Detection of early atherosclerosis using the ultrasound parameter of the intima-media thickness of the common carotid artery in families with familial combined hyperlipidemia.

AIM: The aim of the present study was to quantify intima-media thickness (IMT) of the common carotid artery (CCA) in clinically asymptomatic members of familial combined hyperlipidemia (FCHL) families and to evaluate its association with lipids, apoproteins, blood pressure, surrogate markers of insulin resistance, fibrinogen and hs-CRP. METHODS: The group under study consisted of 82 individuals from 29 FCHL families (47 hyperlipidemic [HL] and 35 normolipidemic [NL]). They were compared with the age and sex adjusted control groups of healthy subjects (HL-c, n=20 and NL-c, n=20). IMT was measured by ultrasound at a far wall of both common carotid arteries. RESULTS: Hyperlipidemic subjects had increased IMT compared with healthy controls (0.695+/-0.118 vs 0.599+/-0.074 mm), with an age and sex corrected difference of 86 mm (p<0.001). No difference in IMT was recorded in NL FCHL members in comparison with their healthy controls. In HL subjects, significantly positive univariate correlations were observed between IMT and age, total cholesterol, LDL-cholesterol, non-HDL-cholesterol, apolipoprotein B, SBP, DBP, BMI, waist, fasting glycemia, C-peptide and proinsulin, whereas in NL subjects IMT correlated only with age. Multivariate regression analysis in FCHL subjects (HL+NL) revealed that age (p<0.001), sex (p<0.001), non-HDL-cholesterol (p<0.01) and BMI (p<0.05) were significant and independent predictors of IMT. CONCLUSIONS: The increase of IMT CCA in hyperlipidemic still clinically asymptomatic FCHL subjects corresponds to acceleration of the clinically 'silent' atherosclerosis by about 8-14 years and is in agreement with their increased risk of atherosclerosis.     

Large brachial and common carotid artery diameter in postmenopausal women with carotid atherosclerosis

Background and purposeIt is recognized that arteries can enlarge to compensate atherosclerosis. The role of diameter enlargement of unaffected arteries is not well known. We hypothesized that brachial and common carotid arteries diameters were larger in subjects with carotid atherosclerosis compared to subjects without these lesions.MethodsWe measured diameters in the common carotid and brachial arteries. Intimal medial thickness (IMT) of carotid arteries and carotid atherosclerosis were also evaluated using ultrasound in 83 cases and 83 disease-free control subjects.ResultsCommon carotid and brachial diameter was greater in cases (subjects with carotid atherosclerosis) than controls (subjects without carotid atherosclerosis) after adjustment for confounding variables (P < 0.02). Common carotid diameter was also larger in individuals with greater IMT (P < 0.0001), whereas brachial artery diameter was not. Subjects with more than one carotid plaque had larger arterial diameters than those with one or without plaques.ConclusionsCommon carotid and brachial artery diameters are both larger in cases than controls. This result suggests that vascular remodeling is a systemic process and not only a local response to atherosclerosis. The relationship between diameters and burden of disease could also suggest a link between vascular remodeling and severity of disease. Finally, if confirmed in prospective studies, brachial artery diameter could help to identify subjects at high cardiovascular risk, at least in postmenopausal women.     

Conjugated estrogen administration improves common carotid artery elastic properties in normotensive postmenopausal women

