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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

No permanent neurologic deficit results from a transient ischemic attack, but patients with these episodes are at risk of stroke. Successful treatment depends on identifying the source of the problem--the heart, blood, or vessel wall. However, anticoagulants and antiplatelet agglutinating agents will reduce only the incidence of TIA's, not the incidence of stroke. Prompt vigorous treatment of progressive stroke may avert completed stroke. Heparin is recommended, unless a specific etiologic factor, such as polycythemia or hypertension, is identified.
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PMID:Current concepts in managing TIAs and stroke. 44 70

41,299 patients entering 914 hospitals up to 24 h (median 4 h) after the onset of suspected acute myocardial infarction were randomised between streptokinase (SK: 1.5 MU infused over about 1 h), tissue plasminogen activator (tPA, duteplase: 0.60 MU/kg infused over about 4 h), or anisoylated plasminogen-streptokinase activator complex (APSAC), anistreplase: 30 U over about 3 min). All patients were to receive aspirin (162 mg/day enteric-coated), with the first tablet chewed for rapid and full antiplatelet effect. Half of all patients were randomly allocated subcutaneous calcium heparin (12,500 IU starting at 4 h and given twice daily for 7 days or until prior discharge) in addition to aspirin, and the other half were to receive aspirin alone. ASPIRIN PLUS HEPARIN VERSUS ASPIRIN ALONE--The addition of heparin to aspirin was associated with an excess of transfused or other major non-cerebral bleeds (1.0% aspirin plus heparin vs 0.8% aspirin alone; 2p < 0.01) and of definite or probable cerebral haemorrhage (0.56% vs 0.40%; 2p < 0.05), but with no significnat differences in total stroke (1.28% vs 1.18%). Reinfarctions were slightly less common among those allocated aspirin plus heparin (3.16% vs 3.47%; 2p = 0.09). There was no signficant difference in the pre-specified endpoint of 35-day mortality (2132 [10.3%] aspirin plus heparin vs 2189 [10.6%] aspirin alone). During the scheduled heparin treatment period there were slightly fewer deaths in the aspirin plus heparin group (days 0-7 in hospital: 1534 [7.4%] vs 1633 [7.9%]; 2 p = 0.06), with a slight convergence by day 35 (598 further deaths [3.1% of survivors] vs 556 [2.9%]). The pattern was similar to that observed in the GISSI-2 trial, so that in both trials combined there was a significant reduction in mortality during the scheduled treatment period (2071 [6.8%] vs 2239 [7.3%]; 2p < 0.01). This indicates avoidance of 5 deaths (SD 2) per 1000 patients allocated this high-dose subcutaneous heparin regimen in addition to aspirin, but some of any early benefit may be lost after heparin ceases, with no significant mortality advantage in days 0-35 (both trials: 3100 [10.0%] vs 3172 [10.2%]) or during follow-up to 6 months. SK VERSUS APSAC--APSAC was associated with significantly more reports of allergy causing persistent symptoms and of non-cerebral bleeds, but not of transfused bleeds or of reinfarctions. There was a slight excess of strokes with APSAC (1.04% SK vs 1.26% APSAC; 2p = 0.08), much of it appearing soon after treatment started (strokes during days 0-1: 0.50% SK vs 0.73% APSAC; 2p < 0.02) and being attributed to cerebral haemorrhage (0.24% SK vs 0.55% APSAC; 2p < 0.0001). No significant difference was observed in reinfarction (3.47% SK vs 3.55% APSAC). There was no significant mortality difference during days 0-35, either among all randomised patients (1455 [10.6%] SK vs 1448 [10.5%] APSAC) or among the pre-specified subset presenting within 0-6 h of pain onset and with ST elevation on the electrocardiogram in whom fibrinolytic treatment may have most to offer (861 [10.0%] SK vs 855 [9.9%] APSAC). No significant difference in 6-month survival was apparent overall or in the subset.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:ISIS-3: a randomised comparison of streptokinase vs tissue plasminogen activator vs anistreplase and of aspirin plus heparin vs aspirin alone among 41,299 cases of suspected acute myocardial infarction. ISIS-3 (Third International Study of Infarct Survival) Collaborative Group. 1111 34

