Carotid intima-media thickness by B-mode ultrasound as surrogate of coronary atherosclerosis: correlation with quantitative coronary angiography and coronary intravascular ultrasound findings.

AIMS: Although well supported by postmortem studies, the reliability of carotid atherosclerosis as surrogate marker of coronary atherosclerosis has been put in doubt by in vivo studies showing a poor correlation between carotid intima-media thickness (IMT) detected by external carotid ultrasound (ECU) and coronary stenosis assessed by quantitative coronary angiography (QCA). In the present study, we have investigated whether a stronger in vivo correlation between the two arteries can be obtained by using homogeneous variables such as carotid and coronary IMT, detected by ECU and intravascular ultrasound (IVUS), respectively. METHODS AND RESULTS: ECU, QCA, and IVUS measurements were made in 48 patients. Carotid IMT was correlated with both angiographic and IVUS findings. A significant but weak correlation was observed between ECU and QCA variables (r approximately 0.35, P < 0.05); the correlation between ECU and IVUS measurements of IMT was higher, with correlation coefficients ranging from 0.49 to 0.55. In patients with a QCA diagnosis of normal/intermediate coronary atherosclerosis, the presence of a carotid-IMT(mean) > 1 mm was associated with an 18-fold increase in risk of having a positive IVUS test (OR = 17.99, 95% CI 1.83-177.14, P= 0.013) and with a seven-fold increased risk of having a significant IVUS coronary stenosis (OR = 7.4, 95% CI 1.27-44.0, P = 0.028). CONCLUSION: Carotid atherosclerosis correlates better with coronary atherosclerosis when both circulations are investigated by the same technique (ultrasound) using the same parameter (IMT). This supports the concept that carotid IMT is a good surrogate marker of coronary atherosclerosis.     

High-frequency transducers for point-of-care ultrasound applications: what is the optimal frequency range?

To compare images obtained using two linear transducers with a different range of frequencies, and to determine if there is a significant difference in the quality of images between the two transducers for medical decision-making. This was a single-blinded, cross-sectional study at an academic medical center. Twenty-five emergency medicine clinical scenarios with ultrasound images (using both 10–5 and 14–5 MHz transducers) covering a variety of point-of-care ultrasound applications were presented to four emergency physician sonographers. They were blinded to the study hypothesis and type of the transducer used to obtain the images. On a scale of 1–10, the mean image quality rating for 10–5 MHz transducer was 7.09 (95 % CI 6.73–7.45) and 6.49 (95 % CI 5.99–6.99) for 14–5 MHz transducer. In the majority of cases (84 %, 95 % CI 75.7–92.3 %), sonographers indicated that images obtained with a 10–5 MHz transducer were satisfactory for medical decision-making. They preferred images obtained with a 10–5 MHz transducer over 14–5 MHz transducer in 39 % (95 % CI 30–50 %) of cases. The images obtained with a 14–5 MHz transducer were preferred over 10–5 MHz transducer in only 16 % (95 % CI 7.7–24.3 %) of the cases. The 14–5 MHz transducer has a slight advantage over 10–5 MHz transducer for ocular, upper airway, and musculoskeletal (tendon) ultrasound applications. A 10–5 MHz linear transducer is adequate to obtain images that can be used for medical decision-making for a variety of point-of-care ultrasound applications.     

Validation of a new ultrasound method for the measurement of carotid artery intima medial thickness and plaque dimensions

