Increase in extracranial atherosclerotic carotid lesions in patients with brain ischemia in Japan. An angiographic study

Epidemiology, Pathophysiology, and Imaging of Atherosclerotic Intracranial Disease

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of stroke worldwide. Among people with stroke, those of East Asia descent and non-White populations in the United States have a higher burden of ICAD-related stroke compared with Whites of European descent. Disparities in the prevalence of asymptomatic ICAD are less marked than with symptomatic ICAD. In addition to stroke, ICAD increases the risk of dementia and cognitive decline, magnifying ICAD societal burden. The risk of stroke recurrence among patients with ICAD-related stroke is the highest among those with confirmed stroke and stenosis ≥70%. In fact, the 1-year recurrent stroke rate of >20% among those with stenosis >70% is one of the highest rates among common causes of stroke. The mechanisms by which ICAD causes stroke include plaque rupture with in situ thrombosis and occlusion or artery-to-artery embolization, hemodynamic injury, and branch occlusive disease. The risk of stroke recurrence varies by the presumed underlying mechanism of stroke, but whether techniques such as quantitative magnetic resonance angiography, computed tomographic angiography, magnetic resonance perfusion, or transcranial Doppler can help with risk stratification beyond the degree of stenosis is less clear. The diagnosis of ICAD is heavily reliant on lumen-based studies, such as computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography, but newer technologies, such as high-resolution vessel wall magnetic resonance imaging, can help distinguish ICAD from stenosing arteriopathies.

The 2023 Taiwan Stroke Society Guidelines for the management of patients with intracranial atherosclerotic disease

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke, especially in Asian populations, which has a high risk of recurrent stroke and cardiovascular comorbidities. The present guidelines aim to provide updated evidence-based recommendations for diagnosis and management of patients with ICAD. Taiwan Stroke Society guideline consensus group developed recommendations for management of patients with ICAD via consensus meetings based on updated evidences. Each proposed class of recommendation and level of evidence was approved by all members of the group. The guidelines cover six topics, including (1) epidemiology and diagnostic evaluation of ICAD, (2) nonpharmacological management of ICAD, (3) medical therapy for symptomatic ICAD, (4) endovascular thrombectomy and rescue therapy for acute ischemic stroke with underlying ICAD, (5) endovascular interventional therapy for postacute symptomatic intracranial arterial stenosis, and (6) surgical treatment of chronic symptomatic intracranial arterial stenosis. Intensive medical treatment including antiplatelet therapy, risk factor control, and life style modification are essential for patients with ICAD.

Functional and Mortality Outcomes with Medical and Surgical Therapy in Malignant Posterior Circulation Infarcts: A Systematic Review

BACKGROUND

There remains uncertainty regarding optimal definitive management for malignant posterior circulation infarcts (MPCI). While guidelines recommend neurosurgery for malignant cerebellar infarcts that are refractory to medical therapy, concerns exist about the functional outcome and quality of life after decompressive surgery.

OBJECTIVE

This study aims to evaluate the outcomes of surgical intervention compared to medical therapy in MPCI.

METHODS

In this systematic review, MEDLINE, Embase and Cochrane databases were searched from inception until 2 April 2021. Studies were included if they involved posterior circulation strokes treated with neurosurgical intervention and reported mortality and functional outcome data. Data were collected according to PRISMA guidelines.

RESULTS

The search yielded 6677 studies, of which 31 studies (comprising 723 patients) were included for analysis. From the included studies, we found that surgical therapy led to significant differences in mortality and functional outcomes in patients with severe disease. Neurological decline and radiological criteria were often used to decide the timing for surgical intervention, as there is currently limited evidence for preventative neurosurgery. There is also limited evidence for the superiority of one surgical modality over another.

CONCLUSION

For patients with MPCI who are clinically stable at the time of presentation, in terms of mortality and functional outcome, surgical therapy appears to be equivocal to medical therapy. Reliable evidence is lacking, and further prospective studies are rendered.

Atherosclerotic carotid plaque characteristics vary with time from ischemic event: A multicenter, prospective magnetic resonance vessel wall imaging registry study

Recent studies report that the rate of recurrent stroke is highest in the stages immediately following cerebral infarction and decreases over time in patients with atherosclerotic carotid stenosis. The purpose of this study was to identify temporal differences in early stage carotid plaque components from acute cerebrovascular ischemic events using carotid MRI. Carotid plaque images were obtained on 3 T MRI from 128 patients enrolled in MR-CAS. Among the 128 subjects, 53 were symptomatic and 75 asymptomatic. The symptomatic patients were classified into three groups based on interval from onset of symptoms to the date of the carotid MRI (Group <14 days; 15-30 days; and > 30 days). The volume of each plaque component was identified and quantified from MR images. The presence of juxtaluminal loose matrix/inflammation (LM/I) was identified as a possible indicator of inflammation on the luminal side. Plaque components were compared between groups using the Wilcoxon rank-sum or the Chi-square test. Patient characteristics and carotid plaque morphology were similar among all four groups. The median volume of LM/I in Group >30 days was significantly lower than in other groups (0 mm3 vs 12.3 mm3 and 18.1 mm3; p = 0.003). In addition, the prevalence of juxtaluminal LM/I decreased over time (ptrend = 0.002). There were no statistically significant differences in other plaque components between the symptomatic groups. The volume of LM/I was significantly smaller in Group >30 days and prevalence of juxtaluminal LM/I in the atherosclerotic carotid plaque was high in the early stages after events. This suggests that carotid plaques undergo rapid evolution after an acute cerebrovascular ischemic event.

