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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peripheral vascular disease (PVD) is an indicator of diffuse atherosclerosis and is associated with a greatly increased incidence of coronary heart and cerebrovascular disease. Although several studies have assessed whether in vivo platelet activation takes place in patients with PVD, no data are available comparing different platelet function tests in this patient population. We have compared prospectively four tests for the measurement of in vivo platelet activation (plasma betaTG, plasma PF4, intraplatelet betaTG and urinary excretion of 11-dehydro-TXB2) and one in vitro platelet function test (ADP-induced platelet aggregation) in 63 well-characterized patients with intermittent claudication and in 18 age- and sex-matched healthy volunteers. No statistically significant difference was found between patients and controls for plasma betaTG (20.0 +/- 11.8 vs. 18.8 +/- 9.0 ng/ml, respectively), plasma PF4 (5.2 +/- 2.9 vs. 6.3 +/- 3.5 ng/ml), betaTG/PF4 ratio (4.0 +/- 2.9 vs. 3.6 +/- 1.8), intraplatelet betaTG (4503 +/- 1482 vs. 4059 +/- 1065 ng/ml), and threshold aggregatory concentration of ADP (1.7 +/- 0.72 vs. 1.45 +/- 0.56 microM). Urinary 11-dehydro-TXB2 was instead significantly higher in the PVD group (55.4 +/- 27.5 vs. 26.7 +/- 7.0 ng/h, p <0.001). Our study shows that urinary 11-dehydro-TXB2 is a more sensitive index of in vivo platelet activation than the measurement of either platelet specific proteins or of in vitro platelet aggregation in patients with PVD.
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PMID:Platelet activation markers in patients with peripheral arterial disease--a prospective comparison of different platelet function tests. 942 90

Sudden extreme physical stress is associated with an increased risk of myocardial infarction mainly in people with preexisting atherosclerosis. In this study we compared the effect of submaximal exercise on coagulation and fibrinolysis in patients with peripheral arterial occlusive disease (PAOD) with that in healthy control subjects. Fifteen PAOD) patients with intermittent claudication and 15 healthy control subjects, matched for age, sex, medication use, smoking habit, and conditioning, were studied. Thrombin-antithrombin III complex (TAT), D-dimer, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI)-1 antigens (Ag), t-PA activity, and plasmin-alpha2-antiplasmin complex (PAP), as well as plasma catecholamines, were measured before and after a treadmill exercise test. At rest, fibrinogen (3.3+/-0.5 versus 2.9+/-0.5 g/L [mean+/-SD]; P<.05), D-dimer (392+/-128 versus 271+/-113 ng/mL; P<.05), t-PA Ag (9.1+/-5.1 versus 5.5+/-1.2 ng/mL; P<.02), and PAI-1 Ag (14.9+/-7.1 versus 7.6+/-3.8 ng/mL; P<.002) levels in plasma were markedly higher in the patient group than in the control group. In patients but not in control subjects, exercise of similar intensity elevated circulating concentrations of TAT (from 3.43+/-1.45 to 4.83+/-2.27 ng/mL; P<.05). Exercise caused a parallel increase in D-dimer, t-PA Ag, t-PA activity, PAP, and catecholamines in both groups, whereas PAI-1 Ag remained stable. Plasma lactic acid was significantly higher in patients after exercise and was associated with lower-limb ischemia. Compared with healthy control subjects, patients with PAOD showed higher t-PA Ag, PAI-1 Ag, and D-dimer levels both at rest and after exercise. Notably, submaximal exercise on a treadmill enhanced thrombin formation in patients with PAOD but not in the control subjects. Sudden catecholamine release and local ischemia during exercise may accelerate the preexisting prothrombotic potential of the atherosclerotic vessel wall.
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PMID:Physical exertion induces thrombin formation and fibrin degradation in patients with peripheral atherosclerosis. 948 89

