Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A multicentre, randomised, open trial with a 2 x 2 factorial design was conducted to compare the benefits and risks of two thrombolytic agents, streptokinase (SK, 1.5 MU infused intravenously over 30-60 min) and alteplase (tPA, 100 mg infused intravenously over 3 h) in patients with acute myocardial infarction admitted to coronary care units within 6 h from onset of symptoms. The patients were also randomised to receive heparin (12,500 U subcutaneously twice daily until discharge from hospital, starting 12 h after beginning the tPA or SK infusion) or usual therapy. All patients without specific contraindications were given atenolol (5-10 mg iv) and aspirin (300-325 mg a day). The end-point of the study was the combined estimate of death plus severe left ventricular damage. 12,490 patients were randomised to four treatment groups (SK alone, SK plus heparin, tPA alone, tPA plus heparin). No specific differences between the two thrombolytic agents were detected as regards the combined end-point (tPA 23.1%; SK 22.5%; relative risk 1.04, 95% Cl 0.95-1.13), nor after the addition of heparin to the aspirin treatment (hep 22.7%, no hep 22.9%; RR 0.99, 95% Cl 0.91-1.08). The outcome of patients allocated to the four treatment groups was similar with respect to baseline risk factors such as age, Killip class, hours from onset of symptoms, and site and type of infarct. The rates of major in-hospital cardiac complications (reinfarction, post-infarction angina) were also similar. The incidence of major bleeds was significantly higher in SK and heparin treated patients (respectively, tPA 0.5%, SK 1.0%, RR 0.57, 95% Cl 0.38-0.85; hep 1.0%, no hep 0.6%, RR 1.64, 95% Cl 1.09-2.45), whereas the overall incidence of stroke was similar in all groups. SK and tPA appear equally effective and safe for use in routine conditions of care, in all infarct patients who have no contraindications, with or without post-thrombolytic heparin treatment. The 8.8% hospital mortality of the study population (compared with approximately 13% in the control cohort of the GISSI-1 trial) indicates the beneficial impact of the proven acute treatments for AMI.
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PMID:GISSI-2: a factorial randomised trial of alteplase versus streptokinase and heparin versus no heparin among 12,490 patients with acute myocardial infarction. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico. 197 87

In a study with 2 x 2 factorial design, 20,891 patients with suspected acute myocardial infarction of less than 6 h duration (12,490 from the GISSI-2 trial and 8401 recruited elsewhere) were randomly allocated to alteplase (recombinant tissue plasminogen activator, tPA) or streptokinase (SK) and to subcutaneous heparin, beginning 12 h after the start of thrombolytic therapy or no heparin. The protocol recommended that, in the absence of specific contraindications, all patients should receive aspirin and intravenous beta-blockade as soon as possible. No significant differences in hospital mortality were found between tPA and SK (8.9% versus 8.5%) or between heparin and no heparin (8.5% versus 8.9%). The incidence of major cardiac complications was also very similar in the different groups. For non-cardiac complications significant differences between the treatment groups were observed: more strokes were reported with tPA than with SK (1.3% versus 1%) while more major bleeds occurred with SK than with tPA (0.6% versus 0.9%). Subcutaneous heparin was likewise associated with an excess of major bleeds (1.0% with heparin versus 0.5% without heparin) but did not affect the incidence of stroke or reinfarction.
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PMID:In-hospital mortality and clinical course of 20,891 patients with suspected acute myocardial infarction randomised between alteplase and streptokinase with or without heparin. The International Study Group. 197 65

A group of 54 patients with acute or chronic limb ischaemia were initially treated with low dose intra-arterial thrombolytic therapy using streptokinase (10,000 units h-1) or plasminogen activator (0.5 mg h-1). Complete thrombolysis was obtained in 90 per cent of patients with symptoms of less than 1 week duration, and in 50 per cent with symptoms of greater than 1 week (P less than 0.05). Successful lysis in 36 patients was followed by successful bypass surgery in seven, percutaneous angioplasty in 13, no further treatment in 13, repeat thrombolysis in two and amputation in one. Failed therapy was associated with major amputation in 40 per cent. One patient died of haemorrhage and another of stroke as a direct result of thrombolytic treatment. The most common complication was haematoma at the site of cannulation of the vessel. Intra-arterial thrombolytic therapy can be very useful for the management of acute and chronic limb ischaemia, but complications do occur and patients should be carefully selected.
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PMID:Intra-arterial thrombolytic therapy in the management of acute and chronic limb ischaemia. 177

