Carotid plaque, intima media thickness, cardiovascular risk factors, and prevalent cardiovascular disease in men and women: the British Regional Heart Study

The relationship between age and carotid artery intima-media thickness, hemoglobin A1c in nondiabetic, healthy geriatric population

The aim of the study was to investigate a casual relationship between age and carotid artery intima-media thickness (IMT) and hemoglobin A1c (HbA1c) levels and to assess the effects of possible risk factors in healthy nondiabetic elderly. Seventy-two healthy, well-educated, nondiabetic, healthy elderlies (mean age: 71.5+/-5.01 years; 43 male, 29 female) were enrolled in the study. Comprehensive assessments including a battery of psychosocial and functional performance tests were performed to all subjects. All of them were also asked about health prevention topics including exercise, dietary habits, smoking, vaccination, cholesterol screening, etc. Carotid artery IMT was measured by ultrasound. Blood samples were obtained for fasting glucose, HbA1c, cholesterol, triglyceride and fibrinogen. The mean carotid artery IMT was 0.94+/-0.13 mm and the mean HbA1c level was 5.29+/-0.65 mg/dl. There was no significant correlation between age and carotid artery IMT (r(s)=0.15), HbA1c levels (r(s)=-0.08) and other possible atherosclerosis risk factors. Also there was no correlation between carotid artery IMT and HbA1c levels (r(s)=0.14). Our data indicated that the carotid artery IMT, HbA1c and age are not associated in a geriatric healthy, well-educated population. Comparative studies done on the elderly who do not benefit from preventive health care programs are needed to establish if preventive health care measures and risk factor modification are important in the elderly age group.

Endothelium-dependent vasodilation and carotid artery wall remodeling in athletes and sedentary subjects

In this study, the relationship between age, carotid artery remodeling, and endothelium-dependent vasodilation is investigated in sedentary subjects and athletes. Thirty-two young and old healthy sedentary subjects and 32 age-matched endurance athletes underwent ultrasonography of the carotid wall for measuring intima-media thickness (IMT) and corrected integrated backscatter (C-IBS), two early indicators of the atherosclerosis process. Endothelium-dependent vasodilation was assessed by intra-brachial acetylcholine (strain-gauge plethysmography), at baseline and during NO sythase inhibitor NG-monomethyl-L-arginine (L-NMMA), and the antioxidant Vitamin C. Response to sodium nitroprusside (SNP) was also evaluated. Independently of trained status, IMT and C-IBS were higher in older than in young individuals (p<0.0001), while response to acetylcholine, but not to SNP, was lower (p<0.0001). Older athletes showed lower IMT, lower C-IBS (p<0.0001), greater response to acetylcholine (p<0.0001), and greater inhibition of acetylcholine by L-NMMA (p<0.001) than older controls. Only in older sedentary individuals, Vitamin C increased response to acetylcholine (p<0.001) and restored the inhibiting effect of L-NMMA (p<0.01). In the whole population maximal acetylcholine-induced vasodilation was inversely related to IMT (r=-0.60, p<0.0001) and to C-IBS (r=-0.56, p<0.0001). In conclusion, regular physical training can attenuate the age-related impairment of endothelium-dependent vasodilation, which is related to an attenuation of the age-induced remodeling of the carotid wall.

Circulating inflammatory markers and risks of cardiovascular and non-cardiovascular disease

There is current interest in the associations of circulating inflammatory markers (C-reactive protein, fibrinogen, white cell count, albumin, erythrocyte sedimentation rate, the factor VIII:von Willebrand factor complex, the tissue plasminogen activator:plasminogen activator inhibitor type 1 complex, fibrin D-dimer) not only with prognosis in acute coronary syndromes and acute stroke, but also in prediction of cardiovascular events in the general population. Recent meta-analyses of long-term prospective studies have established their associations with coronary heart disease (CHD) events, which may be cause, consequence or coincidence. These markers are also associated in epidemiologic studies of general populations with many cardiovascular risk factors (which may confound their associations with CHD risk), and also with asymptomatic arterial disease (of which they be consequences: 'reverse causality'). The causality of their associations with cardiovascular events is questioned by their lack of specificity for risk of cardiovascular events; and by the lack of association of their functional genotypes with CHD in 'Mendelian randomized trials'. Hence, proof of causality awaits testing in randomized-controlled trials of long-term selective reduction by future agents. Markers are of little additional predictive value to current cardiovascular risk scores, and it is premature to advocate their use in screening for cardiovascular risk prior to careful evaluation of costs, risks, and benefits.

Early Carotid Atherosclerosis in Women: Results of an Ultrasonographic Study Measuring Carotid Artery Intima-Media Thickness

Ultrasonography (US) is a useful diagnostic tool in detecting early vascular diseases in women and is particularly relevant in the elderly population. Increased carotid artery intima-media thickness (IMT) is a predictive marker of onset of atherosclerosis and is associated with vascular events. The objective of the present study was to determine carotid artery IMT in asymptomatic women of different age classes and to correlate the results with metabolic and coagulative parameters, age, and menopause. A total of 1200 women age 29-73 years selected from the electoral list of the city of Catania, Italy consented to participate in the US study to determine IMT. The percentage of IMT values exceeding an IMT cutoff value of < 1.3 mm observed in our study groups was significant. Correlations were observed between IMT and total cholesterol (r = .157), high-density lipoprotein (HDL) cholesterol (r = .87), low-density lipoprotein (LDL) cholesterol (r = .149), and fibrinogen (r = .140) values. Increased ultrasonographic markers showing onset of carotid artery remodeling can be observed in asymptomatic women of all ages. Some cardiovascular risk factors are linked to the initial stages of atherosclerosis. We recommend US screening in healthy populations to identify subjects who could develop vascular disease.

Quantification of carotid plaque volume measurements using 3D ultrasound imaging

An accurate and reliable technique used to quantify carotid plaque volume has practical importance in research and patient management. In this study, we develop and investigate a theoretical description of carotid plaque volume measurements made using three-dimensional (3D) ultrasound (US) images and compare it with experimental results. Multiple observers measured 48 3D US patient images of carotid plaque (13.2 to 544.0 mm(3)) by manual planimetry. Coefficients of variation in the measurement of plaque volume were found to decrease with increasing plaque size for both inter- (90.8 to 3.9%) and intraobserver (70.2 to 3.1%) measurements. Plaque volume measurement variability was found to increase with interslice distance (ISD), while the relative measurement accuracy remained constant for ISDs between 1.0 and 3.0 mm and then decreased. Root-mean-square (RMS) difference between our theoretical description of plaque volume measurement variance and the experimental results was 5.7%. Thus, our results support the clinical utility of measuring carotid plaque volume by manual planimetry noninvasively using 3D US.

Impaired lung function and subclinical atherosclerosis

An association between reduced pulmonary function and increased risk of atherosclerotic vascular events has been reported. The mechanisms underlying this association are unknown, but are unlikely to be entirely due to smoking given the presence of the association among non-smokers. Few studies have examined the cross-sectional association between subclinical atherosclerosis and pulmonary function. In 14,000 adults in the ARIC Study, we examined the cross-sectional relationship between lung function, measured by the forced expiratory volume at 1s (FEV(1)), and three markers of subclinical atherosclerosis: ankle-brachial index (ABI), carotid intimal-medial thickness (IMT), and presence of carotid plaques. Mean FEV(1) was computed by ABI category, IMT category, or plaque status, in the full cohort and after stratification by smoking status, adjusted for age, gender, race, study center, height, height-squared, smoking, and pack years. Decreased FEV(1) was associated with decreased ABI and increased IMT in the full cohort and in each smoking group. Further adjustment for CVD risk factors did not alter the ABI association, but attenuated the IMT association, eliminating it in never smokers. Plaque was not associated with FEV(1). These findings suggest a complex relationship between FEV(1) and atherosclerotic vascular disease that invites further study.

