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1.
The fibrinolytic capacity of patients with acute myocardial infarction (AMI) is known to be impaired. The primary regulatory element of the fibrinolytic system is plasminogen activator inhibitor (PAI). It has been previously observed that there are 2 peaks in the plasma PAI level of AMI patients at 4h and 16h after thrombolytic therapy with recombinant tissue plasminogen activator (rtPA). Lanoteplase/SUN9216 is a mutant tPA with a biological half-life longer than that of rtPA. Thrombolytic therapy with mutant tPA or rtPA was carried out consecutively in 21 patients with AMI (8 patients as the mutant tPA group, and 13 patients as the rtPA group). The recanalization time of the mutant tPA group was significantly faster than that of the rtPA group (16.1 +/- 3.9 min vs 39.6 +/- 4.8 min, p<0.01). The PAI activity at 4h after the initiation of thrombolysis was significantly lower in the mutant tPA group than in the rtPA group (8.74 +/- 5.46IU/L vs 26.74 +/- 3.35 IU/L, p<0.01). There was a one mild peak in serial plasma PAI activity levels 24h after the initiation of thrombolysis. The results suggest that thrombolytic therapy with mutant tPA reduced the impairment of fibrinolytic capacity. The mutant tPA gives faster recanalization and lower PAI activity after successful thrombolysis, compared with rtPA.  相似文献   

2.
In the present study we compared the outcome of primary percutaneous coronary angioplasty (PTCA) (PTCA without prior or concomitant administration of thrombolytic drugs) in 82 consecutive patients with acute myocardial infarction (AMI) with the outcome of 82 AMI patients, who were treated with intravenous thrombolysis. The thrombolysis patients were prospectively matched to the angioplasty patients regarding age, sex, duration of symptoms and infarct localisation. The in-hospital mortality was 3.7% in the PTCA group versus 4.9% in the thrombolysis group. Thrombolysis-treated patients had increased use of diuretics and ACE-inhibitors as compared to PTCA-treated patients. The mean ejection fraction was 52 +/- 11% in the PTCA group versus 47 +/- 10% (p = 0.01) in the thrombolysis group. We conclude that initial Danish experience with primary PTCA is promising, and that this treatment may favourably affect the outcome of acute myocardial infarction.  相似文献   

3.
Both thrombolysis and percutaneous transluminal coronary angioplasty (PTCA) are effective methods for the treatment of acute myocardial infarction (AMI). In our centre we perform primary PTCA during the available schedule of the hemodynamics laboratory. In this article we compare the predischarge evolution of patients submitted to each therapeutic procedure. From January 1996 to June 1997, 298 patients were admitted with the diagnosis of AMI. Eighty-four patients (28%) were thrombolysed (TB group) and 30 patients (10%) underwent primary PTCA (PTCA group). There were no significant differences among the two groups concerning demographic characteristics: age (61 +/- 13--TB and 59 +/- 12 years--PTCA); sex (male 81%--TB; 83%--PTCA), risk factors and previous cardiac history. The mean time since the onset of symptoms until arrival at the hospital was 156 +/- 156 minutes for TB and 202 +/- 210 minutes for PTCA (p < 0.02). The delay since admission until the beginning of treatment was 100 +/- 88 minutes for TB and 119 +/- 142 minutes for PTCA. The primary success rate of PTCA was 94% and there were no complications during the procedure. During the hospital stay, 12 patients developed post-infarction angina in the TB group and two patients in the PTCA group; in 15 patients of the TB group a revascularization procedure was performed (surgery in 5 and PTCA in 10 patients); one patient suffered reinfarction in the TB group. Two patients of the TB group (2.4%) had intracranial hemorrhage; the in-hospital mortality was 9.5% in the TB group and 3.3% in the PTCA (p < 0.001). The mean in-hospital stay was 11 +/- 5.6 in the TB group and 7.8 +/- 2.5 days in the PTCA group (p = 0.055). In our experience, primary PTCA in AMI appeared to be a safe procedure with lower occurrence of coronary events and hemorrhagic complication, with an earlier hospital discharge when compared to thrombolysis.  相似文献   