Thrombotic or thromboembolic occlusion of a cerebral artery is the most common pathophysiologic mechanism of acute ischemic stroke. An antithrombotic agent would therefore appear to be an ideal medication for treatment of this condition. Heparin is an effective anticoagulant, but it has poor bioavailability and effects on thrombin and platelets that predispose it to life-threatening complications such as hemorrhage and thrombocytopenia. Low-molecular-weight (LMW) heparins have better bioavailability, a higher anti-Xa:anti-IIa ratio, and less effect on platelets than heparin; yet their heterogeneity has hampered their proper investigation in clinical trials and it has not yet been proven that they exhibit less tendency toward hemorrhage and thrombocytopenia than conventional heparin. The LMW heparinoid, Org 10172, is superior to standard heparin in terms of its bioavailability, anti-Xa:anti-IIa ratio, and lack of effect on platelets. It is less likely than heparin and many LMW heparins to induce thrombocytopenia. Like the various heparins, Org 10172 exhibits dose-dependent hemorrhagic tendencies, yet preliminary studies have found doses that are safe for use in patients with acute ischemic stroke. These studies also suggest that Org 10172 may improve outcome and lessen mortality in this population. A prospective, randomized, double-blind, controlled trial is needed to establish the potential efficacy of Org 10172 in patients who suffer acute or progressing ischemic stroke.
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PMID:Low-molecular-weight heparins and heparinoids and their use in acute or progressing ischemic stroke. 170 55

Multiple clinical trials have demonstrated that thrombolytic treatment early in the course of acute myocardial infarction significantly reduces mortality. Patients under 75 years of age who have had chest pain for no longer than six hours and who demonstrate ST-segment elevation on electrocardiogram are the best candidates for this therapy. Recent studies suggest that there is little difference in effectiveness among streptokinase, alteplase and anistreplase. However, streptokinase is 10 times less expensive than the other agents and causes fewer intracranial bleeds, the major serious adverse effect of thrombolytic therapy. An advantage of anistreplase is that it can be given in a five-minute bolus injection, compared with a one-hour infusion for streptokinase and a three-hour infusion for alteplase. Thrombolytic therapy is contraindicated in patients with known pregnancy, active internal bleeding, uncontrolled hypertension, aortic dissection, intracranial neoplasm or a history of hemorrhagic stroke. Heparin should be administered with both alteplase and streptokinase. Aspirin, beta blockers, nitrates and lidocaine are useful adjunctive therapies in the setting of an acute myocardial infarction.
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PMID:Thrombolytic therapy in acute myocardial infarction. 173 49

Treatment after an ischemic stroke or transient ischemic attack (TIA) should target the presumed cause of the initial episode to facilitate focused prophylaxis. In the majority of ischemic strokes, degenerative large- and small-vessel disease is the cause. In these patients, attention to modifiable risk factors is an important priority. However, uncertainty and controversy remain regarding therapy, although issues are gradually being settled. There are now strong scientific data to support the use of carotid endarterectomy in patients with 70% to 99% stenosis and an ipsilateral TIA or nondisabling stroke. Aspirin is accepted as standard preventive therapy and should be used in all patients with a TIA or stroke, including those who undergo endarterectomy. Although the dose most commonly used in clinical trials is 1,300 mg/day, a daily dose of 325 mg is probably equally effective with less gastrotoxicity. Given present evidence, use of dipyridamole (Persantine) is not warranted. The role of ticlopidine hydrochloride (Ticlid) in stroke prophylaxis is not well defined. Its superiority over aspirin demonstrated in one study may make it the drug of first choice despite its expense and side effects. The efficacy of warfarin sodium (Coumadin, Panwarfin, Sofarin) or heparin in ischemic stroke caused by degenerative cerebrovascular disease is not supported by scientific data, but no prospective controlled studies have demonstrated that these agents are ineffective. Therefore, it seems prudent to reserve anticoagulant therapy for situations in which an ongoing thrombotic process is likely (eg, progressing stroke). Heparin therapy in the immediate post-TIA period is not warranted on the basis of current scientific evidence.
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PMID:Prevention of recurrent ischemic stroke. 174 41