Common carotid artery intima-media thickness for the risk assessment of lacunar infarction versus intracerebral haemorrhage

BACKGROUND AND PURPOSE

Arterial hypertension is the major risk factor for intracerebral haemorrhage (ICH) and lacunar infarction (LI) and both types of cerebral lesions originate from pathology of the same deep perforating small arteries. We aimed to evaluate the relationship between vascular risk factors including common carotid artery intima-media thickness (CCA-IMT) with LI versus ICH.

METHODS

We prospectively collected data from 159 first ever stroke patients (67 cases with ICH and 92 cases with LI) with documented history of hypertension. All subjects underwent B-mode ultrasonographic measurements of the CCA-IMT. Logistic regression modelling was used to determine the factors (established vascular risk factors, severity and duration of hypertension, concomitant medications and CCA-IMT) that may significantly differentiate LI from ICH.

RESULTS

Patients with LI had significantly (p=0.002) larger CCA-IMT values (0.926 mm, 95% CI: 0.881-0.971) than subjects with ICH (0.815 mm, 95% CI: 0.762-0.868) even after adjusting for baseline characteristics and cardiovascular medications. The multivariate logistic regression procedure selected CCA-IMT, diabetes mellitus and hypercholesterolaemia as the only independent factors able to discriminate between LI and ICH. The risk for LI versus ICH increased continuously with increasing CCA-IMT. For each increment of 0.1 mm in CCA-IMT the probability of suffering from LI versus ICH increased by 36.6% (95 % CI: 13%-65.2%, p=0.001) even after adjustment for cardiovascular risk factors.

CONCLUSIONS

Increased CCA-IMT values are a factor favouring LI over ICH in hypertensive patients. The measurement of CCA-IMT may be a useful non-invasive diagnostic tool for the risk assessment of LI with respect to ICH in such patients.

Incident coronary events and case fatality in relation to common carotid intima-media thickness

OBJECTIVES

To evaluate the incidence of coronary events (CE) and case fatality in relation to common carotid intima-media thickness (IMT) and carotid plaque over a median follow up of 7 years.

SUBJECTS

A total of 5163 Swedish middle-aged men and women with no prior myocardial infarction and/or stroke.

METHODS AND RESULTS

The associations amongst B-mode ultrasound determined common carotid IMT, carotid plaque (focal IMT > 1.2 mm) and carotid stenosis (lumen reduction of >15%) and incident CE, were investigated in relation to cardiovascular risk factor levels. Age- and sex-adjusted common carotid IMT, carotid plaque and carotid stenosis were significantly (P < 0.05) related to future CE. Adjustment for established risk factors generally reduced the hazard rate ratios. However, the continuous measure of common carotid IMT, carotid plaque and carotid stenosis were significantly related to incident CE, even after risk factor adjustment. The strength of the associations between common carotid IMT and CE was only to a small extent reduced after adjustment for presence of carotid plaque. There were no statistically significant associations between common carotid IMT, carotid plaque or carotid stenosis and short-term case-fatality rates (28-days mortality) or long-term case-fatality rates (5-years mortality).

CONCLUSIONS

The results show an association between common carotid IMT and incident CE, independently of cardiovascular risk factors and carotid plaque. However, there was no association with short-term or long-term mortality after a CE.

Assessment of arterial medial characteristics in human carotid arteries using integrated backscatter ultrasound and its histological implications

Recently, ultrasound tissue characterization of the carotid arteries with an integrated backscatter (IB) analysis was shown to identify a high-risk group of atherosclerosis. To clarify whether IB ultrasound is useful in assessing arterial sclerosis as well as stiffness beta and whether IB values reflect the histological structure, we measured IB values of common carotid media in 52 subjects without coronary risk factors and in 10 patients with systemic sclerosis (SSc) in the clinical studies and 12 patients in the histological studies with a Philips Medical Systems Sonos 5500. IB values were correlated with age (r=0.69, P<0.0001), intima-media thickness (r=0.72, P<0.0001) and stiffness beta (r=0.80, P<0.0001) in the control subjects. IB values and stiffness beta in the SSc group were greater than in an age- and sex-matched control group (IB values: 9.6+/-2.7dB versus 16.1+/-1.8dB; stiffness beta: 11.5+/-4.5 versus 20.6+/-5.6, P<0.01). IB values of the media were correlated with the elastic fragmentation index (r=0.63, P=0.029) and the collagen fiber index (r=0.59, P=0.046). Measurements of IB values of carotid media are useful for non-invasively evaluating arterial sclerosis.

Lifestyle and cardiovascular disease in middle-aged British men: the effect of adjusting for within-person variation

AIMS

To examine the effect that within-person variation has on the estimated risk associations between cigarette smoking, physical inactivity, and increased body mass index (BMI) and the development of cardiovascular disease (CVD) in middle-aged British men.

METHODS AND RESULTS

In total, 6452 men aged 40-59 with no prior evidence of CVD were followed for major CVD events (fatal/non-fatal myocardial infarction or stroke) and all-cause mortality over 20 years; lifestyle characteristics were ascertained at regular points throughout the study. A major CVD event within the first 20 years was observed in 1194 men (18.5%). Use of baseline assessments of cigarette smoking and physical activity in analyses resulted in underestimation of the associations between average cumulative exposure to these factors and major CVD risk. After correction for within-person variation, major CVD rates were over four times higher for heavy smokers (> or =40 cigarettes/day) compared with never smokers and three times higher for physically inactive men compared with moderately active men. Major CVD risk increased by 6% for each 1 kg/m(2) increase in usual BMI. If all men had experienced the risk levels of the men who had never regularly smoked cigarettes, were moderately active, and had a BMI of < or =25 kg/m(2) (6% of the population), 66% of the observed major CVD events would have been prevented or postponed (63% before adjustment for within-person variation). Adjustment for a range of other risk factors had little effect on the results. Similar results were obtained for all-cause mortality.

CONCLUSION

Failure to take account of within-person variation can lead to underestimation of the importance of lifestyle characteristics in determining CVD risk. Primary prevention through lifestyle modification has a great preventive potential.

Association of carotid intima-media thickness with mesenteric, preperitoneal and subcutaneous fat thickness

Carotid intima-media thickness (IMT) is an established surrogate marker for atherosclerosis. We have previously reported that abdominal fat, notably mesenteric fat, was a major explanatory variable for multiple cardiovascular risk factors. Given the intimate relationships between visceral fat, cardiovascular risk factors and atherosclerosis, we hypothesize that there are independent relationships between mesenteric fat and carotid IMT. Two hundred and eighty-two Chinese subjects (M: 129, F: 153; mean body mass index (BMI): 23.8 kg/m(2); age range: 20-68 years) were recruited. Maximum carotid IMT as well as maximum mesenteric, preperitoneal and subcutaneous fat thickness were measured by carotid and abdominal ultrasound examinations, respectively. Obesity index and conventional cardiovascular risk factors were assessed by physical examination and blood taking. On univariate analysis, mesenteric but not preperitoneal fat thickness was the major correlate with carotid IMT in both men and women. There was also a weak correlation between carotid IMT and subcutaneous fat thickness in women. On multivariate analysis, mesenteric fat thickness was an independent determinant of carotid IMT after adjustment for subcutaneous and preperitoneal fat thickness, age, gender, blood pressure, insulin resistance, lipid and glycaemic parameters. The association of mesenteric fat thickness with carotid IMT appeared stronger in women than in men, which however was not confirmed on multivariate analysis. In conclusion, mesenteric fat thickness measured on ultrasound showed significant association with carotid IMT, lending further support to the linking role of portal adipose tissue in obesity-related atherosclerosis. Effect of gender on the relationships of mesenteric fat with atherosclerosis risk require further elucidation. Measurement of mesenteric fat thickness may be a useful indicator of regional fat distribution in the assessment of cardiovascular risks.

Incidence of stroke is related to carotid IMT even in the absence of plaque

BACKGROUND

The carotid intima-media thickness (IMT) has been associated with incidence of stroke. Whether this association is independent of carotid plaque is controversial.

