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Query: UNIPROT:P00750 (
PLA
)
16,800
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Fifty-nine consecutive patients presenting within 6 hours of the onset of symptoms of an acute myocardial infarction were treated with 150 mg of soluble aspirin orally, and either 70 or 100 mg of
alteplase
divided into 2 intravenous bolus injections separated by 30 minutes. Dosage regimens were either 20 followed by 50 mg (group A), 50 followed by 20 mg (group B), or 50 followed by 50 mg (group C). Coronary angiography 60 minutes after the first bolus showed infarct-related coronary artery patency (Thrombolysis in Myocardial Infarction score 2 or 3) in 13 of 16 (81%) patients in group A, 12 of 17 (71%) in group B, and 10 of 11 (91%) in group C (overall patency rate at 60 minutes: 35 of 44 [80%] patients; 95% confidence interval 68 to 91%). At 90 minutes, patency rates were 15 of 20 (75%) patients in both groups A and B, and 18 of 19 (95%) in group C (overall patency rate 48 of 59 [81%] patients; 95% confidence interval 72 to 91%). Residual thrombus was identified with the 90-minute angiogram in 7 patients in group A, 5 in group B, and 3 in group C. Although there was no statistically significant difference in patency between the 3 dosage regimens at either 60 or 90 minutes there was a trend toward increased patency and more complete thrombolysis at 90 minutes in group C. No episodes of bradyarrhythmia, hypotension or cerebrovascular bleeding were observed after double bolus therapy. There were 7 episodes (12%) of reocclusion, and 3 deaths (5%) within 1-month follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J
Cardiol
1991 Dec 15
PMID:Effectiveness of double bolus alteplase in the treatment of acute myocardial infarction. 174 56
The primary success rate for angioplasty of total occlusions is significantly worse than for subtotal lesions. Pharmacologic recanalization of total occlusions before angioplasty has the potential to improve the primary success rate. To determine the ability of recombinant
tissue-type plasminogen activator
(rt-PA) to recanalize occlusive thrombi before elective percutaneous transluminal coronary angioplasty, 12 patients with total occlusions, 100% obstruction and Thrombolysis in Myocardial Infarction (TIMI) grade 0 flow, and 5 with functional total occlusions, severe stenoses and TIMI grade 1 flow received an intracoronary infusion of rt-PA. The first 10 patients received 0.2 mg/min for 90 minutes, and the next 7 patients received 0.4 mg/min for 60 minutes. Flow improved by greater than or equal to 1 TIMI grade in 11 patients. Mean TIMI flow improved from 0.3 +/- 0.5 to 1.5 +/- 1.2 (p less than 0.0001). There was a significant improvement in severity of stenosis after rt-PA infusion by both digital caliper (99 +/- 2 vs 84 +/- 16%; p less than 0.0001) and quantitative videodensitometric area assessment (99 +/- 3 vs 94 +/- 6%; p less than 0.004). Angioplasty was successful in 16 of 17 patients (94%). There were 2 out-of-laboratory abrupt closures at 4 days; both were medically treated and 1 had a small myocardial infarction. Only 1 patient had a bleeding complication significant enough to need a transfusion. It is concluded that low-dose intracoronary rt-PA is effective at lysing thrombi less than 3 weeks old. This approach warrants further investigation since it may significantly improve the primary success rate of percutaneous transluminal coronary angioplasty in patients with occlusive thrombus.
Am J
Cardiol
1991 Dec 15
PMID:Experience with low-dose intracoronary recombinant tissue-type plasminogen activator for nonacute total occlusions before percutaneous transluminal coronary angioplasty. 174 61
A 42-year-old female with no cardiac risk factors had an acute anterolateral myocardial infarction treated with intravenous (IV)
tissue plasminogen activator (t-PA)
. Selective coronary cineangiography a week later revealed extensive dissection of the left anterior descending coronary artery (LAD) and its second diagonal branch. Sixteen months later, she is asymptomatic. This is the fifth reported case of spontaneous coronary artery dissection treated with thrombolytic therapy during the acute event with uneventful recovery.