Heparin therapy in acute stroke is a controversial issue. It is uncertain, whether heparin has a therapeutic or preventive effect in the early phase of the stroke. From 1984-1989, 1095 patients with acute ischemic stroke were treated, 141 (12.9%) of whom received heparin within 3 days of stroke onset. The mean duration of heparin anticoagulation was 10 days. In 28 cases (20%), heparin was used as antithrombotic agent (25/28 patients suffered a basilar artery occlusion, of whom 22 died). In 113 cases (80%), heparin was used in embolic stroke to prevent recurrence (24% cardioembolic stroke, 54% arterio-arterial embolism, and 22% embolism of unknown etiology). The rate of recurrent stroke in the early phase was 13% with a persistent deficit in 5.3%. The results are comparable with those of other trials reported in the literature. Only 2 patients had an anticoagulation-related haemorrhage with clinical deterioration. Heparin anticoagulation in acute stroke is a low-risk therapy, but its preventive value has not yet been demonstrated.
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PMID:[Heparin therapy in embolic cerebral infarct. A retrospective study]. 194 11

In recent years, several large randomized trials have clarified the role of various interventions in acute myocardial infarction. There is clear evidence that thrombolytic therapy, aspirin, and beta-blockers reduce mortality. Both aspirin and beta-blockers also reduce reinfarction and stroke. Of the thrombolytic agents, comparative trials have established that tissue plasminogen activator and streptokinase have similar effects on mortality, morbidity, and left ventricular function. There appears to be an increased risk of cerebral hemorrhage with tissue plasminogen activator. The benefits of heparin in conjunction with aspirin and a thrombolytic agent are unclear and, at best, are likely to be modest. Heparin increases the risk of hemorrhagic complications twofold. Although trials of vasodilators conducted before the widespread use of thrombolytic therapy and aspirin have been promising, newer trials are needed to evaluate their effects among patients receiving these agents. The aggregate of all trials of the routine use of calcium antagonists or antiarrhythmic agents indicates that these agents do not improve survival.
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PMID:Routine medical management of acute myocardial infarction. Lessons from overviews of recent randomized controlled trials. 197 22

A 55-year-old woman was transferred to our institution from another hospital. The history of her present illness began 17 days earlier with a right-sided cerebral vascular accident (CVA). Three days later she had a superior mesenteric artery (SMA) embolus with infarcted bowel. Her small bowel was resected leaving about 20-25 centimeters of small bowel. A cardiac echo on hospital day 6 documented the presence of a left ventricular embolus, which was considered to be the cause of her CVA and SMA embolus. The cardiologists recommended lifelong anticoagulation, preferably with warfarin when technically feasible. After one month of warfarin therapy, with doses as high as 25 mg/d, the patient's prothrombin times (PTs) were not changed from baseline; however, this was probably due to concomitant therapy with vitamin K. Heparin was incorporated into her total parenteral nutrition (TPN) in preparation for her discharge. Because the TPN was cycled, she required subcutaneous heparin twice daily while off TPN. This patient's clinical course while she was maintained on heparin therapy was complicated by bleeding episodes and extensive thigh and abdominal hematomas, which led to erratic heparin absorption and widely fluctuating partial thromboplastin times. Ten months after the initiation of anticoagulation the patient was again tried on an oral warfarin regimen. She was successfully titrated to achieve the desired PT ratio. This case led to a review of the literature of patients with short-bowel syndrome requiring anticoagulation.
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PMID:Oral anticoagulation in patients with short-bowel syndrome. 211 45

