The European Myocardial Infarction Project: an assessment of pre-hospital thrombolysis.

The use of thrombolytic agents in patients with suspected myocardial infarction has been shown to reduce early and long-term mortality by about 20%, and it has been suggested that since time is an important factor, pre-hospital treatment would give better results. However, health deciders need reliable data on which to base future policies concerning this. The European Myocardial Infarction Project was a European Economic Community-supported double-blind study designed to evaluate the efficacy and safety of pre-hospital early thrombolytic treatment in patients with suspected myocardial infarction compared with the same treatment given later in a hospital setting. A total of 5469 patients in 16 countries were randomised by 198 mobile emergency units to receive either pre-hospital treatment with anistreplase, the thrombolytic agent used, followed by placebo after hospital admission (pre-hospital group; 2750 patients), or placebo followed by anistreplase (hospital group; 2719 patients). The median time delay between the injections was 55 min. A non-significant decrease in 30-day mortality was observed in favour of the pre-hospital group (13%: P = 0.08), whereas the decrease in cardiac death observed, also in favour of the pre-hospital group, was on the borderline of significance (16%; P = 0.049). Although some complications occurred more frequently in the pre-hospital group in the pre-hospital period, the overall incidence for serious complications was similar for both groups. These results show that the pre-hospital thrombolytic strategy in patients with suspected myocardial infarction is both effective and safe when performed by well-equipped well-staffed mobile emergency units.

Prehospital thrombolysis in rural emergency room and subsequent transport to a coronary care unit: Ravenna Myocardial Infarction (RaMI) trial.

OBJECTIVE: To assess the feasibility, safety and efficacy of thrombolysis in the Emergency Room of a Rural Hospital with no Coronary Care Unit, and subsequent transfer to the Coronary Care Unit of a City Hospital. DESIGN: Prospective study, controlled with two parallel groups of consecutive patients (Group 1: Rural Hospital, Group 2: CCU Ravenna) and administration of Anistreplase 30 intravenous unit. SETTING: Rural Emergency Rooms which transmitted the electrocardiogram by cardiotelephone to the Ravenna Coronary Care Unit (average distance 35 km; range: 17-50 km). PATIENTS: 280 (Group 1: 102 patients, Group 2: 178 patients) with suspected acute myocardial infarction and with no contra-indications to fibrinolysis, within 6 h of onset of symptoms. MAIN OUTCOME MEASURES: time saving, accuracy of diagnosis, adverse events, left ventricular function and survival. RESULTS: the median pain to needle time was 90' in Group 1 and 165' in Group 2 (P < 0.001). Accuracy of diagnosis for acute myocardial infarction was 91% and 100%, respectively. Complications were rare and none occurred during transfer. The creatine phosphokinase peak of Group 1 was lower than Group 2 (1389 vs. 2186 IU/l; P < 0.001). The echocardiographic Wall Motion Abnormality Score Index of Group 1 was lower than Group 2 (3.571 vs. 5.589; P < 0.001). Mortality at 35 days in Group 1 was 7.5% vs. 10.7% in Group 2 (-30%; P = n.s.). CONCLUSIONS: The Emergency Room physician, in close collaboration with the cardiologist, supplied a very high standard of pre-Coronary Care Unit diagnosis and therapy. Administration of Anistreplase in the rural Emergency Room brought about a significant reduction of pain to needle time, a significant improvement in left ventricular function and a reduction in mortality.

Current issues concerning thrombolytic therapy for acute myocardial infarction.

Data are now available from three large-scale randomized trials that directly compare the risks and benefits of thrombolytic agents in acute myocardial infarction. In the interpretation of results from the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-2) trial and its International Extension, the Third International Study of Infarct Survival (ISIS-3), and the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-1) trial, there are areas of both agreement and controversy. It is generally agreed that the agents most commonly used in the United States--tissue-type plasminogen activator (t-PA), streptokinase and anisoylated plasminogen streptokinase activator complex (APSAC)--all reduce mortality when given to patients with acute evolving myocardial infarction. Further, it is clear that thrombolytic therapy given to such patients presenting up to 12 h after onset of symptoms reduces the mortality rate by approximately 20%, that aspirin therapy for patients presenting up to 24 h reduces the mortality rate by approximately 23% and that the benefits of thrombolytic therapy and aspirin are additive. Finally, and of most importance, the earlier administration as well as the more widespread use of thrombolytic therapy and aspirin would save many more lives. The totality of evidence clearly indicates that streptokinase produces significantly fewer strokes and cerebral hemorrhages than either t-PA or APSAC. Whether or not accelerated t-PA has a small advantage for mortality is less conclusive.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug eruptions and isotypic antibody responses to streptokinase after infusions of anisoylated plasminogen-streptokinase complex (APSAC, anistreplase).