Clin
Cardiol
1991 Jul
PMID:Thrombolytic therapy in spontaneous coronary artery dissection. 174 72
The adjunctive use of intravenous captopril with tissue plasminogen activator early during acute myocardial infarction offers theoretic advantages of diminishing left ventricular volume, preventing ventricular dilation and improving patient survival. To test the safety and efficacy of combined early administration of intravenous captopril and recombinant
tissue-type plasminogen activator
(rt-PA), 38 patients treated with rt-PA 3 +/- 0.3 h (mean +/- SE) after the onset of myocardial infarction were randomized to intravenous followed by oral captopril or placebo therapy. They underwent cardiac catheterization with measurement of hemodynamic variables and left ventricular function and determination of serum renin, angiotensin and aldosterone levels on days 1 and 7. Oral administration of the selected agent was continued for 3 months along with other antianginal medications, including nonangiotensin-converting enzyme inhibitor vasodilators. Repeat measurements of left ventricular function were obtained before hospital discharge and at 3 months. There were no significant differences in baseline clinical characteristics between groups. One patient in the captopril-treated group became hypotensive during intravenous therapy, requiring discontinuation of treatment. Compared with the placebo-treated group, the captopril-treated group had significant reductions at day 7 in left ventricular end-diastolic pressure (22.5 +/- 1.5 versus 16.3 +/- 1.6 mm Hg, p less than 0.01) and mean systemic arterial pressure (93.6 +/- 3.3 versus 86.2 +/- 2.7 mm Hg, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
J Am Coll
Cardiol
1991 Feb
PMID:A randomized placebo-controlled trial of combined early intravenous captopril and recombinant tissue-type plasminogen activator therapy in acute myocardial infarction. 182 97
Lipoprotein (a) [Lp(a)] and plasminogen share a high degree of homology as recently evidenced by amino acid and deoxyribonucleic acid analysis. As Lp(a) is enzymatically inactive, it has been suggested that high levels of Lp(a) may suppress the profibrinolytic activity at the cell surface and increase the risk for arteriosclerosis and thrombosis by competitive inhibition of plasminogen. The present study evaluated whether high levels of Lp(a) influence thrombolytic therapy in patients with acute myocardial infarction. Forty-one patients with acute myocardial infarction received a combination low-dose thrombolytic therapy with recombinant
tissue-type plasminogen activator
(rt-PA) and human single-chain urokinase-type plasminogen activator (scu-PA). This regimen did not induce plasminemia or a lytic state as indicated by well-maintained levels of fibrinogen. Coronary patency was assessed angiographically 90 minutes after initiation of treatment. Thrombolysis was successful in 30 and unsuccessful in 11 patients. Patients with high Lp(a) levels (greater than or equal to 25 mg/dl) (n = 9) responded equally well to thrombolytic therapy (8 of 9, patency 89%) as did patients with normal or low levels of Lp(a) (22 of 32, patency 70%, difference greater than 0.1). Lp(a) levels did not differ significantly between patients with successful and unsuccessful thrombolysis. Our results demonstrate that high levels of Lp(a) do not affect thrombolysis in patients with acute myocardial infarction when low-dose pharmacologic concentrations of rt-PA and scu-PA are applied in combination.
Am J
Cardiol
1991 Jun 15
PMID:Effects of lipoprotein (a) on success rate of thrombolytic therapy in acute myocardial infarction. 182 24
The demonstration in animals that recombinant
tissue-type plasminogen activator
produces prolonged thrombolysis after its clearance from the circulation has prompted a few pilot studies of bolus administration in patients. Alteplase (bolus dose of 70 mg) resulted in the highest recanalization rate in our previous pilot study comparing bolus doses of 50, 60 and 70 mg of
alteplase
in patients with acute myocardial infarction. The aim of the present trial was to assess the efficacy and safety of the same bolus dose in a larger number of patients. A further objective was to study the angiographic reocclusion rate at 12 to 24 hours in patients who had a recanalized infarct-related coronary artery at 90 minutes and were randomized at that time to a bolus dose or an infusion for 3 hours of 30 mg of
alteplase
. Sixty patients with acute myocardial infarction and angiographically documented total occlusion of the infarct-related coronary artery before thrombolysis were treated within 5 hours of onset of symptoms with an intravenous 70-mg bolus dose of
alteplase
(or 80 mg if body weight was greater than or equal to 90 kg). Each patient received 5,000 IU of heparin intraarterially and 100 mg of aspirin by mouth before administration of
alteplase
. Coronary angiography was repeated 60 and 90 minutes after
alteplase
administration. The recanalization rate of the infarct-related coronary artery was 55% (95% confidence interval, 43 to 66%) at 60 minutes and 48% (95% confidence interval, 37 to 60%) at 90 minutes. Pretreatment levels of lipoprotein (a) were not significantly related to recanalization.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J
Cardiol
1991 Jul 15
PMID:Coronary recanalization rate after intravenous bolus of alteplase in acute myocardial infarction. 182 74
Unstable angina pectoris remains a challenging acute ischemic syndrome to treat despite recent randomized trials that confirm the benefit of intravenous heparin. Coronary angioplasty, which is often required to treat the underlying arterial lesion, is adversely affected by the presence of thrombus with at least a 2-fold increase in abrupt closure. Four studies with heparin treatment prior to angioplasty indicate a reduction of abrupt vessel closure from 8-33% to 0-6% with apparent reduction of morbidity; no controlled trials are thus far available for heparin pretreatment. Another therapeutic alternative, thrombolytic therapy, has had quite equivocal results with several negative small studies. When angioplasty has been performed with thrombolytic therapy, a nonfibrin-specific
plasminogen activator
appears to be preferable. Newer studies that focus on thrombin inhibitors that bind to clot-bound thrombin and potent antiplatelet agents are in the early phase of clinical investigation. This review offers current recommendations for the integration of heparin, thrombolysis, and coronary angioplasty for unstable angina pectoris.