Double-lumen Carotid Plaque Associated with Severe Stenosis Treated with Staged Angioplasty: A Case Report

Double-lumen carotid plaque is a rare pathological condition, and only few reports about this condition have been recorded in the literature. However, no study has used endovascular therapy (EVT) for the treatment of double-lumen carotid plaque. Herein, we present a unique case of double-lumen carotid plaque associated with severe stenosis that was successfully treated with staged angioplasty (SAP). Moreover, a literature review of its pathology and other treatment options has been conducted. SAP is a two-stage carotid artery stenting (CAS) that can prevent hyperperfusion syndrome after revascularization. In this study, a 62-year-old man developed walking disturbance and left hemiparesis. Magnetic resonance imaging (MRI) revealed ischemic lesions in the watershed area of the right hemisphere and an irregular plaque in the right cervical internal carotid artery (ICA). Ultrasonography showed 84% stenosis in the area and a double lumen distal to the stenosis in the right ICA. Digital subtraction angiography (DSA) revealed a double-lumen plaque with 70% stenosis based on the North American Symptomatic Carotid Endarterectomy Trial criteria. SAP was performed after medication therapy and rehabilitation, and the surgery was uneventful. A double-lumen carotid plaque associated with severe stenosis is a rare condition with a high risk of emboli and stroke. In an unstable lesion, carotid endarterectomy is the first option. However, since the patient in this case was at high risk for general anesthesia, SAP was performed. Hence, if an appropriate device is used, EVT can be a safe treatment strategy for unstable and atypical plaques as in this case.

Evaluation of intracranial and extracranial atherosclerotic lesions in patients with symptomatic coronary artery disease

OBJECTIVES

Patients with coronary artery disease (CAD) concomitant with extracranial and intracranial atherosclerotic disease (EICAD) may have an increased risk of stroke and myocardial ischemic events. This study aimed to evaluate the concomitant atherosclerotic lesions in extra- and intracranial arterial beds in patients with CAD.

METHODS

A total of 1274 patients who underwent coronary angiography due to ischemic heart disease were included. All patients underwent ultrasound screening of the extra- and intracranial arteries before coronary angiography, and the degrees of extracranial carotid artery disease (ECAD) and intracranial cerebral artery disease (ICAD) were recorded.

RESULTS

A total of 1062 cases of CAD were confirmed. The prevalence of ECAD, ICAD, and EICAD (ECAD combined with ICAD) in patients with CAD was 15.6%, 11.2% and 11.9%, respectively. For patients with 3-vessel disease, the prevalence was 20.5%, 13.8% and 18.1%, and for patients with severe coronary artery stenosis, the prevalence was 15.8%, 12.1% and 13.2%, respectively. The presence and extent of ECAD and ICAD were positively correlated with the number of lesion vessels and degree of CAD. The posterior circulation arteries were more prone to lesions in patients with ECAD, while the anterior circulation arteries were more vulnerable to lesions in patients with ICAD.

CONCLUSIONS

The prevalence of ECAD, ICAD and EICAD is high in patients with CAD, and the presence of these conditions is positively correlated with the extent and degree of CAD. Evaluations of ECAD and ICAD should be highly recommended for CAD patients to reduce the future risk of cardiovascular diseases.

Risk factors associated with extracranial atherosclerosis in old patients with acute ischemic stroke

The aim of this study was to identify risk factors associated with extracranial atherosclerosis (ECAS) in old Chinese patients with ischemic stroke. Eligible patients were divided into two groups: <60years group and ≥60 years group. The incidence, severity of ECAS and risk factors related to ECAS were compared between the two groups. In total, 921 patients were included in the analysis. The distribution of ECAS between the two age groups did not show difference (P = 0.747).But severe ECAS stenosis was more common in <60years group than in ≥60years group (x² = 8.307, P = 0.013). Compared with <60years group, factors contributed to higher risk of ECAS in ≥60year group were hypertension(OR = 6.279, P = 0.000), heart disease(OR = 5.618, P = 0.032) and atrial fibrillation(OR = 7.477, P = 0.015). However, though smoking was higher in the <60years group (x² = 7.664, P = 0.010) than in ≥60year group, multivariate analysis showed the difference was not significant(P = 0.879). Further studies should focus on risk factors in young ECAS patients. Different risk factors might contribute to ECAS in old age groups compared to young groups. Risk factor prevention/control measures should be strengthened in those with high risk of ECAS for decreasing stroke risk.

Association between metabolic syndrome and carotid atherosclerosis: a community-based study in Hong Kong

BACKGROUND

Carotid atherosclerosis should not be neglected as a cause for stroke in China, despite its low prevalence. This study was performed to evaluate the association between ultrasonographic markers for different stages of carotid atherosclerosis and metabolic syndrome.

METHODS

This was a community-based study in Hong Kong. Metabolic syndrome was defined as having three or more of the following conditions or receiving specific treatment for these conditions: Abdominal obesity, elevated triglycerides, low high-density lipoprotein cholesterol, hypertension, and impaired fasting blood glucose. All subjects underwent carotid duplex ultrasonography. Mean carotid intima media thickness (CIMT) of bilateral common carotid arteries was used as the CIMT value for a single subject. CIMT within the 4(th) quartile was regarded as increased CIMT. Carotid plaque was defined as a focal CIMT of >1.5 mm. A carotid plaque obstructing ≥50% of vessel lumen was considered as carotid stenosis.

