Atherosclerotic Carotid Artery Disease Research Articles

Lipid risk factors for atherosclerotic carotid artery disease in patients on continuous ambulatory peritoneal dialysis

We investigated the relationship between abnormalities of lipid metabolism and carotid atherosclerosis in 20 patients on continuous ambulatory peritoneal dialysis (11 men and nine women). Carotid ultrasonography was used to determine the combined thickness of the intima and media (I‐M thickness). The apo A‐I/apo B ratio showed a significant negative correlation with I‐M thickness (P<0.05). In the patients with carotid plaque, the triglycerides (TG) level and the remnant‐like particle cholesterol level (RLP‐C) were significantly higher than in the patients without plaque (P<0.05), and high density lipoprotein (HDL) cholesterol and the apo AI/apo B ratio were significantly lower than in the patients without plaque (P<0.05). Moreover, there was a strong relationship between the severity of plaque and TG, the apo AI/apo B ratio, and RLP‐C. Thus, abnormal lipid metabolism may contribute to progressive atherosclerosis, while TG, the apo A‐I/apo B ratio, and RLP‐C levels may be useful indicators of atherosclerotic risk in peritoneal dialysis patients.

Lipid risk factors for atherosclerotic carotid artery disease in patients on continuous ambulatory peritoneal dialysis

SUMMARY: We investigated the relationship between abnormalities of lipid metabolism and carotid atherosclerosis in 20 patients on continuous ambulatory peritoneal dialysis (11 men and nine women). Carotid ultrasonography was used to determine the combined thickness of the intima and media (I‐M thickness). the apo A‐I/apo B ratio showed a significant negative correlation with I‐M thickness (P<0.05). In the patients with carotid plaque, the triglycerides (TG) level and the remnant‐like particle cholesterol level (RLP‐C) were significantly higher than in the patients without plaque (P<0.05), and high density lipoprotein (HDL) cholesterol and the apo AI/apo B ratio were significantly lower than in the patients without plaque (P<0.05). Moreover, there was a strong relationship between the severity of plaque and TG, the apo AI/apo B ratio, and RLP‐C. Thus, abnormal lipid metabolism may contribute to progressive atherosclerosis, while TG, the apo AI/apo B ratio, and RLP‐C. levels may be useful indicators of atherosclerotic risk in peritoneal dialysis patients.

Advances in Management of Carotid Atherosclerosis

Carotid artery stenosis is a common and potentially treatable cause of stroke. Stroke risk is increased as the degree of carotid stenosis increases, as well as in patients with neurological symptoms referable to the stenosed carotid artery. Carotid stenosis can be quantified by ultrasound imaging, magnetic resonance angiography, or conventional angiography. Medical treatment with platelet antiaggregants reduces stroke risk in some patients; other patients are best treated with carotid endarterectomy. Experimental treatments for carotid stenosis, including carotid angioplasty with or without stenting, are under investigation. We summarize the current literature and provide treatment recommendations for patients with atherosclerotic carotid artery disease.

Complications associated with therapeutic neck radiation

Purpose: This retrospective study of patients who underwent neck radiation as part of their treatment for squamous cell carcinoma of the oral cavity sought to identify and quantify the morbidity associated with this treatment. Patients and Methods: Thirty-five patients who received neck radiation between 1985 and 1992 were randomly recalled for examination. All patients had been treated in a standardized fashion by the Department of Radiation Oncology. The long-term effects of neck radiation on skin changes, thyroid function, and neck range of motion, of atherosclerotic carotid artery disease, xerostomia, and glottic structures were measured. Results: Fifty-seven percent of patients demonstrated grade 1 skin changes. No severe changes were noted, and no development of secondary neoplasia was observed. There was no linear trend observed between radiation dose and skin changes. Hypothyroidism developed in 14.3% of patients within 3.5 years posttreatment. Logistic regression demonstrated a significant association between hypothyroidism and radiation dose. Limitation of neck mobility was the most significant complication with deficits demonstrated in all ranges of motion. Carotid bruits were documented in 14.3% of patients, with a significant association between the higher neck dosage in N+ cases. Xerostomia was found in 68% of patients. There was persistent glottic erythema in 11.4% of patients. Conclusions: The results of this study indicate that there are persistent complications after neck radiation, which include limitation of neck movement, diminished thyroid function, accelerated carotid artery narrowing, and skin and salivary changes.

