Different Degrees Of Carotid Stenosis Research Articles

Early cerebral hemodynamic changes following unilateral carotid artery stenting in patients with different degrees of carotid stenosis.

Few studies have focused on cerebral hemodynamics in the early stage following carotid artery stenting (CAS). This retrospective cohort study aimed to investigate cerebral hemodynamic changes within 6 hours of unilateral CAS in patients with different degrees of carotid stenosis. A total of 104 patients who underwent CAS accompanied by transcranial color-code Doppler or transcranial Doppler were enrolled in the study. The participants were divided into the following 3 groups based on the degree of carotid stenosis: severe stenosis group, extreme stenosis group, and near occlusion group. Bilateral middle cerebral artery (MCA) peak systolic velocity (PSV) and pulsatility index (PI) were measured using transcranial color-code Doppler before and 1 and 3 hours following CAS. Blood pressure, MCA-PSV, and PI were compared among the 3 groups. At 1 hour following CAS, ipsilateral MCA-PSV increased compared to the baseline in the severe stenosis group [84±21 vs. 93±27 cm/s; 8.1%; interquartile range (IQR), 1.4-20.1%; P<0.001]. A similar hemodynamic change, but of a larger magnitude, was observed in the extreme stenosis group (83±24 vs. 100±29 cm/s; 20.8%; IQR, 5.3-33.1%; P<0.001) and near occlusion group (73±24 vs. 109±29 cm/s, 45.8%; IQR, 24.3-73.1%; P<0.001). At 3 hours after CAS, the hemodynamic changes were the same as those at 1 hour. PI increased in all 3 groups following CAS. A subgroup analysis was performed according to symptoms, sex, smoking status, history of hypertension, and presence of hyperlipidemia or diabetes, and the increase in ipsilateral MCA-PSV was not significant. In terms of adverse events, only 4 patients in the near occlusion group experienced transient post-CAS hyperperfusion. The ipsilateral MCA-PSV and PI in patients following unilateral CAS increased significantly in the initial hours. The increase in ipsilateral MCA-PSV was considerably higher in patients with a severe degree of stenosis. Near occlusion of the carotid artery was an independent risk factor for hyperperfusion after unilateral CAS.

Serum from Stroke Patients with High-Grade Carotid Stenosis Promotes Cyclooxygenase-Dependent Endothelial Dysfunction in Non-ischemic Mice Carotid Arteries

Atherosclerosis is responsible for 20% of ischemic strokes, and severe carotid stenosis is associated with a higher incidence of first-ever and recurrent strokes. The release of pro-inflammatory mediators into the blood in severe atherosclerosis may aggravate endothelial dysfunction after stroke contributing to impair disease outcomes. We hypothesize that environments of severe carotid atherosclerotic disease worsen endothelial dysfunction in stroke linked to enhanced risk of further cerebrovascular events. We mounted nonischemic common carotid arteries from 2- to 4-month-old male Oncins France 1 mice in tissue baths for isometric contraction force measurements and exposed them to serum from men with a recent ischemic stroke and different degrees of carotid stenosis: low- or moderate-grade stenosis (LMGS; < 70%) and high-grade stenosis (HGS; ≥ 70%). The results show that serum from stroke patients induced an impairment of acetylcholine relaxations in mice carotid arteries indicative of endothelium dysfunction. This effect was more pronounced after incubation with serum from patients with a recurrent stroke or vascular death within 1 year of follow-up. When patients were stratified according to the degree of stenosis, serum from HGS patients induced more pronounced carotid artery endothelial dysfunction, an effect that was associated with enhanced circulating levels of IL-1β. Mechanistically, endothelial dysfunction was prevented by both nonselective and selective COX blockade. Altogether, the present findings add knowledge on the understanding of the mechanisms involved in the increased risk of stroke in atherosclerosis and suggest that targeting COX in the carotid artery wall may represent a potential novel therapeutic strategy for secondary stroke prevention.

The importance of blood rheology in patient-specific computational fluid dynamics simulation of stenotic carotid arteries.

