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Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A review is given on the clinical studies performed with aspirin in patients with chronic vascular occlusions of the limbs and on studies in cerebral ischemia using aspirin and sulfinpyrazone. Aspirin reduces the risk of reocclusions in patients after vascular surgery and also reduces the risk of peripheral vascular occlusions in diabetic patients. In doses of 1.2-1.5 g/day it also reduces the frequency of transient ischemic attacks. Conclusive results of similar studies with sulfinpyrazone and dipyridamole can be expected of the ongoing studies. Aspirin has no effect on the course of glomerulonephritis in children. Warfarin plus dipyridamole seem to have some effect in patients renal allografts. Sulfinpyrazone and ASA reduced the incidence of shunt thromboses in hemodialyzed patients. Several case reports in patients with thrombocytemia or Raynaud's syndrome made it likely that treatment with antiplatelet drug reduces the incidence of vascular occlusions.
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PMID:Use of platelet inhibitor drugs in peripheral and cerebral vascular disorders. 36 58

The choice of antithrombotic agent in cerebral ischemia depends on the pathogenesis: thrombosis, embolism, or hemorrhage. Antiplatelet agents are considered most beneficial in thrombotic stroke, anticoagulants are most effective in cardioembolic stroke; antithrombotic agents are generally contraindicated in hemorrhagic stroke. A meta-analysis of 18 trials documented a 23% reduction in stroke risk with antiplatelet agents; aspirin is typically the antiplatelet agent of choice for stroke prevention. There are no definitive data regarding the optimal aspirin dose for stroke prevention and this issue remains controversial. Ticlopidine is the most effective antiplatelet agent, but its adverse effect profile restricts its use. Anticoagulants are highly effective for preventing cardioembolic stroke, but their effectiveness in non-cardioembolic stroke is uncertain because of lack of trial data. Results of the ongoing Warfarin/Aspirin Recurrent Stroke Study (warfarin [INR 1.8-2.8] vs aspirin [325 mg/day]) may clarify this issue. There is renewed interest in thrombolytics because recent data indicate that reperfusion within a few hours of stroke onset appears to be effective in preventing neuronal damage. In addition, when given within 6 hours of stroke onset, thrombolytics appear to be relatively safe. Several direct thrombin inhibitors are being evaluated. Experimentally, hirudin, hirulog, D-Phe-L-Pro-L-Arg-CH2Cl (PPACK), and argatroban are clearly more effective than heparin in inhibiting platelet deposition and thrombus formation, and also show promise in preventing reocclusion after thrombolysis for both experimental thrombotic and embolic stroke. However, the risk of hemorrhage in patients with cerebrovascular disease is unknown for these agents.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antithrombotic agents in cerebral ischemia. 786 71

Nonvalvular atrial fibrillation is associated with an overall risk of stroke of 4.5% per year. Advancing age, prior stroke or transcient cerebral ischemia, diabetes and hypertension are known risk factors. Ischemic stroke in patients with atrial fibrillation are generally more severe than ischemic stroke in patients with sinus rhythm. Warfarin is effective for primary and secondary prevention of ischemic stroke, reducing the risk by 68%. The effect of aspirin is still controversial, reducing the risk by 18-44%. Recent clinical trials have investigated the effect of warfarin given at a very low intensity either alone or combined with aspirin. The results from the SPAF III study demonstrated that a combination of mini-intensity warfarin plus aspirin was insufficient for stroke prevention in atrial fibrillation. Other trials now indicate, that oral anticoagulation at INR-values below 2.0 is not effective for stroke prevention in these patients. It is recommended that patients at high risk of stroke are treated with warfarin at an intensity of INR 2.0-3.0. Patients younger than 65 without other risk factors can be given aspirin 325 mg/day. The present clinical challenge is to ensure effective and safe oral anticoagulation to patients with atrial fibrillation at high risk of stroke.
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PMID:Prevention of thromboembolic events in atrial fibrillation. 919 82

The anticoagulant effect of warfarin should be kept at an international normalised ratio (INR) of about 2.5 (desirable range, 2.0-3.0), although a higher level may be better in a few clinical conditions. The risk of bleeding increases exponentially with INR and becomes clinically unacceptable once the INR exceeds 5.0. Warfarin therapy should be continued for around six weeks for symptomatic calf vein thrombosis, and for 3-6 months after proximal deep vein thrombosis (DVT) that occurs after surgery or limited medical illness. Therapy for six months or longer could be considered for DVT occurring without an obvious precipitating factor, proven recurrent venous thromboembolism (VTE), or if there are continuing risk factors. Oral anticoagulants prevent ischaemic stroke in atrial fibrillation (AF). Maximum efficacy requires an INR > 2.0, but some benefit remains at an INR of 1.5-1.9. Patients aged over 75 years are at greatest risk of intracranial bleeding during warfarin therapy for AF, and the target INR may be reduced to 2.0-2.5, or perhaps as low as 1.5-2.0, in such patients. Warfarin should be withheld if it is more likely to cause major bleeding than to protect from stroke (e.g., in young people with isolated AF where the annual baseline risk of stroke is < 1%). In patients with AF, aspirin is less effective than warfarin (much less effective after such patients have had a stroke or transient cerebral ischaemia). In people with prosthetic heart valves, an INR of 2.5-3.5 is probably sufficient for bileaflet or tilting disc valves, but a higher target INR is necessary for caged ball or caged disc valves. The addition of aspirin (100 mg/day) further decreases the risk of embolism but increases the risk of gastrointestinal bleeding.
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PMID:Consensus guidelines for warfarin therapy. Recommendations from the Australasian Society of Thrombosis and Haemostasis. 1091 7

