Plaques In Extracranial Carotid Arteries Research Articles

Clinical Applications of 3.0t High Resolution Magnetic Resonance Imaging (HRMRI) in the Analysis of Carotid Artery Plaques

Objective: Use of head and neck coils through a 3.0T high resolution magnetic resonance imaging (HRMRI) scanner to scan and analyze extra cranial carotid artery plaque components for its nature, composition, stability, wall thickness, and lumen stenosis. Methods: Ten patients (3 females and 7 males) with 50-99% stenosis of the carotid artery due to atherosclerotic plaque formation were used in this study. They were selected from a pool of hospitalized patients at a university medical center between May and November of 2017. Gadodiamide was injected to contrast the magnetic resonance imaging (MRI) scan image. This was then imported into the carotid artery plaque imaging analysis software for evaluation. Results: Analytical results of HRMRI analysis of plaque stratification in patients with right carotid artery plaques: area unit of mm2 - levels 4 through 7 showing 0 because the areas had only carotid artery without plaque components. Conclusion: The 3.0T HRMRI scanner can accurately analyze carotid artery plaque composition, morphology, and the percentage of stenosis. This technique maybe used as an atraumatic non-radiation study to assess the severity and stability of carotid artery plaques, and in the prediction of risks for embolic stroke.

Extracranial Carotid Plaque Calcification and Cerebrovascular Ischemia: A Systematic Review and Meta-Analysis.

Although coronary calcification quantification is an established approach for cardiovascular risk assessment, the value of quantifying carotid calcification is less clear. As a result, we performed a systematic review and meta-analysis to evaluate the association between extracranial carotid artery plaque calcification burden and ipsilateral cerebrovascular ischemic events. A comprehensive literature search was performed in the following databases: Ovid MEDLINE(R) 1946 to July 6, 2022; OVID Embase 1974 to July 6, 2022; and The Cochrane Library (Wiley). We performed meta-analyses including studies in which investigators performed a computed tomography assessment of calcification volume, percentage, or other total calcium burden summarizable in a single continuous imaging biomarker and determined the association of these features with the occurrence of ipsilateral stroke or transient ischemic attack. Our overall meta-analysis consisted of 2239 carotid arteries and 9 studies. The presence of calcification in carotid arteries ipsilateral to ischemic stroke or in stroke patients compared with asymptomatic patients did not demonstrate a significant association with ischemic cerebrovascular events (relative risk of 0.75 [95% CI, 0.44-1.28]; P=0.29). When restricted to studies of significant carotid artery stenosis (>50%), the presence of calcification was associated with a reduced risk of ischemic stroke (relative risk of 0.56 [95% CI, 0.38-0.85]; P=0.006). When the analysis was limited to studies of patients with mainly nonstenotic plaques, there was an increased relative risk of ipsilateral ischemic stroke of 1.72 ([95% CI, 1.01-2.91]; P=0.04). Subgroup meta-analyses of total calcium burden and morphological features of calcium showed wide variability in their strength of association with ischemic stroke and demonstrated significant heterogeneity. The presence of calcification in carotid plaque confers a reduced association with ipsilateral ischemic events, although these results seem to be limited among carotid arteries with higher degrees of stenosis. Adoption of carotid calcification measures in clinical decision-making will require additional studies providing more reproducible and standardized methods of calcium characterization and testing these imaging strategies in prospective studies.

Association Between Spotty Calcification in Nonstenosing Extracranial Carotid Artery Plaque and Ipsilateral Ischemic Stroke.