BACKGROUND: Various vascular effects of estrogens have been proposed to explain further the beneficial effect of replacement therapy in cardiovascular events. HYPOTHESIS: The study was undertaken to assess the effect of conjugated estrogen on the elastic properties of the large arteries in normotensive, healthy, postmenopausal women. METHODS: Toward this end, we investigated the acute effect of conjugated estrogen on the elastic properties of the common carotid artery (CCA) in 20 normotensive, healthy, postmenopausal women (age 54+/-3 years) at baseline and 20 min after the intravenous administration of 1.25 mg conjugated estrogens. The CCA distensibility was derived by a combination of surface ultrasonographic data and simultaneous blood pressure measurements at the brachial artery. The carotid pulsatility index, a measure of brain impedance, was determined electronically by tracing the CCA Doppler waveform. RESULTS: At baseline, CCA distensibility had a negative correlation with both patients' age and time since menopause (r = -0.57 and r = -0.48, p < 0.05 for both cases). After estrogen administration, estradiol and estrone plasma levels were restored to the range of usual premenopausal values. Estrogen induced a significant increase in CCA distensibility by 0.92+/-0.005 dyne(-1) x cm2 x 10(-6) (from 2.03 to 2.95 dyne(-1) x cm2 x 10(-6)) and a significant reduction in CCA pulsatility index by 0.24+/-0.06, (from 2.17 to 1.93) (p < 0.001 for both cases). The improvement in CCA distensibility had a negative correlation with both patients' age and time since menopause (r= -0.46 and r = -0.44, respectively, p < 0.05 for both cases). CONCLUSIONS: Acute conjugated estrogen administration induced an improvement in CCA elasticity and a reduction in brain impedance in normotensive, postmenopausal women. As the age of women and the time since menopause increased, the improvement in carotid distensibility decreased in such selected subjects.     

Ultrasonic correlates of common carotid atherosclerosis in patients with coronary artery disease

Increased intima-media thickness and plaque development in the extracranial carotid arteries reportedly correlate well with the prevalence of coronary artery diseases. The location of these atherosclerotic lesions in the carotid artery varies with age in patients with coronary artery atherosclerosis. Intima-media thickness, plaque, and calcification in the common carotid artery and bifurcation were assessed with high-resolution B-mode ultrasonography. Forty patients with severe atherosclerosis of the coronary artery and 56 healthy control subjects with no risk factors for coronary atherosclerosis were included in this study. The subjects were divided into a middle-age group (40-59 yr) and an old-age group (60-79 yr). In both groups, the intimamedia thickness in the patients was significantly higher than that in the controls. Intima-media thickness of at least 0.7 mm in the middle-age group and at least 1.0 mm in the old-age group was specific and positively predictive of coronary artery disease. Plaque (> 1.0 mm) and calcification were more significant in patients than in controls. In the middle-age group, intimamedia thickness in the common carotid artery was correlated with coronary atherosclerotic severity. Conversely, in the old-age group, the presence of plaque and calcification at the bifurcation was correlated with coronary atherosclerotic severity. The characteristic manifestation of the atherosclerotic lesion in the carotid artery varied with age in patients with coronary artery disease.     

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.     

Patterns of internal elastic lamina morphology in the canine common carotid artery

The internal elastic lamina (IEL) of normal canine carotid arteries was examined by scanning electron microscopy in pressure-fixed specimens with intact endothelium. IEL appearance showed a marked variation between animals and was classified into fenestrated sheet, fibrous, and mixed varieties. This interpretation of the apparent morphology was confirmed with transmission electron microscopy. It was clear that IEL fenestrae were associated with surface depressions and that in areas of fibrous IEL there was surface elevation over individual fibres. Within individual animals there was little variation in the pattern of IEL either along or between common carotid arteries. If theories of atherogenesis involving the IEL are correct, the variation of IEL patterns between animals would suggest a corresponding variation of incidence and severity of atheromatous lesions of the common carotid artery between animals. Further, the occurrence of fibrous areas distributed throughout the fenestrated sheet would suggest a focal distribution of lesions along such arteries.     

Mechanical properties of the common carotid artery in Williams syndrome

OBJECTIVE—To determine whether arterial wall hypertrophy in elastic arteries was associated with alteration in their mechanical properties in young patients with Williams syndrome.
METHODS—Arterial pressure and intima-media thickness, cross sectional compliance, distensibility, circumferential wall stress, and incremental elastic modulus of the common carotid artery were measured non-invasively in 21 Williams patients (mean (SD) age 8.5 (4) years) and 21 children of similar age.
RESULTS—Systolic and diastolic blood pressures were higher in Williams patients (125/66 v 113/60 mm Hg, p < 0.05). The mean (SD) intima-media thickness was increased in Williams patients, at 0.6 (0.07) v 0.5 (0.03) mm (p < 0.001). Normotensive Williams patients had a lower circumferential wall stress (2.1 (0.5) v 3.0 (0.7) mm Hg, p < 0.01), a higher distensibility (1.1 (0.3) v 0.8 (0.3) mm Hg⁻¹.10⁻², p < 0.01), similar cross sectional compliance (0.14 (0.04) v 0.15 (0.05) mm².mm Hg⁻¹, p > 0.05), and lower incremental elastic modulus (7.4 (2.0) v 14.0 (5.0) mm Hg.10²; p < 0.001).
CONCLUSIONS—The compliance of the large elastic arteries is not modified in Williams syndrome, even though increased intima-media thickness and lower arterial stiffness are consistent features. Therefore systemic hypertension cannot be attributed to impaired compliance of the arterial tree in this condition.