Defibrotide, a deoxypolyribonuclide, has been found to modulate endothelial cell function causing increase in t-PA and decrease in PAI levels and also increase in PGI2 production. In addition, it increases platelet c-AMP levels and decreases MDA and TXB2 formation in human. Defibrotide inhibits platelet aggregate formation in vitro experiments as well as end-to-end anostomosis in rats. So, defibrotide inhibits the activation of platelets. Besides an increase of protein C and S levels a synergic action of heparin was observed in animal experiments. A strong antithrombotic effect has been observed in animal models. The drug has a beneficial effect in the cases of DVT, POVD, stroke and thromboembolism. Through its action we may say that the drug acts in a novel fashion in contrast to the other drugs used in this area. Defibrotide is a single-stranded polydeoxyribonucleotide obtained from deoxyribonucleic acid of mammalian lungs by controlled depolimerization. Since 1981 in our laboratory and in the clinical department we have been investigating a newly developed agent defibrotide in vitro experiments, animal experiments, and also its clinical pharmacology and clinical application. Some of our findings are already published and compared with literature (40, 43, 46). Because of the limited space we are not going to review the literature in detail but we are going to summarize our observations on this compound in the following order. I--in vitro experiments, II--Animal experiments, III--clinical pharmacology in human.
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PMID:The pharmacology and clinical pharmacology of defibrotide: a new profibrinolytic, antithrombotic and anti-platelet substance. 210 24

A drug-use evaluation (DUE) of i.v. alteplase for the treatment of acute myocardial infarction (AMI) in two community hospitals is described. From November 1987 to June 1989, all 118 patients who were treated with i.v. alteplase for suspected AMI at two large community hospitals were monitored daily to determine patterns of use of alteplase, clinical outcomes, the hospital time needed to diagnose AMI and begin therapy, and the pharmacy time needed to prepare and deliver alteplase. Patient inclusion criteria were (1) chest discomfort of less than six hours' duration and unrelieved by nitroglycerin or nifedepine, (2) age less than 75 years, and (3) electrocardiographic evidence of transmural AMI. Each patient received alteplase 100 mg i.v. and i.v. heparin therapy; 58% of the patients were also given aspirin 81-325 mg/day. The data for the two institutions were combined; there was no control group. The mean +/- S.D. age of patients was 58 +/- 10 years; 75% were men. Treatment began at a mean of 181 +/- 111 min after symptom onset, including the time it took for the 96 patients whose symptoms began outside the hospital to reach the hospital. The mean hospital time required to initiate treatment was 89 +/- 65 min. The mean pharmacy time required to prepare and deliver alteplase was 12 +/- 6 min. The in-hospital mortality rate was 6.4%, the rate of patency of the infarct-related artery was 85% at a mean of seven days in the 95 patients who underwent coronary angiography, and the nonfatal reinfarction rate was 1.8%. Severe bleeding complications occurred in only two patients, and no patient suffered a stroke.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Use of alteplase for myocardial infarction in two community hospitals. 211 88

Thirteen (1.8%) of 708 patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I, II and III trials developed a stroke. Four strokes were hemorrhagic and nine were nonhemorrhagic. Of five prespecified risk factors for intracranial hemorrhage (age greater than 65 years, history of hypertension, history of prior cerebrovascular disease, aspirin use and acute hypertension), two patients had two risk factors and one patient had one risk factor. However, 80% of patients without intracranial hemorrhage had at least one risk factor and 31% had two risk factors. No patient with a prior stroke or transient ischemic attack (all greater than 6 months previously) had an intracranial hemorrhage. Of three prespecified risk factors for nonhemorrhagic stroke (atrial fibrillation, prior cerebrovascular disease and large anterior wall infarction), only the occurrence of a large anterior myocardial infarction (with ejection fraction less than 45%) was a predictor (p = 0.0015). The in-hospital death rate was 25% for patients with hemorrhagic stroke versus 11% for patients with a non-hemorrhagic stroke and 6% for those patients without a stroke. Furthermore, the hospital stay was greater than 50% longer in patients who had a stroke than in those who did not. Thus, intracranial hemorrhage remains an unpredictable risk in patients treated with thrombolytic therapy and cerebral infarction is related to anterior myocardial infarction and poor left ventricular function. Both types of stroke are associated with substantial morbidity and mortality.
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PMID:Stroke and acute myocardial infarction in the thrombolytic era: clinical correlates and long-term prognosis. 220 11