Background Small spotty calcifications in the coronary arteries are associated with an increased risk of myocardial infarction. We examined the association between spotty calcifications near the carotid bifurcations and ipsilateral ischemic stroke in patients with <50% luminal stenosis of the extracranial carotid arteries. Methods and Results We used data from the CAESAR (Cornell Acute Stroke Academic Registry), a prospective registry of all patients with acute ischemic stroke admitted to our institution. We included patients who met criteria for cryptogenic stroke and underwent computed tomography angiography and brain magnetic resonance imaging. Patients with extracranial carotid artery stenosis ≥50% and patients with posterior or bilateral anterior circulation infarcts were excluded. We examined the carotid bifurcations for spotty calcifications, defined as ≥1 contiguous regions of luminal calcification ≤3 mm along the long axis of the vessel. We also measured low-density plaque and maximum plaque thickness. The eligible cohort consisted of 117 patients with a mean age of 66.7±1.65 years with a median National Institute of Health Stroke Scale stroke at the time of arrival of 6 (range, 3-13). The number of spotty calcifications present within a low-density plaque was significantly associated with ipsilateral infarction (0.3±0.8 versus 0.1±0.4, P=0.02). Maximum plaque thickness was also significantly associated with ipsilateral infarction (1.4 mm ±1.5 versus 1.0 mm ±1.1, P=0.004). Conclusions Spotty calcifications associated with low-density plaque and maximum plaque thickness were associated with ipsilateral ischemic stroke in patients with nonstenotic carotid atherosclerosis, suggesting a role as imaging markers of high-risk plaque.

Association between Extracranial Carotid Artery Plaque and Cognitive Dysfunction: A Systematic Review and Meta-Analysis

Background: Extracranial carotid atherosclerosis has been variably associated with dementia. Prior studies have focused on the association of carotid intima media thickness or carotid stenosis; however, there is evidence that carotid plaque may contribute to dementia, perhaps via microembolic phenomena. Objectives: We sought to evaluate the role of carotid plaque in contributing to cognitive impairment by performing a systematic review and meta-analysis to summarize the association between extracranial carotid plaque and cognitive dysfunction and dementia. Methods: We performed a comprehensive literature search evaluating the association of extracranial carotid plaque with cognition. We included studies measuring carotid plaque on ultrasound, computed tomography, or MR and also evaluated cognition through neuropsychological testing. Meta-analyses with assessment of study heterogeneity and publication bias were performed. Results were presented in a forest plot and summarized using a random-effects model. Results: After screening 1,674 studies, we included 40 for systematic review and 16 and 7 studies for two meta-analyses with a total of 19,029 and 27,325 patients, respectively. We found a positive relationship between the presence of extracranial carotid plaque and cognitive dysfunction with a pooled random-effects odds ratio (OR) of 1.83 (95% CI, 1.50, 2.24) and a pooled random-effects hazard ratio (HR) of 1.47 (95% CI, 1.15, 1.89), respectively. A sensitivity analysis of only longitudinal studies found a persistent positive association. Measures of heterogeneity showed moderate heterogeneity in each meta-analysis, respectively (I-squared statistic = 57% and 70%). Conclusion: The presence of extracranial carotid plaque is significantly associated with cognitive dysfunction and dementia in both cross-sectional and longitudinal analyses. After further confirmation, our results support carotid plaque being a potentially modifiable risk factor in the development of dementia.

Association of severity between carotid and intracranial artery atherosclerosis.

ObjectiveThis study sought to investigate the relationship of atherosclerosis between intracranial and extracranial carotid arteries using three‐dimensional multicontrast magnetic resonance (MR) vessel wall imaging.MethodsPatients with recent cerebrovascular symptoms in anterior circulation were recruited and underwent MR vessel wall imaging for intracranial and extracranial carotid arteries. The plaque burden, including maximum wall thickness (Max WT) and stenosis, and presence of intraplaque hemorrhage (IPH) were assessed. The correlation of the plaque characteristics between intracranial and extracranial carotid arteries was determined.ResultsIn total, 107 patients (mean age: 57.0 ± 11.1 years, 69 males) were recruited. In discriminating intracranial severe stenosis (≥50% stenosis), the odds ratio (OR) of Max WT of extracranial carotid arteries was 1.41 (95% confidence interval [CI], 0.94–2.11, P = 0.095) and 1.72 (95% CI, 1.04–2.83, P = 0.034) before and after adjusting for confounding factors, respectively. The OR of stenosis of extracranial carotid arteries with increment of 10% was 1.26 (95% CI, 0.99–1.60, P = 0.054) and 1.37 (95% CI, 1.03–1.82, P = 0.033) before and after adjusting for confounding factors, in discriminating intracranial severe stenosis respectively. Receiver operating characteristic analysis revealed that the area under the curve (AUC) of Max WT, stenosis, and IPH of extracranial carotid artery plaques was 0.641, 0.605, and 0.603 in discriminating intracranial severe stenosis, respectively. After adjusting for confounding factors, the AUC of Max WT, stenosis, and presence of IPH in extracranial carotid artery plaques increased to 0.812, 0.817 and 0.781, respectively.InterpretationCarotid artery plaque burden is significantly associated with severe intracranial artery stenosis, suggesting that extracranial carotid plaque burden might be an independent indicator for severity of intracranial artery atherosclerosis.