Intermittent claudication is an indicator of increased risk of cardiac and cerebrovascular morbidity and mortality and as such a reason to look for modifiable risk factors for atherosclerosis. A vascular anamnesis and physical examination can reliably exclude presence of peripheral arterial occlusive disease in the lower extremities, but cannot reliably demonstrate its presence. Certainty about presence or absence of peripheral arterial occlusive disease can be obtained by determination of an ankle-brachial blood pressure index. The main method for the diagnosis of severity and localisation of stenoses and occlusions in the arteries to the legs is the echo-Doppler (duplex) examination. With this method the feasibility of percutaneous transluminal angioplasty (PTA) can also be determined. Consequently, angiography has lost importance as a diagnostic method and is only still indicated as part of an interventional treatment (operation or PTA). Treatment should be aimed at both amelioration of symptoms and reduction of risk factors for atherosclerosis. A key-stone of the treatment is cessation of smoking. The role of pharmacotherapy in reducing symptomatology is only limited. Walking exercise can have a positive effect on walking distance and should always be tried. PTA is the treatment modality of first choice for stenoses in the aortoiliac and femoropopliteal arteries. For segmental occlusions in the iliac pathway, also recanalisation by means of PTA (in combination with stent placement) is a justifiable treatment option. In all other cases operative revascularisations give good functional results. Invasive treatments for patients with intermittent claudication should be performed within a multidisciplinary team.
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PMID:[Consensus diagnosis and treatment of arterial intermittent claudication. Central Guidance Organization for Peer Review]. 955 60

Lumbar spine stenosis most commonly affects the middle-aged and elderly population. Entrapment of the cauda equina roots by hypertrophy of the osseous and soft tissue structures surrounding the lumbar spinal canal is often associated with incapacitating pain in the back and lower extremities, difficulty ambulating, leg paresthesias and weakness and, in severe cases, bowel or bladder disturbances. The characteristic syndrome associated with lumbar stenosis is termed neurogenic intermittent claudication. This condition must be differentiated from true claudication, which is caused by atherosclerosis of the pelvofemoral vessels. Although many conditions may be associated with lumbar canal stenosis, most cases are idiopathic. Imaging of the lumbar spine performed with computed tomography or magnetic resonance imaging often demonstrates narrowing of the lumbar canal with compression of the cauda equina nerve roots by thickened posterior vertebral elements, facet joints, marginal osteophytes or soft tissue structures such as the ligamentum flavum or herniated discs. Treatment for symptomatic lumbar stenosis is usually surgical decompression. Medical treatment alternatives, such as bed rest, pain management and physical therapy, should be reserved for use in debilitated patients or patients whose surgical risk is prohibitive as a result of concomitant medical conditions.
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PMID:Lumbar spine stenosis: a common cause of back and leg pain. 993 Jan 24

Epidemiological evidence suggests that antioxidants protect against the development of atherosclerosis. To determine the effectiveness of antioxidant therapy in patients with lower limb atherosclerosis, a randomized placebo-controlled trial was performed in 120 men and women with intermittent claudication and an ankle/brachial pressure index (ABPI) < or = 0.9. The study was analysed on an intention-to-treat basis. After 2 years, there were no significant differences between antioxidant and placebo groups in plasma cholesterol, lipoproteins, haemostatic or rheological factors. However, after 6 months, low density lipoprotein cholesterol was significantly lower in those taking antioxidant (108.0 mg/dl compared with 120.1 mg/dl, p < 0.05). There were no differences in the ABPI or walking distance, although both groups improved slightly with time. The incidence of cardiovascular events and death was nonsignificantly lower in the antioxidant compared with the placebo group: event rates per year were 5.5% (95% CI 2.4-8.6) in the first year and 9.6% (95% CI 6.8-12.4) in the second year for those on antioxidants; and 7.7% (95% CI 5.1-10.3) and 13.3% (95% CI 8.9-17.7) respectively for those on placebo. Significantly fewer serious adverse events occurred in the antioxidant than the placebo group: 21.8% (95% CI 16.2-27.4) compared with 40.0% (95% CI 33.9-46.1). This study therefore suggests that although antioxidants may prevent cardiovascular events in patients with peripheral atherosclerosis, they do not improve lower limb function.
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PMID:Randomized controlled trial of antioxidants in intermittent claudication. 957 99

