Carotid Intima-Media Thickness and Plaque in Cardiovascular Risk Assessment

Carotid intima-media thickness (CIMT) has been shown to predict cardiovascular (CV) risk in multiple large studies. Careful evaluation of CIMT studies reveals discrepancies in the comprehensiveness with which CIMT is assessed—the number of carotid segments evaluated (common carotid artery [CCA], internal carotid artery [ICA], or the carotid bulb), the type of measurements made (mean or maximum of single measurements, mean of the mean, or mean of the maximum for multiple measurements), the number of imaging angles used, whether plaques were included in the intima-media thickness (IMT) measurement, the report of adjusted or unadjusted models, risk association versus risk prediction, and the arbitrary cutoff points for CIMT and for plaque to predict risk. Measuring the far wall of the CCA was shown to be the least variable method for assessing IMT. However, meta-analyses suggest that CCA-IMT alone only minimally improves predictive power beyond traditional risk factors, whereas inclusion of the carotid bulb and ICA-IMT improves prediction of both cardiac risk and stroke risk. Carotid plaque appears to be a more powerful predictor of CV risk compared with CIMT alone. Quantitative measures of plaques such as plaque number, plaque thickness, plaque area, and 3-dimensional assessment of plaque volume appear to be progressively more sensitive in predicting CV risk than mere assessment of plaque presence. Limited data show that plaque characteristics including plaque vascularity may improve CV disease risk stratification further. IMT measurement at the CCA, carotid bulb, and ICA that allows inclusion of plaque in the IMT measurement or CCA-IMT measurement along with plaque assessment in all carotid segments is emerging as the focus of carotid artery ultrasound imaging for CV risk prediction.     

Baseline reproducibility of B-mode ultrasonic measurement of carotid artery intima-media thickness: the European Lacidipine Study on Atherosclerosis (ELSA)

BACKGROUND AND OBJECTIVE: The European Lacidipine Study of Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multi-national interventional trial to determine the effect of four-year treatment using the calcium antagonist lacidipine versus the beta-blocker atenolol on the progression of carotid atherosclerosis in 2259 asymptomatic hypertensive patients. B-mode ultrasound is used to measure the primary and secondary endpoints including the mean maximum intima-media thickness (IMT) of the carotid bifurcations and the common carotid arteries (CBM(max)), the mean maximum IMT of 12 standard carotid sites (M(max)) and the overall maximum IMT (T(max)). This paper reports the cross-sectional reproducibility of ultrasound measurements at baseline. METHOD: To evaluate measurement reliability, each patient is scanned twice at baseline and again at four annual visits, with 80% of the replicate scans performed by the same sonographer and 20% by a different sonographer; 50% of the replicate scans are read by the same reader and the other 50% by different readers. RESULTS: The overall coefficient of reliability (R) was 0.859 for CBM(max), 0.872 for M(max) and 0.794 for T(max). The reliability for CBM(max) was stable during the 1 3/4-year baseline period (R = 0.848 to 0.953) and was uniform among the 23 field centres (R = 0.798 to 0.926). Intra- and inter-reader reliability were 0.915 and 0.872 respectively, and intra-sonographer reliability was 0.866. CONCLUSION: The results demonstrate that by implementing standardized protocols and strict quality control procedures, highly reliable ultrasonic measurements of carotid artery IMT can be achieved in large multi-national trials.     

Effect of contrast enhancement on measurement of carotid artery intimal medial thickness