Diabetes adversely affects phospholipid profiles in human carotid artery endarterectomy plaques

Patients with diabetes are at higher risk of developing carotid artery stenosis and resultant stroke. Arachidonoyl phospholipids affect plaque inflammation and vulnerability, but whether diabetic patients have unique carotid artery phospholipidomic profiles is unknown. We performed a comprehensive paired analysis of phospholipids in extracranial carotid endarterectomy (CEA) plaques of matched diabetic and nondiabetic patients and analyzed mass spectrometry-derived profiles of three phospholipids, plasmenyl-phosphatidylethanolamine (pPE), phosphatidylserine (PS), and phosphatidylinositol (PI), in maximally (MAX) and minimally (MIN) diseased CEA segments. We also measured levels of arachidonic acid (AA), produced by pPE hydrolysis, and choline-ethanolamine phosphotransferase 1 (CEPT1), responsible for most pPE de novo biosynthesis. In paired analysis, MIN CEA segments had higher levels than MAX segments of pPE (P < 0.001), PS (P < 0.001), and PI (P < 0.03). MIN diabetic plaques contained higher levels than MAX diabetic plaques of arachidonoyl pPE38:4 and pPE38:5 and CEPT1 was upregulated in diabetic versus nondiabetic plaques. AA levels were relatively greater in MIN versus MAX segments of all CEA segments, and were higher in diabetic than nondiabetic plaques. Our findings suggest that arachidonoyl phospholipids are more likely to be abundant in the extracranial carotid artery plaque of diabetic rather than nondiabetic patients.

Carotid Atherosclerosis Progression and Risk of Cardiovascular Events in a Community in Taiwan.

The authors investigated the association between progression of carotid atherosclerosis and incidence of cardiovascular disease in a community cohort in Taiwan. Data has rarely been reported in Asian populations. Study subjects were 1,398 participants who underwent ultrasound measures of common carotid artery intima-media thickness (IMT) and extracranial carotid artery plaque score at both 1994–1995 and 1999–2000 surveys. Cox proportional hazards model was used to assess the risk of incident cardiovascular disease. During a median follow-up of 13 years (1999–2013), 71 strokes and 68 coronary events occurred. The 5-year individual IMT change was not associated with development of cardiovascular events in unadjusted and adjusted models. Among subjects without plaque in 1994–1995, we observed elevated risk associated with presence of new plaque (plaque score >0 in 1999–2000) in a dose-response manner in unadjusted and age- and sex- adjusted models. The associations attenuated and became statistically non-significant after controlling for cardiovascular risk factors (hazard ratio [95% confidence interval] for plaque score >2 vs. 0: stroke, 1.61 [0.79–3.27], coronary events, 1.13 [0.48–2.69]). This study suggested that carotid plaque formation measured by ultrasound is associated increased risk of developing cardiovascular disease, and cardiovascular risk factors explain the associations to a large extent.