RESULTS

A total of 653 subjects (mean age 55.1±10.4; 47.2% male) were recruited. Metabolic syndrome was found in 188 (28.8%) subjects (30.8% in males and 27.0% in females). Mean CIMT was 0.74±0.12 mm. Increased CIMT, carotid plaque, and carotid stenosis were detected in 163 (25.0%), 95 (14.5%), and 6 (1.4%) subjects, respectively. In multivariate linear regression, CIMT significantly increased with increasing numbers of metabolic syndrome components (P<0.001). In multivariate logistic regression analysis, metabolic syndrome was independently associated with increased CIMT [odds ratio (OR) 1.17; 95% confidence interval (CI) 1.11-2.64; P=0.014), but not presence of carotid plaque (OR 1.50; 95% CI 0.92-2.46; P=0.108).

CONCLUSIONS

Metabolic syndrome may be independently associated with the early stage but not the later and advanced stages of carotid atherosclerosis in community residents in China.

Plaque rupture is a determinant of vascular events in carotid artery atherosclerotic disease: involvement of matrix metalloproteinases 2 and 9

BACKGROUND AND PURPOSE

Unstable carotid atherosclerotic plaques are characterized by cap rupture, leading to thromboembolism and stroke. Matrix metalloproteinases (MMPs) have been implicated in the progression of atherosclerosis and plaque rupture. The aim of this study was to assess the relationship between the expressions of MMP-2 and MMP-9 and carotid plaque instability.

METHODS

Eighty atherosclerotic plaques were collected from 74 patients undergoing carotid endarterectomy. Clinical information was obtained from each patient, and plaque morphology was examined at the macroscopic and microscopic levels. The immunohistochemical expressions of MMPs were graded using semiquantitative scales.

RESULTS

Macroscopic ulceration (84.6% versus 63.4%, p=0.042) and microscopic cap rupture (79.5% versus 51.2%, p=0.010) were more common in symptomatic than in asymptomatic patients. Immunoreactivities of MMP-2 and MMP-9 were increased in 40 and 36 atheromatous plaques, respectively. Macroscopic ulceration was strongly correlated with the expressions of MMP-2 (p<0.001) and MMP-9 (p=0.001). There were significant correlations between increased MMP-2 expression and cap rupture (p=0.002), intraplaque hemorrhage (p=0.039), and a thin fibrous cap (p=0.002), and between increased MMP-9 expression and cap rupture (p=0.010) and a large lipid core (p=0.013).

CONCLUSIONS

Plaque rupture was significantly associated with the development of vascular events in carotid atherosclerotic disease. MMP-2 and MMP-9 are strongly correlated with plaque instability.

Magnetic resonance angiography findings in patients with ischemic stroke from North India

BACKGROUND

We sought to evaluate the magnetic resonance (MR) angiography (MRA) findings in patients with ischemic stroke (IS) from North India and correlate the changes with various conventional and nonconventional risk factors.

METHODS

The study took place at a tertiary care teaching hospital. The patients with IS were clinically evaluated including body mass index, dietary habits, and family history of stroke. MR imaging, MRA, and testing for blood sugar, lipid profile, B12, folic acid, and homocysteine were carried out. The MRA abnormalities were considered significant if stenosis was 50% or greater and these were categorized into extracranial (EC), intracranial (IC), or combined lesions. The location of infarct on MR imaging was also noted.

RESULTS

There were 151 patients whose median age was 60 (22-85) years. The EC MRA was abnormal in 56.3% and the IC MRA in 63.3% of patients, the internal carotid artery being the most common site. Corresponding infarct was present in 64.7% and noncorresponding in 45.3% of patients. The MRA abnormality positively correlated with hypertension and diabetes, and negatively with alcohol consumption. The EC MRA abnormality was more common in upper caste Hindus and Muslims and in the city dwellers.

CONCLUSION

In North Indian patients with IS, the frequency of EC and IC MRA abnormality lies between Whites and the Orientals.

Extracranial Carotid Stenosis and Peripheral Arterial Disease in Thai Patients With Coronary Artery Disease

We assessed the prevalence of carotid stenosis (CS) and peripheral arterial disease (PAD) in patients with coronary artery disease (CAD) to determine the relationship between these conditions in a Thai population. All patients with coronary angiography during June 2008 and August 2009 were studied. Carotid duplex and ankle-brachial index (ABI) were performed. One hundred and seventy-seven patients were studied (95 men, mean age of 65). Carotid stenosis and PAD were diagnosed in 16 patients (9%) and 68 patients (38.4%), respectively. The presence of carotid bruit and older age were independent predictors of CS and PAD, respectively. There was no correlation between the presence of CS/PAD and the extent of coronary artery lesions. Although CS was uncommon in patients with CAD, the patients with cervical bruit should be screened for CS. Prevalence of PAD was high, confirming the presence of diffuse atherosclerosis in many patients with CAD.

Increasing frequency and burden of cerebral artery atherosclerosis in Korean stroke patients

PURPOSE

Koreans have been undergoing rapid lifestyle changes that may have an effect on patterns of cerebral artery atherosclerosis. This study was aimed at determining the frequency and distribution of atherosclerosis in the cerebral arteries and associated temporal changes over the past eight-year period among Korean stroke patients.

MATERIALS AND METHODS

By using stroke registry data registered between April 1999 and March 2007, we investigated the presence, severity, and location of cerebral artery atherosclerosis as determined by angiographic findings. Their annual patterns and association with vascular risk factors were investigated.

RESULTS

Of 1,955 patients, 1,517 patients (77.6%) demonstrated atherosclerosis in one or more arteries. A significantly increasing trend of atherosclerosis was observed during the past eight years, which was ascribed to an increase of combined extracranial (EC) and intracranial (IC) atherosclerosis. The number of atherosclerotic arteries increased as the number of risk factors increased. In the multivariate analysis, the year and vascular risk factors were independent predictors of the presence of atherosclerosis.

