Severity of asymptomatic carotid stenosis and risk of ipsilateral hemispheric ischaemic events: results from the ACSRS study.

OBJECTIVES: This study determines the risk of ipsilateral ischaemic neurological events in relation to the degree of asymptomatic carotid stenosis and other risk factors. METHODS: Patients (n=1115) with asymptomatic internal carotid artery (ICA) stenosis greater than 50% in relation to the bulb diameter were followed up for a period of 6-84 (mean 37.1) months. Stenosis was graded using duplex, and clinical and biochemical risk factors were recorded. RESULTS: The relationship between ICA stenosis and event rate is linear when stenosis is expressed by the ECST method, but S-shaped if expressed by the NASCET method. In addition to the ECST grade of stenosis (RR 1.6; 95% CI 1.21-2.15), history of contralateral TIAs (RR 3.0; 95% CI 1.90-4.73) and creatinine in excess of 85 micromol/L (RR 2.1; 95% CI 1.23-3.65) were independent risk predictors. The combination of these three risk factors can identify a high-risk group (7.3% annual event rate and 4.3% annual stroke rate) and a low risk group (2.3% annual event rate and 0.7% annual stroke rate). CONCLUSIONS: Linearity between ECST per cent stenosis and risk makes this method for grading stenosis more amenable to risk prediction without any transformation not only in clinical practice but also when multivariable analysis is to be used. Identification of additional risk factors provides a new approach to risk stratification and should help refine the indications for carotid endarterectomy.     

The risk of stroke in patients with asymptomatic carotid stenosis undergoing cardiac surgery: a follow-up study

During a 7-year period, 4047 patients underwent a battery of noninvasive carotid tests before cardiac surgery. Two thirds of the patients with abnormal studies underwent carotid angiography. One hundred fifty-three patients (3.8%) had significant carotid disease, narrowing the luminal diameter by greater than 50%. The incidence of transient ischemic attack or cerebrovascular accident following cardiac surgery was 1.9% in those patients with no carotid disease and 9.2% in those patients with carotid lesions. The incidence of transient ischemic attack or cerebrovascular accident in 32 patients with inoperable (occluded) carotid vessels was 15.6% and in 121 patients with operable (stenotic) lesions was 7.4%. In the group of patients with stenosis, 57 patients underwent carotid operation with an 8.8% incidence of neurologic deficit. During the last 1 1/2 years, no patient with asymptomatic carotid stenosis underwent simultaneous carotid and coronary surgery. Four of 64 patients with combined lesions but no carotid surgery (6.3%) had a neurologic deficit, one of which was severe and permanent. The highest incidence of neurologic dysfunction occurred in patients with unilateral occlusions and contralateral stenosis. Four of 12 patients in this group had a deficit (three of seven patients underwent operation; one of five did not), one of which was permanent. The operative mortality rate after cardiac surgery was three times higher in patients with carotid disease than in those patients with normal carotid arteries. Combined carotid and coronary surgery is currently reserved for patients with neurologic symptoms and severe cardiac disease.     

Severe contralateral carotid stenosis or occlusion does not have an impact on risk of ipsilateral stroke after carotid endarterectomy

Objective

This study evaluates the impact of severe (>70%) contralateral carotid stenosis or occlusion (SCSO) on outcomes after carotid endarterectomy (CEA).

Patients at elevated risk of major adverse events following endarterectomy for asymptomatic carotid stenosis

Background

Carotid endarterectomy (CEA) as treatment in patients with asymptomatic carotid stenosis is the subject of much debate.

Methods

The National Surgical Quality Improvement Program database from 2005 to 2012 was queried. Patients undergoing CEA for asymptomatic carotid stenosis were identified. Preoperative risk factors and patient demographics were compared using chi-square analysis and logistic regression to determine their relation with stroke and death.