Co-existing intracranial and extracranial carotid artery atherosclerotic plaques and recurrent stroke risk: a three-dimensional multicontrast cardiovascular magnetic resonance study

BackgroundAs a systemic disease, atherosclerosis commonly affects intracranial and extracranial carotid arteries simultaneously which is defined as co-existing plaques. Previous studies demonstrated that co-existing atherosclerotic diseases are significantly associated with ischemic cerebrovascular events. The aim of this study was to investigate the characteristics of co-existing intracranial and extracranial carotid atherosclerotic plaques and their relationships with recurrent stroke by using 3D multi-contrast magnetic resonance (MR) vessel wall imaging.MethodsPatients with recent cerebrovascular symptoms in anterior circulation and at least one carotid plaque were recruited. All patients underwent cardiovascular magnetic resonance (CMR) for brain and intracranial and extracranial arteries. Presence/absence of atherosclerotic plaque at each arterial segment was identified. The maximum wall thickness (Max WT), length, stenosis of each plaque was measured. The presence/absence of calcification, lipid-rich necrotic core (LRNC), and intraplaque hemorrhage (IPH) was assessed. Cerebral old and acute infarcts in anterior circulation were evaluated.ResultsFifty-eight patients (mean age: 58.0 ± 8.5 years old, 34 males) were recruited. Of the 58 patients, co-existing intracranial and extracranial carotid artery plaques were found in 45 patients (77.6%), of which 7 (15.6%) had first time acute stroke and 26 (57.8%) had recurrent stroke. For these 33 patients with stroke, the number of intracranial plaques (OR = 11.26; 95% CI, 1.27–100; p = 0.030) and co-existing intracranial and extracranial carotid artery plaques (OR = 2.42; 95% CI, 1.04–5.64; p = 0.040) was significantly associated with recurrent stroke. After adjusting for traditional risk factors, the number of co-existing plaques was still significantly correlated with recurrent stroke (OR = 3.31; 95% CI, 1.09–10.08; p = 0.035). No correlations were found between recurrent stroke and Max WT, length, stenosis, and compositions of plaques.ConclusionsCo-existing intracranial and extracranial carotid artery plaques are prevalent in symptomatic patients and the number of co-existing plaques is independently associated with the risk of recurrent stroke.

Factors associated with carotid intima-media thickness and carotid plaques in type 2 diabetic patients

Factors associated with carotid atherosclerosis are unclear in type 2 diabetic patients. The aim was to investigate the independent correlates of carotid intima-media thickness (IMT) and plaques in these individuals. In a cross-sectional study, we measured carotid IMT at three sites (common carotid, bifurcation and internal carotid artery) and the severity of extracranial carotid artery (ECCA) atherosclerosis by plaque score in 441 type 2 diabetic patients. Nontraditional cardiovascular risk factors [ambulatory blood pressures (BPs), aortic stiffness, C-reactive protein and ankle-brachial index) were obtained. Multivariate linear and logistic regressions assessed the independent correlates of carotid IMT and ECCA plaque score. Patients with greater carotid IMT or plaque scores had worse clinical and laboratory profile than those with lower IMT and plaque scores, including higher BPs, aortic stiffness and prevalences of diabetic complications. On multivariate analysis, carotid IMT and plaques were mainly associated with older age, male sex, current-past smoking and ambulatory BPs, but not with clinic BPs. Night-time pulse pressure was the most important modifiable determinant of increased carotid IMT. No microvascular complication was independently associated with carotid atherosclerosis, except retinopathy for plaque score. Additionally, internal carotid IMT and plaque score were associated with ankle-brachial index in the subgroup of patients without macrovascular diseases. In type 2 diabetic patients, older age, male sex, smoking status and ambulatory BPs, particularly night-time pulse pressure, were the main independent correlates of ultrasonographic carotid atherosclerosis. This finding reinforces the importance of ambulatory BP monitoring in type 2 diabetes management.

The relationships among serum glucose, albumin concentrations and carotid atherosclerosis in men with spinal cord injury