Previous studies have used standard B-mode ultrasound to quantify the aggregate mean intimal medial thickness (IMT) of the near and far wall of the common carotid artery (CCA). Many investigators have had difficulty in accurately evaluating the near wall IMT secondary to difficulty in discerning the vessel lumen and intima. The purpose of this study is to determine the effect of contrast enhanced ultrasound on IMT measurement when compared with non-enhanced images. Twenty-six patients who had standard carotid ultrasounds completed over a 6-month period were evaluated, with 24 imaged by the same sonographer. Five to six measurements of the near and far walls were obtained over a 1 cm distance, beginning and ending 0.5 cm and 1.5 cm proximal to the carotid bifurcation. The measurements were made with and without the contrast agent Optison (perflutren protein type-A microspheres), which was given as an i.v. bolus (0.5-0.7 cc). Of those imaged by the same sonographer, 40 carotid arteries were examined and a total of 867 measurements were obtained. A total of 10% of the carotid ultrasounds were restudied approximately 1 month after the initial interpretation to assess observer accuracy. The near wall CCA mean (SD) IMT was 0.075 (0.019) cm for left with contrast versus 0.067 (0.023) cm for left without contrast and 0.089 (0.024) cm for right with versus 0.071 (0.022) cm for right without, p < or = 0.0001 both sides. For the far wall of the CCA, the mean (SD) IMT comparison was 0.075 (0.021) cm for left with versus 0.070 (0.016) cm for left without, p = 0.005, and 0.070 (0.023) cm for right with versus 0.070 (0.016) cm for right without, p = 0.68. In conclusion, contrast-enhanced IMT measurement showed a highly statistically significant difference in near carotid wall thickness determinations versus non-contrast values. The thicker measurement is in agreement with previously reported data showing that non-contrast images underestimated near wall common carotid IMT in histologic samples.     

超声测量颈动脉内膜中层厚度与颈动脉斑块的关系

为了探讨颈动脉内膜中层厚度与局限性颈动脉斑块的联系 ,对 91名受试对象的颈总动脉内膜中层厚度及颈内动脉和颈动脉分叉处的斑块进行超声检测 ,并将颈动脉内膜中层厚度进行分级。结果观察到有斑块者较无斑块者其颈动脉内膜中层厚度明显增加 ( 0 .83± 0 .16mm比 0 .6 4± 0 .12mm ,P <0 .0 1) ,且随斑块的严重程度增加 ,其内膜中层厚度呈增厚趋势。该结果支持颈总动脉内膜中层厚度与颈动脉局限性动脉粥样硬化斑块明显相关 ,提示颈动脉内膜中层厚度增厚可能是颈动脉粥样硬化的早期表现     

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.     

The clinical significance of carotid intima-media thickness in cardiovascular diseases: a survey in Beijing

This study is to investigate the relationships between prevalent cardiovascular events (myocardial infarction, stroke and peripheral arterial disease) and carotid intima-media thickness (CIMT) in middle-aged and older adults; to assess which of the indexes, IMT in the common carotid artery (CCA), internal carotid artery (ICA) and carotid bifurcation (CB) separately or in combination, is a better correlate. IMT of the CCA, ICA and CB were measured with duplex ultrasound in 1058 individuals (aged between 37 and 86 years old) in a suburban community of Beijing. Histories of cardiovascular events as well as prevalent risk factors were obtained. CIMT were compared between groups with and without cardiovascular events. Associations of cardiovascular events with IMT measurements in CCA, CB and ICA were ascertained. The group with cardiovascular events had higher mean CIMT (0.74 (0.60-0.98) mm vs 0.65 (0.54-0.80) mm, P=0.000) and higher abnormal CIMT proportion (77.20 vs 64.45%, P=0.000). The odds ratio (OR) for myocardial infarction was 1.74 (P=0.010), for stroke 1.98 (P=0.001) and for peripheral arterial disease 1.80 (P=0.072) in abnormal CIMT. However, after adjustment of traditional risk factors, the correlations disappeared, implying that CIMT may act via other risk factors. After adjustment of age, mean CIMT correlated best with total cardiovascular events (OR: 4.39 (2.39-8.04), P=0.000) and stroke (OR: 4.98 (2.55-9.71), P=0.000) separately; mean posterior CIMT correlated with myocardial infarction best (OR: 2.97 (1.68-5.24), P=0.000). CIMT may act as an intermediate point for cardiovascular diseases. Combined CIMT might be the best index associated with cardiovascular diseases.     