METHODS AND RESULTS

The associations among B-mode ultrasound determined common carotid IMT, carotid plaque (focal IMT>1.2mm) and incident stroke, were investigated in 5163 Swedish middle-aged men and women over a median follow-up of 7 years. Age and sex-adjusted carotid IMT, and carotid plaque were significantly (p<0.05) related to future stroke. Adjustment for cardiovascular risk factors generally reduced the hazard rate ratios, however more prominently so with regard to the carotid measure of plaque than with IMT. The associations between carotid IMT and stroke remained after adjustment for presence of carotid plaque, and graded associations between carotid IMT and stroke was found both among those with and without carotid plaque.

CONCLUSIONS

In this population-based study, common carotid IMT was associated with incidence of stroke. This relation was independent of presence of carotid plaque.

What is the best strategy for reducing deaths from heart disease?

BACKGROUND TO THE DEBATE

Coronary artery disease is a major cause of death worldwide. Two very different approaches have been proposed as a way of reducing these deaths. The "high risk" approach uses tools such as risk factor scoring and carotid ultrasound to try and identify those at highest risk, and then treats them aggressively. The "population" approach aims to shift the distribution of risk factors across a population in a beneficial direction with the goal of reducing heart disease in the whole population.

Carotid intima-media thickness: is it correlated with stroke side?

OBJECTIVE

The objective of the present study was to investigate the possible correlation between the common carotid artery (CCA) intima-media thickness (IMT) and the infarct side.

METHOD

The CCA IMTs in patients with atherosclerotic non-lacunar stroke were measured.

RESULTS

The mean age of the patients was 64.3 +/- 10.7 years (range 40-83 years) and 42 of 100 patients were male. The infarcts were at the left side in 53 patients and at the right side in 47 patients. The mean CCA IMT was 1.02 +/- 0.18 mm at the infarct side and 0.87 +/- 0.17 mm at the contralateral side. The difference between them was statistically significant (P < 0.01). Although the mean age of the patients with a left-sided infarct was greater than that of the patients with a right-sided infarct, the difference was not statistically significant.

CONCLUSION

Our results suggest that CCA IMT may be used in prediction of possible infarct side, and in the prediction of potential risk of stroke by evaluating the IMT of both CCAs separately.

Relationship of carotid intima-media thickness, pulse wave velocity, and ankle brachial index to the severity of coronary artery atherosclerosis

BACKGROUND

Carotid intima-media thickness (IMT), pulse wave velocity (PWV), and the ankle brachial index (ABI) are widely used noninvasive modalities for evaluating atherosclerosis.

HYPOTHESIS

The aim of this study was to determine the relationship of carotid IMT, PWV, and ABI with the severity of coronary artery disease (CAD), expressed as the Gensini score, and the presence of coronary risk factors.

METHODS

We examined 205 consecutive patients (mean age 65 +/- 12 years) who were clinically suspected of having CAD and were scheduled to undergo coronary angiography. Carotid intima-media thickness, brachial-ankle PWV (baPWV), and ABI were measured in all subjects before they underwent coronary angiography.

RESULTS

Of the 205 patients, 124 patients were diagnosed as having CAD based on the presence of >50% stenosis in a major coronary artery; the remaining 81 patients did not have CAD. A relatively good correlation was obtained between carotid IMT and the Gensini score (R = 0.411, p < 0.0001), whereas baPWV correlated only weakly with the Gensini score (R = 0.203, p = 0.0035), and ABI did not correlate with it. A multiple regression analysis revealed that the Gensini score correlated significantly and independently with age, male gender, and carotid IMT.

CONCLUSIONS

Of the three noninvasive methods, carotid IMT may be more useful for determining coronary artery atherosclerosis than baPWV or ABI.

Depressive symptoms are independently predictive of carotid atherosclerosis

The investigators tested whether depressive symptoms were predictive of carotid atherosclerosis, a marker of coronary atherosclerosis. Healthy participants (n = 219) underwent the baseline assessment of cardiovascular risk factors, including self-reported depressive symptoms, and were assessed for carotid plaque at 10-year follow-up. Adjusting for baseline cardiovascular risk factors, participants with elevated depression scores at baseline were >2 times as likely as those with no depressive symptoms to have carotid plaque.

Evaluation of carotid artery wall thickness with high-resolution sonography in obstructive sleep apnea syndrome

PURPOSE

An increased intima-media thickness (IMT) in the carotid arteries is a marker of generalized atherosclerosis, and it has been associated with a high risk of stroke. The aim of this study was to investigate whether patients with obstructive sleep apnea syndrome (OSAS) have an increase in atherosclerotic indicators in the carotid arteries.

METHODS

We studied 30 men with severe OSAS who had an apnea-hypopnea index (AHI) of at least 20. IMT measurement and the presence of stenotic occlusive lesions in the carotid arteries (right common carotid artery [RCCA], right bulb [Rbulb], right internal carotid artery [RICA], left common carotid artery [LCCA], left bulb [Lbulb], and left internal carotid artery [LICA]) were investigated by high-resolution sonography. Results of the sonographic examinations were compared with those for a group of 20 subjects with mild OSAS (AHI <20) and 20 healthy subjects.

RESULTS

The mean IMT of the carotid arteries of patients with severe OSAS was significantly higher than those of patients with mild OSAS and control subjects (RCCA 0.81 versus 0.63 versus 0.58, p <0.01; Rbulb 0.96 versus 0.87 versus 0.65, p <0.001; RICA 0.77 versus 0.69 versus 0.61, p <0.05; LCCA 0.97 versus 0.78 versus 0.67, p <0.01; Lbulb 1.01 versus 0.89 versus 0.72, p <0.01; LICA 0.91 versus 0.75 versus 0.65, p <0.001).

CONCLUSIONS

This study shows that the carotid arteries' IMT is increased in patients with severe OSAS. This increase may predispose the patients to cerebrovascular disease. Additionally, the findings support the hypothesis that patients with OSAS are at risk of developing cerebrovascular disease regardless of the presence or absence of other vascular risk factors (eg, hypercholesterolemia, diabetus mellitus, and hypertension).

Common carotid artery intima media thickness and post-stroke cognitive impairment

BACKGROUND AND PURPOSE

Acute stroke and other forms of cerebrovascular disease are well-recognized causes of cognitive impairment. Common carotid artery intima media thickness (CCA-IMT) has been associated with certain forms of cerebrovascular disease, but its association with cognitive impairment of vascular origin has not been elucidated. The purpose of this study was to investigate whether CCA-IMT is associated with cognitive impairment 1 year after an acute ischemic stroke.

METHODS

A total of 171 consecutive patients with the first ever stroke (mean age 66+/-11.5, 41% female) underwent carotid ultrasonography during hospitalization. Demographic data, vascular risk factors and presenting stroke features were also recorded. One year later, patients' cognitive performance and depression were assessed using the Mini-Mental State Examination (MMSE), and the Montgomery Asberg Depression Rating Scale (MADRS).

RESULTS

Cognitive impairment (MMSE score<24) was found in 67 (39%) of the 171 patients. CCA-IMT was significantly associated with cognitive impairment, and this association remained unchanged (OR 1.94; 95% CI 1.19-3.18) after adjustment for demographic data, vascular risk factors, stroke features, other carotid ultrasonography measurements and depression. Older age, low education level, large hemispheric lesions, hyperdense carotid plaques and depression were also independently associated with post-stroke cognitive impairment.

CONCLUSIONS

In this study, CCA-IMT was independently associated with cognitive impairment 1 year after an acute ischemic stroke, and thus, it might help with the screening of stroke patients at risk of cognitive impairment.

Mannheim intima-media thickness consensus

Intima-media thickness (IMT) is increasingly used in clinical trials as a surrogate end point for determining the success of interventions that lower risk factors for atherosclerosis. The necessity for unified criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is addressed in this consensus statement. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness of > or =1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is recommended in all epidemiological and interventional trials dealing with vascular diseases to improve characterization of the population investigated. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from few exceptions. Although IMT has been suggested to represent an important risk marker, it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of studies incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.