4.
The long-term relative benefits of thrombolysis and mechanical reperfusion therapy following acute myocardial infarction (AMI) have not been established. The purpose of this study was to compare left ventricular function, left ventricular remodeling and late outcome after AMI for different reperfusion therapies. Thirty consecutive patients suffering their first anterior wall myocardial infarction with coronary stenoses limited to the left anterior descending coronary artery were studied. They included 10 patients who underwent intracoronary thrombolysis (ICT), 10 who underwent PTCA and 10 who underwent noninterventional medical treatment. All patients underwent coronary angiography (CAG) during the acute phase of AMI and also during the follow-up period, and left ventriculography during the follow-up period and clinical follow-up was performed (mean clinical follow-up period: 53 +/- 31 months). No significant difference in global ejection fraction was noted among the groups, although the end-diastolic volume index (EDVI) in the PTCA group (79.4 +/- 17.5 ml/m2) was significantly smaller than in the noninterventional (106.1 +/- 25.1 ml/m2) and ICT (107.9 +/- 28.3 ml/m2) group (p < 0.05). The regional wall motion index (RWMI) for the anterior region in the PTCA group (-2.7 +/- 0.8) was greater (p < 0.05) than in the noninterventional (-3.4 +/- 0.6) and ICT (-3.3 +/- 0.6) groups. A significant linear correlation was found between EDVI and % diameter stenosis and also between RWMI and % diameter stenosis following reperfusion (p = 0.01). There was no difference in the incidence of cardiac death, nonfatal reinfarction, bypass surgery or congestive heart failure among the groups. Disturbed left ventricular regional wall motion and remodeling benefit most from angioplasty because of prompt restoration of adequate blood flow. However, there was no difference in late outcomes following AMI among the three groups.  相似文献   

5.
The efficacies of direct percutaneous transluminal coronary angioplasty (PTCA) and thrombolysis for the treatment of acute myocardial infarction were investigated in 80 patients treated within 12 hours of the onset of myocardial infarction by either PTCA (39 patients) or thrombolytic therapy (41 patients) followed by conservative care. The therapeutic approach was selected according to the treatment strategy at each of the 16 participating centers before the admission of the patients. The two treatment groups were closely matched in clinical characteristics except for the history of hypertension which occurred more in the thrombolysis group (22/39 vs 12/41, p = 0.026). The mean time before starting reperfusion therapy from the onset of symptoms was shorter in the thrombolysis group (2.3 +/- 1.5 vs 5.3 +/- 5.7 hours, p = 0.0001). Chest pain resolved more quickly in the PTCA group. Serial changes in the mean numbers of abnormal Q waves and mean values of the sum of elevated ST-segments on the electrocardiograms were similar in both groups. Serial changes of wall motion abnormality index on echocardiograms were similar in both groups. Coronary angiography after 4 weeks showed the thrombolysis group had greater residual luminal stenosis in the infarct-related artery. Left ventriculography after 4 weeks showed the PTCA group had better mean ejection fraction (68.1 +/- 11.2% vs 58.7 +/- 14.2%, p = 0.0263). Death (3/39 vs 1/41) and cardiac events (6/39 vs 6/41) after 4 weeks were similar in both groups. There was no significant difference in death and cardiac events between these two groups. However, the PTCA group had less severe residual luminal stenosis in the infarct-related artery and better left ventricular function after 4 weeks than the thrombolysis group.  相似文献   

6.
BACKGROUND: It has been demonstrated that therapeutic ultrasound effects ultrasound thrombolysis by selectively disrupting the fibrin matrix of the thrombus. This study was conducted to evaluate the clinical feasibility of percutaneous transluminal coronary ultrasound thrombolysis in acute myocardial infarction (AMI). METHODS AND RESULTS: Consecutive patients (n = 15) with evidence of anterior AMI and Thrombolysis in Myocardial Infarction (TIMI) grade 0 or 1 flow in the left anterior descending artery underwent coronary ultrasound thrombolysis. Angiographic follow-up was performed after 10 minutes and 12 to 24 hours. Ultrasound induced successful reperfusion (TIMI grade 3 flow) in 87% of the patients. Adjunct percutaneous transluminal coronary angioplasty (PTCA) after ultrasound thrombolysis produced a final residual stenosis of 20 +/- 12% as determined by quantitative coronary angiographic analysis. There were no adverse angiographic signs or clinical effects during the procedure. There was no change in the degree of flow in any of the patients at the 12- to 24-hour angiograms. During hospitalization, 1 patient had recurrent ischemia on the fifth day after the procedure, and emergent catheterization revealed occlusion at the treatment site. The patient was successfully treated with PTCA. CONCLUSIONS: These results suggest that ultrasound thrombolysis has the potential to be a safe and effective catheter-based therapeutic modality in reperfusion therapy for patients with AMI and other clinical conditions associated with intracoronary thrombosis.  相似文献   