The initiation and progression of atherosclerosis, which is the main cause of cardiovascular diseases, correlate with local haemodynamic factors such as wall shear stress (WSS). Numerical simulations such as computational fluid dynamics (CFD) based on medical imaging have been employed to analyse blood flow in different arteries with and without luminal stenosis. Patient-specific CFD models, however, have assumptions on blood rheology. The differences in the calculated haemodynamic factors between different rheological models have not been fully evaluated. In this study, carotid magnetic resonance imaging (MRI) was performed on six patients with different degrees of carotid stenosis and two healthy volunteers. Using the 3D reconstructed carotid geometries and the patient-specific boundary conditions, CFD simulations were performed by applying a Newtonian and four non-Newtonian models (Carreau, Cross, Quemada and Power-law). WSS descriptors and pressure gradient were analysed and compared between the models. The differences in the maximum and the average oscillatory shear index between the Newtonian and the non-Newtonian models were lower than 12.7% and 12%, respectively. The differences in pressure gradient were also within 15%. The differences in the mean time-averaged WSS (TAWSS) between the Newtonian and Cross, Carreau and Power-law models were lower than 6%. In contrast, a higher difference (26%) was found in Quemada. For the low TAWSS, the differences from the Newtonian to the non-Newtonian models were much larger, in the range of 0.4-31% for Carreau, 3-22% for Cross, 5-51% for Quemada and 10-41% for Power-law. The study suggests that the assumption of a Newtonian model is reasonable when the overall flow pattern or the mean values of the WSS descriptors are investigated. However, the non-Newtonian model is necessary when the low TAWSS region is the focus, especially for arteries with severe stenosis.

Is Mean Platelet Volume a Reliable Marker to Predict Ischemic Stroke in the Follow-Up of Patients with Carotid Stenosis?

The objective of the study is to evaluate the reliability of mean platelet volume (MPV) for predicting ischemic stroke (cerebrovascular event [CVE]) among patients with different degrees of carotid stenosis. Fifty-two patients with CVEs, 136 patients with carotid artery disease (CAD), and 40 healthy volunteers were enrolled in this study. All participants were divided into the following groups according to CAD: absence of stenosis, less than 50% stenosis, 50%-69% stenosis, and 70% or more to total occlusion of the internal carotid artery. For each participant, the parameters of CAD were assessed using ultrasonography. To obtain the values of CRP and MPV and the leukocyte and platelet counts, all samples were processed within 30 minutes after blood collection. Univariate and multivariate analyses were used to evaluate the association between the values of serum C-reactive protein (CRP) and MPV and carotid stenosis. In terms of age and gender, there was no statistically significant difference between the groups (P = .094 and P = .428, respectively). However, CRP values in patients with CAD and CVEs were significantly higher than those in the controls (P < .001). There was no statistically significant difference between the CRP values in patients with CAD and CVEs (P = .249). Moreover, the MPV values did not show any significant difference between the groups (P = .053) and among the patients with CAD (P = .64). There was no positive correlation between serum CRP and MPV values in patients with CAD regarding the degree of carotid stenosis (r = .061, P = .477). The findings of this study claim that MPV has no predictive value during follow-up of the patients with CAD for CVEs.

Distribution of Th1, Th2 and Th17 in peripheral blood of patients with carotid atherosclerotic ischemic stroke

Objective To investigate the distribution of T helper cell 1 (Th1), Th2 and Th17 in peripheral blood of patients with carotid atherosclerotic ischemic stroke. Methods There were a total of 180 patients with carotid atherosclerotic ischemic stroke and 60 normal controls enrolled in this study. According to the degree of carotid artery stenosis, 180 patients were divided into 3 subgroups: mild stenosis group (N = 60), moderate stenosis group (N = 60) and severe stenosis group (N = 60). Flow cytometry (FCM) was used to test the proportion of Th1, Th2 and Th17 cells in peripheral blood. Results Compared with control group, the proportion of Th1 [(5.76 ± 1.81)% vs (3.54 ± 0.29)%, P = 0.000] and Th17 [(0.36 ± 0.13)% vs (0.18 ± 0.03)% , P = 0.000] cells in ischemic stroke group was significantly increased. There were statistical differences in the proportion of Th1 cells [(4.56 ± 0.55)%, (4.88 ± 0.42)% and (7.83 ± 1.69)%; P = 0.000] and Th17 cells [(0.23 ± 0.04)%, (0.34 ± 0.02)% and (0.50 ± 0.09)%; P = 0.000] in peripheral blood of patients with different degrees of carotid stenosis. The proportion of Th1 cells ( P = 0.001, 0.001) and Th17 cells ( P = 0.000, 0.001) in severe stenosis group were higher than those in mild and moderate stenosis groups, and the proportion of Th17 cells was higher in moderate stenosis group than that in mild stenosis group ( P = 0.000). Conclusions Th1 and Th17 cells participate in the pathological process of carotid atherosclerosis. As the degree of carotid atherosclerosis in patients with ischemic stroke is increased, the proportion of peripheral blood Th17 cells is increased, suggesting that cellular immune mechanism is involved in the occurrence and development of atherosclerosis and provide theoretical basis for the immune treatment of carotid atherosclerotic ischemic stroke. DOI: 10.3969/j.issn.1672-6731.2016.09.008