Results

During an 8-year period, 24,211 CEAs performed for asymptomatic carotid stenosis were identified. Patients with dependent functional status (12.5%), recent myocardial infarction (6.3%), chronic heart failure (5.0%), hypoalbuminemia (4.8%), angina (4.1%), dialysis dependence (3.4%), steroid dependence (3.4%), chronic obstructive pulmonary disease (3.3%), and American Society of Anesthesiologists > 3 (3.2%) had a clinically significant increase in risk of stroke and death. Patients with none of the above risk factors had a stroke and death rate of 1.08%, which was significantly less than the overall stroke and death rate (P < .001).

Conclusions

A high-risk subset of patients undergoing CEA for asymptomatic carotid stenosis can be identified. If patient selection is optimized and perioperative morbidity and mortality are minimized, CEA will continue to play an important role in stroke prevention for those with significant asymptomatic carotid stenosis.     

颈动脉斑块常规超声及超声造影预测颈动脉狭窄患者缺血性脑卒中

目的 观察常规超声及超声造影(CEUS)评估颈动脉斑块、预测颈动脉狭窄患者缺血性脑卒中的价值。方法 回顾性分析115例经超声证实的颈动脉斑块致狭窄(狭窄率≥50%)患者,根据近6个月内有无缺血性脑卒中将其分为症状组(n=53)及无症状组(n=62)。以单因素分析及多因素logistic回归分析筛选颈动脉狭窄患者发生缺血性脑卒中的颈动脉斑块超声特征,建立回归模型,绘制受试者工作特征(ROC)曲线,评估其预测患缺血性脑卒中的效能。结果 单因素分析显示,组间颈动脉狭窄率、斑块表面形态及斑块内新生血管分级差异均有统计学意义(P均<0.05)。多因素logistic回归分析显示,斑块表面形态及斑块内新生血管分级为颈动脉狭窄患者发生缺血性脑卒中的独立预测因素,建立回归模型Y=－4.914+2.272X₁+2.354X₂(X₁为斑块表面形态,X₂为斑块内新生血管分级),其预测缺血性脑卒中的曲线下面积为0.886。结论 常规超声联合CEUS评估颈动脉狭窄患者颈动脉斑块有助于预测缺血性脑卒中。     

Modifiable risk factors for occurrence of ipsilateral ischemic events after carotid endarterectomy beyond perioperative period

ObjectiveThe purpose of this study was to quantify the effects of several modifiable variables on the occurrence of stroke after the initial perioperative period for patients who had undergone carotid endarterectomy (CEA).MethodsThe primary outcome for the present study was the development of an ischemic stroke or transient ischemic attack (TIA) in the cerebral hemisphere ipsilateral to CEA after the initial hospitalization. All CEAs in the VQI between January 2003 and May 2022 were queried. We identified 171,816 CEAs in the database. The exclusion criteria for the study were the lack of follow-up data for >30 days, concomitant coronary artery bypass surgery, concomitant proximal or distal carotid intervention at CEA, other arterial interventions at CEA, and stroke or TIA during the initial hospital admission, leaving 126,290 patients for analysis. We used the χ² test for statistical analysis of the outcome of ipsilateral ischemic stroke or TIA after the initial CEA hospital admission to determine the relevant variables. Age was evaluated as an ordinal variable using the Student t test. Variables with P ≤ .05 on univariable analysis were included in the multivariable Cox regression time-to-event analysis for the primary outcome. Kaplan-Meier curves were constructed of the most significant variables on Cox regression as a visual aid.ResultsThe following variables achieved significance on Cox regression for an association with development of ipsilateral hemispheric ischemic events after the index CEA hospital admission: lack of patch placement at CEA site (hazard ratio [HR], 18.24; P < .0001), lack of antiplatelet therapy at long-term follow-up (LTFU; HR, 9.75; P < .0001), lack of statin therapy at LTFU (HR, 3.18; P < .001), lack of statin therapy at hospital discharge (HR, 1.25; P = .015), anticoagulation at LTFU (HR, 1.53; P < .001), development of >70% recurrent stenosis (HR, 2.15; P < .001), and shunt use at surgery (HR, 1.20; P = .007). Patients with patch placement at surgery and patients with confirmed antiplatelet therapy at LTFU had had 99.8% and 99.6% freedom from an ischemic event ipsilateral to the side of the CEA at LTFU, respectively. This finding is in contrast to the 5.7% and 4.7% positivity for ischemic events for those without patch placement at surgery and those not receiving antiplatelet therapy at LTFU, respectively (P < .0001 for both).ConclusionsPerformance of patch angioplasty arterial closure was remarkably protective against ipsilateral cerebral ischemic events at LTFU after CEA. Discharging and maintaining patients with antiplatelet and statin medication after CEA significantly reduces the incidence of future ipsilateral ischemic events. Thus, a significant opportunity exists for enhanced outcomes with improved implementation of these measures.     