Although our understanding of the pathophysiology of atherosclerosis and peripheral vascular disease continues to grow, we have yet to discover a medication that can safely and efficaciously be given to most claudicants that will alleviate their symptoms to prevent disease progression. Many patients with intermittent claudication improve or remain stable without therapy if they attempt to alter their risk factors (e.g., control of diabetes, smoking cessation, lowering of cholesterol levels). However, many require concomitant drug therapy to alleviate symptoms of PVD, and some require surgical intervention. Even with the recent advances in therapeutic development and the promise of agents currently in clinical trials, the questions of who to treat, when treatment should begin, and which agent to use remain uncertain.
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PMID:Pharmacologic management of peripheral vascular disease. 967 56

The risk factors, epidemiology, diagnosis, and treatment of peripheral arterial disease are reviewed. Peripheral arterial disease is characterized by a gradual reduction in blood flow to one or more limbs secondary to atherosclerosis. Risk factors include smoking, diabetes mellitus, hyperlipidemia, and hypertension. The most common clinical manifestation is intermittent claudication. The prevalence of intermittent claudication in people over the age of 50 is 2-7% for men and 1-2% for women. The ankle:brachial pressure index (ABPI) is a useful measure of disease severity; an ABPI of 0.5-0.9 is common in intermittent claudication. The goals of therapy are to relieve or reduce ischemic symptoms, alleviate disability, improve in functional capacity, prevent progression that may result in gangrene and limb loss, and prevent cardiovascular and cerebrovascular events. Treatment includes risk-factor modification, drug therapy (primarily with antiplatelet agents), and revascularization procedures. Aspirin has been shown to be effective in reducing the associated risk of myocardial infarction and stroke. Ticlopidine appears to be a reasonable alternative for patients who are hypersensitive to aspirin. Clopidogrel has been shown to be more effective than aspirin in patients with recent myocardial infarction, recent stroke, or established peripheral arterial disease. There is controversy over the appropriate treatment for acute arterial occlusions. Risk-factor modification and antiplatelet drugs are the mainstays of therapy for patients with intermittent claudication, the most common manifestation of peripheral arterial disease.
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PMID:Management of peripheral arterial disease. 978 99

Peripheral arterial disease has received less attention from epidemiologists than coronary and cerebrovascular disease. Prevalence and incidence data typically show that peripheral arterial disease increases with age, is more common in men than women, and that symptomatic disease is only the tip of the iceberg. Studies concerning the prevalence of peripheral arterial disease rely mainly on the Rose questionnaire, which is used to screen for intermittent claudication, and on the ankle/brachial index, used to detect asymptomatic disease. Although there is a certain parallel between the 2 sets of data, the figures for asymptomatic disease consistently surpass those for clinical disease, and there is a wide variation between frequencies obtained in individual studies. In general, the prevalence of peripheral arterial disease is estimated to be under 2% for men aged less than 50 years, increasing to over 5% in those aged more than 70 years. Women reach these rates almost 10 years after men, although this gender difference decreases with increasing age. Figures for incidence follow a similar trend. The incidence of chronic critical ischaemia is estimated to be between 0.05% and 0.1% of the population. Asymptomatic disease detected with noninvasive tests is 3 to 4 times more frequent than intermittent claudication: its prevalence increases from under 5% for individuals aged less than 50 years to over 20% for individuals aged more than 70 years. The classical risk factors for atherosclerosis also apply to peripheral arterial disease, although their order of importance may be different from that for coronary and carotid disease. Several studies have shown that peripheral arterial disease correlates most strongly with cigarette smoking. Smoking is also the single greatest predictor of the progression of peripheral arterial disease. Other risk factors include hypertension, raised lipid levels (cholesterol and triglycerides for severe disease), diabetes, increased plasma viscosity, fibrinogen and homocysteine levels. Divergent views have been expressed in individual epidemiological studies with regard to the respective contribution of these risk factors to the development and progression of peripheral arterial disease. The natural history of peripheral arterial disease is characterised by a relatively benign local evolution. It can be estimated that, in general, 3 of 4 men presenting with intermittent claudication will never have a serious problem necessitating vascular intervention, and that no more than 5% are ever likely to require a major amputation. However, the underlying atherosclerotic pathology progresses with time: nondiseased arteries become obliterated and disease with an initially unilateral pattern frequently progresses to become bilateral. In addition, the few patients who do progress to critical ischaemia are at a significantly higher risk of amputation. The general prognosis for patients with peripheral arterial disease is particularly negative. There is a high prevalence of coronary heart disease and cerebrovascular disease in such patients, although the exact percentages depend on the patient population selected and on the method used for their evaluation. Coronary heart disease is detected in 40 to 60% of patients through a medical history combined with electrocardiography, while systematic coronary angiography detects coronary heart disease in 90% of those undergoing surgery. Although few patients with peripheral arterial disease have a history of stroke, in studies of surgical patients almost 30% appear to have significant extracranial disease. Patients with peripheral arterial disease have a poor life expectancy: the mortality rate is 3 to 5% per year in those with intermittent claudication and 20% per year in those with critical ischaemia. Coronary heart disease accounts for half of the total mortality, while vascular disease in general accounts for almost two-thirds.
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PMID:[Epidemiology and prognosis of peripheral obliterative arteriopathy]. 984 97