Sleep Apnea and Asymptomatic Carotid Stenosis: A Complex Interaction

BACKGROUND: Carotid arteriosclerosis and sleep apnea are considered as independent risk factors for stroke. Whether sleep apnea mediates severity of carotid stenosis remains unclear. Sleep apnea comprises two pathophysiologic conditions: OSA and central sleep apnea (CSA). Although OSA results from upper airway occlusion, CSA reflects enhanced ventilatory drive mainly due to carotid chemoreceptor dysfunction.METHODS: Ninety-six patients with asymptomatic extracranial carotid stenosis of ≥ 50% underwent polysomnography to (1) determine prevalence and severity of sleep apnea for different degrees of carotid stenosis and (2) analyze associations between OSA and CSA, carotid stenosis severity, and other arteriosclerotic risk factors.RESULTS: Sleep apnea was present in 68.8% of patients with carotid stenosis. Prevalence and severity of sleep apnea increased with degree of stenosis (P≤ .05) because of a rise in CSA (P≤ .01) but not in OSA. Sleep apnea (OR, 3.8;P≤ .03) and arterial hypertension (OR, 4.1;P≤ .05) were associated with stenosis severity, whereas diabetes, smoking, dyslipidemia, BMI, age, and sex were not. Stenosis severity was related to CSA (P≤ .06) but not to OSA. In addition, CSA but not OSA showed a strong association with arterial hypertension (OR, 12.5;P≤ .02) and diabetes (OR, 4.5;P≤ .04).CONCLUSIONS: Sleep apnea is highly prevalent in asymptomatic carotid stenosis. Further, it is associated with arteriosclerotic disease severity as well as presence of hypertension and diabetes. This vascular risk constellation seems to be more strongly connected with CSA than with OSA, possibly attributable to carotid chemoreceptor dysfunction. Because sleep apnea is well treatable, screening should be embedded in stroke prevention strategies.

Relación entre la historia reproductiva femenina y la aterosclerosis carotídea

ObjectiveEstrogens have been implicated in the development of atherosclerotic disease in the lower limbs and abdominal aorta. The reproductive history study of patients with carotid stenosis may contribute to the understanding of the risk factors for atherosclerosis. The main objective of this study was to investigate whether there are differences in reproductive history between women with carotid occlusive disease and healthy women, and the influence of these differences on its severity. Material and methodsA case-control study was conducted on 153 patients with (78), and without (75) carotid occlusive disease. Patients with carotid stenosis were sub-divided according to the Doppler ultrasound results, into slight (<30%, 16.6%), moderate (30-49%, 16.6%), significant (50-60%, 12.8%), severe (70-99%, 34.6%), and thrombosed (100%, 19.2%). A validated questionnaire of 54 questions was used to gather information on reproductive history (age at menarche and menopause, number of children, use of contraceptives and hormone replacement therapy, and gynecological surgery), comorbidities (diabetes, dyslipidemia, smoking, coronary artery disease, and peripheral artery disease), and concomitant drug therapy. ResultsBoth groups were comparable in age, weight, height, and comorbidities. There were significant differences in the number of children (1.4 ± 1 vs 3.2 ± 2, P=.04) and statin use (92.0 ± 28% vs 13.3 ± 35%, P=.02), being higher in the group of women with carotid disease. The possible influence of hormonal factors such as age at menarche and menopause, as well as oral contraceptives or estrogen replacement was not demonstrated during the study. No significant differences were found in reproductive history between different degrees of carotid stenosis. ConclusionsMultiparity is associated with increased carotid occlusive disease. This finding suggests that motherhood might behave as an atherosclerotic risk factor and should be considered when determining cardiovascular risk in women. The real role of estrogen in carotid occlusive disease still needs to be studied.