Relation of smoking with carotid artery wall thickness and stenosis in older adults. The Cardiovascular Health Study. The Cardiovascular Health Study (CHS) Collaborative Research Group.

Cigarette smoking has been associated with increased risk of atherosclerotic diseases in hospital-based studies and in studies of middle-aged populations but not in population-based studies of older adults with and without clinical cardiovascular disease. We investigated the relation of smoking to carotid artery atherosclerotic disease, expressed as intimal-medial wall thickness and arterial lumen narrowing (stenosis) measured by ultrasound. Subjects were 5116 older adults participating in the baseline examination of the Cardiovascular Health Study, a community-based study of cardiovascular diseases in older age. With increased smoking there was significantly greater internal and common carotid wall thickening and internal carotid stenosis: current smokers > former smokers > never-smokers; for instance, the unadjusted percent stenosis was 24%, 20%, and 16%, respectively (P < .0001). A significant dose-response relation was seen with pack-years of smoking. These findings persisted after adjusting for other cardiovascular risk factors and were also confirmed when analyses were restricted to those without prevalent cardiovascular disease. The difference in internal carotid wall thickness between current smokers and nonsmokers was greater than the difference associated with 10 years of age among never-smoking participants (0.39 mm versus 0.31 mm). Among all participants, the prevalence of clinically significant (> or = 50%) internal carotid stenosis increased from 4.4% in never-smokers to 7.3% in former smokers to 9.5% in current smokers (P < .0001). These findings extend previous reports of a positive relation between smoking and carotid artery disease to a population-based sample of older adults using several different indicators of atherosclerotic disease.

Surgical Management of Carotid Artery Atherosclerotic Disease*

Cerebrovascular disease remains an important cause of disability and death in the geriatric population. This paper reviews the current state of knowledge with respect to the pathogenesis and medical and surgical treatment of carotid atherosclerosis. The majority of strokes are probably due to embolization from an ulcerated atherosclerotic plaque at the carotid bifurcation rather than from ischemia produced by global reduction in cerebral blood flow related to obstruction of the carotid arteries. Ultrasonography is an appropriate screening examination, but most vascular surgeons consider contrast angiography to be essential in the preoperative evaluation. Large clinical trials have evaluated the efficacy of stroke prevention by carotid endarterectomy in symptomatic patients. The North American Symptomatic Carotid Endarterectomy Trial clearly demonstrated a benefit of surgery in stroke prevention as compared with optimal medical therapy after only 18 months of follow-up. The European Carotid Surgery Trial and a VA Cooperative Study produced similar conclusions. Much less information is available concerning the patient with carotid atherosclerosis who has no cerebral symptoms. No convincing evidence that surgery is beneficial has yet been demonstrated, but a large multicenter clinical trial (Asymptomatic Carotid Atherosclerosis Study) remains in progress.

Anterior ischemic optic neuropathy is not associated with carotid artery atherosclerosis.

The relation between anterior ischemic optic neuropathy and carotid artery atherosclerotic disease is unclear. We studied patients with anterior ischemic optic neuropathy to determine if they had an increased occurrence of carotid artery stenosis. Fifteen consecutive patients with anterior ischemic optic neuropathy were evaluated prospectively for cervical carotid artery stenosis and compared with 30 age- and sex-matched asymptomatic patients and also with 11 age- and sex-matched patients experiencing transient monocular blindness. There was no difference in the mean stenosis of the internal carotid artery between patients with anterior ischemic optic neuropathy (mean carotid stenosis, 19%) and asymptomatic patients (mean carotid stenosis, 9%; p > 0.05), whereas patients with transient monocular blindness had significantly more stenosis (mean, 77%) in the cervical carotid arteries than both control subjects (p < 0.0001) and patients with anterior ischemic optic neuropathy (p < 0.0001). There was also no difference in the percentage of patients with stenosis > or = 30% in anterior ischemic optic neuropathy (two of 15) and asymptomatic patients (five of 30), whereas 10 of 11 patients with transient monocular blindness had stenoses > or = 30%, significantly more than patients with anterior ischemic optic neuropathy (p < 0.0001) and asymptomatic patients (p < 0.0001). Anterior ischemic optic neuropathy is not a marker for atherosclerotic carotid artery stenosis. The pathogenesis of nonarteritic anterior ischemic optic neuropathy does not involve carotid artery stenosis in most patients.