Mathematical estimation of the potential effect of vascular remodelling/dilatation on B-mode ultrasound intima-medial thickness

BACKGROUND

Arterial diameter changes are known to impact wall thickness, but the clinical relevance of the changes is unclear.

AIM

To use known mathematical relationships to estimate anticipated changes in arterial wall thicknesses occurring with enlargement of atherosclerotic regions.

DESIGN

Mathematical relationships between a cylinder's diameter and its wall thickness were used to calculate the theoretical effect of diameter enlargement on the thickness of an atherosclerotic wall.

METHODS

Equating the wall areas of two cylinders, one of smaller diameter than the other, allowed estimation of the degree of thickening that would be needed to maintain intima-medial thickness (IMT) after arterial remodelling. The difference in cylinder diameters was based on arterial diameter enlargement reported with atherosclerosis progression. Thus, the calculated wall changes estimate arterial changes which could go undetected if only IMT is measured by ultrasound.

RESULTS

The expected IMT change for diameter enlargement is not a linear function of the diameter change, but varies depending upon initial size (diameter and IMT). Thus a 0.6 mm arterial diameter enlargement would be expected to cause a 0.039-0.235 mm change in IMT, depending on artery size. The estimated IMT change is similar to that associated with major atherosclerotic risk factors.

DISCUSSION

The level of vascular remodelling reported with atherosclerosis could have a measurable impact on IMT, suggesting that indicators incorporating both diameter and IMT may be better disease indicators than IMT alone. Arterial diameters, as well as IMT, should be obtained in ultrasound studies of atherosclerosis.

Sex differences in body fat distribution and carotid intima media thickness: cross sectional survey using data from the British regional heart study

OBJECTIVE

To determine the role of central adiposity in explaining sex differences in carotid intima media thickness (IMT).

DESIGN

Cross sectional survey.

SETTING

Two British towns.

PARTICIPANTS

800 men and women aged 56-75 years.

MAIN OUTCOME MEASURES

Carotid IMT.

RESULTS

There was a continuous linear association between waist-hip ratio and IMT in both men and women. The magnitude of the association between waist to hip ratio and IMT was identical in both sexes. In age adjusted analyses IMT was 14% greater in men compared with women (age adjusted male to female ratio of geometric means 1.14; 95% confidence interval 1.07 to 1.21) with adjustment for waist to hip ratio this attenuated to no difference (1.00; 0.92 to 1.09). Adjustment for body mass index and for lifestyle risk factors had very little effect on the sex difference in mean intima media thickness.

CONCLUSIONS

Sex differences in body fat distribution may explain sex differences in arterial atherosclerosis.

Blood pressure and atherosclerotic plaques in carotid, aortic and femoral arteries in elderly Finns with diabetes mellitus or impaired glucose tolerance

The aim of the study was to evaluate the occurrence of atheromatous plaques in carotid, aortic and femoral arteries, focusing on blood pressure (BP). The study subjects consisted of 65-year-old Finns drawn from a population-based cohort. Ultrasonographic measurements were performed on 54 diabetic subjects, 97 subjects with impaired glucose tolerance (IGT) and 57 normoglycaemic subjects (NGT). High systolic BP (SBP) was defined as >or=160 mmHg and high diastolic BP as >or=95 mmHg. High pulse pressure (PP) was defined as the highest tertile (>or=75 mmHg) of PP and high mean BP (MBP) as the highest tertile (>or=111 mmHg) of MBP. The prevalence of atheromatous plaques was 77% (160/208) in carotid arteries, 94% (195/208) in aorta and 77% (161/208) in femoral arteries. A total of 64% (134/208) of the subjects had plaques in both carotid and femoral arteries, and they were compared with those who had plaques in 0-1 of these arteries. In addition to male gender and long-lasting smoking, the occurrence of plaques in both carotid and femoral arteries were associated with high SBP and high MBP. According to the results of multiple regression analyses, the adjusted odds ratio for plaques in both carotid and femoral arteries was 3.1 (95% CI 1.5-6.5) in subjects with high SBP compared to those with lower SBP. When SBP was replaced by high MBP, the adjusted odds ratio for it was 2.3 (95% CI 1.1-4.8).

Hypertension and subclinical carotid atherosclerosis in a suburban general population in China

OBJECTIVE

To explore the association of hypertension and carotid atherosclerosis in a general population in China.

METHODS

A population-based cardiovascular epidemiology survey was performed in a total of 1198 residents in suburban Beijing, 426 men and 776 women aged 43-73 years. Carotid plaque and the intima-media thickness were measured using duplex ultrasound.

RESULTS

The intima-media thickness, the prevalence of plaque and the number of plaques were found significantly positively related to hypertension categories (optimal, normal, high-normal, stage 1, 2 and 3 hypertension, according to The Chinese Hypertension Guidelines) as well as to the duration of hypertension, with a dose-response pattern in both genders (trend test, P < 0.01). After adjustment for age, total cholesterol, high-density lipoprotein-cholesterol, fasting glucose, smoking, antihypertensive treatment, stroke, myocardial infarction and angina, the relationship still existed, particularly in women. The associations of carotid atherosclerosis with duration of hypertension were weakened by further adjustment for systolic blood pressure, diastolic blood pressure or hypertension categories.

CONCLUSION

Hypertension was associated with subclinical carotid atherosclerosis. A prolonged course of the disease may aggravate the carotid atherosclerosis, independently of the level of blood pressure.

Carotid atherosclerosis in chronic renal failure-the central role of increased plaque burden

Studies on carotid artery atherosclerosis have been performed in order to understand the high risk for cardiovascular disease in chronic renal failure (CRF). The purpose of this study was to evaluate the extent and nature of carotid artery atherosclerosis in patients with CRF. Of the 135 patients with CRF (52 +/- 11 years), 58 had moderate to severe predialysis CRF (PR), 36 were on dialysis treatment (DI), and 41 were renal transplant recipients (TR). In addition, 58 control subjects (CO) were examined. Common carotid artery intima-media thickness (IMT), plaque prevalence, plaque score, and stiffness index beta were determined. Furthermore, plaque calcification and internal carotid artery stenoses were classified. Plaque prevalence (PR 64%, DI 61%, TR 51%, CO 28%; P < 0.001) and plaque score (PR 3.3 +/- 4.3, DI 3.0 +/- 3.4, TR 2.5 +/- 3.2, CO 0.8 +/- 1.7 mm; P < 0.001) were significantly greater in the CRF patient groups compared to the controls, whereas no difference in IMT was noted between the study groups. The prevalences of plaque calcification and internal carotid artery stenoses were higher among the CRF patient groups. In addition, the stiffness index beta was higher in the CRF patient groups. The present study shows that the characteristic alterations of the carotid arteries in CRF include increased plaque burden, calcification and increased arterial stiffness.

Significance of the intima-media thickness of the thoracic aorta in patients with coronary atherosclerosis

BACKGROUND

The prevalence and clinical significance of atherosclerotic aortic disease have now been documented in a variety of patient populations by use of transesophageal echocardiography (TEE). There are many reports that atherosclerotic aortic plaques detected by TEE are a marker for coronary artery disease (CAD).

HYPOTHESIS

The study was undertaken to evaluate the significance of the intima-media thickness (IMT) and formation of atherosclerotic plaques of the thoracic aorta (TA) in patients with CAD, especially in terms of a correlation between the IMT of the TA and the extent of coronary atherosclerosis.

METHODS

The IMT of the TA was measured using TEE. The study population comprised 100 patients (68 men, mean age 59 years). The extent of coronary atherosclerosis was divided into four groups (0, 1, 2, 3) according to the number of coronary arteries narrowed > or = 50%.