BACKGROUND: Anisoylated plasminogen-streptokinase complex (APSAC, anistreplase) is a thrombolytic agent (131 kd) used for treatment of myocardial infarction. Like its principal antigenic determinant, streptokinase, APSAC has been reported to cause a variety of allergic reactions. OBJECTIVE: This study was intended to determine any association between isotypic antibody responses to streptokinase and observed allergic reactions to APSAC. METHODS: We measured sequential IgM, IgG, IgA, and IgE antistreptokinase serum levels in 21 patients who received APSAC or tissue-type plasminogen activator in a prospective, double-blind study. RESULTS: Of 11 patients who received APSAC, four had maculopapular rashes and one had urticaria; those with maculopapular rashes had significantly higher rises in serum IgM, IgG, IgA, and IgE antistreptokinase levels. We could not, however, define a temporal relationship between rises in antistreptokinase levels of a particular isotype and the onset of maculopapular rashes. The patient who had urticaria had no antistreptokinase responses but had also received several other potentially causal drugs. None of 10 patients who received tissue-type plasminogen activator had allergic reactions or significant rises in serum antistreptokinase levels. CONCLUSION: The more vigorous panisotypic antistreptokinase responses observed in patients who received APSAC and had maculopapular rashes may reflect generalized immune system activation that included other immune responses (such as cell-mediated hypersensitivity) that were responsible for these reactions.

Assessment of the practicality and safety of thrombolysis with anistreplase given by general practitioners.

BACKGROUND: Recent guidelines recommend that patients with obvious acute myocardial infarction receive thrombolysis, unless contraindicated, within 60-90 minutes of summoning assistance. If this target is to be achieved, an increasing number of general practitioners are likely to be involved in the administration of thrombolytic agents. AIM: This study aimed to assess the practicality and safety of thrombolysis with anistreplase when given by general practitioners. METHOD: An observational study was conducted in 805 general practices throughout the United Kingdom. Between March 1991 and September 1992, a total of 3383 patients with a clinical diagnosis of myocardial infarction were recruited--888 by 344 general practitioners who wished to include anistreplase in their management of myocardial infarction ('user' group) and 2495 by 776 general practitioners who did not wish to use anistreplase but who were willing to provide information about their cases ('comparison' group). RESULTS: More than half the patients were seen within two hours of onset of symptoms. A high frequency of contra-indications to thrombolysis, diagnostic uncertainty, and other, mainly practical, reasons limited the number of occasions on which anistreplase was administered. Thus, only 310 patients were given anistreplase in the community. The general practitioners in the study used anistreplase safely. Their diagnostic accuracy was high (of the 310 patients given anistreplase 69% had a definite, possible or probably myocardial infarction, 4% a definite non-cardiac diagnosis), the number of patients given anistreplase in spite of a documented contraindication was small (seven patients), and the doctors appeared to be aware of potential bleeding problems associated with thrombolysis. In all cases, the complications of acute myocardial infarction appeared to be managed appropriately. CONCLUSION: General practitioners can use anistreplase both appropriately and safely in the early management of acute myocardial infarction. Recognized contraindications to thrombolysis and practicalities of diagnosis and drug administration may, however, limit the number of occasions on which anistreplase is used.

Comparison of front-loaded recombinant tissue-type plasminogen activator, anistreplase and combination thrombolytic therapy for acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) 4 trial.

