ro-48-3657 and Myocardial-Infarction

Antiplatelet drugs have an established place in the prevention of vascular events in a variety of clinical conditions, such as myocardial infarction, stroke and cardiovascular death. Both European and American guidelines recommend the use of antiplatelet drugs in patients with established coronary heart disease and other atherosclerotic disease. In high-risk patients, such as those with post-acute myocardial infarction (AMI), ischaemic stroke or transient ischaemic attack, and in patients with stable or unstable angina, peripheral arterial occlusive disease or atrial fibrillation, antiplatelet treatment may reduce the risk of a serious cardiovascular event by approximately 25%, including reduction of non-fatal myocardial infarction by 1/6, non-fatal stroke by 1/4 and cardiovascular death by 1/6. Some data indicate that antiplatelet drugs may also have a role in primary prevention. In people who are aged over 65 years, or have hypertension, hypercholesterolaemia, diabetes, obesity or familial history of myocardial infarction at young age, aspirin may reduce both cardiovascular deaths and total cardiovascular events. Aspirin has been studied and used most extensively. It may exert its beneficial effect not only by acting on platelets, but also by other mechanisms, such as preventing thromboxane A2 (TXA2)-induced vasoconstriction or reducing inflammation. Indeed, experimental data show that low-dose aspirin may suppress vascular inflammation and thereby increase the stability of atherosclerotic plaque. Moreover, in human studies, aspirin seems to be most effective in those with elevated C-reactive protein levels. Vascular events, however, do occur despite aspirin administration. This may be due to platelet activation by pathways not blocked by aspirin, intake of drugs that interfere with aspirin effect or aspirin resistance. In the CAPRIE (Clopidogrel vs. Aspirin in Patients at Risk of Ischaemic Events) study, long-term clopidogrel administered to patients with atherosclerotic vascular disease was more effective than aspirin in reducing the combined risk of ischaemic stroke, myocardial infarction or vascular death. In the setting of coronary stenting, a double regimen including aspirin and ticlopidine or clopidogrel has proved more effective in the prevention of in-stent thrombosis than aspirin alone. Chronic oral administration of the inhibitors of platelet membrane receptor GP IIb/IIIa has been largely disappointing.

Topics: Aspirin; Benzamidines; Clopidogrel; Coronary Artery Disease; Humans; Myocardial Infarction; Oximes; Piperidines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Pyridines; Stroke; Ticlopidine; Treatment Outcome

Numerous clinical trials have established the benefits of intravenous glycoprotein IIb/IIIa inhibition in the management of coronary artery disease. In contrast, the recent large-scale, placebo-controlled, randomized trials of the oral glycoprotein IIb/IIIa antagonists have failed to provide commensurate reductions in late composite ischemic end points despite potent inhibition of platelet aggregation.. The ORs for death, myocardial infarction, urgent revascularization, and major bleeding from the 4 large-scale, placebo-controlled, randomized trials with oral glycoprotein IIb/IIIa inhibitors were calculated and combined. Stratification by low-dose or high-dose therapy and the use of concurrent aspirin was also undertaken. In 33 326 patients followed for >30 days, a consistent and statistically significant increase in mortality was observed with oral glycoprotein IIb/IIIa therapy (OR, 1.37; 95% CI, 1.13 to 1.66; P:=0.001). This effect was evident regardless of aspirin coadministration and treatment with either low-dose or high-dose therapy. Although a reduction in urgent revascularization was observed with oral glycoprotein IIb/IIIa inhibition, pooled analysis favored an increase in myocardial infarction that did not demonstrate statistical significance.. Although we found a highly significant excess in mortality consistent across 4 trials with 3 different oral glycoprotein IIb/IIIa inhibitor agents, this was associated with a reduction in the need for urgent revascularization and no increase in myocardial infarction. These findings suggest the potential for a direct toxic effect with these agents and argue against a prothrombotic mechanism. Further investigation to elucidate the cause of this increased fatality risk is warranted.

Topics: Administration, Oral; Alanine; Aspirin; Benzamidines; Clinical Trials, Phase III as Topic; Coronary Disease; Dose-Response Relationship, Drug; Drug Therapy, Combination; Hemorrhage; Humans; Incidence; Multicenter Studies as Topic; Myocardial Infarction; Oximes; Piperidines; Platelet Glycoprotein GPIIb-IIIa Complex; Pyrrolidines; Randomized Controlled Trials as Topic

Platelet membrane glycoprotein IIb/IIIa inhibitors, a new class of potent antiplatelet agents, have been used in the treatment of acute coronary syndromes as well as in the prevention of complications after percutaneous coronary interventions. Approximately 50,000 patients with coronary artery disease have been enrolled in randomized studies of glycoprotein IIb/IIIa inhibitors. The purpose of this article is to review the pharmacology of glycoprotein IIb/IIIa inhibitors, the results of the clinical trials using these agents, and their current use in percutaneous coronary interventions and the treatment of acute coronary syndromes.