RESULTS

There was no significant difference in the IMT of the ascending TA according to the presence of significant (> 50% narrowed) coronary stenosis, but there was a significant difference in the IMT of the descending TA (1.39 vs. 1.88 mm, p = 0.005). There was a significant correlation between the extent of coronary atherosclerosis and the IMT of the ascending and descending TA (r = 0.24, p < 0.05; r = 0.352, p < 0.001, respectively). The plaques in the TA were seen in 7, 41, 52, and 65% of patients in Groups 0, 1, 2, and 3, respectively. Among atherosclerosis risk factors, hyperlipidemia was the only factor analyzed that affected the IMT of the descending TA (2.11 vs. 1.78 mm, p < 0.05).

CONCLUSION

The IMT of the TA correlates significantly with coronary atherosclerosis, and correlation of the descending TA IMT with coronary atherosclerosis is better than that of ascending TA IMT. Age is associated with coronary atherosclerosis, and TA IMT and hyperlipidemia are associated with descending TA IMT. Therefore, although TEE is not recommended for measuring TA IMT or for evaluating aortic plaques in patients with CAD, measurement of TA IMT as well as carotid artery IMT is very helpful for understanding the extent of coronary atherosclerosis.

The influence of lifestyle modification on carotid artery intima-media thickness in a suburban Japanese population

To evaluate the influence of lifestyle modification with and without lipid-lowering drug therapy on the carotid arterial wall, we did a 2 year prospective ultrasound study of carotid intima-media thickness (IMT) in 1390 male and female residents of a suburban Japanese town. According to total cholesterol (TC) level at baseline, subjects were classified into a lifestyle modification alone group (TC >/= 220 mg/dl, n = 437), a lifestyle modification with lipid-lowering drug group (TC >/= 220 mg/dl, n = 159), and a control group (TC < 220 mg/dl, n = 794). After 2 years of follow-up, both sexes of both treatment groups showed significant reductions of TC, low-density lipoprotein cholesterol (LDL-C), and IMT, although TC continued over 220 mg/dl in some subjects in the lifestyle modification group. The reduction of TC and LDL-C was significantly higher in the lifestyle modification with lipid-lowering drug group than in the lifestyle modification alone group. Although the IMT reduction was not statistically different between the treatment groups of either sex, the reduction of IMT was greater in the lifestyle modification with lipid-lowering drug group than in the lifestyle modification alone group. Our results indicate that comprehensive lifestyle modification can reduce carotid IMT in the general population, with or without the use of lipid-lowering drugs and that cholesterol reduction is of benefit even when TC level remain above the recommended level.

Prevalence and correlates of carotid atherosclerosis among elderly Japanese men

We determined intima-media thickness (IMT) and diameter of carotid artery and estimated their correlations with cardiovascular risk factors in 1129 men aged 60-74 years, who participated in a cardiovascular risk survey in three Japanese communities. The multivariate odds ratios (95% confidence interval) for the maximum IMT > or = 1.1 mm in the common carotid artery (CCA) were 1.3 (1.1-1.5) per 4 years of age, 1.8 (1.4-2.5) for hypertension, 1.4 (1.2-1.7) for a 34.4 mg/dl increase in serum total cholesterol, 0.7 (0.6-0.8) for a 14.7 mg/dl increase in serum HDL-cholesterol, and 2.4 (1.1-5.0) for history of stroke, while the maximum IMT > or = 1.5mm in the internal carotid artery (ICA) were 1.6 (1.4-1.8) per 4 years of age, 1.9 (1.5-2.4) for hypertension, 1.6 (1.2-2.1) for current smoking, and 3.5 (1.6-7.6) for history of stroke. Age, height, hypertension, current smoking, ethanol intake and history of coronary heart disease were independent determinants of both the outer and inner CCA diameter. Maximum IMT correlated positively with the outer diameter and inversely with the inner diameter in the CCA. Carotid atherosclerosis suggests to be a risk factor for stroke among Japanese elderly men, although future prospective studies are required to confirm this finding.

Association of High Sensitivity C-Reactive Protein With Coronary Heart Disease Prediction, but not With Carotid Atherosclerosis, in Patients With Hypertension

BACKGROUND

Inflammation is believed to predict coronary heart disease (CHD) in healthy subjects and in patients with atherosclerosis. We investigated the association of high sensitivity C-reactive protein (HS-CRP) and other inflammatory markers on cardiovascular outcome, and carotid atherosclerosis in hypertensive patients.

METHODS AND RESULTS

We conducted a cross-sectional study of 122 hypertensive patients and compared them with 64 normotensive volunteers. We measured circulating levels of HS-CRP, white blood cells (WBC), albumin, fibrinogen, erythrocyte sedimentation rate, and interleukin-6, and examined the associations with traditional risk factors of CHD, carotid atherosclerosis, and a 10-year risk of CHD, based on the risk prediction algorithm of the Framingham model. The mean of blood pressure (BP) of the hypertensive patients was 163/102 mmHg (normotensives; 118/79 mmHg). The 10-year risk of CHD was higher in the hypertensive patients (9.3 +/- 7.3%) compared with the normotensive volunteers (4.3 +/- 4.2%). Albumin and HS-CRP were significantly higher in the hypertensive patients. Multivariate analysis showed that among markers, only HS-CRP was associated with 10-year risk of CHD (beta=0.13, p=0.03). The BP, body mass index, high-density lipoprotein, WBC count, fibrinogen, and cardiac hypertrophy increased across quartiles of HS-CRP. There was no association between HS-CRP and carotid atherosclerosis in subjects with hypertension and normotension.

CONCLUSION

A higher HS-CRP level was associated with a higher risk score of CHD, but not with carotid atherosclerosis, in patients with hypertension.

Abdominal obesity and carotid artery wall thickness. The Los Angeles Atherosclerosis Study

OBJECTIVE

To determine whether or not abdominal obesity is associated with the intima-media thickness (IMT) of the carotid artery wall independently of total body obesity and major risk factors for atherosclerosis.

DESIGN

: Longitudinal epidemiological study.

SUBJECTS

A total of 573 middle-aged employees of a utility company.

MEASUREMENTS

Sagittal and transverse abdominal diameters, their ratio and difference were used as measures of abdominal obesity.

RESULTS

Abdominal diameters and body mass index (BMI) were significantly associated with blood pressure, serum lipoproteins and fasting insulin. In cross-sectional multiple regression models, the sagittal/transverse ratio and BMI were significantly associated with IMT in the presence of atherosclerosis risk, but the sagittal diameter was not. In longitudinal models, baseline BMI was an independent predictor of IMT progression but the sagittal and transverse diameters were not.

CONCLUSION

These findings do not support the hypothesis that abdominal obesity is an independent predictor of carotid artery IMT. The consistent pattern of association of measures of general obesity with carotid artery IMT emphasizes the continuing need for prevention and control of this important risk factor.

The prognostic importance of endothelial dysfunction and carotid atheroma burden in patients with coronary artery disease

OBJECTIVES

The goal of this study was to determine the relative prognostic importance of noninvasive measures of endothelial function and atheroma burden in patients with coronary artery disease (CAD).

BACKGROUND

Direct measurement of atherosclerosis by carotid ultrasound and endothelial function assessment by brachial artery flow-mediated dilation (FMD) have both been shown to predict vascular events. The combined prognostic utility of carotid ultrasound and FMD relative to traditional risk markers and cardiovascular fitness has not been evaluated.

METHODS

A total of 152 patients with CAD underwent metabolic testing, exercise stress tests, carotid ultrasound, and endothelial function measurements.

RESULTS

Patients were followed for 34 +/- 10 months during which 22 vascular events occurred. Peak FMD (p = 0.012) and FMD/nitroglycerin-mediated dilation (NMD) ratio (p = 0.008) were lower in subjects with events. Univariate analysis with Cox proportional hazards modeling identified plaque area (p = 0.0047), total area (p = 0.0085), peak FMD (p = 0.01), FMD/NMD ratio (p = 0.008), stress test workload (p = 0.027), long-acting nitroglycerin (NTG) (p = 0.0071), and calcium blockers (p = 0.0057) as predictors of adverse events. Multivariate analysis showed that FMD/NMD ratio (p < 0.0001), carotid plaque area (p = 0.06), and NTG (p = 0.005) were independent predictors. Based on median values, subjects were divided into high and low "plaque burden" groups and into high and low FMD/NMD subgroups. Patients with high FMD/NMD had low event rates irrespective of the degree of carotid atheroma. Patients with low FMD/NMD and high "plaque burden" had the highest event rate (p < 0.05).