7.
The combination of hypertriglyceridemia and low high-density lipoprotein cholesterol (HDL-C) appears to be an excessively high risk factor for coronary artery disease (CAD). In the Helsinki study, both coronary events and mortality were decreased by gemfibrozil, especially in subjects with low HDL-C and high triglycerides (TG). On the other hand, it is known that high levels of TG can be associated with high levels of circulating plasminogen activator inhibitor (PAI), which is also a possible risk factor for CAD. The aim of the present study was to see: 1) whether the combination of low HDL-C and high TG is associated with a more impaired fibrinolytic response than in either isolated condition, and 2) whether gemfibrozil administration can improve fibrinolysis in patients with both high TG and low HDL-C. Twelve non-obese, non-diabetic subjects (eight men, four women; mean age 55 +/- 13 yrs) with low HDL-C (< 35 mg/dL men; < 45 mg/dL women) and high TG (mean 253.6 +/- 42.6 mg/dL) entered the study (Group A). Additionally fourteen comparable subjects with normal HDL-C were also investigated (Group B), plus 12 comparable subjects with isolated low HDL-C (Group C). Ten healthy people served as the control group. The following plasma fibrinolytic parameters were measured: tissue plasminogen activator antigen, PAI antigen and activity, euglobulin fibrinolytic activity (EFA) on fibrin plates, plasminogen and alpha-2-antiplasmin activities. All except the latter two values were also measured after venous occlusion (vo). In baseline conditions, patients in Groups A and B had higher EFA values before vo and higher PAI-1 antigen and alpha-2-antiplasmin levels after vo than those of controls or the subjects in Group C. The relationship between PAI antigen and PAI activity and TG was not confirmed in our population (n = 48). We also saw no interference due to HDL-C, while there was a significant relationship between EFA before vo and both TG and cholesterol. After gemfibrozil treatment (600 mg bid for 12 weeks), the lipid profiles of subjects with high TG and low HDL-C were significantly improved. There was also a slight reduction of PAI activity after vo, while the PAI-1 antigen had decreased significantly from baseline after vo (56.3 +/- 13 ng/mL before vo; 48.4 +/- 21 ng/mL after vo; P = 0.04). The higher risk of CAD in patients with low HDL-C and high TG might be in part related to impairment of fibrinolysis, which occurs in patients with isolated high TG. The close relationship existing between both TG and cholesterol levels and fibrinolytic activity confirm the key role of this latter process in the development of CAD.  相似文献   

8.
BACKGROUND: Activated platelets tether and activate myeloid leukocytes. To investigate the potential relevance of this mechanism in acute myocardial infarction (AMI), we examined cytokine induction by leukocyte-platelet adhesion and the occurrence of leukocyte-platelet conjugates in patients with AMI. METHODS AND RESULTS: We obtained peripheral venous blood samples in 20 patients with AMI before and daily for 5 days after direct percutaneous transluminal coronary angioplasty (PTCA) and in 20 patients undergoing elective PTCA. Throughout the study period, CD41 immunofluorescence of leukocytes (flow cytometry) revealed increased leukocyte-platelet adhesion in patients with AMI compared with control patients (mean +/- SE of fluorescence [channels] before PTCA: 77 +/- 16 versus 35 +/- 9; P = .003). In vitro, thrombin-stimulated fixed platelets bound to neutrophils and monocytes. Within 2 hours, this resulted in increased mRNA for interleukin (IL),1 beta, IL-8, and monocyte chemoattractant protein (MCP)-1 in unfractionated leukocytes. After 4 hours, IL-1 beta and IL-8 concentration of the cell-free supernatant had increased by 268 +/- 36% and 210 +/- 7%, respectively, and cellular MCP-1 content had increased by 170 +/- 8%. Addition of activated platelets to adherent monocytes had a similar effect and was associated with nuclear factor-kappa B activation. Inhibition of binding by anti-P selectin antibodies reduced the effect of activated platelets on cytokine production. CONCLUSIONS: In patients with AMI, leukocyte-platelet adhesion is increased. Binding of activated platelets induces IL-1 beta, IL-8, and MCP-1 in leukocytes. Our findings suggest that leukocyte-platelet adhesion contributes to the regulation of inflammatory responses in AMI.  相似文献   