Limited information is available that examines the interrelationships between glucose tolerance, serum albumin, subclinical inflammation, and carotid atherosclerosis (CA) in patients with spinal cord injury (SCI). We prospectively recruited 110 male patients with traumatic SCI, 57 with SCI at thoracic level 6 or above (SCI-T6) and 53 with SCI at T7 or below (SCI-T7), and 62 age-matched able-bodied controls from the National Taiwan University Hospital. The associations among glucose levels after oral glucose tolerance tests (OGTT), serum albumin, high-sensitivity C-reactive protein (hs-CRP), and CA in terms of the extracranial carotid artery (ECCA) plaque score and common carotid artery (CCA) intima-media thickness (IMT) were examined. Results showed significantly higher post-challenge glucose levels and carotid plaque scores and lower serum albumin in the SCI-T6 patients. In addition, serum albumin was negatively associated with CA and post-challenge glucose levels. The higher post-challenge glucose levels at 120 min (Glu120) were associated with higher serum hs-CRP levels and lower serum albumin levels. In addition, lower serum albumin levels were associated with a thicker CCA IMT and a higher prevalence of ECCA plaque. Mixed models revealed that body mass index, age, LDL-cholesterol, Glu120, homeostasis model assessment for insulin resistance (HOMA-IR), lower serum albumin and smoking habits were positively associated with CCA IMT. Age, HOMA-IR, LDL-cholesterol, and lower serum albumin were identified as the important factors for the presence of carotid plaque by multiple linear regression analyses. In conclusion, post-challenge hyperglycemia and serum albumin levels are important indicators of CV health in men with SCI.

C-reactive protein and the metabolic syndrome correlate differently with carotid atherosclerosis between men and women in a Taiwanese community

Little is known about the role of C-reactive protein (CRP) and metabolic syndrome (MetS) in carotid atherosclerosis among Chinese. In the present cross-sectional study, we examined this relationship and emphasized the sex differences in 456 men and 354 women aged 39 years and older who participated in a community-based cohort study in Taiwan. These participants received measurements for high-sensitivity CRP and ultrasound examinations for common carotid artery intima-media thickness (IMT) and extracranial carotid artery plaques. Metabolic syndrome was defined by the US National Cholesterol Education Program Adult Treatment Panel III criteria. The women had higher median CRP (1.3 vs 1.1 mg/L) and MetS prevalence than the men (58.8 vs 34.2%). Thicker IMT was associated with MetS in women (multivariate-adjusted odds ratio [OR], 2.07; 95% confidence interval, 1.04-4.11) but not in men. Compared with participants with CRP <1 mg/L, men with CRP >3 mg/L had an elevated OR with the presence of plaque (OR, 1.99; 95% confidence interval, 1.10-3.61), but not women. Compared with men with CRP <1 mg/L and no MetS, individuals with MetS and CRP level >3 mg/L were 2.2 times ( P = .046) more likely to have artery plaque. In conclusion, thicker IMT is related to MetS in women, whereas the presence of plaque is associated with elevated CRP in men, and this association is enhanced by MetS.

Xanthelasma is not associated with increased risk of carotid atherosclerosis in normolipidaemia

Extracranial carotid artery (ECCA) atherosclerosis is well known to be associated with cardiovascular diseases. This study aims to investigate the difference of ECCA atherosclerosis between patients with xanthelasma and control subjects in normolipidaemia. Carotid atherosclerosis (CA) of 41 (8 males and 33 females) patients with xanthelasma and normolipidaemia, defined as levels of cholesterol below 6.21 mmol/l and triglyceride below 2.26 mmol/l, recruited from Department of Dermatology was compared with that of 85 age- and gender-matched control subjects. The extent and severity of CA were measured by high-resolution B-mode ultrasound and expressed as the mean intima-media thickness (IMT) of the common carotid artery (CCA) and ECCA plaque score. Mixed-effects model and multivariate logistic regression analyses were used to estimate the association between xanthelasma and CA. Patients with xanthelasma showed significantly higher levels of low-density lipoprotein cholesterol (LDL-C) levels and higher body mass index (BMI) compared with the control group. Mixed models identified age, male gender, smoking and subjects of hypertension with medication, but not the presence of xanthelasma, were associated with an increase of CCA IMT. Multivariate logistic regression analysis revealed subjects of male gender, and hypertension with medication, but not the presence of xanthelasma, associated with thicker IMT, defined as IMT >or= 75th percentile, or ECCA plaque score >or= 3. Normolipidaemia with xanthelasma is not significantly associated with CA, but did relate with adverse cardiovascular profiles, such as higher BMI, waist circumference and LDL-C levels.