Non-valvular atrial fibrillation (NVAF) is responsible for up to 10% of all ischaemic strokes. The risk of stroke in these patients is substantial, particularly when associated with past cerebral ischaemia, hypertension, diabetes and age over 65. Warfarin has recently been shown to reduce this risk by two-thirds with relative safety. The files of 103 patients with chronic NVAF on recent presentation to hospital were studied to see if they had been given warfarin beforehand. Two-thirds would have been ideal candidates, having at least one added risk factor for stroke, and no contraindication for the use of warfarin. Yet fewer than 10% were taking it. Sixteen of these 103 patients had an ischaemic event at presentation, mostly stroke. Twelve were ideal candidates for warfarin prophylaxis, but none had received it for this purpose. Much more must be done to prevent stroke in these patients.
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PMID:Stroke prevention in patients with non-valvular atrial fibrillation: a current community perspective. 1863 77

OPININION STATEMENT: All patients with ischemic stroke should undergo a comprehensive assessment of cardiovascular risk. Patients with carotid artery disease, symptoms of cerebral ischemia and high cardiovascular risk profiles should be considered for noninvasive testing for coronary artery disease (CAD). Routine testing for CAD before carotid endarterctomy is not recommended. Patients with coexisting coronary and carotid artery disease should be more aggressively treated for reducing their "very high" risk of cardiovascular events. In patients candidates to carotid revascularization, a preoperative coronary angiography and coronary revascularization are not recommended. Warfarin is recommended in all patients with moderate to high risk of stroke. Novel oral anticoagulants represent an attractive alternative to warfarin. However, their place in therapy in clinical practice is not yet established. Percutaneous closure of the left atrial appendage for stroke prophylaxis may be considered in selected patients with atrial fibrillation and contraindications for oral anticoagulant therapy. Warfarin is not indicated in patients with heart failure who are in sinus rhythm. Percutaneous closure of patent foramen does not seem to be superior to medical therapy for the prevention of recurrences in patients with cryptogenic stroke.
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PMID:Interactions between cardiovascular and cerebrovascular disease. 2309 95

We describe the case of a patient who presented with transient ischemic attack 4 years after bicuspid aortic valve repair, ascending aorta, and hemiarch replacement. Workup included cross-sectional imaging consistent with thrombus in the ascending aorta graft. Warfarin was initiated, but another episode of cerebral ischemia occurred despite therapeutic anticoagulation. Surgery was performed to avoid further embolization as re-replacement with a homograft aorta. Histologic analysis of the material found within the graft demonstrated large B cell lymphoma. At 39 months' follow-up, there have been no additional episodes of embolization and no evidence of recurrent cancer.
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PMID:Lymphoma of prosthetic aortic graft presenting as recurrent embolization. 2555 49

The authors present a unique case of recurrent stroke, discovered to be secondary to hemorrhagic conversion of microemboli from a mechanical aortic valve despite anticoagulation with Coumadin. The complexity of this case was magnified by the patient's young age, a mechanical heart valve (MHV), and a need for anticoagulation to maintain MHV patency in a setting of potentially life-threatening intracranial hemorrhage. Anticoagulant and antiplatelet therapy are risk factors for hemorrhagic conversion post-cerebral ischemia; however, the pathophysiology underlying endothelial cell dysfunction causing red blood cell extravasation is an active area of basic and clinical research. The need for randomized clinical trials to aid in the creation of standardized treatment protocol continues to go unmet. Consequently, there is marked variation in therapeutic approaches to treating intracranial hemorrhage in patients with an MHV. Unfortunately, patients with an MHV are considered at high thromboembolic (TE) risk, and these patients are often excluded from clinical trials of acute stroke due to their increased TE potential. The authors feel this case represents an example of endothelial dysfunction secondary to microthrombotic events originating from an MHV, which caused ischemic stroke with hemorrhagic conversion complicated by the need for anticoagulation for an MHV. This case offers a definitive treatment algorithm for a complex clinical dilemma.
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PMID:Recurrent Hemorrhagic Conversion of Ischemic Stroke in a Patient with Mechanical Heart Valve: A Case Report and Literature Review. 2931 62