9.
BACKGROUND: Elevated levels of plasminogen activator inhibitor 1 (PAI-1) have been associated with the occurrence of thrombotic disease, and inhibition of PAI-1 activity in vivo resulted in enhanced thrombolysis and a reduction in reocclusion. Besides monoclonal antibodies and peptides, no suitable agents that are able to block PAI-1 activity are available to date. The present study was designed to test the interaction between a nonantibody, nonpeptide, diketopiperazine-based inhibitor of PAI-1, XR5118, and PAI-1 and to assess the effect of XR5118 on PAI-1 activity in vitro and on in vivo thrombolysis and thrombus growth in an experimental thrombosis model in rabbits. METHODS AND RESULTS: The binding site of XR5118 on the PAI-1 molecule was studied by competitive binding experiments with mapped anti-PAI-1 monoclonal antibodies by use of surface plasmon resonance experiments. XR5118 selectively and competitively inhibited binding of the PAl-1-inhibiting monoclonal antibody CLB-2C8, indicating that binding of XR5118 to PAI-1 takes place at the area between amino acids 110 and 145 of the PAI-1 molecule, which is known to be involved with the binding of PAI-1 to tissue plasminogen activator (TPA). Incubation of plasma or platelet releasate with XR5118 resulted in a dose-dependent inhibition of PAI-1 activity. Systemic infusion of XR5118 induced a significant reduction in plasma PAI-1 activity levels from 23.7+/-4.9 to 10.9+/-3.4 IU/mL. Administration of XR5118 resulted in a significant, twofold increase in endogenous thrombolysis compared with the control. Thrombus growth in rabbits receiving both XR5118 and rTPA was significantly attenuated compared with rabbits receiving rTPA alone (13.5+/-2.7% versus 19.9+/-3.8%, respectively). CONCLUSIONS: XR5118 binds to PAI-1 and reduces plasma PAI-1 activity levels. Furthermore, XR5118 promotes endogenous thrombolysis and inhibits thrombus accretion and is the first nonpeptide compound with significant anti-PAI-1 activity in vivo in these models.  相似文献   

10.
BACKGROUND: AMI reperfusion by thrombolysis does not improve TIMI flow and LV function. The role of infarct-related artery (IRA) stenosis and superimposed changes in coronary vasomotor tone in maintaining LV dysfunction must be elucidated. METHODS AND RESULTS: Forty patients underwent diagnostic angiography 24 hours after thrombolysis. Seventy-two hours after thrombolysis, the culprit lesion was dilated with coronary stenting. During angioplasty, LV function was monitored by transesophageal echocardiography. Percent regional systolic thickening was quantitatively assessed before PTCA, soon after stenting, 15 minutes after stenting, and after phentolamine 12 microg/kg IC (n=10), the alpha1-blocker urapidil 600 microg/kg IV (n=10), or saline (n=10). Ten patients pretreated with beta-blockers received urapidil 10 mg IC. Coronary stenting significantly improved thickening in IRA-dependent and in non-IRA-dependent myocardium (from 27+/-15% to 38+/-16% and from 40+/-15% to 45+/-15%, respectively). Simultaneously, TIMI frame count decreased from 39+/-11 and 40+/-11 in the IRA and non-IRA, respectively, to 23+/-10 and 25+/-7 (P<0.05). Fifteen minutes after stenting, thickening worsened in both IRA- and non-IRA-dependent myocardium (to 19+/-14% and 28+/-14%, P<0.05), and TIMI frame count returned, in both the IRA and non-IRA, to the values obtained before stenting. Phentolamine and urapidil increased thickening to 36+/-17% and 41+/-14% in IRA and to 48+/-11% and 49+/-17% in non-IRA myocardium respectively, and TIMI frame count decreased to 16+/-6 and to 17+/-5, respectively. Changes were attenuated with beta-blocker pretreatment. CONCLUSIONS: Our finding that alpha-adrenergic blockade attenuates vasoconstriction and postischemic LV dysfunction supports the hypothesis of an important role of neural mechanisms in this phenomenon.  相似文献   