Thickness of carotid artery atherosclerotic plaque and ischemic risk

Noninvasive duplex scanning of carotid artery atherosclerotic plaque was performed in 286 consecutive patients referred to a cerebrovascular diagnostic laboratory. The presence and thickness of such plaque in the region of the carotid bifurcation were examined for association with the degree of vessel stenosis, age, sex, smoking history, history of prior transient ischemic attack or stroke, and systemic manifestations of atherosclerotic disease. Atherosclerotic plaque thickness was positively correlated with degree of vessel stenosis (P less than 0.0001). Both parameters were independent predictors of cerebrovascular events but plaque thickness was a better predictor of prior transient ischemic attacks (P less than 0.05), and vessel stenosis was a better predictor of prior stroke (P less than 0.005). Patient age (P less than 0.001) and pack-years of cigarette use (P less than 0.001) were independent positive predictors of carotid atherosclerotic plaque thickness. The greatest effect of smoking and atherosclerotic plaque thickness was seen in heavy smokers younger than age 55. Both carotid artery plaque thickness and pack-years of smoking were significant independent predictors of other systemic manifestations of atherosclerotic disease (P less than 0.05). Such noninvasive scanning of carotid artery atherosclerotic plaque demonstrates the significant role of age and smoking in the progression of disease. It also suggests a significant role for carotid atherosclerotic artery plaque in the pathophysiology of cerebrovascular events, especially transient ischemic attacks, even prior to the production of a flow-limiting stenosis. Finally, noninvasive screening of carotid artery plaque may provide a useful marker for the patient at risk for systemic atherosclerotic disease and identify the patient for whom maximal atherosclerotic risk factor modification is needed.     

Immediate and long-term results of carotid endarterectomy for asymptomatic high-grade stenosis

We examined the operative risks and long-term results of carotid endarterectomy for asymptomatic patients in terms of stroke, death, and recurrent stenosis. The results of a nonrandomized study with a follow-up of 1 to 104 months (mean 46 months) is reported. A tertiary referral center served as the setting for this report. One hundred consecutive patients with severe but asymptomatic carotid artery stenosis out of a total of 514 patients undergoing carotid endarterectomy were entered into this study. The severity of carotid disease was determined by duplex scanning and confirmed arteriographically. No patients were lost to follow-up after surgery. Eighty-nine operations (77%) were done under cervical block anesthesia and all arteries were closed with saphenous vein patches. Life-table analysis showed that the stroke-free rate at 5 years was 96.3% with an ipsilateral stroke-free rate of 98.2%. The 5-year overall survival rate was 78.2% with a stroke-free survival rate of 75%. Carotid endarterectomy can be performed safely for asymptomatic patients believed to be at risk for stroke. The potential for early death due to myocardial disease, late stroke, and recurrent stenosis do not justify advising patients against undergoing prophylactic carotid endarterectomy for asymptomatic high-grade stenosis.     