A dietary and exercise intervention slows menopause-associated progression of subclinical atherosclerosis as measured by intima-media thickness of the carotid arteries

OBJECTIVES: The object of this study was to assess the effects of menopause and a diet/exercise intervention on subclinical atherosclerosis progression. BACKGROUND: Subclinical atherosclerosis has been linked to higher coronary heart disease and stroke rates and is greater among postmenopausal women according to cross-sectional analyses. Whether menopause is associated with an accelerated progression of subclinical disease is unknown, as is the extent to which lifestyle intervention can alter the course of progression. METHODS: Intima-media thickness (IMT) measures of the common carotid artery (CCA), internal carotid artery (ICA), and bulb segments of the carotid arteries were measured twice during the course of 4 years in 353 women from the Women's Healthy Lifestyle Project, a dietary and exercise clinical trial designed to prevent adverse risk factor changes through the menopause. A third measure was obtained 2.5 years later for 113 women. RESULTS: The progression of IMT was observed for the average of all segments (AVG), the CCA, and the bulb (0.007 mm/year, 0.008 mm/year, and 0.012 mm/year; p < 0.01 for all), but not for the ICA. Among controls, menopause was associated with accelerated IMT progression (0.003 mm/year for premenopausal women vs. 0.008 mm/year for perimenopausal/postmenopausal women for AVG IMT; p = 0.049). Additionally, among the 160 perimenopausal/postmenopausal women, the intervention slowed IMT progression (0.008 mm/year for the control group vs. 0.004 mm/year for the intervention group for AVG IMT; p = 0.02). Similar results were found for the CCA and bulb segments. CONCLUSIONS: These data demonstrate that the menopause transition is associated with accelerated subclinical atherosclerosis progression and that a diet/exercise intervention slows menopause-related atherosclerosis progression.     

Improved common carotid elasticity and intima-media thickness measurements from computer analysis of sequential ultrasound frames

B-mode ultrasound has gained popularity as a non-invasive method for direct visualization of superficial vessels. With B-mode ultrasound, arterial stiffness can be directly measured since image acquisition of the arterial wall thickness and vessel diameter can be obtained simultaneously in a dynamic fashion throughout the cardiac cycle. Recently, a method was developed to measure carotid arterial diameter and intima-media thickness (IMT) from B-mode images that utilizes computerized edge tracking-multiframe image processing that automatically measures arterial diameter and IMT in multiple sequential frames spanning several cardiac cycles. To evaluate this method, replicate B-mode common carotid artery ultrasound examinations and blood pressure measurements were obtained in 24 subjects 1-2 weeks apart. Approximately 80 sequential frames spanning two cardiac cycles were analyzed from each ultrasound examination to obtain maximum arterial diameter (D(max)), minimum arterial diameter (D(min)), and IMT using a computerized edge detection method. The intraclass correlations of D(max), D(min), and IMT were 0.97-0.99 and the mean absolute difference for these measurements were 0.03-0.11 mm. The coefficient of variation for D(max) and D(min) were 1.28 and 1.18%, respectively. The intraclass correlation for several standard arterial stiffness indices, Peterson's elastic modulus, Young's modulus, arterial distensibility, compliance, and the beta stiffness index ranged between 0.84 and 0.89. Additionally, it was determined that averaging IMT over five frames centered at D(min) reduced single frame IMT measurement variability by 27% (P=0.005) compared with IMT measured from a single frame corresponding to D(min). Comparison of the phasic relationship of D(max) and D(min) measured from the B-mode ultrasound image with the simultaneously recorded electrocardiogram (ECG) signal in the 24 subjects, provided a more accurate method of frame selection for arterial diameter extrema independent of the ECG signal. The method of computerized edge detection-sequential multiframe image processing presented in this paper represents a technological advance for image analysis of B-mode ultrasound images of common carotid arterial dimensions that is highly reproducible and directly applicable to noninvasive imaging of atherosclerosis.     