BACKGROUND: Carotid ultrasound is an accepted method for the detection of subclinical atherosclerosis. Valid methods that allow quantitation of carotid atheroma burden may be useful for stratifying risk. OBJECTIVE: To validate the results of intima medial thickness (IMT) and plaque measurements using a newly created software algorithm by comparing them with those obtained using a previously validated method. METHODS: Carotid ultrasound videotapes (n=24) were analyzed by experienced observers using a validated method and a new method. Ultrasound parameters were compared by measuring the difference +/- SD to yield indexes of accuracy and precision. Performance was also assessed using correlation and Bland-Altman analyses. RESULTS: Average IMT (n=24), plaque area (n=46), and several indexes that integrate IMT and plaque measurements were all found to be comparable with measurements obtained using the previously validated method. For example, the plaque area showed excellent accuracy and precision (-0.17+/-2.0 mm2, P=0.56), excellent correlation (r=0.98, standard error of the estimate = 2.01 mm2, P<0.001) and no evidence of bias using Bland-Altman analyses (Spearman's rho = 0.04, P=0.82). CONCLUSIONS: A new algorithm for the quantitation of carotid atheroma burden yields results that are comparable with those of a previously validated and widely used method. Availability of valid tools for measuring carotid ultrasound should facilitate the incorporation of this procedure into clinical risk stratification paradigms.     

Transcutaneous very-high resolution ultrasound for the quantification of carotid arterial intima-media thickness in children - Feasibility and comparison with conventional high resolution vascular ultrasound imaging

ObjectiveTo study the accuracy and feasibility of very-high resolution ultrasound (VHRU, 25–55 MHz) and conventional high resolution ultrasound (HRU, 12 MHz) in the assessment of common carotid intima-media thickness (IMT) in healthy children between 0 and 18 years of life.MethodsIMT was measured with VHRU and HRU in 135 children. Seventeen similar sized porcine arterial specimens were imaged with VHRU and HRU, and the IMT measurements compared to histology.ResultsAdequate imaging was obtained and IMT quantified in all children with 25 and 35 MHz, but the far wall was rarely reached with 55 MHz, even in small children. HRU-IMT was significantly thicker compared with VHRU-IMT in young children (<12 years; HRU: 0.434 ± 0.040 vs. VHRU: 0.341 ± 0.054 mm, N = 66; p < 0.001). No differences between HRU-IMT and VHRU-IMT were found among older children. No differences were found between far and near wall VHRU-IMT. An increase in porcine arterial IMT with decreasing transducer frequency was observed in comparison to histology. HRU-IMT was significantly overestimated compared with VHRU-IMT and histology-IMT in porcine vessels with an IMT within the pediatric range (0.20–0.50 mm).ConclusionVHRU is feasible and more accurate than HRU in quantifying CIMT in young children (<12 years). We recommend using the highest ultrasound transducer frequency applicable to quantify CIMT in the pediatric population.     

Association between carotid atherosclerosis and markers of inflammation in rheumatoid arthritis patients and healthy subjects

OBJECTIVE: To examine the relationship between markers of systemic inflammation and carotid atherosclerosis in patients with rheumatoid arthritis (RA) and healthy controls. METHODS: Carotid artery intima-media thickness (IMT) and carotid plaque were measured using high-resolution B-mode ultrasound in 204 patients with RA, ages 40-85, and 102 age- and sex-matched healthy persons. No subject in either group had ever smoked cigarettes. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were used to measure systemic inflammation. The relationship of the carotid artery IMT and carotid plaque to inflammation markers was examined, adjusting for age, sex, RA versus control status, and the cardiovascular (CV) risk factors hypercholesterolemia, systolic blood pressure, diabetes mellitus, and body mass index (BMI). RESULTS: A significant linear trend for increased carotid artery IMT was associated with increasing ESR and CRP categories (r = 0.16, P = 0.004 for ESR, and r = 0.13, P = 0.02 for CRP). These trends did not differ among RA cases and controls, and were independent of age, sex, and CV risk factors. The difference in carotid artery IMT between the lowest and highest categories of ESR was 0.221 mm (95% confidence interval [95% CI] 0.767-1.020, P = 0.02). The difference between extreme CRP categories was 0.275 mm (95% CI 0.039-0.509, P = 0.02). Both remained significant after CV risk factor adjustment. Carotid plaque displayed a similar relationship to markers of inflammation. CONCLUSION: Increased carotid artery IMT and the presence of carotid plaque are associated with markers of systemic inflammation in patients with RA and in healthy subjects. This observation is consistent with hypotheses that assign a role to systemic inflammation in atherosclerosis, and may have implications regarding RA and other chronic inflammatory diseases.     