Pulse pressure, aortic regurgitation and carotid atherosclerosis: a comparison between hypertensives and normotensives

Pulse pressure (PP) has often been associated with cardiovascular morbidity and mortality. Patients with aortic regurgitation (AR) often have increased PP. The aim of this study is to investigate the associations among PP, AR and extracranial carotid artery (ECCA) carotid atherosclerosis (CA) in hypertensives and age- and sex-matched normotensives. Two hundred and sixty-three hypertensive patients and 270 normotensive subjects from the Chin-Shan Community Cardiovascular Cohort participated in this study in 1996. CA, expressed as maximal common carotid artery intima-media thickness (IMT) > or = 75th percentile and ECCA plaque score > 6, was measured using high-resolution B-mode ultrasonography. The presence of AR was assessed by echocardiography, and their relationships with CA were evaluated. Results showed measurements of CA significantly associated with increased PP. Presence of AR associated with CA, but this relationship was attenuated after controlling for age. Multivariate logistic regression analyses revealed that an ECCA score > 6 significantly increase the risk in conjunction with PP, age and smoking in hypertensives. Correspondingly, CA increased with age, smoking and left ventricular hypertrophy on electrocardiography but not PP in normotensives. In conclusion, higher PP is strongly associated with CA in patients with hypertension. In terms of risk stratification, PP is more important in hypertensives than in normotensives which seem to imply that pulsatile haemodynamic component of BP is crucial in association with atherosclerosis.

Body composition and fat repartition in relation to structure and function of large arteries in middle-aged adults (the SU.VI.MAX study)

To investigate associations of body composition assessed by bioimpedance analysis and anthropometric indicators of fat repartition with carotid structure and function. Cross-sectional epidemiological study. A total of 1014 middle-aged apparently healthy adults participating in the SU.VI.MAX study. Body composition (fat mass, fat-free mass) was assessed by bioimpedance analysis and anthropometric indicators of fat repartition (waist circumference (WC); waist-hip-ratio (WHR)) were simultaneously collected. Carotid ultrasound examination included measurements of intima-media thickness (IMT) at the common carotid arteries (CCA) and assessment of atherosclerotic plaques in extracranial carotid arteries. Carotid-femoral pulse-wave velocity (PWV) was used as a marker of aortic stiffness. In multivariate analyses adjusted for major known cardiovascular risk factors in addition to age, gender and height, fat-free mass, fat mass (FM), and WC were positively associated with CCA-IMT and lumen diameter. No significant association was found with occurrence of carotid plaques. PWV was only associated with WC. Associations of CCA-IMT and PWV with WC were not significant anymore after further adjustment on body mass index (BMI) or FM. WC was the only measurement positively associated with both early atherosclerosis markers such as CCA-IMT and arterial stiffness. Although this association depends on overall adiposity, as assessed by the BMI, it emphasizes the importance of WC in clinical practice and prevention programs as a screening tool for individuals at risk for cardiovascular disease.

Hypertension Status Is the Major Determinant of Carotid Atherosclerosis

Extracranial carotid artery (ECCA) atherosclerosis has been associated with hypertension-related stroke. The present study was aimed at investigating the determinants of ECCA atherosclerosis in patients with hypertension in Taiwan. The extent and severity of ECCA atherosclerosis were measured by high-resolution B-mode ultrasonography and expressed as maximal intima-media thickness (IMT) of the common carotid artery, ECCA plaque score, and carotid stenosis >/=50%. From July through December 1996, 263 hypertensive patients (146 with hypertension and 117 with borderline hypertension) and 270 normotensive adults from the Chin-Shan Community Cardiovascular Cohort participated in this study. Risk factors and ECCA atherosclerosis were stratified by the blood pressure status. A significant dose-response relationship was found between the status of hypertension and the severity of carotid atherosclerosis. Multivariate logistic regression models revealed that hypertension (including borderline), male gender, smoking, and age >/=65 years significantly increased the risk of thicker IMT. The risk of ECCA plaque score >6 increased significantly in conjunction with hypertension, age >/=65 years, left ventricular hypertrophy on ECG, and smoking. However, hypertension and smoking were the 2 evident determinants of carotid stenosis >/=50% after adjustment for other covariates. Compared with the normotensive subjects, the ORs (and 95% CIs) for the hypertensive patients to develop carotid atherosclerosis were 5.0 (3.0 to 8.4) indexed by maximal common carotid artery IMT >/=75th percentile, 3.7 (1.8 to 7.9) by ECCA score >6, and 4.8 (1.4 to 16.5) by carotid stenosis >/=50%. Hypertension strongly influence carotid atherosclerosis. Our findings reinforce the hypothesis that hypertension has a major role in the pathogenesis of atherosclerosis.