Natural history of patients with unoperated atherosclerotic carotid artery disease—results from a retrospective study

The natural history of carotid artery disease was studied in a retrospective study of 609 angiograms performed during 1969-1979 on patients who had subsequently not been operated on. The indication for angiography differed, but was aimed at clarifying suspected cerebrovascular events. 578 patients could be followed-up after a median time of 10.4 years (0-22). The median survival time after angiography was 9.7 years for the 355 men and 12.8 years for the 223 women (p = 0.0099). Internal carotid stenosis of > 50% was seen in 9.0% (bilaterally in 2.2%), a stenosis > 75% in 4.5% (bilaterally in 0.9%) and occlusion in 9% (bilaterally in 0.7%). Ulceration was present in 10.7% (bilaterally in 1.6%). 26.5% of the patients had a cerebrovascular event during follow-up, of which 31.4% had transient ischaemic attack or amaurosis fugax. Survival was not influenced by the degree of stenosis, but presence of arteriosclerotic carotid artery disease significantly reduced the median survival time from 11 to 3 years. The main cause of death for men was myocardial infarction (27.7%) and for women a cerebrovascular event (27.8%), a significant difference. From this study, in selected patients it can be concluded that the annual frequency of cerebrovascular events was low, approaching frequencies reported in asymptomatic patients. The cause of death differed between men and women, with more cardiac deaths among men and more cerebrovascular deaths among women.

Management of Coexistent Carotid and Coronary Artery Atherosclerotic Disease: An Unresolved Controversy: Report of Clinical Experience and Literature Review

The outcomes of 44 patients undergoing concomitant carotid endarterecto my and coronary artery bypass grafting were reviewed along with significant liter ature to date. In the 44 patients receiving concomitant procedures there were no deaths, no myocardial infarctions, 3 transient neurologic deficits (6.8%), and 1 permanent neurologic deficit (2%). In the world experience with concomitant procedures, the incidence of myocardial infarction is 3.7% (64 of 1742) and the incidence of cerebral infarction is 6.7% (116 of 1742). These results compare favorably with an incidence of myocardial infarction as high as 20% in similar patients undergoing isolated carotid endarterectomy, and similarly, to an inci dence of cerebral infarction as high as 25% in similar patients undergoing iso lated coronary artery bypass grafting. Concomitant carotid endarterectomy and coronary artery bypass grafting offers an approach to the management of coex istent carotid and coronary artery occlusive disease with improved results when compared with isolated or staged procedures performed in the setting of coexis tent disease. A rational approach for preoperative evaluation is suggested that emphasizes the value of noninvasive carotid testing.

Patterns of failure of aspirin treatment in symptomatic atherosclerotic carotid artery disease

Over a 24-month period, 291 patients were consecutively admitted to the West Haven Veterans Administration Medical Center with new ischemic neurological symptoms. Of these, 90 patients (31%) developed ischemic neurological symptoms while taking aspirin (aspirin treatment failure). Of those in whom aspirin treatment failed, 66 patients had ischemic symptoms in the distribution of the carotid artery. Aspirin treatment failed in 21 patients with severe carotid stenosis (greater than 75% stenosis). Eleven of these 21 patients had cerebral infarctions while taking aspirin, and 7 of these 11 infarcts occurred without the prior warning of transient ischemic attacks. Aspirin treatment failed in 45 patients with lesser degrees of carotid stenosis. Transient ischemic attack without permanent ischemia was the most common manifestation of failure in these patients. Infarction occurred in only 12 of these 45 patients and in only 4 patients did infarction occur without warning. We conclude that patients with symptomatic high-grade carotid stenosis (greater than 75%) in whom aspirin treatment failed are likely to suffer an infarct without warning as the first sign of treatment failure (P less than 0.033). We suggest that this subgroup of patients should be considered for alternative forms of therapy.