Accuracy of carotid plaque detection and intima–media thickness measurement with ultrasonography in routine clinical practice

BackgroundCurrent guidelines in cardiovascular disease prevention advocate the use of carotid ultrasound measurements for risk stratification. Carotid abnormalities (plaques or increased intima–media thickness (IMT)) are associated with high risk of coronary and peripheral artery disease. An office-based measurement by clinicians would considerably broaden the clinical applicability of carotid ultrasound. In the present study we have assessed the accuracy of ultrasound detection of carotid plaques and intima–media thickness by trained internists in a routine outpatient setting.Methods and resultsCarotid ultrasound was performed in 112 vascular outpatients by internists, after a six-week training period. The internists' results were independently compared to the reference standard, consisting of carotid ultrasound performed in a specialized vascular laboratory. Sensitivity and specificity were calculated for plaque detection and IMT determination. The mean time required to perform the scans on the outpatient department was 7.3 min (range 4.5 to 16.7 min). A high level of accuracy for detecting plaques (sensitivity 78.5%; specificity 93.6%) was achieved. Identifying abnormal IMT had lower sensitivity but adequate specificity of 46.7% and 87.6%, respectively.ConclusionsIn conclusion, our findings demonstrate that clinicians can be trained well enough in six weeks to accurately and efficiently detect carotid plaques in an outpatient setting. IMT abnormalities were less accurately detected in the office-based approach and may require a specialized vascular laboratory.     

Coronary and peripheral artery remodeling in patients undergoing PTCA: An intracoronary and transcutaneous ultrasound study.

The aim of this study was to assess the relationship between the plaque burden of nonstenotic coronary artery segments and the wall thickness of peripheral arteries using intracoronary and transcutaneous ultrasound imaging, respectively. Intracoronary ultrasound (CVIS, 3.5 Fr) was performed in 27 patients undergoing percutaneous transluminal coronary angioplasty. Carotid arteries were imaged by B-mode ultrasound with semiautomatic edge detection and radial arteries by high resolution A-mode echotracking (NIUS 2). Quantitative measurements included coronary artery intima-media cross-sectional area (IM(CSA)) and cross-sectional narrowing (CSN), as well as intima-media thickness (IMT) and lumen radius (r) of the common carotid and the radial arteries. Intima-media thickness was increased in coronary, carotid, and radial arteries. Coronary arteries had an IM(CSA) of 7.7 +/- 2.5 mm(2) and a CSN of 24% +/- 8%. Despite this moderate plaque burden, lumen area was preserved (12.3 +/- 4.2 mm(2)) because of compensatory enlargement of coronary arteries. Right and left carotid and right radial arteries had an IMT of 575 +/- 78 microm, 570 +/- 129 microm, and 328 +/- 61 microm, respectively. There was no correlation between coronary IM(CSA) and carotid IMT (r = 0.07) or radial IMT (r = 0.02), and there was no correlation between coronary CSN and carotid IMT/r (r = 0.12), or radial IMT/r (r = 0.25). In conclusion, in these patients with symptomatic ischemic disease no relationship between IMT of the coronary arteries and IMT of carotid or radial arteries was found. Although increasingly popular, IMT of peripheral arteries may be of limited value as surrogate marker for the severity of coronary artery disease. Cathet. Cardiovasc. Intervent. 48:12-17, 1999.     

Atherosclerotic calcification and intimal medial thickness of the carotid arteries