CONCLUSION

We found that the atherosclerotic burden has been increasing for the past eight years in Korean stroke patients, particularly the combined EC and IC subtype. Lifestyle changes and increase in vascular risk factors may be contributing factors.

Extracranial carotid plaque is increasing in Japanese ischemic stroke patients

OBJECTIVE

The objectives of this study were to investigate the prevalence of extracranial carotid plaque and the association between risk factors and carotid plaque in Japanese patients with ischemic stroke.

METHODS

We consecutively recruited patients with ischemic stroke admitted to our hospital from January 2000 to September 2002. Neurologic signs and a brain magnetic resonance imaging diagnosed ischemic stroke. All subjects underwent a carotid ultrasonography. Multiple logistic regression analysis was used to determine the risk factors that independently contributed to the presence of carotid plaques.

RESULTS

Carotid plaques were identified in 76.2% of the patients and bilateral plaques were found in 58.2%. These lesions were more frequent in comparison with previous Japanese reports. The risk factors that independently contributed to the presence of extracranial carotid plaques were hypertension, age, smoking and past history of ischemic stroke.

CONCLUSIONS

This study demonstrates that extracranial carotid plaque is increasing in Japanese patients with ischemic stroke.

Prevalence of concomitant atherosclerotic arterial diseases in patients with significant cervical carotid artery stenosis in Taiwan

BACKGROUND

Atherosclerotic stenosis of extracranial carotid arteries is an important cause of ischemic stroke in Taiwan, an ethnic Chinese population. Concurrent atherosclerotic arterial disease is an important issue in the management of patients with carotid stenosis, but its prevalence and extent are unknown.

METHODS

One hundred and sixty-three consecutive patients with angiographically proven significant cervical carotid artery stenosis (>or=50% stenosis) were enrolled in this study. Angiography was done to document concurrent coronary, renal, and limb artery stenosis. Clinical symptoms and signs were also correlated with the angiographic findings.

RESULTS

One or more significant concurrent arterial stenotic disease was found in 73% of the patients. The most frequent were coronary artery disease, found in 68% of the patients, while renal artery stenosis and limb artery stenosis were found in 20% and 21% of the patients, respectively. Age, diabetes, history of angina pectoris, intermittent claudication, and asymmetric arm blood pressures were significantly associated with the presence of concurrent arterial stenosis. However, 41% of the patients with concurrent coronary artery disease did not have any clinical symptoms or history of myocardial infarction.

CONCLUSIONS

Our data indicated that concurrent advanced and extensive arterial disease is common in patients with significant cervical carotid stenosis, and also suggest the importance of global evaluation of systemic atherosclerosis in these patients to achieve optimal management.

High Blood Pressure in Acute Ischemic Stroke and Underlying Disorders

BACKGROUND

The Acute Candesartan Cilexetil Therapy in Stroke Survivors (ACCESS) study indicated that early treatment with an angiotensin type 1 receptor blocker in acute stroke patients who had relatively high blood pressure improved cardiovascular morbidity and mortality in the chronic stage. To better interpret the findings of this study, we determined whether stroke patients with high acute blood pressure had specific underlying conditions.

METHODS

We divided 712 consecutive patients who were hospitalized within 48 h after the onset of brain infarction into two groups: 77 patients with high acute blood pressure that met the criteria of the ACCESS study and the 635 remaining patients. Underlying risk factors and comorbidities, stroke characteristics, as well as mortality, vascular events, and disability at 3 weeks were compared between the two groups.

RESULTS

Patients with high acute blood pressure more frequently had diabetes mellitus (p < 0.01), intracranial arterial stenosis (p < 0.02), higher levels of hemoglobin A1c (p < 0.005), higher creatinine levels (p < 0.005), and tended to more frequently have ischemic heart disease (p < 0.09) and infarcts <1.5 cm in diameter (p < 0.09) than the other patients. On multivariate analysis, high levels of hemoglobin A1c, high creatinine levels, and intracranial arterial stenosis were independently predictive of high acute blood pressure. At 3 weeks after the stroke onset, patients with high acute blood pressure were more dependent in their daily living activities (p < 0.02) and more frequently developed vascular events or death (p < 0.005) than the other patients.

CONCLUSIONS

Poorly controlled diabetes mellitus and advanced renal damage appeared to correlate with acute hypertension after stroke. Since intracranial arterial stenosis also seemed to contribute to high acute blood pressure, one should be careful not to induce cerebral hypoperfusion by the early use of antihypertensives.

Can the presence of carotid artery calcification on panoramic radiographs predict the risk of vascular diseases among 80-year-olds?

OBJECTIVE

The purpose of this study was to evaluate whether subsequent vascular diseases and related death could be predicted by the presence of carotid artery calcification detected on panoramic radiographs among elderly persons.

STUDY DESIGN

We evaluated 659 panoramic radiographs from 262 male and 397 female 80-year-old subjects and their general medical examination data to assess the relationship between the presence of carotid artery calcification and vascular disease risk at baseline examination. Of these subjects, the occurrence of vascular diseases within 5 years after baseline examination was examined in 191 subjects. Further, the causes of death were examined in 108 subjects who died within 5 years after baseline examination.

RESULTS

There was a significant difference in the history of past vascular diseases among subjects with and without carotid artery calcifications; however, no significant difference in the occurrence of subsequent vascular diseases was found among them. Further, there was no significant difference in the occurrence of vascular disease-related death within 5 years after baseline examination among subjects with and without carotid artery calcifications (P = 0.719).

CONCLUSION

Our results suggest that the presence of carotid artery calcifications on panoramic radiographs may be related to the history of past vascular diseases; however, this is not a useful marker for subsequent vascular diseases and related death among 80-year-olds.