Peripheral arterial disease of the lower limbs is a manifestation of atherosclerosis, and may also affect other vascular territories such as the coronary and cerebral arteries. Progressive narrowing of the vessels up to total occlusion can present as intermittent claudication or pain at rest, with or without cutaneous lesions. Patients with intermittent claudication are at a low risk of amputation, and the symptom has to be regarded as a warning signal for myocardial infarction and stroke. Nevertheless, if the patient's walking distance is too limited to allow a near-normal life, symptomatic treatment to improve quality of life should be considered. Treatment may consist of walking exercise, surgical or interventional radiological revascularisation, or, in some cases, administration of vasoactive drugs. Antiplatelet agents should be administered in an attempt to limit disease progression and prevent cardiac and cerebrovascular complications, together with active measures to reduce established risk factors such as smoking, diabetes, hyperlipidaemia, and arterial hypertension. The presence of pain at rest indicates that a lower limb is jeopardised, especially when the criteria for critical ischaemia have also been met. These criteria include the presence of chronic (lasting for more than 2 weeks) symptoms of ischaemia at rest and a systolic blood pressure less than 50 mm Hg or 30 mm Hg at the ankle or big toe, respectively. In such a situation, revascularisation should be attempted whenever possible. If this is not possible or if the procedure has failed, prostacyclin administered intravenously for days or weeks is an alternative. After revascularisation, early reocclusion may be prevented by administering anticoagulants and late reocclusion by antiplatelet agents, in conjunction with eradication of risk factors. In all situations, therapeutic decision-making should be undertaken in a multidisciplinary setting and should include the following: specialists in angiology (an internist) and interventional radiology; a vascular surgeon; an orthopaedic surgeon, if necessary; and diabetes and infectious disease specialists.
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PMID:[Drug treatment strategies for peripheral obliterative arteriopathy]. 984 99

Atherosclerosis is the primary cause of peripheral arterial disease. Because atherosclerosis is a generalised disease, it is possible that patients with peripheral arterial disease may have other arterial disorders. Such patients have a reasonable chance of continuing to walk, although their general prognosis is less favourable because of high cardiovascular morbidity and mortality. Nevertheless, the following approaches can be used to improve the management of patients with peripheral arterial disease: diagnosis of peripheral arterial disease in its early stages by systematic measurement of the ankle/brachial index; improvement in screening for lesions in other arteries by analysing the clinical symptomatology and performing simple complementary examinations; improvement in the management of atherosclerosis risk factors, particularly cigarette smoking, as well as in the treatment of diabetes, arterial hypertension and hypercholesterolaemia; enhancement of antithrombotic agents by the development of new, more effective antiplatelet drugs. Finally, quality of life should be considered an essential factor governing treatment choice. A self-administered questionnaire concerning intermittent claudication has been used to assess the quality of life of patients with peripheral arterial disease undergoing treatment with ifenprodil tartrate. This study showed that the evaluation of intermittent claudication should not be limited to walking distance alone, but that a more general criterion, better adapted to atherosclerotic disease, should be considered: measurement of quality of life.
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PMID:[Quality of life and peripheral obliterative arteriopathy. Perspective for the future]. 984 2


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