11.
BACKGROUND: The relation between residual myocardial viability after acute myocardial infarction (AMI) and ventricular remodeling has yet to be fully elucidated. We hypothesized that the presence of residual viability would favorably influence left ventricular remodeling after AMI and that serial changes in left ventricular dimensions might be related to the extent of myocardial viability in the infarct zone. METHODS AND RESULTS: Ninety-three patients with a first AMI successfully treated with primary coronary angioplasty underwent two-dimensional echocardiography within 24 hours of admission and low-dose dobutamine echocardiography at a mean of 3 days after AMI. Two-dimensional echocardiography and coronary angiography were obtained in all patients 1 and 6 months after coronary angioplasty. On the basis of dobutamine echocardiography responses, patients were divided in two subsets: those with (n=48; group I) and those without (n=45; group II) infarct-zone viability. There was no difference in minimal lesion diameter and infarct-related artery patency at 1 and 6 months between the two groups. Group II patients had significantly greater end-diastolic (76+/-18 versus 53+/-14 mL/m2; P<.0003) and end-systolic (42+/-17 versus 22+/-11 mL/m2; P<.0003) volumes at 6 months than did patients in group 1. The extent of infarct-zone viability was significantly inversely correlated with percent changes in end-diastolic volumes at 6 months (r=-.66; P<.000001) and was the most powerful independent predictor of late left ventricular dilation. CONCLUSIONS: After reperfused AMI, the degree of left ventricular dilation, when it occurs, is inversely related to the extent of residual myocardial viability in the infarct zone. Thus, the absence of residual infarct-zone viability discriminates patients who develop progressive left ventricular dilation after reperfused AMI from those who maintain normal left ventricular geometry.  相似文献   

12.
OBJECTIVE: To compare the efficacy of Yagin, a factor Xa inhibitor derived from the leech Hirudo medicinalis, with those of heparin and hirudin as adjuncts to recombinant tissue-type plasminogen activator (rTPA) thrombolysis in a rabbit thrombosis model. METHODS: Thirty-one animals were allocated randomly to three groups, all administered four boluses of 0.25 mg/kg rTPA every 10 min for 30 min, 17 mg/kg aspirin intravenously, and heparin (as a 100 IU/kg bolus followed by infusion of 50 IU/kg heparin per h), hirudin (as a 2 mg/kg bolus followed by infusion of 1 mg/kg hirudin per h), or Yagin (as an 80 micrograms/kg bolus followed by infusion of 43 micrograms/kg Yagin per h). RESULTS: Administration of Yagin was associated with a significant acceleration of the reflow time, this time being 14.5 +/- 1.2 min with Yagin, 25.8 +/- 5.2 min with heparin (P < 0.0001, versus Yagin), and 28.7 +/- 16.0 min with hirudin (P = 0.012, versus Yagin). Overall patency did not differ significantly among the three groups. CONCLUSIONS: At the indicated single doses, inhibition of factor Xa by a relatively low concentration of Yagin was found to be superior than that with either heparin or hirudin for accelerating rTPA thrombolysis.  相似文献   