Preoperative extracranial carotid artery examination with ultrasonography in patients undergoing coronary artery bypass grafting in Japan

PURPOSE

We investigated the incidence, degree, and plaque characteristics of extracranial carotid stenosis with carotid ultrasonography (CUS) in patients undergoing coronary artery bypass grafting (CABG).

MATERIALS AND METHODS

Preoperative CUS was performed on 221 patients (442 carotid arteries) undergoing CABG. The degree of extracranial carotid stenosis was calculated based on the area stenosis, and it was classified into six grades as follows: grade (G) 0, G1 (1%-29%), G2 (30%-49%), G3 (50%-69%), G4 (70%-99%), and G5 (occlusion).

RESULTS

The incidence of G4 was 4.1% and G5 1.6%. There were 48 arteries rated G3 or G4. Hypoechoic plaque was detected in 28 of the 48 arteries (58%), and heterogeneous plaque was detected in 37 arteries (73%). Ulcerative plaque was detected in 27 arteries (56%); when comparing the G3 and G4 groups, ulcerative plaque was found more frequently in G4 than in G3 (14/18 vs 13/30 arteries, P < 0.02).

CONCLUSION

Our study demonstrated that patients undergoing CABG with extracranial severe carotid stenosis tend to have heterogeneous, hypoechoic, and ulcerative plaque. We believe that preoperative CUS should be used to evaluate the plaque characteristics of extracranial carotid stenosis.

A possible explanation for the racial difference in distribution of large-arterial cerebrovascular disease: ancestral European settlers evolved genetic resistance to atherosclerosis, but confined to the intracranial arteries

The pattern of cerebral atherosclerosis is not the same among different races. White patients rarely have intracranial large arterial steno-occlusive disease even if their systemic arteries are extensively involved, while non-white patients frequently have their intracranial arteries affected. We postulate that during human population diversification, those who settled in Europe had acquired a stroke-suppressor genotype that increases their resistance against atherogenesis, but with protection confined to the intracranial large arteries. The contemporary affluent lifestyle accelerates the development of atherosclerosis. In the whites, it involves the whole arterial bed except the intracranial vessels. People living in non-Western countries used to have a healthier way of living. They did not develop significant atherosclerotic diseases until recently when a westernised lifestyle was adopted. Unlike the whites, their intracranial arteries will not be spared. Atherosclerosis has become a major cause of premature mortality in the modern world, and an anti-atherogenic mechanism would confer a selection advantage. With further adaptive intensification, this protection may extend to the rest of the arterial bed. As a result, future Homo sapiens will be able to tolerate an affluent lifestyle without much adverse sequel such as premature vascular death. Alternatively, if the mediator of this anti-atherogenic mechanism can be identified and applied therapeutically, we will have an ultimate mean to prevent atherosclerosis.

Contribution of an imbalance between oxidant—antioxidant systems to plaque vulnerability in patients with carotid artery stenosis

OBJECT

Reactive species of oxygen and nitrogen mediate the oxidative modification of low-density lipoprotein (LDL). Oxidation of LDL is inhibited by endogenous radical scavenging enzymes such as manganese superoxide dismutase (SOD) and Cu-ZnSOD that catalyze dismutation of oxygen to H2O2. Low-molecular antioxidants such as uric acid regulate the inactivation that appears to be linked to an increase in peroxynitrite resulting in oxidized LDL (OxLDL) elevation. The authors evaluated whether a focal imbalance between pro- and antioxidant systems induces plaque vulnerability in patients with carotid artery (CA) stenosis.

METHODS

Carotid artery plaques obtained in 35 patients who had undergone carotid endarterectomy were classified as vulnerable or stable based on histopathological findings. In vulnerable plaques, OxLDL, measured using enzyme-linked immunosorbent assay, was significantly higher (p < 0.01) and SOD activity significantly lower than in stable plaques (p < 0.05). The plaque and plasma OxLDL levels were inversely correlated with plaque SOD activity (p < 0.01). The physiological uric acid level in all plaques was one fourth to one eighth of that in plasma and appeared to be unable to protect Cu-ZnSOD from degradation by H2O2. Immunohistochemical analysis showed increased peroxynitrite and OxLDL in vulnerable plaques. There was a significant correlation between plaque and plasma OxLDL levels (p < 0.01).

CONCLUSIONS

Analysis of the results suggests that a focal imbalance between pro- and antioxidant defense systems in patients with CA plaques induces an increase in plaque OxLDL levels and consequent plaque instability, contributing to high levels of plasma OxLDL.

Stroke in Patients on Maintenance Hemodialysis: A 22-Year Single-Center Study

BACKGROUND

Few studies have reported the detailed clinical features of stroke in patients with end-stage renal disease. We examined the frequency of the subtypes, mechanism, and outcome of stroke in patients receiving hemodialysis (HD).

METHODS

We studied 151 consecutive patients who developed an acute stroke among the maintenance HD population in our kidney center during 22 years, divided into the initial 17-year (n = 61) and the more recent 5-year (n = 90) groups. For purposes of comparison, we also studied 1,017 stroke patients with normal renal function.