Much of the research related to cardiopulmonary bypass in recent years has been directed toward defining the changes in plasma and blood cells during bypass. In this review, recent information is reexamined for six areas of current interest. These areas are complement activation, immune response, anaphylactic reactions, coagulation, and cerebral dysfunction. Complement may be activated by either the classical or alternate pathway during cardiopulmonary bypass and protamine administration. Membrane oxygenators appear to diminish the degree of complement activation. Complement is a major factor in the whole body inflammatory response; which often accompanies cardiopulmonary bypass. A product of complement activation, C5a- desArg, causes activation and aggregation of granulocytes. Other products of complement activation lead to lysis of blood cells including granulocytes and red cells. Bubble oxygenators appear to have a distinct disadvantage compared to membrane oxygenators regarding infection. Airborne microorganisms are more likely to be entrained into circulating blood with bubble oxygenators than with membrane oxygenators. Bubble oxygenators cause a greater decrease in leukocyte number and function than membrane oxygenators. Anaphylactic reactions have been associated with use of antibiotics, blood products, protamine, and volume expanders during cardiopulmonary bypass. Protamine reactions may be on an immunological basis or due to direct toxicity of the drug. Free radicals including superoxide, hydrogen peroxide, and the hydroxyl radical may be generated during cardiopulmonary bypass and reperfusion. Free radical scavengers including; vitamin E, coenzyme Q, vitamin C, mannitol, and glutathione have been studied. The avoidance of blood transfusion because of risk of transmitted infection including AIDS has become a major goal in cardiac surgery. Factors that correlate with increased transfusion requirement include low hematocrit, female gender, increased age, small body size, low ejection fraction, reoperation, and emergency operation. Heparin resistance due to antithrombin III deficiency is being recognized more commonly. Antithrombin III deficiency may be corrected with fresh frozen plasma. Patients with heparin induced thrombocytopenia may be difficult to manage. Several management protocols are suggested. The most straightforward appears to be the use of aspirin preoperatively and platelet transfusions postoperatively. The incidence of cerebral dysfunction after cardiopulmonary bypass depends on the sensitivity of the test or indicator used. Perioperative stroke is associated with intrinsic cerebrovascular disease and atherosclerosis of the ascending aorta. Retinal angiograms during cardiopulmonary bypass show that microemboli are very common. Cerebroplegia has been shown to extend the period of safe circulatory arrest in animals. Much of the new knowledge concerning cardiopulmonary bypass is the result of close collaboration between cardiac surgeons and nonsurgical scientists.
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PMID:Pathophysiology of cardiopulmonary bypass: current issues. 213 41

Thrombolytic therapy has become an established procedure in patients with acute myocardial infarction (AMI). However, the aftercare of such patients is still uncertain. A meta-analysis of twenty trials of intravenous or subcutaneous heparin in AMI performed during the prethrombolysis period indicated a significant reduction in mortality, reinfarction, and stroke in treated patients. More recently, a study (SCATI) aimed at investigating the clinical effects of subcutaneous heparin (12.500 U two times daily) in the setting of thrombolytic therapeutical strategy in AMI, showed a lower in-hospital mortality, a trend towards lesser transient ischemic episodes in patients given streptokinase, and no difference in recurrent infarction rate. Ventricular thrombi were markedly reduced by heparin. Anti-platelet drugs were not permitted in the SCATI. In both GISSI 2 (Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto Miocardico) and International tissue plasminogen activator/streptokinase trials, aspirin was a recommended treatment, and subcutaneous heparin was randomized. No difference in mortality was noted in patients given heparin. In GISSI 2 recurrent ischemic episodes were also similar in treated and control groups, whereas embolic events were reduced by heparin. Major bleedings were rare in all trials. In conclusion, subcutaneous heparin is beneficial in AMI: however, the association with aspirin does not add consistent benefits. Heparin is effective in preventing thrombus formation and embolic complications - such effects are not shared by aspirin.
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PMID:Heparin in acute myocardial infarction. 215 Jun 62


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