BACKGROUND AND PURPOSE: Carotid intimal medial thickness (IMT) is a measure of subclinical atherosclerosis and is predictive of future cardiovascular events. The purpose of this study was to determine the significance and magnitude of association between IMT and atherosclerotic calcification of the carotid arteries. METHODS: Forty-five subjects underwent electron beam computed tomography of the neck to ascertain the extent of atherosclerotic calcification in the carotid arteries followed by B-mode carotid ultrasonography for IMT. RESULTS: The mean age, BMI and total cholesterol to HDL ratio were 61.4, 26.2 and 4.3, respectively. Forty-one percent were women. The overall mean IMT was 0.91 mm with the mean for the right and left being 0.93 and 0.87 mm, respectively. The median total carotid calcium score (CCS) was 48.4 [range: 0-973]. Age-adjusted correlations were significant between the overall mean IMT and total CCS (r=0.53, p<0.01), mean right IMT and right CCS (0.31, 0.05), mean left IMT and left CCS (0.31, 0.05), right common carotid IMT and right CCS (0.53, <0.01) and left common carotid IMT and left CCS (0.31, 0.05). The mean IMT was 0.14 mm greater in subjects with any carotid calcification adjusted for risk factors. A 0.05 mm increase in the carotid IMT was associated with an approximate 3-fold increase in risk for the presence of atherosclerotic calcification. CONCLUSIONS: Carotid IMT is significantly correlated with and predictive of atherosclerotic calcification. Conversely, individuals with any carotid calcification have significantly greater intimal medial thicknesses.     

原发性高血压患者微量白蛋白尿与无症状性脑血管损害的研究

目的探讨原发性高血压(EH)患者微量白蛋白尿(MAU)与无症状性脑血管损害及颈动脉粥样硬化的关系。方法根据24h尿蛋白滤过率(UAER)测定结果,将162例EH患者分为正常白蛋白尿(NAU)组101例和MAU组61例。应用高频多普勒超声检测颈动脉内膜中层厚度(IMT)及颈动脉粥样硬化斑块;头颅MRI评价腔隙性脑梗死。采用logistic回归分析颈动脉IMT增厚和腔隙性脑梗死相关的危险因素。结果162例EH患者中MAU的阳性率为37.7%;与NAU组比较,MAU组颈动脉IMT明显增厚[(1.00±0.26)mmvs(0.86±0.20)mm,P<0.01],腔隙性脑梗死的发生率明显增高(62.3%vs44.6%,P<0.05);MAU与颈动脉IMT增厚及腔隙性脑梗死的发生独立相关(OR=2.639,95%CI:1.240～5.615,P<0.05及OR=2.369,95%CI:1.156～4.856,P<0.05)。结论MAU是高血压患者发生腔隙性脑梗死和颈动脉IMT增厚的一个预测指标,可作为判断无症状性脑血管损害及颈动脉粥样硬化的早期指标。     

Carotid atherosclerosis as a risk factor for complex aortic lesions in patients with ischemic cerebrovascular disease.

Aortic arch atherosclerotic lesions can cause ischemic cerebrovascular disease (ICVD). The association between carotid and aortic atherosclerosis was examined, and it was investigated whether noninvasive carotid evaluation aids in the identification of aortic lesions as potential ICVD risk. The subjects comprised 147 patients with ICVD who had undergone carotid ultrasonography and transesophageal echocardiography. Carotid and aortic arch atherosclerosis was evaluated by measuring the maximum intima - media thickness (IMT), with aortic IMT of at least 4 mm, mobile plaques and/or ulcers defined as complex aortic lesions with potential ICVD risk. Carotid IMT was linearly associated with aortic IMT (r=0.53, p<0.001), and the association was independent of traditional cardiovascular risk factors (beta =0.36, p<0.001). Also, each 1 SD greater carotid IMT was associated with 4.2-fold (95% confidence interval: 2.5-7.0) higher likelihood of complex aortic lesions, with the likelihood little modified when controlling for cardiovascular risk factors. In particular, complex aortic lesions were found in 78% of patients with the highest carotid IMT tertile, compared with 14% of those with the lowest tertile (p<0.05). Based on these findings, carotid atherosclerosis is associated with aortic atherosclerosis, representing a risk factor for aortic lesions that are a potential ICVD risk.     