American society of echocardiography report. Clinical application of noninvasive vascular ultrasound in cardiovascular risk stratification: a report from the American Society of Echocardiography and the Society for Vascular Medicine and Biology

Noninvasive measures of atherosclerosis have emerged as adjuncts to standard cardiovascular disease (CVD) risk factors in an attempt to refine risk stratification and the need for more aggressive preventive strategies. Two such approaches, carotid artery imaging and brachial artery reactivity testing (BART), are ultrasound based. Numerous carotid artery imaging protocols have been used, and methodologic aspects are described in detail in this review. The panel recommends that protocols: (1) use end-diastolic (minimum dimension) images for intimal-medial thickness (IMT) measurements; (2) provide separate categorization of plaque presence and IMT; (3) avoid use of a single upper limit of normal for IMT because the measure varies with age, sex, and race; and (4) incorporate lumen measurement, particularly when serial measurements are performed to account for changes in distending pressure. Protocols may vary in the number of segments wherein IMT is measured, whether near wall is measured in addition to far wall, and whether IMT measurements are derived from B-mode or M-mode images, depending on the application. BART is a technique that requires meticulous attention to patient preparation and methodologic detail. Its application is substantially more challenging than is carotid imaging and remains largely a research technique that is not readily translated into routine clinical practice.     

Carotid and femoral atherosclerotic lesions in patients with coronary heart disease confirmed by angiography

INTRODUCTION: Clinically evident atherosclerosis is preceded by preclinical changes in the arterial wall. These changes are characterised by increased thickness of the intima-media complex (IMT). AIMS: A complex ultrasound assessment of the peripheral vessels as well as an attempt to find ultrasound parameters correlating with the burden of atherosclerotic lesions of the coronary arteries. METHODS: 231 patients who underwent both coronary angiography and ultrasound examination of the following arteries: common carotid artery (CCA), carotid bulb and common femoral artery (CFA) were enrolled. The IMT value, presence of plaque and Doppler blood flow parameters were evaluated. Selected clinical and biochemical risk factors of atherosclerosis were assessed. Two groups of patients were analysed: 200 patients with coronary artery disease confirmed by angiography (study group), and 31 patients with normal coronary arteries (control group). RESULTS: Significantly higher values of the IMT in the peripheral arteries were observed in patients with coronary artery lesions than in those without (CCA - 0.91 vs 0.61 mm, carotid bulb -- 1.31 vs 0.67 mm, CFA -- 1.38 vs 0.63 respectively, p<0.0001). Atherosclerotic plaques were present only in patients with coronary artery disease. Additionally, IMT values of the CCA, carotid bulb and CFA were significantly higher in patients with severe coronary artery disease (three vessel disease) than in patients with lesions in one or two coronary arteries. CONCLUSIONS: Patients with coronary lesions present with increased IMT values and higher plaque occurrence. Complex ultrasound evaluation of different peripheral arteries (CCA, carotid bulb and CFA) may be used as part of the cardiovascular risk stratification.     

老年高血压患者血压昼夜节律与颈动脉粥样硬化的相关性研究

目的探讨老年高血压患者血压昼夜节律与颈动脉粥样硬化的相关性。方法2003￣2004年来我院老年高血压患者共72例(男68例女4例),根据动态血压监测(ABPM)结果分为正常昼夜节律组,即杓型组(n=37,男35例女2例)和异常昼夜节律组,即非杓型组(n=35,男33例女2例)。对所有患者均行颈动脉超声检查,测定右侧颈总动脉(RCCA)、颈内动脉(RICA)内膜中层厚度(IMT)、管腔内径(D),并计算各自的IMT/D值,测定右侧颈动脉分叉处(RBIF)的IMT,观察并记录双侧颈动脉系统斑块的大小、数量。结果(1)两组年龄(Age)、体重指数(BMI)、总胆固醇(TC)、甘油三酯(TG)、全天平均收缩压(24hMSP)、全天平均舒张压(24hMDP)比较均无显著性差异(P>0.05)。(2)两组的RCCA及RICA的IMT、D、IMT/D比较均无显著性差异(P>0.05)。而右颈动脉分叉处IMT,非杓型组明显高于杓型组(P<0.001)。(3)两组总斑块检出率无显著差异,但多发性斑块检出率非杓型组显著高于杓型组(P<0.05)。结论老年高血压患者血压昼夜节律与颈动脉粥样硬化明显相关,异常的血压昼夜节律提示可能存在更严重的靶器官损害。     