Keywords: elastin; Williams syndrome; hypertension; compliance     

Quality control of ultrasonic measurement of carotid artery intima-media thickness

Background To report quality control methods and baseline reproducibility data of the ultrasound measurements of carotid artery intima-media thickness in the project of Establishment of an Integrated System for Coronary Heart Disease Prevention and Treatment. Methods Standard ultrasound scanning and measuring protocols were established by the study group. All sonographers and readers were trained by the carotid ultrasound core lab and all digital ultrasound images were centrally read. Ten subjects were scanned twice （with 1 week interval） by 2 sonographers independently and images were read by a single reader to evaluate the sonographer variability. Twenty subjects＇ images were read twice （with 1 week interval） by a single reader to assess the reader variability and the reproducibility of IMT measured at different carotid segments. Results The intraclass correlation （ICC） of intra- and inter-sonographer and intra- reader for mean IMT measurements was 0.99, 0.98 and 0.97 respectively; while for max IMT, it was 0.97, 0.99 and 0.95 respectively. Among different carotid segments and sites, ICC for mean 1MT measurements of common carotid （CCA）, carotid artery bulb （Bulb）, internal carotid artery （ICA）, overall near wall and overall far wall was 0.97, 0.99, 0.89, 0.93 and 0.98 respectively. Conclusion The reproducibility of IMT measurements according to our protocol is acceptable, although better reproducibility is found when measuring the mean IMT than max IMT, CCA and Bulb IMT than ICA IMT, and far wall IMT than near wall IMT.     

Sonographic measurement of intimal thickness of the common carotid artery in diabetics

Incidence of atherosclerotic cardiovascular diseases in diabetics is known to be 2-4 times higher than in nondiabetic subjects. Intima-media-thickness of common carotid artery (IMT ACC) measured by B-mode sonography positively correlates with the severity of atherosclerotic changes in coronary arteries. This study compares sonographically assessed IMT ACC in patients with type 2 diabetes mellitus (27 patients, mean age 66.57 +/- 6.06 years) vs. 66 nondiabetic subjects (mean age 63.58 +/- 9.09 years). Intima-media thickness in diabetics was significantly higher when compared with the control group (0.826 +/- 0.29 mm vs. 0.647 +/- 0.26 mm). In the whole cohort of investigated subjects IMT ACC positively correlates with age. When adjusted for age, the mean IMT ACC level was significantly higher in men than in women.     

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，斑决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痛的诊断提供依据。     

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。     

青年精神分裂症患者早期颈动脉硬化临床观察

目的:应用颈动脉超声检查,研究青年精神分裂症患者颈动脉硬化药物的关系。方法:病例组为56例青年精神分裂症住院患者,年龄19～39岁,平均年龄(25.23±3.69)岁;对照组为年龄、性别与研究组匹配的56例健康人,应用颈动脉超声检测双侧颈动脉内中膜厚度,同时检测血糖、血脂及体质量指数并在两组间进行对比研究。结果:大部分青年精神分裂症住院患者颈动脉内中膜厚度高于正常对照者,青年精神分裂症组血糖、TC、LDL-C均高于对照组,HDL-C低于对照组,体质量指数(BMI)差异无统计学意义。结论:颈动脉内中膜厚度超声检测于青年精神分裂症患者早期动脉粥样硬化。     

Non-invasive ultrasonic measurement of the elastic properties of the human abdominal aorta