Carotid intima-media thickness as a marker of cardiovascular risk in patients with subclinical hypothyroidism

Subclinical hypothyroidism (SH) has been associated with an increased risk for coronary disease. Carotid intima-media thickness (IMT), as assessed by ultrasonography, is a precise marker of atherosclerotic changes and can be used as an endpoint for cardiovascular events. Aims of this study were to determine carotid IMT in a group of patients with SH and its possible association with an increase in cardiovascular risk. There were no significant differences in mean carotid IMT between patients and controls. Results of both groups were, respectively: common carotid arteries, 0.573 +/- 0.070 mm and 0.576 +/- 0.068 mm (p= 0.904); carotid bifurcation, 0.602 +/- 0.079 mm and 0.617 +/- 0.102 mm (p= 0.714). Similar results were obtained when analyzing subgroups with serum TSH < or > 8 mIU/L and with positive or negative titers of TPOAb. The mean carotid IMT in these subgroups were: TSH 4-8 mIU/L: 0.579 +/- 0.070 mm and 0.586 +/- 0.063 mm; TSH > 8 mIU/L: 0.569 +/- 0.073 mm and 0.616 +/- 0.091 mm; TPOAb+: 0.585 +/- 0.070 mm and 0.621 +/- 0.085 mm; TPOAb-: 0.554 +/- 0.072 mm and 0.571 +/- 0.066 mm. No differences in the lipid profile and in the apoprotein B and lipoprotein (a) levels between the groups were found. These findings suggest that mild SH with no related metabolic changes is not associated with an increase in cardiovascular risk, as assessed by carotid IMT.     

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.     

Carotid intima-media thickness in patients with isolated coronary artery ectasia

OBJECTIVE: Carotid artery intima-media thickness (IMT) is now widely used as a surrogate marker for atherosclerotic disease. Carotid IMT measured by ultrasound has been shown to be correlated with coronary artery disease as defined by angiography. However, the relation between carotid IMT and isolated coronary artery ectasia (CAE) has not been investigated. The aim of our study was to assess this relation. METHODS: Twenty-five patients with isolated CAE without stenosis and 25 control subjects with angiographically normal coronary arteries were included in this study. These were examined by B-mode ultrasound to measure the IMT at the far wall of the common carotid artery. RESULTS: Patients with isolated CAE had significantly higher carotid IMT compared to control subjects with angiographically normal coronary arteries (0.95+/-0.12 versus 0.71+/-0.10mm respectively, p<0.0001). In addition, we detected a significant positive correlation between the presence of CAE and carotid IMT (r=0.748, p<0.001). CONCLUSION: We have shown for the first time an association between increased carotid IMT and isolated CAE, suggesting that atherosclerosis may be involved in the pathogenesis of isolated CAE in the adult population.     

老年人外周动脉粥样硬化与冠心病的相关性

目的 探讨老年人外周动脉粥样硬化与冠心病的相关性. 方法 选择拟行冠状动脉造影的老年住院患者152例,年龄62～91岁.于冠状动脉造影前1周内行颈动脉和股动脉超声检查.分别测量颈动脉和股动脉内膜-中膜厚度(IMT)、斑块总面积及颈动脉斑块总积分,并判断颈动脉粥样硬化分型,冠心病病变的程度和范围以冠状动脉病变支数及Gensini积分表示. 结果颈动脉IMT、斑块发生率、斑块总面积及斑块总积分在冠心病单支病变组(16例)分别为(0.93±0.10)mm、61.3%、(0.58±0.11)mm~2及(3.82±2.11)分;双支病变组(41例)分别为(0.92±0.14)mm、72.5%、(1.57±0.37)mm~2及(4.59±3.39)分;3支病变组(72例)分别为(0.95±0.11)mm、87.3%、(1.88±0.15)mm~2及(6.67±5.90)分;非冠心病组(23例)分别为(0.81±0.13)mm、42.7%、(0.28±0.69)mm~2及(1.83±1.65)分.股动脉IMT、斑块发生率及斑块总面积在冠心病单支病变组分别为(0.97±0.11)mm、38.3%及(0.24±0.26)mm~2;双支病变组分别为(1.07±0.15)mm、57.9%及(0.51±0.21)mm~2;3支病变组分别为(1.15±0.14)mm、59.5%及(0.59±0.23)mm~2;非冠心病组分别为(0.90±0.13)mm、26.8%及(0.20±0.17)mm~2.冠心病各组上述各项指标高于非冠心病组(均P<0.05),其中双支病变组和3支病变组颈动脉斑块总面积、股动脉斑块总面积及股动脉IMT高于单支病变组(均P<0.05),3支病变组颈动脉斑块总积分高于单支病变组和双支病变组(均P<0.05).相关分析结果表明.颈动脉粥样硬化分型、斑块总积分及面积与冠脉病变支数间呈正相关(r分别为0.282、0.307及0.494,均P<0.01);颈动脉粥样硬化斑块面积与Gensini积分呈正相关(r=0.472,P<0.01).股动脉IMT、斑块总面积与冠脉病变支数呈正相关(r分别为0.415及0.692,均P<0.01),与Gensini积分亦呈正相关(r分别为0.404、0.648,均P<0.01).颈动脉斑块总面积(OR=2.2;95%CI 0.79～2.46)、股动脉斑块总面积(OR=1.6;95%CI 0.28～1.35)及股动脉IMT(OR=1.6;95% CI 1.20～15.10)是冠状动脉Gensini积分的独立预测因子. 结论 超声检查结果评价老年人外周动脉粥样硬化与冠心病的严重程度相关.     