Korelacija između aktivnosti alfa naftil acetat esteraze i različitog stepena suženja humane karotidne arterije

Inspite the constantly growing body of biomedical knowledge and techniques, scientists are still far from a complete understanding of molecular system dysfunctions and their relevance in atherogenesis. Accordingly, cellular non specific esterases represent a special field of research, due to their role in a wide range of diseases, including atherosclerosis. This paper deals with linear correlation between relative a-naphthyl acetate esterase (ANAE) score values and different degrees of carotid stenosis in patients with various morphological atherosclerotic lesions of this blood vessel. In our study analysis of ANAE cytochemical activity was performed in imprints of carotid plaques obtained from patients with different morphological groups of atherosclerotic lesions (n=100), as well as in control group of patients with kinking and/or coiling of carotid arteries (n=25). ANAE status was determined by cytochemical scoring system (Hayhoe and Quaglino's method modified by Cvetković, Radak and Đorđević Denić). Our results show that there is difference in relative score value of ANAE activity in carotid artery/plaque tissue between investigated groups of patients. One can, also, observed linear correlation between relative ANAE score values and different degrees of carotid stenosis in patients with various morphological atherosclerotic lesions of this blood vessel. This findings may indicate importance of ANAE in atherogenesis.

Cognitive functions of carotid artery stenosis in the aged rat

Carotid artery stenosis appears to be an independent risk factor for cognitive impairment. But the mechanisms of cognitive impairments occurring in patients with asymptomatic carotid stenosis are poorly understood. One important reason is the absence of a good carotid stenosis model. In the present study, after establishing different degrees of carotid stenosis models in aged rats successfully, we investigated their cognitive function. Wistar rat models with carotid artery stenosis were established by ligating the common carotid artery along with various gauges of needle and then removing the needle. The cognitive performance was assessed using Morris water maze (MWM) task. Cholinergic markers like acetylcholine (ACh) were evaluated in hippocampus. Neuronal damage was also studied through morphological changes. Severe carotid stenosis led to impairment in learning ability and memory retrieval, accompanied with a decrease in ACh level and morphological damage in hippocampus. Moderate carotid stenosis rats had a partial cognitive impairment, but there were no changes in ACh level and morphological damage in hippocampus. Meanwhile, mild carotid stenosis rats had no cognitive impairment compared to sham-operated rats. The results of this study suggest that different degrees of carotid stenosis induce different cognitive changes in aged rats.

Abstract 5132: Serum Pentraxin 3, Matrix Metalloproteinase 9 and Intraplaque Hemorrhage in Carotid Atherosclerosis

Background - Carotid intraplaque hemorrhage (IPH) is a marker of atheroma instability. In the present study, we evaluated the potential association between serum levels of pentraxin 3 (PTX3, a novel marker of vascular inflammation) and matrix metalloproteinases (MMPs) with in vivo assessment of IPH by high-resolution magnetic resonance imaging (MRI). Methods and Results - Consecutive patients submitted to carotid endarterectomy underwent high-resolution MRI; independent evaluation of neurological symptoms; histological analysis and measurement of serum PTX3, MMP-3 and MMP-9. IPH was determined non-invasively by the presence of a hyperintense signal on MRI. Eighty-two predominantly male (65%) and hypertensive (89%) patients (67±9 years-old) were studied. MR angiography identified 19(23%) patients with 50 – 69% stenosis, 23(28%) with 70 –90% stenosis, and 40(49%) with &gt; 90% stenosis. High-resolution MRI depicted a hyperintense signal suggestive of intraplaque bleeding in 48 (58.5%) subjects. No usual clinical characteristic was predictive of the hyperintense signal on MRI (all p values &gt;0.10). Serum PTX3 and MMPs levels were similar in different degrees of carotid stenosis assessed by MR angiography, but were significantly augmented in patients with signs of IPH on MRI and on histological analysis (all p values &lt;0.05). We observed a strong positive association between PTX3 and MMP-9 levels (r=0.76; p&lt;0.0001) and a weak to moderate association between hs-C-reactive protein and PTX3 (r=0.40; p=0.0002) and MMP-9 (r=0.35; p=0.001). In a multivariate logistic regression model adjusted for potential blood-derived markers, clinical neurological instability was the only variable independently associated to MRI-based IPH. Conclusions - MRI-based IPH identified neurologically unstable patients, with increased levels of PTX3 and MMP-9, regardless of the degree of carotid luminal stenosis.