OBJECTIVES: The aim of our study was to determine a superior thrombolytic regimen from three: anistreplase (APSAC), front-loaded recombinant tissue-type plasminogen activator (rt-PA) or combination thrombolytic therapy. BACKGROUND: Although thrombolytic therapy has been shown to reduce mortality and morbidity after acute myocardial infarction, it has not been clear whether more aggressive thrombolytic-antithrombotic regimens could improve the outcome achieved with standard regimens. METHODS: To address this issue, 382 patients with acute myocardial infarction were randomized to receive in a double-blind fashion (along with intravenous heparin and aspirin) APSAC, front-loaded rt-PA or a combination of both agents. The primary end point "unsatisfactory outcome" was a composite clinical end point assessed through hospital discharge. RESULTS: Patency of the infarct-related artery (Thrombolysis in Myocardial Infarction [TIMI] grade 2 or 3 flow) at 60 min after the start of thrombolysis was significantly higher in rt-PA-treated patients (77.8% vs. 59.5% for APSAC-treated patients and 59.3% for combination-treated patients [rt-PA vs. APSAC, p = 0.02; rt-PA vs. combination, p = 0.03]). At 90 min, the incidence of both infarct-related artery patency and TIMI grade 3 flow was significantly higher in rt-PA-treated patients (60.2% had TIMI grade 3 flow vs. 42.9% and 44.8% of APSAC- and combination-treated patients, respectively [rt-PA vs. APSAC, p < 0.01; rt-PA vs. combination, p = 0.02]). The incidence of unsatisfactory outcome was 41.3% for rt-PA compared with 49% for APSAC and 53.6% for the combination (rt-PA vs. APSAC, p = 0.19; rt-PA vs. combination, p = 0.06). The mortality rate at 6 weeks was lowest in the rt-PA-treated patients (2.2% vs. 8.8% for APSAC and 7.2% for combination thrombolytic therapy [rt-PA vs. APSAC, p = 0.02; rt-PA vs. combination, p = 0.06]). CONCLUSIONS: Front-loaded rt-PA achieved significantly higher rates of early reperfusion and was associated with trends toward better overall clinical benefit and survival than those achieved with a standard thrombolytic agent or combination thrombolytic therapy. These findings support the concept that more rapid reperfusion of the infarct-related artery is associated with improved clinical outcome.

[Recurrent ST segment elevations in continuous ECG analysis in the acute phase of myocardial infarct treated with thrombolytic therapy]. / Auftreten erneuter ST-Strecken-Hebungen bei der kontinuierlichen EKG-Analyse in der akuten Phase des Myokardinfarkts mit thrombolytischer Behandlung.

Early fluctuations of the ST-segment elevation indicating intermittent opening and reocclusion of the infarct artery has been well documented by angiographic monitoring in individual acute myocardial infarction patients undergoing thrombolytic therapy. However, the frequency of such episodes has not been studied in a consecutive patient group. Furthermore, it is not known what impact this finding has on the reinfarction risk during hospitalization and on left ventricular healing. The present investigation included 79 patients with acute myocardial infarction (pain < or = 6 h). Continuous Holter monitoring of the infarct-related ST elevation was initiated before or directly after starting thrombolytic therapy. During the 24-h observation period, 34 patients (43%) showed episodes of recurrent ST elevation after an initial resolution (group 1). Among those without episodes, ST elevation resolved within 4 h in 34 (43%, group 2) and persisted > or = 4 h in 11 (14%, group 3). Episodes of re-elevation were more frequent during the first 4 h (0.25 episodes per hour) than in the late part of the observation period (0.04 episodes per hour). Most episodes were transient and short lasting; only nine patients showed persistent re-elevations longer than 60 min. During hospitalization, group 1 patients had a higher incidence of reinfarctions and severe ischemic events than those without episodes (group 1 12/34 (35%) vs. group 2 4/34 (12%) vs. group 3 1/11 (9%), p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

[Hypersensitivity vasculitis after thrombolytic therapy with APSAC (anisoylated plasminogen streptokinase activator complex). Presentation of a clinical case and review of the literature]. / Vasculite da ipersensibilità post-terapia trombolitica con APSAC (anisoylated plasminogen streptokinase activator complex). Presentazione di un caso clinico e revisione della letteratura.