Factors of Carotid Arterial Enlargement in a Population Aged 59 to 71 Years

Factors of carotid arterial enlargement are not well known in general populations. The purpose of this study was to assess the cross-sectional associations of arterial wall lesions and cardiovascular risk factors with carotid lumen diameter in elderly subjects. B-mode ultrasound examinations of the carotid arteries and risk factor assessment were made in 1272 participants in the EVA (Etude sur le vieillissement artériel) Study, a longitudinal study designed to evaluate vascular and cognitive aging in men and women aged 59 to 71 years. Ultrasound examinations included measurements of intima-media thickness (IMT) and interadventitial and lumen diameters of the common carotid arteries and quantification of atherosclerotic plaques in extracranial carotid arteries. Men showed greater IMT interadventitial and lumen diameters of the common carotid arteries than did women. In both sexes, common IMT and plaque score were positively associated with common interadventitial and lumen diameters. Stepwise multiple regression analysis showed that male sex, body height and weight, common IMT, plaque score, systolic blood pressure, and alcohol consumption were positively and independently related to lumen diameter. On the other hand, an independent negative association was observed between low density lipoprotein cholesterol and lumen diameter. In 59- to 71-year-old subjects, increased IMT and atherosclerotic plaques were accompanied by an increase in lumen diameter of the common carotid arteries, indicating an overcompensation. Luminal enlargement observed with several risk factors and with high blood pressure in particular might be partially counteracted by high lipid levels.

Ultrasonographic correlates of carotid atherosclerosis in transient ischemic attack and stroke.

Atherosclerotic plaques in extracranial carotid arteries, particularly in the bifurcation of the common carotid and internal carotid arteries, may cause transient cerebral ischemia and stroke by lumen stenosis or plaque-related thromboembolism. B-mode ultrasound imaging has the capability of providing information on plaque thickness, characteristics, and location in carotid arteries. A retrospective analysis of 242 stroke and 336 transient ischemic attack (TIA) patients, recruited for the B-Scan Ultrasound Imaging Assessment Program, was performed to determine the ultrasonographic correlates of carotid atherosclerosis and acute cerebral ischemia. A matched case-control study design was used to compare brain hemispheres with ischemic lesions ("cases") to unaffected contralateral hemispheres ("controls") with regard to the presence and characteristics of carotid artery plaques. The first set of analyses examined the association between the presence of carotid plaques ipsilateral to the brain lesion and the occurrence of stroke or TIA and showed an association with recent episodes of TIA and stroke (odds ratio [OR], 1.6; P = .03) but not with past episodes. In a subset (n = 232) of patients with plaques in both carotid arteries and recent cerebral ischemic events, stroke was associated with ipsilateral carotid artery occlusion (P = .02). Lumen measurements at the site of the minimum residual lumen (MRL) diameter showed a significant association between a narrower lumen diameter in the carotid artery ipsilateral to case hemisphere and stroke (difference, 1.0 mm; P = .0003). TIA patients showed an association between both hypoechoic carotid plaques (OR, 3.0; P = .005) and the presence of longitudinal lesion motion (OR, 3.0; P = .02) with ipsilateral brain involvement. Plaque thickness at the MRL was positively correlated with both ipsilateral TIA (ipsilateral side, 4.4 +/- 0.15 mm; contralateral side, 3.9 +/- 0.16 mm; P = .007) and stroke (ipsilateral side, 4.2 +/- 0.23 mm; contralateral side, 3.3 +/- 0.21 mm; P = .0006). These data demonstrate significant relationships between carotid artery ultrasound plaque characteristics and ischemic cerebrovascular events. These findings encourage further prospective studies in asymptomatic subjects focused on echographic carotid plaque characteristics as predictors of subsequent TIA or stroke.