RESULTS

Stroke patients receiving HD were younger (age, 64 +/- 10 versus 67 +/- 13 years; P < 0.02) and more frequently had hypertension (87% versus 43%; P < 0.0001) and diabetes (53% versus 23%; P < 0.0001) compared with stroke patients with normal renal function. In the initial HD group, brain hemorrhage was the major subtype of stroke (52%), whereas in the more recent group, brain infarction (BI) replaced hemorrhage as the leading subtype (68%; P < 0.005). In patients with BI, large-artery atherosclerosis was more prevalent in the more recent group than in the initial HD group (33% versus 12%; P < 0.05). A vertebrobasilar territory infarct was more prevalent for HD patients than for those with normal renal function (48% versus 33%; P < 0.05). BI (especially large-artery atherosclerosis and cardioembolism) occurred more frequently during or less than 30 minutes after the dialysis procedure (34%) than brain hemorrhage (19%; P < 0.05). Receiving HD was an independent indicator for poor functional outcome and mortality after stroke.

CONCLUSION

In our maintenance HD population, stroke showed several unique characteristics compared with the control population, including a predominance of vertebrobasilar arterial territory infarcts. The dialysis procedure itself seems to be associated more frequently with ischemic rather than hemorrhagic strokes.

Intracranial atherosclerosis: incidence, diagnosis and treatment

Intracranial atherosclerosis is considered a cause of approximately 8% of all strokes in the western society. However, its frequency is much higher in Asian countries. In our hospital-based study, among the patients who had angiographic abnormalities, the frequency of intracranial atherosclerosis was approximately 70% far exceeding that of extratracranial atherosclerosis. Symptomatic atherosclerotic diseases were most often found in the middle cerebral artery. Generally, it has been shown that obesity and hyperlipidemia are related to extracranial diseases while advance hypertension is associated with intracranial diseases. However, these results have not always been replicated, and certain genetic factors may be related with the ethnic differences in the location of atherosclerosis. Recent studies using diffusion weighted MRI showed that the main mechanisms of stroke in patients with intracranial atherosclerosis are the branch occlusion, artery to artery embolism and both. The intracranial stenosis, especially symptomatic one, is not a static condition and may progress or regress in a relatively short period of time. Progressive stenosis of intracranial arteries is clearly related to the development of ischemic events. The annual risk of stroke relevant to the stenosed intracranial vessel is approximately 8%. In retrospective studies including ASID, anticoagulation was found to be superior to aspirin in reducing the stroke events. However, a recent prospective study failed to confirm the superiority of anticoagulation over aspirin in patients with intracranial stenosis. Moreover, anticoagulation resulted in excessive central nervous system bleeding as compared to aspirin. Because aspirin alone seems to be insufficient in the prevention of progression of intracranial stenosis, a combination of antiplatelets has been tried. Recently, we found that a combination of aspirin + cilostazol was superior to aspirin monotherapy in the prevention of progression of symptomatic intracranial stenosis. However, further studies are required to find out the best combination of antiplatelets for symptomatic intracranial stenosis. The effect of other atheroma stabilizers such as statins should also be properly evaluated. Angioplasty/stent is another important option for the relatively severe intracranial stenosis. According to previous studies, immediate success rate has reached up to 90%. If patients are carefully selected, and procedures done by experienced hand, angioplasty/stent can be of benefit especially in relatively young patients with proximal, short-segment, severe symptomatic stenosis. However, this procedure is not without complications or long-term re-stenosis. Further studies are required to elucidate the best therapeutic strategy in patients with intracranial atherosclerosis.

Prevalence and correlates of carotid atherosclerosis among elderly Japanese men

We determined intima-media thickness (IMT) and diameter of carotid artery and estimated their correlations with cardiovascular risk factors in 1129 men aged 60-74 years, who participated in a cardiovascular risk survey in three Japanese communities. The multivariate odds ratios (95% confidence interval) for the maximum IMT > or = 1.1 mm in the common carotid artery (CCA) were 1.3 (1.1-1.5) per 4 years of age, 1.8 (1.4-2.5) for hypertension, 1.4 (1.2-1.7) for a 34.4 mg/dl increase in serum total cholesterol, 0.7 (0.6-0.8) for a 14.7 mg/dl increase in serum HDL-cholesterol, and 2.4 (1.1-5.0) for history of stroke, while the maximum IMT > or = 1.5mm in the internal carotid artery (ICA) were 1.6 (1.4-1.8) per 4 years of age, 1.9 (1.5-2.4) for hypertension, 1.6 (1.2-2.1) for current smoking, and 3.5 (1.6-7.6) for history of stroke. Age, height, hypertension, current smoking, ethanol intake and history of coronary heart disease were independent determinants of both the outer and inner CCA diameter. Maximum IMT correlated positively with the outer diameter and inversely with the inner diameter in the CCA. Carotid atherosclerosis suggests to be a risk factor for stroke among Japanese elderly men, although future prospective studies are required to confirm this finding.

Evaluation of calcified carotid artery atheromas detected by panoramic radiograph among 80-year-olds

OBJECTIVE

To evaluate the incidence among 80-year-olds of calcified carotid artery atheromas (CCAAs) as detected on panoramic radiographs. The relationship between CCAAs and general and oral health was also evaluated.

STUDY DESIGN

Six hundred and fifty-nine panoramic radiographs (262 males, 397 females), obtained from 80-year-old residents of Fukuoka Prefecture, Japan, were used for evaluation of CCAAs.

RESULTS

Of 659 panoramic radiographs, 33 (5%) were noted to have CCAAs. These appeared as a radiopaque nodular mass or masses adjacent to or just below the intervertebral space between C3 and C4. CCAAs were found in 8 males and 25 females. There were marginally significant differences between males and females in CCAAs (P = 0.06). Seventy-four percent of CCAAs were detected in the right side. There appeared to be very little relationship between CCAAs and general and oral health.

