, arterial stiffness, and hemodynamics in the CCA in patients with essential hypertension. A prospective 24 month study of treatment with valsartan (80-160 mg/day) was performed in 24 hypertensive patients. An ultrasound of the CCA was carried out to determine IMT, the cross-sectional distensibility coefficient (CSDC), the carotid arterial stiffness index beta, and diastolic flow velocity to systolic flow velocity ratio (Vd/Vs). Treatment with valsartan for 24 months reduced systolic and diastolic blood pressure significantly. Compared to baseline, the decrease in pulse pressure was greater after 24 months treatment than after 12 months treatment. Valsartan did not influence IMT; however, after 24 months, it caused a significant increase in CSDC and a decrease in stiffness index beta compared to baseline. These changes were not observed after 12 months of treatment. In addition, Vd/Vs, a sensitive marker of relative diastolic blood flow, increased after 24 months' treatment with valsartan. These results suggest that long-term treatment with valsartan improves vascular wall function and hemodynamics in patients with essential hypertension.

Non-invasive cardiac imaging techniques and vascular tools for the assessment of cardiovascular disease in type 2 diabetes mellitus

Cardiovascular disease is the major cause of mortality in type 2 diabetes mellitus. The criteria for the selection of those asymptomatic patients with type 2 diabetes who should undergo cardiac screening and the therapeutic consequences of screening remain controversial. Non-invasive techniques as markers of atherosclerosis and myocardial ischaemia may aid risk stratification and the implementation of tailored therapy for the patient with type 2 diabetes. In the present article we review the literature on the implementation of non-invasive vascular tools and cardiac imaging techniques in this patient group. The value of these techniques as endpoints in clinical trials and as risk estimators in asymptomatic diabetic patients is discussed. Carotid intima-media thickness, arterial stiffness and flow-mediated dilation are abnormal long before the onset of type 2 diabetes. These vascular tools are therefore most likely to be useful for the identification of 'at risk' patients during the early stages of atherosclerotic disease. The additional value of these tools in risk stratification and tailored therapy in type 2 diabetes remains to be proven. Cardiac imaging techniques are more justified in individuals with a strong clinical suspicion of advanced coronary heart disease (CHD). Asymptomatic myocardial ischaemia can be detected by stress echocardiography and myocardial perfusion imaging. The more recently developed non-invasive multi-slice computed tomography angiography is recommended for exclusion of CHD, and can therefore be used to screen asymptomatic patients with type 2 diabetes, but has the associated disadvantages of high radiation exposure and costs. Therefore, we propose an algorithm for the screening of asymptomatic diabetic patients, the first step of which consists of coronary artery calcium score assessment and exercise ECG.

Extracting the small vibrations of a vessel wall

Cardiac and vascular diseases are among the main causes of mortality. Diagnosis of these diseases in the early stages can be very helpful for their treatments. One of the effects of atherosclerosis is the reduction of vessel wall vibrations. Echocardiography images cannot show these vibrations, due to their lack of resolution. In this study a new model for vessel simulation in an ultrasonic system is proposed that can be used for RF signal generation for imaging vessel wall layers. To extract the high frequency vibrations, at the first stage large motion of the vessel wall due to heartbeat is removed from RF signals using continuous wavelet transform and then these simulated vibrations are estimated by calculating the phase difference between Hilbert transforms of signals. This method may be used to detect the areas with atherosclerotic plaque non-invasively and with a respectable spatial resolution. The proposed method has been used for real data from the inferior wall of the aorta and the anterior wall of the hepatic vein to evaluate the efficiency of this method for real ultrasound data.

Impact of statin therapy on left ventricular function and carotid arterial stiffness in patients with hypercholesterolemia

BACKGROUND

Hypercholesterolemia is a well-established risk factor for the development of vascular events. Statins have pleiotropic effects beyond reducing the low-density lipoprotein-cholesterol (LDL-C) concentration. This study sought to determine whether treatment with pitavastatin affects latent regional left ventricular (LV) systolic and diastolic dysfunction and carotid arterial stiffness in patients with hypercholesterolemia and preserved LV ejection fraction (LVEF), using newly developed ultrasonic strain imaging and carotid ultrasonography.

METHODS AND RESULTS

A total of 30 patients with hypercholesterolemia (>or=220 mg/dl for serum total cholesterol, and/or >or=140 mg/dl for LDL-C) were randomized to either administration of pitavastatin (1 or 2 mg/day; n=15) or no statin therapy (n=15) for 12 months. LV systolic and diastolic functions were evaluated by measuring transmitral flow velocity, mitral annular motion velocity, and the myocardial strain and strain rate profiles using pulsed Doppler, tissue velocity, and ultrasonic strain imaging. Subclinical atherosclerosis also was determined by measuring the intima - media thickness (IMT) and stiffness beta of the left and right common carotid arteries using B- and M-mode ultrasonography. During the follow-up period, the mean peak systolic strains of the LV posterior and inferior walls increased from 39.2+/-15.9% to 51.5+/-17.7% (p<0.01) and 46.0+/-12.2% to 57.5+/-10.3% (p<0.01), respectively, in the pitavastatin group compared with the no statin group. The mean peak early diastolic strain rates of the LV posterior and inferior walls also increased from -6.5+/-2.9 s(-1) to -9.5+/-2.8 s(-1) (p<0.01) and -6.5+/-2.5 s(-1) to -9.1+/-2.7 s(-1) (p<0.01), respectively, in the pitavastatin group. The stiffness beta decreased from 5.6+/-2.5 to 4.1+/-0.8 (p<0.05) in the pitavastatin group, whereas there was no significant change in IMT.