Am J
Cardiol
1991 Sep 03
PMID:Integration of anticoagulation, thrombolysis and coronary angioplasty for unstable angina pectoris. 189 61
Unstable angina is a clinical syndrome of recurrent myocardial ischemia. In some cases, this reflects episodic platelet activation and coronary thrombosis. Thus, the biosynthesis of thromboxane A2, which is largely derived from activated platelets, is increased, often coincident with chest pain. The major role of platelets in unstable angina may influence the response to plasminogen activators. Platelets increase the resistance of thrombi to lysis, by inducing clot retraction and cross-linking and by releasing inhibitors. Thus, coronary thrombi in unstable angina may be resistant to lysis. Furthermore, both
t-PA
and streptokinase cause platelet activation and thrombin formation in vivo, possibly via plasmin. Plasmin can activate platelets and factor V directly. These prothrombotic effects of plasminogen activators may limit their activity in unstable angina. At the very least, their therapeutic efficacy may be highly dependent on the coadministration of potent antiplatelet agents and anticoagulants.
Am J
Cardiol
1991 Sep 03
PMID:Platelet activation in the pathogenesis of unstable angina: importance in determining the response to plasminogen activators. 189 67
Ample evidence exists to support the major role of intracoronary thrombosis superimposed on a disrupted plaque in unstable angina. Consequently, thrombolytic treatment, already established to be highly beneficial in patients with acute myocardial infarction, might also be indicated in patients with unstable angina. The clinical response to thrombolytic treatment has been evaluated in several small-sized studies with inconsistent and somewhat deceiving results. Thus, the role of thrombolysis in the treatment of unstable angina is still controversial. Two ongoing large-scale, randomized, controlled trials, the Third Thrombolysis in Myocardial Infarction (TIMI III) in the United States testing recombinant
tissue-type plasminogen activator
and UNASEM in Europe testing anisoylated plasminogen-streptokinase activator complex will, it is hoped, solve the debate. At present, early thrombolysis might be considered for the treatment of the subset of patients with severe rest angina associated with transient ST-T ischemic changes.
Am J
Cardiol
1991 Sep 03
PMID:Thrombolysis in unstable angina: results of clinical studies. 189 74
Regional ventricular wall motion analysis utilizing three different methods was performed on predischarge left ventriculograms from 291 of 367 patients enrolled in a randomized trial of single chain recombinant
tissue-type plasminogen activator
(rt-PA), aspirin and heparin with and without immediate angioplasty in patients with acute myocardial infarction. With univariate analysis, no difference in regional wall motion variables between the two treatment groups was observed. However, with individual baseline risk assessment by multivariate linear regression analysis using baseline characteristics known to be related to left ventricular function after thrombolytic therapy or outcome of coronary angioplasty, or both, an excess of high risk patients in the invasive treatment group was detected. To adjust for this unequal distribution of baseline risk, multivariate linear regression analysis was performed. No benefit of immediate coronary angioplasty was observed after adjustment. Reocclusion or reinfarction, or both, occurred more frequently in the invasive than in the noninvasive treatment group (18% versus 13%, respectively). Among patients with a patent infarct-related vessel on angiography between days 10 and 22 and without reinfarction before angiography, there was a trend toward benefit from the invasive strategy, indicating that reocclusion and reinfarction might be responsible for the lack of benefit of the invasive strategy. This implies that immediate coronary angioplasty may be beneficial in selected patients, provided that these complications can be prevented.
J Am Coll
Cardiol
1991 Jan
PMID:Reasons for the lack of benefit of immediate angioplasty during recombinant tissue plasminogen activator therapy for acute myocardial infarction: a regional wall motion analysis. European Cooperative Study Group. 189 51
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