CONCLUSIONS

The structural and functional status of the vasculature are independent predictors of coronary events as shown by noninvasive measurement of endothelial function and carotid atheroma burden in patients with CAD. Preserved endothelial function attenuates the risk of future events associated with a high plaque burden.

The relationship between carotid atherosclerosis and platelet aggregation in elderly

The aim of this study is to assess the relationship between the carotid wall intima media thickness (IMT) and atheroma plaques due to atherosclerosis and platelet aggregation among elderly. The first stage of the study was performed by analyzing platelet aggregation in a total of 28 elderly patients divided into two groups. The first group consisted of 14 cases with carotid atheroma plaque (Patient group I) and the second group of patients were without carotid atheroma plaque (Control group I). At the second stage of the study, the cases were regrouped according to the carotid IMT. Patients with IMT above 1 mm (Patient group II, n=10) and under 1 mm (Control group II, n=14) were compared regarding platelet aggregation. Platelet aggregation was induced in the platelet-rich plasma using 5 micro M ADP, 0.2 mg/ml collagen and 1.2 mg/ml ristocetin. Between patients with and without atheroma, no difference was noted in terms of platelet aggregation. Between platelet aggregation results of patients with intimal thickness above and under 1 mm, no significant difference was also noted. Between elderly cases with or without atherosclerosis, there was no difference with respect to platelet aggregation. Platelet aggregation measurements cannot be used as a marker of atherosclerosis in elderly population.

Impact of carotid atherosclerosis on long-term mortality in chronic hemodialysis patients

BACKGROUND

Cardiovascular event is the major cause of mortality in patients on maintenance hemodialysis. We prospectively tested the predictive values of atherosclerotic parameters for all-cause and cardiovascular outcomes in 219 hemodialysis patients (age, 58 +/- 13 years; time on hemodialysis, 13 +/- 7 years; male/female, 144/75).

METHODS

We measured blood homocysteine (Hcy), ultrasound carotid artery intima media thickness (IMT) and % aortic wall calcification at L2/3 region [% of calcification index in the abdominal aortic wall (%ACI)] by computed tomography (CT) scan, and followed all patients for 5 years.

RESULTS

During the follow-up periods, 54 patients (25%) died, 40 (74%) of them of cardiovascular causes. IMT was significantly higher in patients who expired (0.75 +/- 0.02 mm) than in those who survived (0.62 +/- 0.01 mm). IMT was significantly correlated with age (r = 0.47, P < 0.01) and %ACI (r = 0.27, P < 0.01). The survival rate during the observation was significantly lower in the final IMT third (58%) than in the first (90%) and the middle IMT third (80%) (P < 0.01). Multivariate Cox proportional hazards analysis revealed that diabetes and IMT became independent determinants of all-cause and cardiovascular death. Adjusted hazards ratios of all-cause and cardiovascular mortality for an increase of 0.1 mm in IMT were 1.31 (95% CI, 1.07 to 1.59) and 1.41 (95% CI, 1.12 to 1.76). In contrast, %ACI at abdominal aorta and blood Hcy did not affect their 5-year mortality.

CONCLUSION

These findings suggested that measurement of carotid artery IMT is useful for predicting long-term mortality in patients receiving maintenance hemodialysis.

Prevalence of diabetes and/or ischaemic heart disease in classes of increasing carotid artery atherosclerosis: an ultrasonographic study

AIMS

To evaluate the prevalence of non-diabetic subjects and diabetic patients, with or without ischaemic heart disease (IHD), in different classes of increasing carotid atherosclerotic damage.

METHODS

Using high-resolution B-mode ultrasound, we studied 598 subjects without known cardiovascular disease (CVD) or diabetes, 74 diabetic patients without CVD, 74 non-diabetic subjects with IHD and 36 patients with both diabetes and IHD. Carotid atherosclerosis was classified as: normal; thickened intima-media; non-stenotic plaque; stenotic plaque.

RESULTS

Compared with subjects without diabetes or CVD, the frequency of patients with diabetes without known CVD increased significantly from 'normal' to 'stenotic plaque' (4.1%, 6.4%, 13%, 14.8% for normal, thickened intima-media, non-stenotic plaque and stenotic plaque, respectively; P = 0.0057). The same figures were 6%, 7.6%, 10.2%, 23.3% (P = 0.0007) for non-diabetic subjects with IHD, and 0%, 2%, 5.6%, 15.9% (P < 0.0001) for diabetic patients with IHD. No difference was found comparing subjects with diabetes without CVD with non-diabetic patients with IHD (P = 0.56). Using polychotomous logistic regression analysis, diabetic patients without CVD and non-diabetic subjects with IHD showed a similar association with the increasing degree of carotid atherosclerosis (P = 0.59), but significantly stronger compared with subjects without diabetes or CVD (P < 0.03 for both).

CONCLUSIONS

Diabetic patients without known CVD show an advanced degree of carotid atherosclerotic damage similar to non-diabetic subjects with IHD and significantly higher compared with non-diabetic subjects without CVD. Our data support the need for an aggressive early prevention of CVD in diabetic subjects.

Implication of earlier carotid atherosclerosis for stroke and its subtypes

In addition to advanced stenosis, earlier stages of carotid atherosclerosis are associated with the risk for stroke. Based on a recent report, this review will focus on the associations between carotid atherosclerosis and stroke subtypes. The authors report increased severity of carotid atherosclerosis in atherothrombotic and lacunar infarction patients, compared to nonstroke patients. However, the severity was similar between nonstroke patients and those with cardioembolic infarction and cerebral hemorrhage. By receiver operating characteristic curve analyses, although evaluation of carotid atherosclerosis appears to help for risk assessment of atherothrombotic and lacunar infarction, the potential for benefit may be greater for atherothrombotic. Large prospective studies are still necessary to establish the link between earlier carotid atherosclerosis and the future risk for specific stroke subtypes.

Epidemiology of smoking-induced cardiovascular disease

Cigarette smoking is a major cause of coronary heart disease, stroke, aortic aneurysm, and peripheral vascular disease. The risk is manifest both as an increased risk for thrombosis of narrowed vessels and as an increased degree of atherosclerosis in those vessels. The cardiovascular risks owing to cigarette smoking increase with the amount smoked and with the duration of smoking. Risks are not reduced by smoking cigarettes with lower machine-measured yields of tar and nicotine, but those who have only smoked pipes or cigars seem to have a lower risk for cardiovascular diseases. Cessation of cigarette smoking reduces disease risks, although risks may remain elevated for a decade or more after cessation.

Free testosterone plasma levels are negatively associated with the intima-media thickness of the common carotid artery in overweight and obese glucose-tolerant young adult men

OBJECTIVE

To evaluate the relation between free testosterone (FT) levels and the intima-media thickness of the common carotid artery (IMT-CCA) in overweight and obese glucose-tolerant (NGT) young adult men.

DESIGN

Cross-sectional study of FT and IMT-CCA in obese men.

SUBJECTS

A total of 127 overweight and obese NGT male individuals, aged 18-45 y.

MEASUREMENTS

FT plasma levels; IMT-CCA, as measured by high-resolution B-mode ultrasound imaging; central fat accumulation, as evaluated by waist circumference; body composition, as measured by bioimpedance analysis; insulin resistance, as calculated by homeostatic model assessment (HOMA(IR)); systolic and diastolic blood pressure; and fasting concentrations of glucose, insulin, and lipids.