13.
OBJECTIVES: This study sought to assess the maximal rate of acute Thrombolysis in Myocardial Infarction (TIMI) grade 3 patency that can be achieved in unselected patients. BACKGROUND: Early and complete (TIMI grade 3 flow) reperfusion is an important therapeutic goal during acute myocardial infarction. However, thrombolysis, although widely used, is often contraindicated or ineffective. The selective use of primary and rescue percutaneous transluminal coronary angioplasty (PTCA) may increase the number of patients receiving reperfusion therapy. METHODS: A cohort of 500 consecutive unselected patients with acute myocardial infarction were prospectively treated using a patency-oriented scheme: Thrombolysis-eligible patients received thrombolysis (n = 257) and underwent 90-min angiography to detect persistent occlusion for treatment with rescue PTCA. Emergency PTCA (n = 193) was attempted in patients with contraindications to thrombolysis, cardiogenic shock or uncertain diagnosis and in a subset of patients admitted under "ideal conditions." A small group of patients (n = 38) underwent acute angiography without PTCA. Conventional medical therapy was used in 12 patients with contraindications to both thrombolysis and PTCA. RESULTS: Ninety-eight percent of patients received reperfusion therapy (thrombolysis, PTCA or acute angiography), and angiographically proven early TIMI grade 3 patency was achieved in 78%. Among patients with TIMI grade 3 patency, thrombolysis alone was the strategy used in 37%, emergency PTCA in 40% and rescue PTCA after failed thrombolysis in 15%; spontaneous patency occurred in 8%. CONCLUSIONS: Reperfusion therapy can be provided to nearly every patient (98%) with acute myocardial infarction. Rescue and direct PTCA provided effective early reperfusion to patients in whom thrombolysis failed or was excluded.  相似文献   

14.
24 model rabbits with femoral arterial thrombosis were divided into two groups: the treatment group consisting of 12 rabbits which received API0134, and the control group composed of another 12 rabbits. 2 hours after recanalization by urokinase thrombolysis, reocclusion occurred only in 1/12 vessel (8%) with incomplete occlusion in the treated group, but in 8/12 (67%) with complete occlusion in the control group as assessed by angiograsphy. Pathological examination of specimen taken 24 hours after thrombolysis showed that 6/12 (50%) of the treated group gave the evidence of thrombus occlusion, and milder intimal injury and less adhered blood cells than in the control group, 83% of which had thrombus occlusion. In comparision with the control group, the function of platelet in the treated group demonstrated lower platelet aggregation rate (PAgR) and plasma thromboxane A2 (TXA2) level, higher prostacyclin (PGI2) and plasminogen activator (PA) activity as well as lower plasminogen activator inhibitor (PAI) activity. From the above it may be concluded that the preventive effect of API0134 on reocclusion might be due to inhibition of platelets aggregation and promotion of fibrinolysis.  相似文献   

15.
BASIC PROBLEM AND OBJECTIVE: Percutaneous transluminal coronary angioplasty (PTCA) is being increasingly considered as an alternative to thrombolytic treatment of acute myocardial infarction. Studies performed so far, some on selected groups of patients, have produced high initial results of success. This prospective study was undertaken to determined primary success, complications and recurrence after primary PTCA in acute myocardial infarction (AMI). PATIENTS AND METHODS: Primary treatment in the form of immediate PTCA of the infarct vessel was undertaken in 111 patients (84 men, 27 women; mean age 58.6 +/- 10.3 years) with AMI. PTCA was judged successful if the infarct vessel had been reopened to perfusion grade 3 and restenosis was < 50%. No thrombolytic treatment was given, but heparin infusions were given during and for 24-48 hours after the procedure. 13 patients (11.7%) were in cardiogenic shock or required cardiopulmonary resuscitation for infarct-related arrhythmias. RESULTS: The primary success rate of PTCA for the whole group was 91% (101 of 111 patients), but only 77% (ten of 13) among patients in cardiogenic shock and (or) after resuscitation. Acute re-occlusion (0-6 days after PTCA) occurred in seven patients. Eight patients (7.2%) died during the hospital phase (0-4 weeks), seven of whom had been in shock or required resuscitation (death rate 54%). The overall complication rate of the intervention was 6.3%. No emergency aortocoronary bypass was necessary. Repeat coronary angiography was performed in 71 of the 101 successfully treated patients 6 or 12 weeks after the PTCA. Re-occlusion was demonstrated in four (5.6%), a restenosis of more than 50% in 25% of patients. Mean left ventricular ejection fraction, obtained by planimetry from the levocardiogram was 58.6 +/- 9.3%. CONCLUSION: PTCA, performed immediately after acute myocardial infarction is an effective therapeutic measure with a high primary success rate.  相似文献   