Topics: Abciximab; Acetates; Acute Disease; Administration, Oral; Alanine; Angioplasty, Balloon, Coronary; Antibodies, Monoclonal; Anticoagulants; Benzamidines; Coronary Disease; Eptifibatide; Hemorrhage; Humans; Immunoglobulin Fab Fragments; Myocardial Infarction; Oximes; Peptides; Piperidines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Pyrrolidines; Randomized Controlled Trials as Topic; Stents; Syndrome; Thrombocytopenia; Thrombolytic Therapy; Tirofiban; Tyrosine

Platelet aggregation plays a central role in the pathogenesis of thrombosis and the acute coronary syndromes. When given intravenously, potent selective antagonists of fibrinogen binding to the glycoprotein (GP) IIb/IIIa receptor, the final common pathway for platelet aggregation, have been effective in the treatment of acute coronary syndromes. Their benefit ceases, however, with the end of the infusion. Aspirin reduces the incidence of secondary vascular events by 25% to 30% after an acute coronary syndrome, and clopidogrel provides modest improvement over aspirin. However, both are relatively weak antiplatelet agents that each block only one of many pathways to platelet activation and surface membrane expression of the competent GP IIb/IIIa receptor. With the success of the intravenous GP IIb/IIIa antagonists in the acute setting, recent interest has focused on the potential benefit of oral GP IIb/IIIa antagonists used long-term for secondary prevention. The oral agents tested in phase III studies thus far have not performed up to expectations, however. The following paper reviews these studies and the implications of their results.

Topics: Alanine; Angina, Unstable; Aspirin; Benzamidines; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Humans; Myocardial Infarction; Oximes; Piperidines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Pyrrolidines; Syndrome; Treatment Outcome

The central role of platelet-rich thrombus in the pathogenesis of acute coronary syndromes (ACSs) is well-known. Glycoprotein IIb/IIIa (Gp IIb/IIIa) receptor antagonists are potent inhibitors of platelet function that may be expected to affect favorably the natural history of ACSs.. To define the optimal role of Gp IIb/IIIa inhibitors in treatment strategies for ACSs.. A MEDLINE search was performed to identify all English-language articles regarding use of Gp IIb/IIIa inhibitors in ACSs published between 1966 and June 2000. In addition, relevant abstracts from the annual meetings of the American Heart Association, American College of Cardiology, and the European Society of Cardiology were reviewed.. Only studies of 500 or more patients were included. Of 15 studies identified, 10 randomized, placebo-controlled, double-blind trials of Gp IIb/IIIa inhibitors in ACSs were selected for review.. Data quality was determined by publication in the peer-reviewed literature or presentation at an official cardiology society-sponsored meeting, as well as by verification with the primary author.. Three members of this class of drugs are available for intravenous use. Abciximab, eptifibatide, and tirofiban hydrochloride, each have data demonstrating their value in improving the outcomes of patients presenting with ACSs. Current evidence supports use of these drugs in both conservative and invasive treatment strategies. Glycoprotein IIb/IIIa-blocking therapy is safe, and with proper precautions, bleeding risks can be minimized. Biological differences exist among these agents, but as of yet, no head-to-head comparisons have been made of their clinical efficacy. Unlike intravenous Gp IIb/IIIa inhibitors, available data regarding any role of oral Gp IIb/IIIa inhibitors are not favorable.. Current data indicate that intravenous Gp IIb/IIIa inhibitor therapy merits a prominent role in the initial management of patients with ACSs. JAMA. 2000;284:1549-1558.

Topics: Abciximab; Acute Disease; Alanine; Angina, Unstable; Angioplasty, Balloon, Coronary; Antibodies, Monoclonal; Anticoagulants; Benzamidines; Drug Therapy, Combination; Eptifibatide; Heparin, Low-Molecular-Weight; Humans; Immunoglobulin Fab Fragments; Myocardial Infarction; Oximes; Peptides; Piperidines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Pyrrolidines; Randomized Controlled Trials as Topic; Stents; Tirofiban; Tyrosine