RESULTS

IMT-CCA was positively correlated with age, body mass index (BMI), fat mass (FM), waist circumference, and fasting glucose concentrations, and inversely associated with FT levels. After multivariate analysis, IMT-CCA maintained an independent association with BMI, FM, and FT levels. This study indicates that IMT-CCA is negatively associated with FT levels, independent of age, total body fat, central fat accumulation, and fasting glucose concentrations in overweight and obese NGT patients.

CONCLUSION

Hypotestosteronemia may accelerate the development of atherosclerosis and increase the risk for CHD in obese men.

Leisure time physical activity and early atherosclerosis: the Los Angeles Atherosclerosis Study

PURPOSE

Some studies of leisure time physical activity find a cardiovascular benefit for moderate activity, whereas others find benefit only for regular vigorous activity. We examined the relation between physical activity and 3-year progression of carotid atherosclerosis.

METHODS

Baseline examinations were conducted during 1995 to 1996 with two follow-up examinations at 1.5-year intervals. Intima-media thickness of the common carotid arteries was determined by B-mode ultrasound in a cohort of 500 randomly sampled women and men, aged 40 to 60 years, who were asymptomatic for cardiovascular disease. Sedentary leisure activity was defined as the lowest quartile of a general activity measure, whereas vigorous activity was defined as aerobic activity > or = 3.5 times per week. The remainder defined the moderate activity group. Analyses were adjusted for confounding variables.

RESULTS

The mean (+/- SE) age- and sex-adjusted rates of progression of intima-media thickness declined from 14.3 +/- 1.7 microns per year in sedentary subjects, to 10.2 +/- 1.0 microns per year in moderately active subjects, to 5.5 +/- 1.5 microns per year in vigorously active subjects (P for trend <0.0001), and remained statistically significant after adjustment for other confounding factors (P for trend = 0.0004). Compared with the moderate activity group, the vigorous activity group had lower body mass index and resting heart rate and increased high-density lipoprotein cholesterol level, whereas the sedentary group had an increased resting heart rate. Workplace activity was not protective.

CONCLUSION

Physical activity during leisure is inversely related to the progression of atherosclerosis in the carotid artery. This benefit appears to increase throughout the activity continuum.

A comparison of acute phase proteins and traditional risk factors as markers of combined plaque and intima-media thickness and plaque density in carotid and femoral arteries

OBJECTIVES

To test the hypothesis that some acute phase proteins may be better independent predictors of objective measures of arterial wall impairment than traditional risk factors.

DESIGN

Cross-sectional study.

MATERIALS AND METHODS

C-reactive protein (CRP), fibrinogen, C3 complement and traditional risk factors were measured in 288 men aged 55-64 years, randomly chosen from the local registry lists. By ultrasound assessment of the bifurcations of carotid and femoral arteries, maximum combined plaque/intima-media thickness (CPIMTmax) and mean plaque density (MPD, in a grey scale from 0 to 255) were also measured.

RESULTS

In multivariate analysis only traditional risk factors remained associated with the overall CPIMTmax: smoking (r = 0.35, p < 0.0001), cholesterol (r = 0.23, p = 0.0001), age (r = 0.22, p = 0.0002), glucose (r = 0.18, p = 0.002) and systolic blood pressure (r = 0.13, p = 0.02). However, with regard to carotid disease only, fibrinogen was the strongest covariate of CPIMT (r = 0.18, p = 0.002). The overall MPD was independently associated with CRP (r = 0.25, p = 0.0008), physical activity (r = 0.19, p = 0.009), triglycerides (r = -0.18, p = 0.02) and body mass index (r = 0.15, p = 0.04). CRP was mainly associated with femoral MPD, while triglycerides were the major (inverse) covariate of carotid MPD.

CONCLUSIONS

Traditional risk factors are the main determinants of CPIMTmax, although fibrinogen seems to play a role in carotids. CRP was associated with high density femoral plaques. Finally, no acute phase protein was independently associated with low density, potentially vulnerable, plaques.

[Endothelial dysfunction and intima-media thickness in relation to cardiovascular risk factors in patients without clinical manifestations of atherosclerosis]

INTRODUCTION

Endothelial dysfunction and increased intima-media thickness are early findings in the development of atherosclerosis that can be assessed non-invasively by echography. The aim of this study was to investigate endothelial function and intima-media thickness, and the relation between these processes and cardiovascular risk factors in patients without clinical atherosclerosis.

PATIENTS AND METHOD

Fifty-two subjects were studied, 39 with one or more cardiovascular risk factors and 13 with none. Vascular echography was performed to analyze endothelium-dependent vascular dilatation in the brachial artery and intima-media thickness in the common carotid artery.

RESULTS

Compared to patients without risk factors, patients with cardiovascular risk factors more frequently had impaired vascular dilatation after ischemia, 11.98 4.61% vs 2.77 2.57%, (P<.0.001; mean difference = 9.21%, 95% CI of the difference 6.33-12.07%) and a greater intima-media thickness, 0.085 0.024% vs 0.057 0.014 cm (P < 0.0001; mean difference = 0.028 cm, 95% CI of the difference, 0.017-0.04 cm). There was a significant negative correlation between intimal-media thickness and endothelial dysfunction (r = -0.357; P<0.01). Linear regression analysis showed that intima-media thickness was independently related to age and the presence of hypertension, while endothelial function was related only with the presence of hypertension, smoking, and hyperlipoproteinemia.

CONCLUSIONS

In patients without clinical atherosclerotic disease, cardiovascular risk factors were associated with impaired endothelial function and increased intima-media thickness. There was a negative correlation between endothelial-dependent vascular dilatation and intima-media thickness.

An association between atherosclerosis and venous thrombosis

BACKGROUND

In about a third of patients with venous thromboembolism, the cause of the disorder is unexplained. In patients with atherosclerosis, activation of both platelets and blood coagulation and an increase in fibrin turnover are detectable, which may lead to thrombotic complications. Whether atherosclerosis is associated with an increased risk of venous thrombosis is unknown.

METHODS

We performed ultrasonography of the carotid arteries in 299 unselected patients who had deep venous thrombosis of the legs without symptomatic atherosclerosis and in 150 control subjects. Patients with spontaneous thrombosis, patients with secondary thrombosis from acquired risk factors, and control subjects were assessed for plaques.

RESULTS

At least one carotid plaque was detected in 72 of the 153 patients with spontaneous thrombosis (47.1 percent; 95 percent confidence interval, 39.1 to 55.0), 40 of the 146 with secondary thrombosis (27.4 percent; 95 percent confidence interval, 20.2 to 34.6), and 48 of the 150 control subjects (32.0 percent; 95 percent confidence interval, 24.5 to 39.5). The odds ratios for carotid plaques in patients with spontaneous thrombosis, as compared with patients with secondary thrombosis and with controls, were 2.3 (95 percent confidence interval, 1.4 to 3.7) and 1.8 (95 percent confidence interval, 1.1 to 2.9), respectively. In a multivariate analysis that accounted for risk factors for atherosclerosis, the strength of this association did not change.

CONCLUSIONS

There is an association between atherosclerotic disease and spontaneous venous thrombosis. Atherosclerosis may induce venous thrombosis, or the two conditions may share common risk factors.

Intima media thickness of carotid arteries is reduced in heterozygous carriers of the Gly972Arg variant in the insulin receptor substrate-1 gene

BACKGROUND

The Gly972Arg mutation in the IRS-1 gene has been found to be associated with insulin resistance and type II diabetes. A recently published study described an association between the Arg allele and an increased risk for coronary artery disease. In the present study we asked whether the presence of the codon 972 mutation in the IRS-1 gene is associated with higher IMT values of the carotid arteries.

MATERIALS AND METHODS

To address this question, genotypes of the codon 972 polymorphism were determined in 1018 healthy unrelated individuals aged 40-65 years. Three homozygous carriers of the mutation were excluded for statistical analysis. In all subjects, intima media thickness (IMT) and B-scores of carotid arteries as well as a large number of metabolic parameters were determined.