非手术指征颈动脉斑块患者缺血性脑卒中的危险因素分析

目的:探讨颈动脉狭窄≤50%的颈动脉斑块患者的MRI斑块特征及临床因素与发生缺血性脑卒中的关系。方法:选取2014年9月—2016年2月超声筛选颈动脉狭窄≤50%的颈动脉斑块患者43例,所有患者行核磁共振黑血成像检查,分析MRI斑块特征及其他危险因素与缺血性脑卒中的关系。结果:43例患者的颈动脉斑块狭窄程度5%～50%,随访时间1.9～19.4个月。随访期间发现脑梗死患者共4例。单因素与多因素Logistic回归分析结果显示,仅MRI的斑块内出血与缺血性脑卒中的发生有明显关系(OR=297.797,95%CI=2.638～33620,P=0.018),而其他斑块特征及临床因素均无明显关系(均P0.05)。Kaplan-Meier生存分析显示,有斑块内出血者较无斑块内出血者的中位无脑卒中时间明显缩短(14.3个月vs. 18.6个月,P=0.001);有冠心病者较无冠心病者的中位无脑卒中时间也明显缩短(12.1个月vs. 18.7个月,P=0.029);Cox回归分析显示,斑块内出血(HR=18.2,95%CI=2.7～123.3,P=0.003)及冠心病(HR=27.4,95%CI=1.6～464.3,P=0.022)是缺血性脑卒中发生的独立危险因素。结论:在颈动脉狭窄≤50%的颈动脉斑块患者中,斑块内出血与冠心病是缺血性卒中的发生密切相关。     

Carotid-subclavian arterial reconstruction: concomitant ipsilateral carotid endarterectomy increases risk of perioperative stroke

BACKGROUND: Carotid-subclavian bypass (CSB) and carotid-subclavian transposition (CST) have excellent long-term patency with low perioperative mortality and morbidity. Carotid endarterectomy (CEA) is necessary for severe ipsilateral internal carotid artery stenosis in a small subset of these patients. CEA can be performed as a combined or separate procedure. This study was undertaken to delineate the results of CSB and CST at our institution and to determine if concomitant CEA with CSB or CST is safe. METHODS: We evaluated the outcome of 36 patients with symptomatic subclavian artery stenosis treated surgically at a single institution during a 22-year period. Outcomes of patients undergoing CSB or CST with concomitant CEA were compared with those of patients undergoing CSB or CST alone. Available literature was reviewed to compare the rate of perioperative stroke following CSB or CST with concomitant CEA versus CSB or CST alone. RESULTS: Twenty-one patients underwent CST and 15 patients underwent CSB. There were 2 (5.6%) deaths and 2 (5.6%) strokes within 30 days of surgery. Concomitant CEA was performed in 6 CST patients and 2 CSB patients. Both perioperative strokes occurred in patients who had concomitant CEA. There were no strokes in the CST or CSB alone group (P = .044). In a collected review of 12 evaluable studies plus our experience, the rate of perioperative stroke was 0.32% in 617 patients who underwent CSB or CST alone versus 4.73% in 148 patients who had concomitant CEA with CSB or CST (P < .001). CONCLUSIONS: Both CSB and CST are safe and effective for symptomatic subclavian artery stenosis, with excellent long-term results. In patients also requiring CEA, the rate of perioperative stroke is significantly higher with a combined procedure. Consideration should be given to performing CEA separately from CSB or CST.     

Early carotid endarterectomy after ischemic stroke: the results of a prospective multicenter Italian study.

OBJECTIVES: To evaluate safety of early carotid endarterectomy (CEA) in patients with acute brain ischemia presenting to the emergency department stroke units (EDSU). METHODS: The neurologists, neuroradiologists and vascular surgeons on duty in emergency departments enrolled 96 patients who underwent very early CEA according to a predefined protocol within two years. The protocol included evaluation of neurological status by National Institute of Health Stroke Scale (NIHSS), neuroimaging assessment, ultrasound of the carotid arteries and Transcranial Doppler. Patients with NIHSS>22 or whose neuroimaging showed brain infarct >2/3 of the middle cerebral artery territory were excluded. All eligible patients underwent CEA as soon as possible. Primary end points of the study were mortality, neurological morbidity by NIHSS and postoperative hemorrhagic conversion on neuroimaging. Statistical analysis was performed by univariate analysis. RESULTS: The mean time elapsing between the onset of stroke and endarterectomy was 1.5 days (+/-2 days). The overall 30-day morbidity mortality rate was 7.3% (7/96). No neurological mortality occurred. On hospital discharge, three patients (3%) experienced worsening of the neurological deficit (NIHSS score 1 to 2, 1 to 3 and 9 to 10 respectively). Postoperative CT demonstrated there were no new cerebral infarcts nor hemorrhagic transformation. At hospital discharge 9/96 patients (9%) had no improvement in NHISS scores, 37 were asymptomatic and 45 showed a median decrease of 4.5 NIHSS points (range 1-18). By univariate analysis none of the considered variables influenced the clinical outcome. CONCLUSION: Our protocol selected patients who can safely undergo very early (<1.5 days) surgery after acute brain ischemia. Large randomized multicenter prospective trials are warranted to compare very early CEA versus best medical therapy.     