Patterns of Failure of Aspirin Treatment in Symptomatic Atherosclerotic Carotid Artery Disease

Abstract Over a 24-month period, 291 patients were consecutively admitted to the West Haven Veterans Administration Medical Center with new ischemic neurological symptoms. Of these, 90 patients (31%) developed ischemic neurological symptoms while taking aspirin (aspirin treatment failure). Of those in whom aspirin treatment failed. 66 patients had ischemic symptoms in the distribution of the carotid artery. Aspirin treatment failed in 21 patients with severe carotid stenosis (&amp;gt;75% stenosis). Eleven of these 21 patients had cerebral infarctions while taking aspirin, and 7 of these 11 infarcts occurred without the prior warning of transient ischemic attacks. Aspirin treatment failed in 45 patients with lesser degrees of carotid stenosis. Transient ischemic attack without permanent ischemia was the most common manifestation of failure in these patients. Infarction occurred in only 12 of these 45 patients and in only 4 patients did infarction occur without warning. We conclude that patients with symptomatic high-grade carotid stenosis (&amp;gt;75%) in whom aspirin treatment failed are likely to suffer an infarct without warning as the first sign of treatment failure (P&amp;lt; 0.033). We suggest that this subgroup of patients should be considered for alternative forms of therapy.

Procoagulant activity expression by macrophages from atheromatous vascular plaques.

Embolization of thrombi from ulcerated plaques is an important cause of morbidity from atherosclerotic carotid artery disease. Factors controlling thrombus formation on these lesions are not well understood. Macrophages were isolated from atherosclerotic plaques to assess their potential to promote local fibrin deposition. Plaques were collected from 11 patients undergoing carotid endarterectomy and 9 patients undergoing reconstructive procedures for atherosclerotic disease of their distal aorta or femoral arteries. Blood was also collected concurrently to isolate monocytes. Procoagulant activity (PCA) of carotid macrophages (8.6 +/- 4.1 mU/10(6) cells) was significantly higher than that of macrophages from non-carotid lesions (0.35 +/- 0.20 mU/10(6) cells; P less than 0.05) or blood monocytes from either group of patients. The PCA of carotid plaque macrophages from patients with recent emboli was 16.1 +/- 8.4 mU/10(6) cells (n = 5) compared to 2.4 +/- 0.8 mU/10(6) cells (n = 6) for plaque macrophages from assymptomatic carotid endarterectomy patients. Carotid macrophage PCA was factor V and factor VII dependent. Its functional activity was inhibited by an anti-tissue factor antibody, and immunohistochemical studies on tissue sections from carotid plaques showed tissue factor in areas where macrophages were abundant. These studies demonstrate that macrophages within carotid artery plaques have augmented procoagulant activity compared with blood monocytes and macrophages from other atherosclerotic lesions and indicate that carotid plaque macrophages are activated. Augmented macrophage PCA may contribute to thrombus formation on ulcerated plaques.

Neovascularization of the Optic Disc Associated with Obstruction of the Central Retinal Artery

Neovascularization of the optic disc (NVD) has, to the authors' knowledge, rarely been reported in association with acute obstruction of the central retinal artery (CRAO). The authors recently retrospectively reviewed 168 cases of CRAO. In this group, NVD developed in three patients soon after their CRAG, an occurrence rate of 1.8%. Rubeosis iridis also developed in two of these three patients. Although all three patients had either atherosclerotic carotid artery disease, diabetes mellitus, or both, in none of the cases was there clinical evidence implicating these diseases as the direct cause for the NVD. All three eyes received panretinal laser photocoagulation, with eventual resolution of the new vessels.

Noninvasive Evaluation of the Extracranial Carotid Arteries in Patients With Cerebrovascular Events and Atrial Fibrillations