We describe a rare case of hypersensitivity vasculitis associated with APSAC administration in a 54-year-old man. Fifteen days after receiving thrombolytic therapy (APSAC 30 U) for acute myocardial infarction, the patient was admitted to our department for myalgia, livedo reticularis and erythema of the legs with an ulcerative necrotic lesion of the fifth toe of the right foot. The presence of circulating immune complexes at high titer supported the diagnosis of hypersensitivity vasculitis.

[The adult respiratory distress syndrome as a complication of the APSAC treatment of acute myocardial infarct. Apropos a case]. / Síndrome de distrés respiratorio del adulto como complicación del tratamiento del infarto agudo de miocardio con APSAC. A propósito de un caso.

Thrombolytic therapy has shown to be effective in acute myocardial infarction, and its benefits on left ventricular function and later survival are well known. However it is not a therapy free of complications and side effects. Allergic reactions, anafilaxia, hypotension, and several kinds of hemorrhages have been reported. Adult respiratory distress syndrome after streptokinase administration has been also described, and one case, recently communicated, after APSAC therapy. We present the case of a male with acute myocardial infarction who developed adult respiratory distress syndrome after APSAC therapy, with different outcome than the first case published in the literature. Finally, we discussed the mechanisms by means these drugs can produce such a complication.

A double-blind randomised dose-effect trial of anisoylated plasminogen streptokinase activator complex (APSAC) in acute myocardial infarction. The APSAC Research Group.

A double-blind controlled trial was performed to evaluate the dose-effect relationship of APSAC on coronary reperfusion in patients with acute myocardial infarction. A total of 103 patients were recruited in 14 centres and randomly allocated to receive 3.75, 7.5, 15.0 or 30.0 U of anisoylated plasminogen streptokinase activator complex (APSAC), a thrombolytic. Angiograms were taken at baseline to assess eligibility and at six times after administration at 15-min intervals (up to 90 min). A control angiogram was performed at 24 h for patients with a patent artery at 90 min. Angiograms were read centrally by independent readers. There was a non-significant difference between the four groups for the main outcome, reperfusion of an initially occluded artery: 5/20 (25%; 3.75 U); 13/22 (59%; 7.5 U); 11/22 (50%; 15.0 U); 14/25 (56%; 30.0 U); p = 0.11. There was no apparent difference between group 7.5 U, 15.0 U and 30.0 U (mean recanalisation rate: 55%), but the reperfusion rate in the 3.75 U group was significantly lower (p = 0.02). No apparent differences were observed for the delay of recanalisation between the four groups. The mean values of minimum fibrinogen concentration were different in the four groups, with a clear dose-effect relationship (p = 0.0004). The side effects were not found to be dose-dependent.

Reporting Bayesian analyses of clinical trials.

Many clinicians wrongly interpret p-values as probabilities that treatment has an adverse effect and confidence intervals as probability intervals. Such inferences can be validly drawn from Bayesian analyses of trial results. These analyses use the data to update the prior (or pre-trial) beliefs to give posterior (or post-trial) beliefs about the magnitude of a treatment effect. However, for these methods to gain acceptance in the medical literature, understanding between statisticians and clinicians of the issues involved in choosing appropriate prior distributions for trial reporting needs to be reached. I focus on two types of prior that deserve consideration. The first is the non-informative prior giving standardized likelihood distributions as post-trial probability distributions. Their use is unlikely to be controversial among statisticians whilst being intuitively appealing to clinicians. The second type of prior has a spike of probability mass at the point of no treatment effect. Varying the magnitude of the spike illustrates the sensitivity of the conclusions drawn to the degree of prior scepticism in a treatment effect. With both, graphical displays provide clinical readers with the opportunity to explore the results more fully. An example of how a clinical trial might be reported in the medical literature using these methods is given.

The incidence and mechanism of hypotension following thrombolytic therapy for acute myocardial infarction with streptokinase-containing agents--lack of relationship to pretreatment streptokinase resistance.