Effect of carotid endarterectomy on cognitive function in patients with asymptomatic carotid artery stenosis

Background

This study was conducted to determine if patients with asymptomatic carotid artery stenosis show cognitive function decline, and if they experience any changes in cognitive function after carotid endarterectomy (CEA).

Method

Cognitive function was examined in 15 patients (12 males and three females, 70.0?±?6.5 years) with asymptomatic carotid artery stenosis before and 3 months after CEA. Cognitive function was assessed with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), two subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R 2 subtests), and the Japanese version of National Adult Reading Test (JART). The patients’ average scores were compared with the normal average by one-sample t-tests, and the before and after scores were compared with paired t-tests. Changes in each patient were calculated from difference before and after CEA using 95 % confidence intervals.

Results

Before surgery, patients showed significant cognitive decline in RBANS total scale and immediate memory, language, and attention. At 3 months after CEA, the total scale and the immediate memory were not significantly different from the normal average. The average total scale score, the immediate memory and attention, and the WAIS-R 2 subtests scores were increased after treatment. Changes in each patient were calculated from the scores before and after CEA. At 3 months after CEA, the rate of increase in RBANS scores were 60.0 % of the patients for immediate memory, 26.7 % for visuospatial/constructional, 33.3 % for language and attention, 26.7 % for delayed memory, 47.7 % for total scale and 26.7 % for WAIS-R 2 subtests. Thus, so-called asymptomatic patients exhibit mild cognitive impairment before surgery, but after CEA, patients recover normal memory abilities.

Conclusions

Our findings of mild cognitive dysfunction in asymptomatic patients suggest that they might be symptomatic after all.     

Bilateral severe carotid stenosis or occlusion and computed tomographic scan positive hemispheric stroke with neurologic deficit: Immediate contralateral carotid endarterectomy

In the last 10 years, 13 patients presented with acute, hemispheric, computed tomographic scan-positive stroke; neurologic deficit; and bilateral carotid stenosis greater than 90% (N=9) or ipsilateral occlusion with contralateral stenosis greater than 90% (N=4). To improve ipsilateral flow without elevation of pressure to levels causing hemorrhagic infarction, all patients underwent carotid endarterectomy on the side contralateral to the hemispheric stroke from two to 10 days (average 6.6 days) from onset of symptoms. Those with fluctuating deficits stabilized to the initial fixed deficit and all 13 improved over the next six months. Four patients with ipsilateral internal carotid occlusion and one with ipsilateral severe siphon stenosis were discharged on antiplatelet therapy; of the remaining eight patients, seven underwent subsequent ipsilateral carotid endarterectomy from 42 to 111 days (average 58.4 days) from onset of symptoms. Mortality and stroke rate were 0. The four patients with internal carotid occlusion and the one with severe siphon stenosis filled both hemispheres from the contralateral carotid artery arteriographically in four and by oculoplethysmography in one. One patient demonstrated preferential flow from contralateral to the ipsilateral hemisphere, but not the reverse; one patient demonstrated pericallosal collaterals. Immediate endarterectomy of the severely diseased carotid artery contralateral to a hemisphere with a computed tomographic scan-positive stroke causing neurologic deficit resulting from a severe carotid stenosis is a safe treatment option and may be beneficial in those with fluctuating neurologic deficits.Presented at the New England Society for Vascular Surgery, September 14, 1990, Newport, Rhode Island.     