Carotid Intima-Media Thickness as Surrogate for and Predictor of CVD

Carotid artery intima-media thickness (IMT) is a noninvasive measurement of the artery wall thickness, inclusive of atherosclerotic plaque, obtained using ultrasound imaging. In the MESA (Multi-Ethnic Study of Atherosclerosis) study, IMT measurements are used as a surrogate for subclinical cardiovascular disease and as a variable predictive of cardiovascular events. IMT measurements of the common carotid artery are available in more than 99% of the MESA population and are predictive of cardiovascular events. More importantly, IMT and plaque thickness measurements made in the internal carotid artery and carotid bulb are also available in more than 98% of the population and are also strongly predictive of cardiovascular events. This article reviews the techniques used to obtain the MESA IMT values, compares them to those made in other epidemiological studies, and summarizes how they have been used in the MESA study as both surrogates for and predictors of cardiovascular disease.     

High prevalence of subclinical atherosclerosis in psoriatic arthritis patients without clinically evident cardiovascular disease or classic atherosclerosis risk factors

OBJECTIVE: To assess the presence of subclinical atherosclerosis in patients with psoriatic arthritis (PsA) without clinically evident atherosclerosis or its complications, and to assess whether demographic or clinical factors affect the development of atherosclerotic disease in a series of patients with PsA attended to in a community hospital. METHODS: Fifty-nine patients with PsA who fulfilled the Moll and Wright criteria were recruited from Hospital Xeral-Calde (Lugo, Spain). Patients seen during the period of recruitment who had classic cardiovascular risk factors or had experienced cardiovascular or cerebrovascular events were excluded. Fifty-nine healthy matched controls were also studied. Carotid artery intima-media thickness (IMT) and carotid plaques were measured in the right common carotid artery. The study was performed using high-resolution B-mode ultrasound. RESULTS: Patients with PsA exhibited greater carotid artery IMT than did matched controls (mean +/- SD 0.699 +/- 0.165 mm versus 0.643 +/- 0.111 mm; P = 0.031; difference of means 0.056; 95% confidence interval 0.005-0.108). Adjusted for age, the carotid IMT was correlated with age at the time of PsA diagnosis (partial correlation coefficient [r] = -0.264, P = 0.04), disease duration (r = 0.264, P = 0.04), total cholesterol (r = 0.233, P = 0.01), and low-density lipoprotein cholesterol (r = 0.243, P = 0.01). CONCLUSION: The present study demonstrates that patients with PsA without cardiovascular risk factors or clinically evident cardiovascular disease have a high prevalence of macrovascular disease in the form of increased carotid artery IMT compared with ethnically matched controls.     

Carotid artery intima-media thickness in patients with Type 2 diabetes mellitus and impaired glucose tolerance: a systematic review.