16.
BACKGROUND: The vasoreactivity after direct percutaneous transluminal coronary angioplasty (PTCA) in patients with previous myocardial infarction remains unknown. We examined the constrictor response to ergonovine of the infarct-related coronary artery in comparison with that of noninfarct-related coronary artery after angioplasty. METHODS: Ergonovine was administered intravenously to 17 patients with previous myocardial infarction (group I) and to 21 patients with stable angina (group II) 1 year after PTCA. The effects of ergonovine on lumen diameter were analysed quantitatively at the PTCA segment, nonPTCA segment (proximal to the PTCA segment), and nonPTCA artery. RESULTS: The ergonovine-induced decrease in minimal lumen diameter at the PTCA segment was significant in group I (decrease from 2.12 +/- 0.56 to 1.39 +/- 0.74 mm, P < 0.01), but not in group II (decrease from 1.60 +/- 0.35 to 1.43 +/- 0.33 mm, NS). Patients in group I showed a constrictor response at the nonPTCA artery (decrease in diameter from 2.54 +/- 0.90 to 1.94 +/- 0.77 mm, P < 0.01), and a tendency to constrict at the nonPTCA segment (2.56 +/- 0.67 to 2.11 +/- 0.66 mm, P = 0.06), whereas those in group II showed no significant constrictor response to ergonovine at any of the three segments examined. The changes in diameter at the three segments in patients in group I were significantly greater than those in group II (all P < 0.01). Subtotal coronary spasm at the PTCA segment was provoked only in three patients in group I (18%). CONCLUSIONS: The constrictor response to ergonovine of the infarct-related coronary artery was enhanced compared with that of the noninfarct-related coronary artery. This difference in coronary vasoreactivity at the angioplasty segment may be due to previous hypersensitivity of the smooth muscle.  相似文献   

17.
BACKGROUND: Thrombolysis to normal flow in patients with acute myocardial infarction preserves left ventricular function and decreases mortality. Failure of early reperfusion, reocclusion, or residual thrombus may be due to concurrent activation of the platelet-coagulation system. Thus, we hypothesized that the best concomitant antithrombotic therapy (recombinant [r]-hirudin, heparin, or aspirin) will maximally accelerate thrombolysis by r-tissue-type plasminogen activator (rTPA) and reduce residual thrombus. METHODS AND RESULTS: Occlusive thrombi were formed in the carotid arteries of 29 pigs (by balloon dilatation followed by endarterectomy at the site of injury-induced vasospasm) and matured for 30 minutes before rTPA was started, with or without antithrombotic therapy. Thrombolysis was assessed with the use of angiography and measurement of residual thrombus. Pigs were allocated to one of five treatments: placebo, rTPA, rTPA plus r-hirudin, rTPA plus heparin, or rTPA plus intravenous aspirin. No placebo-treated pig reperfused. Two of six animals treated with rTPA alone reperfused compared with seven of seven animals treated with rTPA plus r-hirudin (reperfusion time, 33 +/- 10 minutes), six of seven animals treated with rTPA plus heparin (reperfusion time, 110 +/- 31 minutes), and two of six animals with rTPA plus aspirin. The activated partial thromboplastin time was prolonged in only the rTPA plus r-hirudin group (25 +/- 0.1 times baseline) and the rTPA plus heparin group (5.3 +/- 0.2 times baseline). Residual 111In-platelet and 125I-fibrin(ogen) depositions were lower in the heparin-treated group and lowest in the r-hirudin-treated group (heparin versus hirudin, respectively; incidence of residual macroscopic thrombus was six of six animals versus two of seven [P = .01]; 125I-fibrin(ogen), 170 +/- 76 versus 48 +/- 6 x 10(6) molecules/cm2 [P = .02]; 111In-platelets, 47 +/- 15 versus 13 +/- 2 x 10(6)/cm2, P = .10). No pigs developed spontaneous bleeding. CONCLUSIONS: Thrombin inhibition with heparin or r-hirudin significantly accelerated thrombolysis of occlusive platelet-rich thrombosis, but only the best antithrombotic therapy (r-hirudin) eliminated or nearly eliminated residual thrombus.  相似文献   