Post-processing reproducibility of the structural characteristics of the common carotid artery in a Flemish population

IntroductionCommon carotid artery (CCA) intima-media thickness (IMT), lumen diameter, and maximum plaque thickness were assessed on ultrasound images. The objective of the study was to evaluate the intra- and inter-reader reproducibility of the measurements following a standardised protocol.MethodsTwo readers performed the off-line measurements on B-mode ultrasound images of the distal CCA, in a randomly selected subset (n = 60) from a Flemish population cohort (FLEMENGHO). We calculated the coefficient of variation, the interclass correlation coefficient (ICC) and reproducibility according to the Bland–Altman method.ResultsThe intra-reader bias for the measurements of left and right side CCA IMT were −0.003 ± 0.04 mm (p = 0.55) and 0.01 ± 0.04 mm (p = 0.03), respectively. The intra-reader bias of the lumen diameter was −0.04 ± 0.25 mm (p = 0.27) for the left and 0.02 ± 0.22 mm (p = 0.45) for the right side. The measurements for the maximum plaque thickness showed no intra-reader differences with bias 0.07 ± 0.2 mm (p = 0.26) for the left and −0.03 ± 0.2 mm (p = 0.55) for the right side. The inter-reader analysis showed good reproducibility for the left and right side CCA IMT with bias 0.004 ± 0.06 mm (p = 0.57) and −0.008 ± 0.05 mm (p = 0.19), respectively, but the lumen diameter measurements showed inter-reader differences, with bias 0.17 ± 0.27 mm (p < 0.0001) for the left and 0.10 ± 0.21 mm (p = 0.0006) for the right side. The inter-reader bias for the maximum plaque thickness were 0.07 ± 0.2 mm (p = 0.21) and −0.1 ± 0.4 mm (p = 0.26) for the left and right side, respectively.ConclusionThe results demonstrated a reliable reproducibility of carotid wall structural measurements, allowing for an adequate further analysis of the entire population cohort.     

Ultrasound velocity criteria for carotid in-stent restenosis.

OBJECTIVE: To examine duplex ultrasound (US) criteria for carotid in-stent restenosis (ISR). BACKGROUND: Carotid artery stent (CAS) placement is an alternative to surgery for the treatment of carotid stenosis in high surgical risk patients. US is the primary method used to follow carotid stent patency. This study investigates US velocity measurements in carotid ISR. METHODS: Two hundred sixty consecutive patients with CAS placement from June 2000 to June 2004 were followed with serial US. ISR was determined by using the standard US velocity criteria for nonstented carotid artery using peak systolic velocity (PSV), end-diastolic velocity (EDV), and internal carotid artery to common carotid velocity ratio (ICA/CCA ratio). Patients suspected of having carotid ISR > or =50% by US, underwent invasive angiography with stenosis graded by NASCET criteria. Results were compared to patients with nonstented carotid artery stenosis using Two-tailed Student's t-test. RESULTS: PSV and ICA/CCA ratio increased to a greater degree in ISR. In 50-69% stenotic arteries, the mean ICA/CCA ratio was 2.76 +/- 0.7 in the ISR group compared to 2.04 +/- 0.3 in the nonstented carotid group (P < 0.05). In > or =70% stenotic arteries, there were increases in PSV (520 +/- 93 vs. 362 +/- 60, P < 0.05) and ICA/CCA ratio (7.58 +/- 2 vs. 4.51 +/- 1.3, P < 0.05) in ISR versus nonstented carotid arteries, respectively. CONCLUSION: PSV and ICA/CCA ratio in ISR increased to a greater extent for angiographic stenosis > or =50%. PSV 240 cm/sec and ICA/CCA ratio 2.45 are optimal thresholds for > or =50% ISR, and PSV 450 cm/sec and ICA/CCA ratio 4.3 are optimal thresholds for > or =70% ISR.     