AIMS: To review the difference in carotid artery intima media thickness (IMT) between patients with Type 2 diabetes (DM) or impaired glucose tolerance (IGT), and control subjects. METHODS: Systematic reviews were made in order to identify cross-sectional studies using the ultrasound method. The differences between IMT in DM or IGT and control subjects were calculated. Meta-analysis using random-effects modelling was used to calculate summary measures. RESULTS: Twenty-three studies included 24,111 subjects; 4019 with DM and 1110 with IGT. In 20 of 21 studies, the diabetic patients had greater carotid artery IMT than the subjects in the control groups. The estimated mean difference in IMT was 0.13 (95% CI: 0.12-0.14) mm. Heterogeneity was observed and likely sources of variation were study size, diabetes duration, and ultrasound method. In three out of nine studies, the IGT patients had significant greater carotid artery IMT than the subjects in the control groups. The estimated mean difference in IMT was 0.04 (95% CI: 0.014-0.071) mm. CONCLUSIONS: Type 2 diabetes was associated with an 0.13 mm increase in IMT compared with control subjects. In patients with IGT, the increase in IMT was about one-third of that observed in diabetes. The observed difference in IMT can be interpreted as if the diabetes patients were more than 10 years older than the control groups, and that the relative risks of myocardial infarction and stroke were increased by almost 40%, respectively.     

Detection of carotid atherosclerosis in individuals with masked hypertension and white-coat hypertension by self-measured blood pressure at home: the Ohasama study

OBJECTIVE: To investigate carotid atherosclerosis in individuals with masked hypertension (MHT) and white-coat hypertension (WCHT) in a general population. METHODS: Self-measurement of blood pressure at home (HBP) and casual blood pressure (CBP) measurements were recorded in 812 individuals aged at least 55 years (mean 66.4 years) from the general Japanese population. The intima-media thickness (IMT) of the near and far wall of both common carotid arteries was measured and averaged. The relationships between carotid atherosclerosis (IMT and plaque) and the four blood pressure groups (sustained normal blood pressure: HBP < 135/85 mmHg, CBP < 140/90 mmHg; WCHT: HBP < 135/85 mmHg, CBP >or= 140/90 mmHg; MHT: HBP >or= 135/85 mmHg, CBP < 140/90 mmHg; sustained hypertension: HBP >or= 135/85 mmHg, CBP >or= 140/90 mmHg) were examined using multivariate analysis adjusted for possible confounding factors. RESULTS: Adjusted IMT in individuals with sustained hypertension [0.77 mm; 95% confidence interval (CI) 0.75 to 0.79 mm] and MHT (0.77 mm; 95% CI 0.73 to 0.80 mm) was significantly greater than in those with sustained normal blood pressure (0.71 mm; 95% CI 0.69 to 0.72 mm) and WCHT (0.72 mm; 95% CI 0.71 to 0.74 mm) (P < 0.0001). The odds ratios for the presence of plaques in all four groups were similar to the trends in IMT. CONCLUSIONS: Our findings imply that CBP measurements alone are insufficient to distinguish individuals at high risk of carotid atherosclerosis from those at low risk. However, these individuals do have distinct HBP measurements, suggesting that HBP measurement could become a valuable tool for predicting carotid atherosclerosis.     

颈动脉粥样硬化与冠心病关系的研究

目的:研究颈动脉粥样硬化与冠心病的关系。方法:对301例冠状动脉造影的患者作双侧颈动脉超声检查,根据冠脉造影结果分为正常组及冠心病组,冠心病组根据冠状动脉病变支数再分为一支病变组,二支病变组,三支病变组3个亚组。测量颈总动脉后壁内中膜厚度(IMT),斑块厚度,计算斑块积分及粥样斑块发生率。结果:(1)冠心病组IMT,斑块积分及斑块发生率明显高于正常对照组(P<0.01)。(2)随冠脉病变支数增加,斑块积分及IMT增加,亚组比较有显著性差异(P<0.01)。(3)以IMT>0.85mm和(或)出现粥样斑块预测冠心病,特异性75.3％,敏感性84.6％,阳性预测率88.4％。结论:通过颈动脉超声检查可为冠心病的诊断提供依据。     

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.