CONCLUSIONS

One year of pitavastatin treatment improved not only carotid arterial stiffness but also regional LV systolic and diastolic function in patients with hypercholesterolemia and preserved LVEF. Ultrasonic strain imaging has the potential to become a sensitive tool for detecting the effects of early medical intervention on latent regional LV myocardial dysfunction in this patient population.

Association between hemodynamics in the common carotid artery and severity of carotid atherosclerosis in patients with essential hypertension

BACKGROUND

Carotid intima-media thickness (IMT) and plaque burden evaluated by B-mode ultrasound have been used as relevant indicators for carotid atherosclerosis. This study was aimed to investigate the relationship between hemodynamic parameters in the common carotid artery (CCA) and the severity of carotid atherosclerosis in untreated hypertensive patients.

METHODS

Carotid IMT and plaque burden were evaluated in bilateral CCA, bifurcations, external and internal carotid arteries using duplex ultrasound in 80 untreated hypertensive patients. The patients were divided into four groups according to plaque burden. Hemodynamic parameters of CCA, including peak and mean circumferential wall tension (CWT), tensile stress (TS), wall shear stress (WSS), and Young's elastic modulus (YEM), were calculated after measurements of internal diameter (ID), IMT, and peak and mean flow velocities of CCA. Arterial stiffness was also assessed using the brachial-ankle pulse wave velocity (baPWV).

RESULTS

Age, pulse pressure, creatinine, carotid IMT, and mean TS were shown to have significant differences among the four plaque groups (P < 0.05). Peak CWT and peak TS were also shown to have marginal differences. In univariate analysis, the peak and mean CWT and TS were significantly correlated with plaque score. Stepwise multiple regression analysis showed that carotid IMT, age, and peak CWT were independently associated with plaque score.

CONCLUSIONS

These results suggest that the CWT and TS of the CCA are associated with the severity of carotid atherosclerosis in untreated hypertensive patients. Hence, the hemodynamics of vessels may contribute to the plaque burden of low-resistance arteries.

A one-year study of the antiatherosclerotic effect of the angiotensin-II receptor blocker losartan in hypertensive patients. A comparison with angiotension-converting enzyme inhibitors

Angiotensin receptor blockers (ARB) have been emerging as drugs to treat atherosclerosis. The effectiveness of the ARB losartan at reducing atherosclerosis was compared with that of ACE inhibitors in hypertensive patients. A total of 50 patients with hypertension were divided into 3 groups: a control group receiving neither an ARB nor an ACE inhibitor (n = 14), a losartan group (n = 22) receiving 50 mg/day of losartan, and an ACE inhibitor group (n = 14) receiving either 5 mg/day of enalapril or 5 mg/day of imidapril. Atherosclerosis was evaluated based on the intima-media thickness (IMT) of the common carotid artery measured by B-mode ultrasound at baseline and after approximately 12 months of treatment. After the treatment, IMT significantly decreased with losartan (from 0.87 +/- 0.14 to 0.79 +/- 0.16 mm, P < 0.05) and with ACE inhibitor (from 0.81 +/- 0.14 to 0.74 +/- 0.11 mm, P < 0.05). The reduction was comparable between the two groups, -0.078 +/- 0.136 with losartan and -0.073 +/- 0.109 mm with ACE inhibitor, and the rate of the reduction was similar between the two drugs; -0.098 +/- 0.142 mm/year with losartan and (-0.076 +/- 0.118 mm/year) with ACE inhibitor. On the contrary, IMT did not change in the control group (from 0.90 +/- 0.20 to 0.95 +/- 0.26 mm) during the treatment period. Concomitant medication and coronary risk factors such as hyperlipidemia, diabetes mellitus, and smoking did not differ significantly among the groups. The antiatherosclerotic effect of losartan on the carotid artery was comparable to that of ACE-inhibitors, and less adverse effects, such as coughing that occurs with ACE inhibitors, were observed. Losartan appears to be a better alternative to ACE inhibitors for treating atherosclerosis in Japanese hypertensive patients.