CONCLUSIONS

The results of this study gives further support to the idea of using panoramic radiographs to detect CCAAs. Therefore, we feel that panoramic radiographs should be evaluated not only for pathosis of the teeth and jaws, but also for other incidental findings, especially in the soft-tissue region of the neck. The findings from this study provide potentially life-saving information especially for those elderly people who are at risk for stroke.

Effects of carotid endarterectomy on cerebral blood flow and neuropsychological test performance in patients with high-grade carotid stenosis

We examined the changes in cognitive function following carotid endarterectomy (CEA) in relation to the cerebral blood flow (CBF) in patients with high-grade carotid stenosis. The subjects consisted of 23 patients who underwent CEA and 17 controls matched by age and education. Single photon emission computed tomography (SPECT) and neuropsychological tests were performed 2 weeks before and 4 weeks after CEA in all patients. The preoperative CBF tests revealed a decreased vasodilatory reserve in the ipsilateral cerebral hemisphere in nine patients, which was increased after CEA. In these patients, the grade of carotid stenosis was significantly higher than in those with a normal perfusion reserve (90.2+/-8.1% vs. 78.6+/-11.3%, respectively, p<0.05). In the patient group, the postoperative scores (27.2+/-2.9) of the mini-mental state examination (MMSE) improved significantly over the preoperative ones (26.1+/-3.2, p<0.05). Moreover, the scores in the block-design test after CEA (86.8+/-19.8) were significantly higher than those before the operation (81.8+/-22.3, p<0.01). The error score in immediate retention improved from 9.0+/-3.1 to 7.7+/-4.0 following CEA (p<0.05). In the control group, none of the test scores showed significant improvement between the first and second tests. In the patients with an impaired vasodilatory reserve, the mean score of the block-design test significantly improved from 65.6+/-22.1 to 74.0+/-19.2 after CEA compared with those in patients without impairment (p<0.05). High-grade carotid stenosis was thus concluded to cause cognitive impairment due to cerebral hemodynamic failure, which is presumably reversed by CEA.

Changes in carotid atherosclerosis patterns detected by ultrasonography in Japanese elderly patients with aortic aneurysm

To clarify current changes in the patterns of carotid atherosclerosis in Japan, carotid ultrasonographic findings in Japanese male patients with aortic aneurysm were compared between two groups examined in different periods. The first group was recruited from 42 consecutively examined patients in 1997, while the second group consisted of 40 consecutive patients from September, 2001 to January, 2002. Carotid lesions were analyzed by computer, and classified into three types based on the texture: echolucent, hyperechoic, and heterogeneous types. The mean age of the first group was 72 years, similar to that of the second group. In the first group, cigarette smoking was frequently noted, while the mean BMI was greater and IHD and CVD were frequent in the second group. Fifty carotid lesions were seen in each group. Severe stenosis and hypoechoic type lesions were more frequent in the second group than in the first group. These findings indicated that hypoechoic-type lesions, which are considered to be lipid deposition, hemorrhage, or loose fibrous tissue, and severe stenosis, were increased in the more recent group. This predicted that circulatory disturbance due to unstable atherosclerotic lesions may increase in the future among the elderly because carotid lesions reflect vascular change in other organs.

[Marked decrease of intracranial atherosclerosis in contrast with unchanged coronary artery stenosis in Japan]

We conducted comparative studies on intracranial atherosclerosis and coronary artery stenosis over the past 28 years. Two-year consecutive autopsy case studies from an urban geriatric hospital between 1974-1975 (Group I. 484 cases). 1986-1987 (Group II, 504 cases) and 2000-2001 (Group III, 273 cases) were employed. Atherosclerotic changes of the bilateral middle cerebral arteries and basilar artery were semiquantitatively evaluated as none (0), mild (1), moderate (2) and severe (3) and values of the 3 arteries were totalled to give a value of 0-9 which was taken as the intracranial atherosclerotic index (ICAI). The coronary stenotic index was calculated as previously reported (Sugiura et al 1969). ICAI and CSI were directly compared with each other, together with risk factors for each, including mean blood pressure (BP), serum level of total cholesterol (Tch) and the history of diabetes mellitus (DM+). Chronologically ICAI decreased dramatically but CSI did not change at all. There was continuous lowering of BP, elevation of Tch and increased incidence of DM+. There was a significant positive correlation in BP in relation to both ICAI and CSI (p < 0.01). DM+ vs. CSI (p < 0.01) and ICAI (p < 0.05), and Tch vs. CSI (p < 0.01) but not ICAI. Regression analysis highlighted age and BP as major risk factors for ICAI. Our study provides the first morphological confirmation of marked decrease of the intracranial atherosclerosis in the recent 28 years, in contrast with unchanged coronary stenosis in Japanese elderly subjects.

Diffusion-weighted MRI in evaluation of transient ischemic attack

Diffusion-weighted magnetic resonance imaging (DWI) is a sensitive diagnostic tool for detecting recent ischemic lesions in patients with transient ischemic attacks (TIAs), but the interpretation of the presence or absence of DWI abnormalities in TIA patients still remains controversial. To elucidate the pathophysiology underlying those lesions, we analyzed DWI abnormalities in patients with recent TIAs. Based on 45 consecutive patients with TIAs who underwent DWI within 10 days of onset, demographic data and clinical manifestations were analyzed in relation to the DWI abnormalities. According to the method utilized in the Oxfordshire Community Stroke Study, clinical manifestations were classified into classical lacunar syndrome and non-lacunar symptoms. Based on the vascular distributions of ischemic lesions, the DWI abnormalities were classified into small-vessel and large-vessel lesions. DWI abnormalities were detected in 14 (31%) of 45 TIA patients. Seven (50%) of 14 DWI-positive patients had occlusive vascular lesions on intracranial magnetic resonance angiography, while only 5 (16%) of 31 DWI-negative patients had occlusive lesions (P < .05). No other demographic or clinical features, including risk factor and presence of cardiac disease, differed significantly between the DWI-positive and DWI-negative patient groups. Four (46%) of 9 DWI-positive patients who had a classical lacunar syndrome also showed small-vessel lesions on DWI, whereas all 5 patients who had non-lacunar symptoms showed large-vessel lesions. We concluded that although DWI abnormalities were detected in only one third of our TIA patients, DWI abnormalities were closely related to intracranial vascular occlusive lesions. The combination of DWI and MRA was useful for detecting large-artery lesions in patients displaying a classical lacunar syndrome.