Noninvasive carotid artery testing was performed in 73 patients with nonvalvular atrial fibrillation who were referred because of symptoms or signs of cerebrovascular disease. Thromboembolism related to atrial fibrillation without valvular heart disease was the probable source of cerebral ischemia in 25 (80%) of 31 patients with stroke and coexisting atherosclerotic disease at the carotid artery bifurcation in six (20%). Nonvalvular atrial fibrillation was the probable source of symptoms in nine (70%) of 13 of patients with transient cerebral ischemia, while coexisting carotid artery disease was present in four (30%). Nonvalvular atrial fibrillation accounted for the symptoms in four of five patients with amaurosis fugax, with atherosclerotic carotid artery disease present in one. The remaining 24 patients had nonhemispheric symptoms of cerebrovascular disease, including vertebrobasilar insufficiency, dizziness, and syncope, and only one had a carotid lesion. A significantly higher proportion of patients with focal hemispheric symptoms had coexisting carotid disease than patients with nonfocal symptoms had, suggesting that atherosclerotic cerebrovascular disease contributes to stroke in patients with nonvalvular atrial fibrillation. Noninvasive carotid artery testing may be helpful in identifying atherosclerotic lesions at the carotid artery bifurcation in patients with atrial fibrillation and cerebrovascular disease, because different therapeutic modalities may be appropriate when two potential sources of cerebral ischemia are present.

Atherosclerotic carotid artery disease in patients with retinal ischemic syndromes.

The extracranial carotid systems of 105 patients with retinal ischemia were examined using B-mode ultrasonography with integrated pulsed Doppler. Sixty-four patients had amaurosis fugax (AF), 17 central retinal artery occlusions (CRAO), and 21 branch retinal artery occlusions (BRAO). The prevalence of carotid stenosis (greater than or equal to 60%) ipsilateral to the symptomatic eye was low (16%). Eighty-six percent of AF patients had either no plaque causing less than a 60% stenosis. A significant proportion of subjects with normal duplex scans had alternative explanations for their retinal ischemia (eg, migraine, cardiac embolus). Patients with Hollenhorst plaques were more likely to have stenotic or ulcerated plaque (p = 0.04). The degree of carotid stenosis correlated significantly with the number of vascular risk factors identified in individual patients (p = 0.02). The presence of risk factors was more common in CRAO and BRAO patients compared with the AF group. Combined ultrasound-Doppler investigations of the carotid bifurcation are valuable noninvasive tools for the screening of patients with retinal ischemia.

Carotid duplex sonography: a multicenter recommendation for standardized imaging and Doppler criteria.

A complex duplex carotid evaluation involves high resolution imaging and characterization of the carotid plaque as well as quantitative Doppler spectral analysis to determine the presence and degree of flow restriction. Each of the components of the examination is essential to evaluate the carotid arteries adequately for the presence of disease. Both of these components should be assimilated into a final report that can be used to determine who is at risk for embolic as well as flow restrictive disease. By carefully following the reporting system described in this paper, an accurate and reproducible means of evaluating the carotid arteries can be achieved that permits comparison of studies. In addition, this will allow accurate communications among institutions and help to insure a better understanding of the etiology and pathogenesis of atherosclerotic carotid artery disease.

Symptoms of amaurosis fugax in atherosclerotic carotid artery disease.

Amaurosis fugax is a term used to describe transient monocular visual loss due to atherosclerosis of the ipsilateral internal carotid artery. It is differentiated from other causes of transient monocular blindness, especially retinal migraine. It is said that amaurosis fugax episodes are short in duration and only occasionally include "positive" visual phenomena such as scintillations. Monocular migraine is more prolonged and often accompanied by scintillations. We studied 37 patients with amaurosis fugax and angiographic evidence of carotid atherosclerosis ipsilateral to the symptomatic eye. Nearly one-third of the patients had long attacks or positive visual phenomena. In many patients, transient monocular visual loss due to carotid atherosclerosis cannot be differentiated from retinal migraine based on clinical symptoms alone.

Clinical diagnosis of atherosclerotic carotid artery disease.

Clinical diagnosis of atherosclerotic carotid artery disease.

Radiation-induced carotid artery disease.

Nine patients with atherosclerotic carotid artery disease associated with neck radiation were compared to 40 control patients. The data suggest that significant differences in age, incidence of coronary and peripheral vascular disease, elevated lipids and serum cholesterol, and the angiographic incidence of disseminated atherosclerosis justify the description of radiation-induced carotid disease as a clinical entity. Elevated serum cholesterol and hyperlipidemia may contribute to the development of radiation-induced vascular disease. Successful surgical reconstruction does not appear to be influenced by the prior radiotherapy, although periarterial fibrosis and increased difficulty in separating the plaques from the vascular media was encountered.