Optimal region-of-interest settings for tissue characterization based on ultrasonic elasticity imaging

Pathologic changes in arterial walls significantly influence their mechanical properties. We have developed a correlation-based method, the phased tracking method, for measurement of the regional elasticity of the arterial wall. Using this method, elasticity distributions of lipids, blood clots, fibrous tissue and calcified tissue were measured by in-vitro experiments of excised arteries (mean +/- SD: lipids, 89 +/- 47 kPa; blood clots, 131 +/- 56 kPa; fibrous tissue, 1022 +/- 1040 kPa; calcified tissue, 2267 +/- 1228 kPa). It was found that arterial tissues can be classified into soft tissues (lipids and blood clots) and hard tissues (fibrous tissue and calcified tissue) on the basis of their elasticity. However, there are large overlaps between elasticity distributions of lipids and blood clots and those of fibrous tissue and calcified tissue. Thus, it was difficult to differentiate lipids from blood clots and fibrous tissue from calcified tissue by setting a threshold for a single elasticity value. Therefore, we previously proposed a tissue classification method using the elasticity distribution in each small region. In this method, the elasticity distribution of each small region of interest (ROI) (not a single pixel) in an elasticity image is used to classify lipids, blood clots, fibrous tissue and calcified tissue by calculating the likelihood function for each tissue. In the present study, the optimum size of the ROI and threshold T(o) for the likelihood function were investigated to improve the tissue classification. The ratio of correctly classified pixels to the total number of classified pixels was 29.8% when the size of a small region was 75 microm x 300 microm (a single pixel). The ratio of correctly classified pixels became 35.1% when the size of a small region was 1,500 microm x 1,500 microm (100 pixels). Moreover, a region with an extremely low likelihood with respect to all tissue components was defined as an unclassified region by setting threshold T(o) for the likelihood function to 0.21. The tissue classification of the arterial wall was improved using the elasticity distribution of a small region whose size was larger than the spatial resolution (800 microm x 600 microm) of ultrasound. In this study, the arteries used in construction of the elasticity databases were classified into each tissue using the constructed elasticity databases. Other arteries, which are not used for constructing the elasticity databases, should be classified in future work to thoroughly show the effectiveness of the proposed method.

Carotid intima-media thickness predicts the development of cardiovascular events in patients with rheumatoid arthritis

OBJECTIVE

To establish whether carotid intima-media wall thickness (IMT) may be a good predictor for the development of cardiovascular (CV) events in patients with rheumatoid arthritis (RA).

METHODS

A series of 47 RA patients who at the time of recruitment did not have traditional CV risk factors or CV disease were assessed by carotid ultrasonography. Carotid IMT and carotid plaques were measured in the right common carotid artery. Then, a prospective assessment of the CV outcome was performed over a 5-year period. Logistic regression models and receiver operating characteristic curves were performed to evaluate the ability of different variables to predict CV events.

RESULTS

Carotid IMT was greater in RA patients who over the extended follow-up experienced CV events (1.01 +/- 0.16 mm) compared with the remaining RA patients who did not have CV complications (0.74 +/- 0.12 mm) (P < 0.001). Also, carotid IMT categorized in quartiles was strongly associated with CV events. In this regard, none of the patients with carotid IMT less than 0.77 mm had CV events. However, 6 of the 10 patients with carotid IMT greater than 0.91 mm experienced CV events (P value for the trend <0.001). Carotid IMT yielded a high predictive power for the development of CV events over the 5-year follow-up period. The area under the receiver operating characteristic curve was 0.93 for a model that only included carotid IMT and 0.90 for carotid plaque.

CONCLUSIONS

The results from the present study support the use of carotid ultrasonography as a predictor of CV events in RA.

Vascular disease and apathy in old age. The Leiden 85-Plus Study

BACKGROUND

Apathy is defined as an important loss of motivation in all domains of daily functioning. Especially in old age, apathy might be a specific neuropsychiatric syndrome separate from depression. There are indications that apathy in elderly subjects is related to vascular disease.

OBJECTIVE

To assess the relation between vascular disease and apathy in subjects aged 85 years and older.

METHODS

The Leiden 85-plus Study is a prospective, population-based study of 500 elderly subjects. Vascular disease including myocardial infarction, angina pectoris or myocardial ischemia, claudicatio intermittens, and arterial surgery was determined at baseline. Symptoms of apathy were assessed annually from age 85 through 90 years using the apathy questions of the 15-item Geriatric Depression Rating Scale (GDS). Diagnostic accuracy of the apathy questions was validated using the Apathy Scale at age 90 years. The association between vascular disease and apathy was estimated both at baseline and longitudinally.

RESULTS

The apathy items of the GDS showed a sensitivity of 69% and a specificity of 85%. At baseline, 69 subjects with apathy but free of depression had significantly more cardiovascular pathologies compared to 287 subjects without apathy. In the 287 subjects who were free of apathy and depression, increase of apathy but not depression during follow-up was significantly higher for each additional cardiovascular pathology at baseline.

CONCLUSION

In community dwelling elderly, those with vascular disease were at higher risk of developing apathy but not depression. This suggests that apathy and depression in old age have different etiologies.