Association between carotid hemodynamics and asymptomatic white and gray matter lesions in patients with essential hypertension.

The aim of this study was to clarify the magnitude of common carotid artery (CCA) structural and hemodynamic parameters on brain white and gray matter lesions in patients with essential hypertension (EHT). The study subjects were 49 EHT patients without a history of previous myocardial infarction, atrial fibrillation, diabetes mellitus, impaired glucose tolerance, chronic renal failure, symptomatic cerebrovascular events, or asymptomatic carotid artery stenosis. All patients underwent brain MRI and ultrasound imaging of the CCA. MRI findings were evaluated by periventricular hyperintensity (PVH), deep and subcortical white matter hyperintensity (DSWMH), and état criblé according to the Japanese Brain dock Guidelines of 2003. Intima media thickness (IMT), and mean diastolic (Vd) and systolic (Vs) velocities were evaluated by carotid ultrasound. The Vd/Vs ratio was further calculated as a relative diastolic flow velocity. The mean IMT and max IMT were positively associated with PVH, DSWMH, and état criblé (mean IMT: rho=0.473, 0.465, 0.494, p=0.0007, 0.0014, 0.0008, respectively; max IMT: rho=0.558, 0.443, 0.514, p=0.0001, 0.0024, 0.0004, respectively). Vd/Vs was negatively associated with état criblé (rho=-0.418, p=0.0038). Carotid structure and hemodynamics are potentially related to asymptomatic lesions in the cerebrum, and might be predictors of future cerebral vascular events in patients with EHT.     

颈动脉粥样硬化与血管性痴呆的相关性分析

目的探讨颈动脉粥样硬化对血管性痴呆发生、发展的影响。方法对61例血管性痴呆（VaD）患者（VaD组）及70例健康体检者（对照组）行高频超声检查,测定其颈总动脉、颈内动脉内-中膜厚度（IMT）及内径,颈动脉粥样硬化斑块的发生情况及斑块性质,采用全自动生化分析仪测定血TC、TG、HDL—C及LDL-C水平。结果VaD组颈总动脉IMT及颈内动脉IMT均明显大于对照组,颈总动脉及颈内动脉内径均明显小于对照组（P均〈0．05）;VaD组斑块发生率明显高于对照组（P〈0．05）;TC、TG、LDL-C水平均明显高于对照组、HDL-C明显低于对照组（P均〈0．05）。结论颈动脉粥样硬化形成与VaD的发生密切相关。     

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.     

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.     

Increased carotid intima media thickness and cardiac biomarkers in HIV infected children

OBJECTIVES: To assess carotid intima media thickness (IMT) and cardiac biomarkers in HIV infected children on antiretroviral therapy (ART). METHODS: This was a single site, cross sectional, controlled observational study. We assessed carotid IMT, homocysteine, high-sensitivity C-reactive protein and myeloperoxidase levels in HIV infected children on stable ART for >or= 6 months. Carotid IMT was reported as internal carotid artery (ICA) and common carotid artery (CCA) thickness; left and right sides were measured separately. Groups were compared using appropriate two-sample tests. RESULTS: Of the 62 subjects enrolled, 31 were HIV positive (50%), 66% were female, and 69% were African-American. Median CD4% was 32% and 26 patients (84%) had HIV-1 RNA< 400 copies/ml. Sixteen patients had been taking protease inhibitors for a median duration of 27 months. None had hypertension or smoked. HIV infected children had higher HOMA-IR, waist-to-hip ratio, cholesterol, triglycerides, myeloperoxidase and lower homocysteine levels. Left and right CCA IMT, and left and right ICA IMT were significantly higher in the HIV infected group. Significant predictors of carotid IMT measurements in uninfected controls were body mass index and homocysteine, but only the duration of ARV therapy was predictive of IMT in the HIV infected group. CONCLUSION: Higher levels of carotid IMT and some cardiac markers were found in ART treated HIV infected children when compared to matched uninfected controls. These results suggest that HIV infected children receiving ART may be at increased risk of cardiovascular disease.     