Prospective controlled study of the natural history of asymptomatic 60% to 69% carotid stenosis according to ultrasonic plaque morphology

BACKGROUND/PURPOSE: In spite of the conclusions of the Asymptomatic Carotid Atherosclerosis Study, some clinicians are still reluctant to recommend carotid endarterectomy (CEA) for patients with asymptomatic > or = 60% carotid stenosis (ACS). This study analyzes the natural history of 60% to 69% ACS according to ultrasonic plaque morphology and its implication on treatment. PATIENT POPULATION AND METHODS: During a 2-year period, patients with 60% to 69% ACS entered into a protocol of carotid duplex scan surveillance/clinical examination every 6 months. The ultrasonic plaque morphology was classified as heterogeneous (group A, n = 162) or homogeneous (group B, n = 229) with HDI 3000/HDI 5000 systems (Advanced Technology Laboratories, Bothwell, Wash). CEA was done if lesion progressed to > or = 70% stenosis or became symptomatic. RESULTS: Three hundred eighty-two patients (391 arteries) were followed for a mean interval of 37 months. The clinical/demographic characteristics were similar for both groups. The incidence rate of future ipsilateral strokes was significantly higher in group A than in group B: 13.6% versus 3.1% (P =.0001; odds ratio [OR], 5). Similarly, the incidence rate of all neurologic events (stroke or transient ischemic attack [TIA]) was higher in group A than in group B: 27.8% versus 6.6% (P =.0001; OR, 5.5). Progression to > or = 70% stenosis was also higher in group A than in group B: 25.3% versus 6.1% (P =.0001; OR, 5.2). Forty-four late CEAs (27.2%) were done in group A (16 for stroke, 21 for TIA, and seven for > or = 70% ACS) versus 13 (5.7%) in group B (five for stroke, seven for TIA, and one for > or = 70% ACS; P =.0001; OR, 6.2). CONCLUSION: Patients with 60% to 69% ACS with heterogeneous plaque had a higher incidence rate of late stroke, TIA, and progression to > or = 70% stenosis than patients with homogeneous plaque. Prophylactic CEA for 60% to 69% ACS may be justified if associated with heterogeneous plaque.     

Progression of asymptomatic carotid stenosis: A natural history study in 1004 patients

Purpose: The purpose of this study was to delineate the natural history of the progression of asymptomatic carotid stenosis. Methods: In a 10-year period, 1701 carotid arteries in 1004 patients who were asymptomatic were studied with serial duplex scans (mean follow-up period, 28 months; mean number of scans, 2.9/patient). At each visit, stenoses of the internal carotid artery (ICA) and the external carotid artery (ECA) were categorized as none (0 to 14%), mild (15% to 49%), moderate (50% to 79%), severe (80% to 99%), preocclusive, or occluded. Progression was defined as an increase in ICA stenosis to ≥50% for carotid arteries with a baseline of <50% or as an increase to a higher category of stenosis if the baseline stenosis was ≥50%. The Cox proportional hazards model was used for data analysis. Results: The risk of progression of ICA stenosis increased steadily with time (annualized risk of progression, 9.3%). With multivariate modeling, the four most important variables that affected the progression (P < .02) were baseline ipsilateral ICA stenosis ≥50% (relative risk [RR], 3.34), baseline ipsilateral ECA stenosis ≥50% (RR, 1.51), baseline contralateral ICA stenosis ≥50% (RR, 1.41), and systolic pressure more than 160 mm Hg (RR, 1.37). Ipsilateral neurologic ischemic events (stroke/transient ischemic attack) occurred in association with 14.0% of the carotid arteries that were studied. The progression of ICA stenosis correlated with these events (P < .001), but baseline ICA stenosis was not a significant predictor. Conclusion: In contrast to recently published studies, we found that the risk of progression of carotid stenosis is substantial and increases steadily with time. Baseline ICA stenosis was the most important predictor of the progression, but baseline ECA stenosis also was identified as an important independent predictor. Contralateral ICA stenosis and systolic hypertension were additional significant predictors. We found further that the progression of ICA stenosis correlated with ischemic neurologic events but not baseline stenosis. The data provide justification for the use of serial duplex scans to follow carotid stenosis and suggest that different follow-up intervals may be appropriate for different patient subgroups. (J Vasc Surg 1999;29:208-16.)