Intraplaque hemorrhage assessed by high-resolution magnetic resonance imaging and C-reactive protein in carotid atherosclerosis

Carotid intraplaque hemorrhage is a marker of atheroma instability. Noninvasive assessment of bleeding can be performed by high-resolution magnetic resonance imaging (MRI), but its association with inflammatory markers has not been clearly demonstrated. We evaluated consecutive carotid endarterectomy patients that underwent high-resolution MRI, independent evaluation of neurologic symptoms, C-reactive protein measurement, and histologic analysis. Intraplaque hemorrhage was determined by the presence of a hyperintense MRI signal (T1-weighted sequence). The study included 70 predominantly male (66%) and hypertensive (89%) patients (89%) aged 66 +/- 9 years old. MR angiography identified 15 patients (21.5%) with stenosis between 50% and 69%, 15 (21.5%) with stenosis between 70% and 90%, and 40 (57%) with stenosis >90%. High-resolution MRI depicted a hyperintense signal suggestive of intraplaque bleeding in 45 subjects (64%). All patients who had had transient ischemic attacks >90 days before the surgery showed a hyperintense signal on MRI (P = .007). Age, gender, traditional cardiovascular risk factors, and history of myocardial infarction or peripheral arterial disease were similar in patients with or without signs of intraplaque bleeding on MRI. There was excellent agreement between acute or recent hemorrhage on histologic and MRI findings (kappa coefficient, 0.91; 95% confidence interval, 0.81 to 1.00). Only one of 45 patients (2%) with a hyperintense signal on MRI did not have acute or recent hemorrhage in the histologic analysis (P < .001). High-sensitivity C-reactive protein levels were similar for different degrees of carotid stenosis as assessed by MR angiography, but they were significantly higher in clinically unstable patients (P = .006) and in those with a positive hyperintense MRI signal (P = .01). In an aggregated analysis of neurologic symptoms and MRI findings, we found a progressive increase of high-sensitivity C-reactive protein levels (P = .02). Intraplaque hemorrhage evaluated by MRI identified neurologically unstable patients with increased levels of high-sensitivity C-reactive protein regardless of the degree of carotid stenosis.

Volume Flow Rate Evaluation in Patients with Obstructive Arteriosclerotic Disease

This study was performed to quantify the volumetric impact of extracranial arteriosclerotic lesions. We investigated patients with different degrees of carotid stenosis as defined by conventional velocity-based duplex criteria and different patterns of collateralization. We studied the volume flow rate (color duplex M-mode device) in 37 patients with symmetrical internal carotid artery (ICA) plaques (<50% stenosis) and compared these data to 43 patients with a unilateral 50–74% stenosis, 75–99% stenosis (n = 73) and occlusion of the ICA (n = 37). A 75–99% stenosis caused an ipsilateral flow reduction of 36% with a wide interindividual variability, and an occlusion of 51%. Collateralization via the ophthalmic artery only caused a nonsignificant ipsilateral volume flow increase, whereas the contralateral volume flow was significantly higher in patients with a patent anterior communicating artery. The increase was more pronounced in patients with an occluded vessel. Our data demonstrate a wide diversity of the hemodynamic impact of carotid stenosis as defined by ‘classical’ Doppler criteria. Collateral flow reflects a dynamic quantitative process.

Stroke with internal carotid artery stenosis.

Stroke patterns in patients with different degrees of carotid stenosis have not been systematically studied. To determine first-ever stroke subtypes in nonselected patients with extracranial internal carotid artery (ICA) stenosis, based on a primary care hospital stroke registry. One hundred seventy-three patients who experienced their first-ever stroke and who had 50% or greater (North American Symptomatic Carotid Endarterectomy Trial method) ipsilateral extracranial ICA stenosis, corresponding to 6.5% of 2649 patients with anterior circulation stroke included in the Lausanne Stroke Registry, were studied. All these patients underwent Doppler ultrasonography, carotid angiography (conventional or magnetic resonance angiography), neuroimaging (computed tomography or magnetic resonance imaging), and other investigations from the standard protocol of the Lausanne Stroke Registry. We found the following types of infarct in the middle cerebral artery territory: anterior pial in 54 (31%) of the patients; subcortical, 34 (20%); posterior pial, 32 (19%); large hemispheral, 20 (12%); and border zone, 17 (10%). There were multiple pial in 14 (8%) and multiple deep infarcts in 2 (1%) of the patients. Moderate (50%-69%) ICA stenosis was significantly associated with large hemispheral infarcts and a normal contralateral ICA (P =.04 and P =.02, respectively). Seventy percent to 89% of ICA stenosis was associated with prior transient ischemic attacks (P =.02). After adjusting for cardioembolism, border zone infarcts showed a strong trend to appear mostly in patients with 90% to 99% ICA stenosis (P =.06). The association of a large hemispheral infarct with moderate ICA stenosis suggests a large embolism and/or an inadequate collateral supply. While an embolism may also contribute, the association of border zone infarcts with 90% to 99% ICA stenosis emphasizes the significance of hemodynamic disturbance in the pathogenesis of these types of infarct.