A case of transradial carotid stenting in a patient with total occlusion of distal abdominal aorta

We report a case with severe carotid stenosis in which carotid stenting was performed via the radial artery due to total occlusion of distal abdominal aorta. The radial approach offers a potential alternative in cases in which the femoral approach is problematic.

Aortic atheromatous lesions developed in APA hamsters with streptozotocin induced diabetes: a new animal model for diabetic atherosclerosis. 1. Histopathological studies

To develop an adequate animal model for atherosclerosis in large vessels of patients with diabetes, i.e. diabetic macroangiopathy, we induced diabetes in APA hamsters with a single injection of streptozotocin (SZ) and examined the aorta histopathologically and immunohistochemically. As a result, hyperglycemia and hyperlipidemia were continuously observed for 26 weeks after the SZ injection (WAI) in APA hamsters. Fatty streaks characterized by a subendothelial accumulation of many foam cells were observed, limited to the aortic arches as early as 6 WAI. In addition to larger fatty streaks developing with the duration of diabetes, fibrous plaques and plaques containing calcium deposits or cholesterol clefts developed at 26 WAI. These lesions are generally similar to the atheromatous lesions developed in humans. Moreover, depositions of apolipoprotein E and advanced glycation end-products immunohistochemically detected in the lesions were very similar to those found in humans. The diabetic APA hamster is therefore considered to be a useful model for studying the formation of atheromatous lesions in diabetic patients.

Comparison of the prevalence of asymptomatic carotid atherosclerosis detected by high-resolution ultrasonography in rural and urban middle-aged Japanese men

BACKGROUND AND PURPOSE

We have recently shown that extracranial carotid atherosclerosis is not uncommon in urban regions of Japan. Rural data have, however, been scarcely reported. The aim of this study was to investigate the prevalence of asymptomatic extracranial carotid lesions in rural populations compared with urban populations.

METHODS

The subjects in the rural region consisted of 249 men, aged 50 to 69 years. Urban subjects were 610 men of the same age range. Carotid ultrasound examinations were performed with 7.5-MHz high-resolution ultrasonography.

RESULTS

Detection of severe atherosclerosis (stenosis of 50%) was significantly higher (P<.05) in rural subjects (9.6%) than in urban subjects (4.6%). Multiple regression analysis of carotid atherosclerosis showed significant relationships with age, fasting blood glucose, hypertension, pack-years of smoking, total serum cholesterol, and high-density lipoprotein cholesterol for the rural subjects as well as for the urban subjects (P<.05).

CONCLUSION

The present cross-sectional study showed that, in middle-aged men, the prevalence of severe carotid atherosclerosis was higher in rural populations compared with urban populations of Japan. This was attributed to long-term exposure to hypertension.

Stroke topography in diabetic and nondiabetic patients by magnetic resonance imaging

Stroke is more frequent in diabetic than in nondiabetic patients. We studied lesion topography in 61 stroke patients with diabetes mellitus and 77 without diabetes using magnetic resonance imaging. Location, number and size of infarcts were investigated. Prevalence of hypertension did not differ between diabetic and nondiabetic patients. In elderly subgroups (> or = 65 years), infratentorial infarcts > or = 5 mm in diameter were more frequent in diabetic than in nondiabetic patients (32 vs. 12%, P < 0.05), while supratentorial infarcts were not different (56 vs. 68%, ns). Asymptomatic hemorrhage combined with silent infarction was significantly less frequent in diabetic than in nondiabetic patients (5 vs. 22%, P < 0.05). In nondiabetic patients with significant stenosis in the carotid system, supratentorial infarction measuring > or = 15 mm was more frequent than in those without stenotic lesions, but the number of infarcts per patient irrespective of size was smaller when stenosis was present. On the other hand, the number of infarcts in diabetic patients was similar between those with and without carotid system stenosis. The present study demonstrated that infratentorial infarcts were more common in elderly diabetic patients, suggesting the vulnerability of vertebrobasilar circulation in diabetes.

Angiographic patterns of carotid ischemic cerebrovascular disease in Saudi Arabia

The angiographic findings in 100 Saudi patients with carotid ischemic cerebrovascular disease (CVD) (transient ischemic attacks (TIA) or strokes) were retrospectively reviewed. These patients were representative of all patients with similar disorders in the terms of sex, frequency of diabetes mellitus and ischemic heart disease. They were, however, significantly younger, smoked more, had more cervical bruits and less atrial fibrillation. Analysis of the data showed that a significant stenosis (> 70%) of the carotid artery origin was found only in 12% of TIA cases, 4% in the lacunar infarction cases and 6% of the large infarction cases on the symptomatic side and only in one case of TIA in the asymptomatic side. These frequencies were significantly lower than those found in similar studies performed in western countries. This study suggests that stenoses and occlusions of extracranial carotid artery plays a smaller role in the pathogenesis of ischemic CVD in Saudis than in Caucasians. The low consumption of cigarettes among elderly and females may be one of the explanations.