Ultrasound Examination of Carotid Arteries with Intima Media Measurement: An Underestimated Tool in the Diagnosis of Takayasu's Disease

The diagnosis of Takayasu's arteritis is often clinically difficult. The ultrasound examination of the arteries originating from the aortic arch, especially with the assessment of intima media thickness of common carotid arteries, is easily available and can add valuable information. Eighteen patients, 16 women and 2 men, aged 11–62, with established diagnosis of Takayasu's arteritis and 17 age- and sex-matched controls were examined using duplex color doppler ultrasound. The flow in subclavian, common, internal, external carotid and vertebral arteries was visualized. The mean intima media thickness of the common carotid arteries proximal to the bulb (CCA) and in the carotid bulb were measured in different planes, off-line from digitized images by a single reader, helped by a computerized system for averaging and analysis. A total occlusion of left common carotid arteries in three patients and right CCA in one patient was detected. An occlusion of the brachiocephalic trunk was found in one patient and significant narrowing found in two others. A significant (>-50%) stenosis or occlusion of at least one subclavian artery was present in a majority of patients (87%), with a predilection for the left subclavian artery. In 5 patients, a steal syndrome grade II or III was found in the vertebral arteries. The value of the mean IMT of the CCA is patients with Takayasu's disease was significantly higher than in controls (mean ± SEM; 1.1 ± 0.1 vs 0.59 ± 0.01 mm). In healthy controls, the intima media thickness of the bulb was higher than that in the CCA (0.7 ± 0.03 vs 0.59 ± 0.01 mm). In patients with Takayasu's disease, that proportion was inversed (0.81 ± 0.05 vs 1.1 ± 0.1 mm). Higher intima media thickness found in the common carotid artery than in the bulb can rise a suspicion of Takayasu's arteritis.     

ICEBERG: Intimal Carotid Evaluation Before Echocardiography Reveals Global Vascular Risk

Background

There is growing evidence that carotid ultrasonography provides important prognostic information about cardiovascular risk assessment. Our objective was to determine whether abbreviated rapid carotid ultrasonographic screening would reveal important global vascular risk information in statin-naive patients referred for routine transthoracic echocardiography (TTE).

Methods

Abbreviated carotid ultrasonographic imaging was performed in 560 consecutive patients undergoing TTE. The common carotid artery (CCA), the carotid bulb, and the internal carotid artery (ICA) were scanned. Maximal CCA intima-media thickness (IMT) was measured in the far wall. Carotid plaque was defined using the Atherosclerosis Risk in Communities (ARIC) study criteria.

Results

Of the 2283 patients who underwent TTE during a 1-year period, a total of 560 patients met inclusion criteria. There were 241 men, with a mean age of 63.2 ± 12.8 years and a mean CCA IMT of 1.11 ± 0.48 mm; 61% (147) had carotid plaque. The 319 women had a mean age of 66.3 ± 10.8 years and a mean CCA IMT of 1.03 ± 0.36 mm; 62.4% (199) had carotid plaque. All patients with plaque were considered to be at high risk.

Conclusions

Of the 560 consecutive statin-naive patients referred for TTE with no history of vascular disease, a large proportion of both men (61%) and women (62.4%) had carotid plaque, indicating a high risk for vascular events according to the Canadian lipid guidelines. Although such patients are seen in the echocardiography laboratory, the addition of an abbreviated carotid ultrasonographic screening provides important information regarding risk stratification and the implementation of preventive therapy.