18.
A limitation of current fibrinolytic drugs is the procoagulant activity induced by their administration. TNK is a mutant of tissue plasminogen activator (t-PA) with high fibrin specificity, resistance to plasminogen activator inhibitor-1 and slow plasma clearance, which is administered in a single intravenous bolus. In this study we investigated the procoagulant effect of TNK-t-PA compared to streptokinase, rt-PA or no thrombolysis. Twenty-nine patients with acute myocardial infarction, treated within 6 hours of symptom onset with 1.5 MU streptokinase over 1 hour (n = 12), 100 mg rt-PA in 1.5 hours (n = 12) or 30-40 mg TNK-t-PA in 15 s (n = 5), were studied and compared to 7 patients with contraindications to thrombolysis (control group). All patients received a similar i.v. heparin regimen for at least 24 hours. Blood samples were drawn before the start of treatment (time 0) and after 2 hours. Thrombin formation was assessed as plasma concentrations of thrombin-antithrombin complex (TAT). The four patient groups did not differ significantly in age, sex, time to treatment, infarct location, and TAT values at time 0 (mean value +/- standard error of the mean 9 +/- 2 micrograms/l). Mean TAT levels at 2 hours were 26 +/- 6 micrograms/l in streptokinase treated patients (p = 0.005 vs time 0), 21 +/- 4 micrograms/l in rt-PA treated patients (p < 0.05 vs time 0), 5 +/- 0.6 micrograms/l in TNK treated patients, and 4 +/- 0.4 micrograms/l in controls (NS vs time 0 for TNK and controls). In conclusion, our data suggest that, in patients with acute myocardial infarction, bolus TNK-t-PA, unlike streptokinase or rt-PA infusions, is devoid of procoagulant effects, evaluated 2 hours after its administration.  相似文献   

19.
BACKGROUND: In patients with pulmonary embolism, thrombi resist fibrinolysis induced by plasminogen activators. Because the molecular basis of this thrombus resistance is poorly understood, we used a potent inhibitor to examine the potential role of alpha 2-antiplasmin (alpha 2AP) in experimental pulmonary embolism. METHODS AND RESULTS: Lysis of experimental pulmonary emboli was measured 4 hours after embolization in anesthetized ferrets. All animals received heparin (100 U/kg). Five experimental groups were studied: (1) no recombinant tissue plasminogen activator (rTPA); (2) rTPA at 1 mg/kg; (3) rTPA at 2 mg/kg; (4) rTPA at 1 mg/kg plus a control monoclonal antibody (MAb); and (5) rTPA at 1 mg/kg plus an alpha 2AP inhibitor (MAb 77A3). In comparison with ferrets receiving no rTPA (15.6 +/- 10.5% lysis, mean +/- SD), rTPA-treated groups showed significantly greater lysis (P < .01). Animals treated with rTPA and alpha 2AP inhibitor (56.2 +/- 4.7% lysis) showed significantly greater lysis than all other treatment groups, including ferrets treated with the same dose of rTPA alone (38.5 +/- 6.3%, P < .01), with twice the rTPA dose alone (45.0 +/- 6.5%, P < .05), or with a control MAb (35.2 +/- 4.6%, P < .01). The combination of rTPA treatment and alpha 2AP inhibition caused no consumption of fibrinogen. CONCLUSIONS: Inhibition of alpha 2AP significantly amplified the lysis of experimental pulmonary emboli by rTPA without increasing fibrinogen consumption. These results suggest that alpha 2AP may play an important role in thrombus resistance in patients with venous thromboembolism.  相似文献   

20.
Most patients in acute myocardial infarction (AMI) undergo emergent coronary angiography (CAG). However, when to analyze lipoprotein profiles in AMI is not clear. To determine whether lipoprotein profiles change during catheterization, we measured serum lipid and apolipoprotein concentrations in 65 patients (51 men and 14 women) before and after catheterization. Heparin was injected at 50 units/kg for CAG and 200 units/kg for percutaneous transluminal coronary angioplasty (PTCA). We found that cholesterol and triglyceride decreased by 9.4% (P < 0.001) and 53.1% (P < 0.001), respectively, after catheterization. Apolipoproteins also decreased significantly. Variables decreased two to five times more after PTCA than after CAG. Lipoprotein lipase mass was higher after PTCA (267.8 +/- 135.3 micrograms/L) than after CAG (93.3 +/- 48.4 micrograms/L; P < 0.05). In conclusion, lipoprotein profiles change during catheterization. We recommend avoiding analysis of lipoprotein profiles after emergent CAG in AMI.  相似文献   

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