A new echo tracking device linked to real time ultrasonic B mode equipment was developed to measure non-invasively the elastic properties of the human abdominal aorta. Pulsatile diameter change and mean diameter of the abdominal aorta were measured in 61 subjects with this ultrasonic device. Strain and pressure-strain elastic modulus Ep were calculated from pulsatile diameter change, diameter, and pulse pressure obtained by the auscultatory method. Strain significantly decreased with age; 0.076(0.024) (mean(SD)) in group 1 (20 young adults below the age of 35 years); 0.048(0.024) in group 2 (21 middle aged subjects between the ages of 35 and 60 years); and 0.030(0.010) in group 3 (20 elderly subjects over the age of 60 years). Ep values were 0.99(0.34) X 10(5), 1.55(0.68) X 10(5), and 3.80(2.05) X 10(5) N X m-2 in groups 1, 2, and 3 respectively. Ep in group 3 was significantly higher than in groups 1 and 2. The regression equation relating Ep to age was Ep = (-0.72 + 0.058 X age) X 10(5) N X m-2 (r = 0.73). The Ep value and its age related increase agreed with the findings in postmortem arteries. The elastic properties of the abdominal aorta could, therefore, be determined non-invasively by this ultrasonic method.     

颈、股动脉粥样硬化超声标识与冠心病的关系研究

目的:利用高频超声研究颈、股动脉粥样硬化超声标识与冠状动脉粥样硬化的关系。方法:对91例冠状动脉造影受检者术前行双侧颈、股动脉超声检查,测定血管后壁内膜中层厚度(IMT)和斑块厚度,记录斑块数目,半定量估计斑块的严重程度。根据冠状动脉造影结果分为正常组和冠心病组。冠心病组分别按血管狭窄≥50%所累及主要病变血管支数分:单支病变、双支病变、3支病变,其中左主干累及定为双支病变。结果:随着冠状动脉病变程度的增加,颈、股动脉IMT值均增加,冠心病组与正常组比较差异有统计学意义(P<0.05);颈、股动脉斑块分级与冠状动脉病变血管支数分级间显著相关(P<0.05);股动脉斑块对冠心病预测的准确度(69.23%)高于颈动脉斑块(56.04%)。结论:颈、股动脉粥样硬化超声标识似用以预测冠心病的严重程度。     

The stiffness of the common carotid artery in patients with Graves' disease.

BACKGROUND: Thyroid hormone excess is accompanied by many cardiovascular symptoms. We hypothesised that mechanical properties of the large arteries are also involved in hyperthyroidism-induced cardiovascular changes and set out to investigate this further. METHODS: We compared 2 groups: one composed of hospitalized patients with newly diagnosed, non-treated Graves' disease (Graves' group) and the other (control group) composed of healthy persons or patients with euthyroid goiter (n=25 and n=23, respectively). We determined values of cross-sectional compliance (CC(100)), distensibility (DC(100)) and stiffness coefficients (alpha(100)) estimated for blood pressure P(n)=100 mmHg by measuring the blood pressure with the oscillometric method and measuring differences in the diameter of the common carotid artery with ultrasonographic vascular echo Doppler system. RESULTS: We found no differences in CC(100) (10.6 vs 10.3 10(-4)m(2)/Mpa), DC(100) (29.7 vs 29.6 1/Mpa) or alpha(100) (2.67 vs 2.72) between the 2 groups. However, there were strong correlations between all stiffness parameters and plasma thyroid hormone concentrations in the Graves' group (r(s)=0.4698, p<0.001 for DC(100), r(s)=0.4342, p<0.003 for CC(100), r(s)=-0.4698, p<0.001 for alpha(100) and fT3, respectively). This relationships remained significant after statistical corrections for age and lipid levels (r(p)=0.22, p<0.03 for DC(100) and fT3 or r(p)=-0.457, p<0.02 for alpha(100) and fT3, respectively). CONCLUSIONS: These results indicate that in the Graves' group the stiffness of the common carotid artery might be affected by the thyroid hormone level and the lower the level, the more severe the activity of the hyperthyroidism reflected by the plasma concentration of fT3 or fT4.