B-mode-detected carotid artery plaque in a general population. Atherosclerosis Risk in Communities (ARIC) Study Investigators.

There is little information on the distribution of atherosclerotic lesions of the extracranial carotid artery wall in free-living populations. The purpose of the present study was to describe the prevalence from 1987 through 1989 of extracranial carotid artery plaque and plaque with acoustic attenuation (shadowing) lesions in a general population of white and black adults from four US communities. B-mode ultrasound was used to characterize wall lesions in the common and internal carotid arteries and at the carotid artery bifurcation in 14,046 men and women 45 to 64 years old who participated in the Atherosclerosis Risk in Communities Study baseline survey. Thirty-four percent of participants had plaque and 6.4% had plaque with acoustic shadowing. The prevalence of plaque with acoustic shadowing increased steadily with age from 2.5% at ages 45 to 49 to 12.4% at ages 60 to 64. Overall, whites had more plaque with acoustic shadowing lesions than blacks (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.02 to 1.46), and men had more than women (OR, 1.42; 95% CI, 1.22 to 1.63). However, plaque lesions in the common carotid artery were less common among whites than among blacks, and no racial difference was observed in the prevalence of plaque with acoustic shadowing at this segment. Although these prevalence rates are likely to be underestimated because of the emphasis on arterial boundary visualization of the scanning protocol, they show a large, mostly asymptomatic burden of atherosclerosis in these populations, especially among older individuals. Site-specific frequency rates of plaque varied between blacks and whites. Among those with plaque, however, whites had more lesions with acoustic shadowing attenuation.

Amount of smoking independently predicts carotid artery atherosclerosis severity.

Cigarette smoking is correlated with extracranial carotid artery plaque thickness. Our aim in the present study was to determine whether the level of prior cigarette use is a significant predictor of carotid artery plaque thickness when age, history of hypertension, and history of diabetes are controlled. We studied a continuous sample of 790 patients with a history of smoking referred for diagnostic ultrasound imaging of the carotid arteries. Subjects (mean age 61 years) had an average of 51 pack-years of cigarette use. History of hypertension was present in 44% and history of diabetes in 18%. Right and left maximum carotid artery plaque thicknesses were averaged for each patient; the average of this value for all 790 subjects was 1.9 mm. In bivariate analysis, age (p less than 0.0001), pack-years (p less than 0.0001), history of hypertension (p = 0.0003), and history of diabetes (p = 0.037) were each positively associated with carotid artery plaque thickness. In multiple regression analysis, age (p less than 0.0001), pack-years (p = 0.0005), and history of hypertension (p = 0.0044) were statistically significant independent predictors of carotid artery plaque thickness, but history of diabetes (p = 0.2451) was not. In smokers, the level of cigarette use is associated with an acceleration of carotid artery atherosclerosis development. This effect is independent of age, hypertension, and diabetes. These results support smoking abatement as an important element to stroke prevention in clinical practice.

Risk factors for site specific extracranial carotid artery plaque distribution as measured by B-mode ultrasound

The effect of age, sex, diabetes, hypertension, pulse rate and cigarette smoking on extracranial carotid artery plaque thickness evaluated by B-mode ultrasonography was investigated in a cross-sectional study of 698 white men, 730 white women, 77 black men and 76 black women as part of a clinical ultrasound registry. Subjects were between 24 and 98 years of age, with a mean age of 63 years. Arterial locations evaluated were: proximal, mid and distal common carotid; the bifurcation; and the proximal and mid internal and external carotids. In a general linear multivariate analysis with plaque thickness at each site as the outcome variable, cigarette smoking and age were the two most consistent risk factors, and affected plaque thickness at all the investigated sites. Hypertension affected more sites than diabetes, men had more plaques than women, and except for the common carotid, whites had more plaques than blacks. Thus, risk factors were not uniformly associated with atherosclerosis at all sites of the extracranial carotid arteries.