All thrombolytic agents convert plasminogen to plasmin, either directly, as in the case of urokinase, saruplase, and alteplase, or indirectly, as in the case of streptokinase. In the majority of recent clinical trials with streptokinase, a high-dose (0.7-1.5 million units), brief-duration (30-90 minutes) drug regimen has been used. After a mean interval of 4.2 hours from onset of chest pain to intravenous infusion of streptokinase, repeat angiography performed 60-90 minutes after the start of thrombolytic treatment gave a reperfusion rate of 43%; the corresponding figures for anistreplase, saruplase, and alteplase are 56%, 67%, and 69%. The patency rates obtained in similar studies with the same end point are 56% for streptokinase, 77% for anistreplase, 62% for urokinase, 71% for saruplase, and 75% for alteplase. The in-hospital mortality in randomized trials (six large studies in a total of 31,713 randomized patients) with intravenous high-dose streptokinase decreased from 12.0% in the control group to 9.47% in the streptokinase group. In a mortality study involving 1,258 patients randomized to intravenous anistreplase or placebo, the 30-day mortality was reduced by 47%, from 12.2% to 6.4%. In a large trial in which 5,011 patients were randomized to alteplase or placebo, the 30-day mortality was 7.2% compared with 9.8% in controls, a reduction of 27% by alteplase. In another trial, 721 patients were randomized to placebo or alteplase; all patients received acetylsalicylic acid and intravenous heparin. The 14-day mortality was only 2.8% in the alteplase group, 51% less than that in the control group. It is most important that the favorable impact on hospital survival be maintained at 1 year for any thrombolytic drug. Large-scale trials directly comparing mortality after alteplase, streptokinase, or anistreplase are being performed or are in the planning phase. The risk of bleeding exists with any thrombolytic agent; intracranial bleeding is the most serious risk. In a large trial in 5,011 patients with acute myocardial infarction, stroke occurred in 1.1% of alteplase-treated patients compared with 1.0% in placebo-treated controls. Haunting problems are residual stenosis of the coronary artery and reocclusion. Urgent angioplasty does not seem to be the right answer; more effective antithrombotic strategies have yet to be developed.
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PMID:Thrombolytic treatment in acute myocardial infarction. 211 32

12,490 patients from the GISSI-2 trial were randomly allocated to alteplase (recombinant tissue-type plasminogen activator, t-PA) or streptokinase (SK) and beginning 12 hours after the start of thrombolytic therapy to subcutaneous heparin or no heparin. No significant differences in hospital mortality were found between the two thrombolytic treatments as well as between heparin and no heparin administration. The incidence of major cardiac complications was also very similar in the different groups. The incidence of major bleedings was significantly higher in SK and heparin treated patients, whereas the overall incidence of stroke was similar in all groups. SK and t-PA with or without post-thrombolytic heparin treatment appear equally effective and safe for use in routine conditions care, in all patients with acute myocardial infarction (AMI).
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PMID:[Tissue-type plasminogen activator (t-PA): comments on results of the GISSI-2 study]. 212 81

Plasma tissue-type plasminogen activator and plasminogen activator inhibitor were determined during the acute, recovery and sequelae stages of patients with ischemic stroke by chromophoric substrate assay. The result showed that t-PA activity was elevated during the acute phase, remained elevated during the recovery stage and declined during the sequelae stage. Lowering of PAI activity was found during acute phase, which reversed during recovery phase and remained significantly elevated during sequelae stage. As a result, the ratio of PAI/t-PA fluctuated during different stages of the disease. Significant elevation of PAI and PAI/t-PA ratio during sequelae stage may be one of the risk factors of further thrombosis and contribute partly to the high relapsing rate of the disease. In addition, a positive correlation was found between PAI and serum cholesterol content.
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PMID:[Determination of plasma tissue type plasminogen activator and plasminogen activator inhibitor activity in patients with ischemic stroke]. 212 60

Thrombotic disorders such as myocardial infarction and stroke are the leading causes of death and disability in industrialized nations. Timely institution of thrombolytic therapy can achieve a reduction of infarct size, a preservation of left ventricular function, and a reduction in mortality. The administration of streptokinase, urokinase, and acylated plasminogen-streptokinase activator complex (APSAC) can be associated with a complete breakdown of the hemostatic system. Tissue-type plasminogen activator (t-PA) and single-chain urokinase-type plasminogen activator (scu-PA, prourokinase) are more fibrin specific; however, at the large dosages of activator needed for therapeutic efficacy, bleeding complications are still a problem. New approaches to optimizing the risk/benefit ratio for the patient by improving efficacy without sacrificing specificity include the use of synergistic combinations of plasminogen activators, mutants of t-PA and scu-PA, chimeric molecules, and antibody-targeted thrombolytic agents. The last approach opens the possibility of targeting several different components of the clot with either fibrinolytic or antiplatelet effector functions in one optimized molecule.
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PMID:Future directions in plasminogen activator therapy. 218 64


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