The incidence, amplitude, mechanism and relationship to prior exposure to streptococcal antigen of blood pressure changes to streptokinase-containing thrombolytic agents were investigated in 125 patients treated with either 1.5 x 10(6) IU streptokinase over 60 min or 30 U anistreplase over 5 min, within 6 h of onset of acute myocardial infarction. Twenty-one of 52 patients with anterior and 34 of 73 with inferior myocardial infarction had a hypotensive response. There were no significant differences in the incidence, duration or amplitude of hypotension between the two treatment groups. The maximum mean fall in systolic blood pressure was 16.9 mmHg (95% confidence limits, CL 12.2 to 24.5 mmHg), and the maximum mean fall in diastolic blood pressure was 13.7 mmHg (CL 10.3 to 17.1 mmHg), starting 4 min after start of therapy and resolving within 34 min. Blood pressure changes were well tolerated. Hypotension was not related to pretreatment streptokinase resistance titre, or anti-SK IgG concentration, to changes in plasma fibrinogen, B-beta 15-42 peptide, D-dimer--as indices of thrombin activation and fibrin (-ogen) breakdown--to plasma viscosity. The blood pressure changes following treatment with streptokinase-containing thrombolytic agents in acute myocardial infarction are frequent but well tolerated. The mechanism of hypotension remains unclear, but is not related to prior exposure to streptococcal antigen.

Comparison of results of intravenous infusion of anistreplase versus streptokinase in acute myocardial infarction.

This randomized study compares the coronary perfusion rate in patients with acute myocardial infarction (AMI) treated with 2 different intravenous thrombolytic agents: streptokinase 1.5 million U given over 60 minutes and anisoylated human plasminogen streptokinase activator complex (anistreplase) administrated as a bolus of 30 U over 5 minutes. One hundred seventy-five patients (149 men and 26 women, mean age 54 years) have been included in this study. Eighty-nine patients were treated with anistreplase and 86 patients with streptokinase. AMI was inferior in 54 patients (61%) in the anistreplase group and in 54 patients (63%) in the streptokinase group. It was anterior in 35 (40%) and 32 (37%) patients, respectively. Coronary angiography and ventriculography were performed at a mean time (+/- SEM) of 207 +/- 11 minutes after the beginning of thrombolysis in 170 patients. A perfusion score grade of 2 or 3 according to the Thrombolysis in Myocardial Infarction trial was found in 63 patients (72%) in the anistreplase group and in 56 patients (68%) in the streptokinase group (p = NS). Severe bleeding occurred in 7 patients (8%) after anistreplase and in 6 patients (7%) after streptokinase. No cerebral hemorrhage occurred. Nine patients (5%) died during their hospital stay: 6 after anistreplase and 3 after streptokinase. It is concluded that intravenous administration of anistreplase or streptokinase is efficient and safe. Coronary patency 207 minutes after fibrinolysis, incidence of adverse events and mortality are similar in both groups.

An overview of the patency and stroke rates following thrombolysis with streptokinase, alteplase, and anistreplase used to treat an acute myocardial infarction.

The results of an overview of early (90-240 min) and late (24 hours or more) patency and of stroke rates for each of the three commercially available thrombolytic agents, streptokinase, alteplase, and anistreplase are presented. Studies included in this analysis are all those published between 1985 and March 1992 and focus on the licensed dosage regimens of each agent. The rates of early and late patency for streptokinase were 64.7% and 80.8%; for alteplase, 66.6% and 73.7%; and for anistreplase, 72.1% and 84.5%. The rates of total and hemorrhagic stroke for streptokinase were 0.69% and 0.17%; for alteplase, 1.27% and 0.50%; and for anistreplase 0.91% and 0.38%. These results provided evidence that the rates of early and late patency appeared to be greatest for anistreplase and that the rates of stroke are within "acceptable" ranges for all three thrombolytic agents with streptokinase affording the lowest rate.

Oesophageal dissection after thrombolytic treatment for myocardial infarction.

A 62 year old woman admitted with a history suggesting acute myocardial infarction had thrombolytic treatment with anisoylated plasminogen-streptokinase activator complex, which resulted in submucosal haemorrhage in the oesophagus; this caused dissection of the wall of the oesophagus and complete dysphagia. The haematoma resolved spontaneously, leaving behind a diverticulum, with reduced peristalsis and delayed emptying but no obstruction.