RESULTS

Heterozygous carriers of the Arg972 allele exhibited significantly lower IMT and B-score values than noncarriers. Total cholesterol, LDL-cholesterol and serum levels of apolipoprotein B were significantly lower in the carriers. Furthermore, a significant interaction between Gly972Arg-carrier status and mean daytime 24-h systolic blood pressure with regard to IMT could be observed; carriers with a systolic blood pressure above the median had lower IMT values than carriers with a systolic blood pressure equal or below the median. All these effects were more pronounced in females and remained significant after adjustment for sex, age, BMI, systolic blood pressure and serum apolipoprotein B levels. No significant differences between the carriers and the noncarriers could be found for BMI, insulin sensitivity or frequency of type II diabetes.

CONCLUSIONS

The results of our study demonstrate that the presence of the Arg972 allele is associated with lower IMT values of the carotid arteries. This finding is partly explained by lower serum levels of apolipoprotein B in carriers. The protective effect of the Gly972 Arg mutation seems to be stronger in the presence of a higher systolic blood pressure. Our data contradict previous findings suggesting an increased risk for insulin resistance, type II diabetes and atherosclerotic vascular disease in carriers of the mutation.

Quantitative measurement of carotid intima-media roughness--effect of age and manifest coronary artery disease

Atherosclerotic changes of the common carotid artery (CCA) may appear like irregularities of the intima-media thickness (abbreviated as IM roughness) in B-mode ultrasound. The purposes of the present study were to investigate whether the CCA IM roughness changes with age and differs between individuals presumed to be healthy and patients with coronary artery disease (CAD).

METHODS AND RESULTS

Based on a new automatic identification (AI) program, the segmental intima-media thickness (IMT) and IM roughness of the CCA far wall were measured in B-mode images of 15 younger and 22 older volunteers presumed to be healthy, and 46 patients with known CAD. The mean and maximum CCA IMT were lowest in the young group (0.55+/-0.05; 0.65+/-0.06 mm), higher in the older group (0.77+/-0.16; 0.87+/-0.18 mm) and highest in CAD patients (0.88+/-0.18; 1.01+/-0.27 mm) (P<0.01 among all groups). The CCA IM roughness was greatest by far in the CAD patients (0.075+/-0.02 mm; P<0.01 vs. both groups) and increased only slightly with age (younger: 0.035+/-0.008 mm; older: 0.040+/-0.014 mm; P<0.05). Areas under the curve (AUC) of receiver-operating characteristic curves (ROC) predicting patients with CAD were higher for the CCA IM roughness (0.80) than for the mean (0.66) and maximum IMT (0.71).

CONCLUSIONS

It is suggested that the CCA IM roughness increases with age, and helps to discriminate between individuals presumed to be healthy and patients with manifest CAD better than the CCA mean and maximum IMT.

Quantification of the wall inhomogeneity in B-mode sonographic images of the carotid artery

OBJECTIVE

The process of atherosclerosis has been assessed increasingly by sonography in B-mode images of the carotid arteries. Carotid artery atherosclerosis is thought to be associated with major atherosclerotic diseases in other regions of the arterial bed, especially the coronary arteries. In addition to the intima-media thickening as an established surrogate parameter of the atherosclerotic wall process, changes of the sonographic morphologic pattern of the intima-media layer might reflect this process.

METHODS

After automatic identification of the intimal and adventitial boundaries of the distal common carotid artery wall, the gray level inhomogeneity of the circumscribed intima-media area was quantified. Older subjects without cardiovascular disease (mean +/- SD, 66.2 +/- 3.8 years; n = 43) were compared with young subjects without cardiovascular disease (24.4 +/- 5.3 years; n = 34) and patients with manifest coronary artery disease (65.0 +/- 9.2 years; n = 69).

RESULTS

Patients with coronary artery disease had a significantly higher intima-media thickness (0.92 +/- 0.21 mm; P < .05) and wall inhomogeneity (4.56 +/- 0.97; P < .001) than the old group (0.86 +/- 0.15 mm and 3.83 +/- 0.62). Both parameters were lowest in the young group (0.56 +/- 0.05 mm and 2.53 +/- 0.76; P < .05 for both parameters and groups).

CONCLUSIONS

Measurement of gray level wall inhomogeneity of the intima-media layer of the common carotid artery may help discriminate between subjects with high and low atherosclerotic burden and may show age-related changes of the intima-media layer. This new quantitative parameter is thought to reflect the atherosclerotic wall process in addition to the intima-media thickness measurement.

The carotid artery as a noninvasive window for cardiovascular risk in apparently healthy individuals

Cardiovascular diseases are the leading cause of death and disability in industrialized countries. Because the etiologies are related to alteration of arterial wall properties, the noninvasive evaluation could help the presymptomatic diagnosis and potentially the prevention of future events. Ultrasound (US) is currently the only modality to image the arterial wall in real-time with sufficient resolution to allow for observation of its morphological, hemodynamic and elastic properties. Increased wall thickness and atheromatous plaques of carotid arteries are associated with cardiovascular risk factors and diseases. Also, carotid Doppler waveforms and wall elasticity may have associations with arterial health. Although evaluation of these arterial properties are currently limited to the research laboratories, most of such properties can be evaluated in the standard setting of carotid ultrasonography. This article reviews "potential" utilities of carotid US evaluation for cardiovascular risk assessment in apparently healthy individuals.

Carotid artery intima-media thickness and plaque score for the risk assessment of stroke subtypes

As measures for the severity of carotid atherosclerosis, we compared common carotid artery (CCA) intima-media thickness (IMT) and plaque score (PS) for risk assessment of respective stroke subtypes. The subjects comprised 792 nonstroke and 311 stroke patients, including 72 with atherothrombotic infarction (AI), 113 with lacunar infarction (LI), 54 with cardioembolic infarction and 29 with cerebral hemorrhage. IMT was bilaterally measured on CCA far walls, and averaged. PS was obtained by summing up the maximum thickness of all plaques in bilateral carotid arteries. Both IMT and PS were greater in AI and LI patients than in nonstroke patients (all p < 0.05), but similar between other subtype and nonstroke patients. By receiver operating characteristic (ROC) curve analyses, both measures discriminated the likelihood for AI and LI (all p < 0.05), but not for other subtypes. When discriminating AI, ROC area defined by PS (0.80) was greater than that defined by IMT (0.68) (p < 0.05). Thus, although both CCA IMT and PS appear to help for risk assessment of AI and LI, risk of AI may be more effectively assessed by PS.

Carotid atherosclerosis, intima media thickness and risk factors--an analysis of 1781 asymptomatic subjects in Taiwan

The aim of this study was to investigate the association of intima media thickness (IMT) and plaque with risk factors for atherosclerosis in asymptomatic subjects in Taiwan. Between 1998 and 2001, the study recruited 1781 asymptomatic subjects (1131 men and 650 women [mean age, 49 years; range 18-85 years]). These were examined by B-mode ultrasound to measure the IMT at the far wall of the common carotid artery (CCA) and the extent of plaque formation. A wide range of vascular risk factors including age, gender, smoking, body mass index, blood chemistry, and previous history were surveyed. The mean (+/-S.D.) IMT observed was 0.68 (+/-0.12) and 0.66 (+/-0.11) mm for men and women, respectively, (P=0.0008). The mean (S.D.) IMT of the CCA was 0.66 (+/-0.12) mm on the right side and 0.68 (+/-0.12) mm on the left side (P=0.0004). IMT increased with aging, according to the equation IMT=(0.005xage in years)+0.403 [corrected]. Higher IMT was associated with male gender, and IMT was greater in the left CCA. About 36.9% of subjects had carotid plaques. The percentage of plaque increased with aging. The plaque prevalence was positively associated with IMT. The value of IMT over the cut point of 0.68 mm correlated with obviously increased risk of carotid atherosclerosis. Age, systolic blood pressure and fasting blood sugar were independent risk factors related to both carotid atherosclerosis and thick IMT.