Evidence-based medications (EBM) are underused in older patients despite potentially larger absolute benefits. Little is known about factors influencing prescribing in the elderly with acute coronary syndromes.. Among the 15,904 patients from the Sibrafiban vs aspirin to Yield Maximum Protection from ischemic Heart events postacute cOroNary sYndromes (SYMPHONY) and second SYMPHONY trials, we examined the rates of use of EBM according to age (< 75 or > or = 75 years, and 3 subgroups of 5 year increments among patients > or = 75 years).. Ninety-day mortality increased with age (< 75 years, 1.3%; > or = 75 to < 80 years, 4.4%; > or = 80 to < 85 years, 6.0%; > or = 85 years, 9.6%). Compared with subjects < 75 years (n = 14,043), acute EBM use was lower among patients > or = 75 years (n = 1794): aspirin (83% vs 85%), heparin (73% vs 78%), and beta-blockers (70% vs 76%). Similarly, discharge use of beta-blockers (69% vs 76%) and statins (28% vs 40%) was lower, although this was not the case for angiotensin-converting enzyme inhibitors (44% vs 41%). These patterns persisted among eligible patients. Beyond the age of 75 years, EBM use was not further influenced by age except for statins and angiotensin-converting enzyme inhibitors, which were used less frequently in those > or = 85 years. Among patients aged > or = 75 years, prediction for use of each EBM in multivariable modeling was modest (C indices, approximately 0.7); except for statins, increasing age did not predict lower EBM use.. Despite higher mortality risk, EBM use was lower among older patients even considering eligibility. Among those aged > or = 75 years, age was no longer the major factor predicting EBM use. The modest C indices suggest other factors are associated with prescribing, underscoring the need for treatment algorithms and quality assurance measures in older patients.

Topics: Aged; Aged, 80 and over; Angina, Unstable; Aspirin; Cardiovascular Agents; Evidence-Based Medicine; Female; Humans; Male; Myocardial Infarction; Oximes; Piperidines; Platelet Aggregation Inhibitors

Stroke is a rare but serious event that complicates the course of patients with acute coronary syndromes (ACS). The type, outcome, and risk factors of stroke occurring in stabilized patients with ACS have not been previously reported.. We evaluated stroke incidence, subtypes, and outcomes, in addition to demographics and clinical risk characteristics associated with stroke among patients enrolled in the Sibrafiban versus Aspirin to Yield Maximum Protection from Ischemic Heart Events Post-acute Coronary Syndromes (SYMPHONY) and 2nd SYMPHONY trials.. Of 15,904 stabilized patients with ACS, 113 (0.71%) had a stroke over a median follow-up of 90 days. The majority of strokes occurred within 30 days of presentation, and the time course for stroke occurrence paralleled that of myocardial (re)infarction. Most strokes were ischemic (78%), and 52% resulted in moderate or severe disability or death. Patients with stroke were older and more often had hypertension, diabetes, peripheral vascular disease, and atrial fibrillation. Among patients with stroke who had cardiac catheterization, percutaneous coronary intervention, or coronary artery bypass grafting, stroke occurred predominantly after the procedure. No difference in occurrence or type of stroke was observed in the assigned treatment groups. In multivariable modeling age, heart failure, prior stroke, left bundle branch block, and systolic blood pressure predicted the occurrence of stroke.. In patients stabilized after presenting with a spectrum of ACS and treated with sibrafiban and/or aspirin, stroke occurred in fewer than 1% within 90 days but carried a significant mortality and morbidity risk.

Topics: Acute Disease; Aged; Angina, Unstable; Angioplasty, Balloon, Coronary; Aspirin; Coronary Artery Bypass; Female; Follow-Up Studies; Humans; Incidence; Male; Middle Aged; Myocardial Infarction; Oximes; Piperidines; Platelet Aggregation Inhibitors; Proportional Hazards Models; Recurrence; Risk Factors; Stroke

We sought to assess the incidence and clinical significance of elevated cardiac troponin I (cTnI) after percutaneous coronary intervention (PCI).. Elevated creatine kinase-MB (CK-MB) is prognostically important after PCI, but the prognostic significance of elevated cTnI after PCI is uncertain.. In a prospective substudy of the Sibrafiban Versus Aspirin to Yield Maximum Protection From Ischemic Heart Events Post-acute Coronary Syndromes (SYMPHONY) trials, which randomized patients with acute coronary syndromes (ACS) to receive aspirin or sibrafiban, we measured cTnI (positive, > or =1.5 ng/ml) and CK-MB (positive, > or =7 ng/ml) in 481 patients with PCI. Samples were collected immediately before and at 0, 8 and 16 h after PCI and analyzed by a core laboratory. The primary end point was the Kaplan-Meier estimate of death, myocardial infarction or severe, recurrent ischemia at 90 days.. Overall, 230 patients (48%) had elevated cTnI after PCI. Such patients underwent PCI sooner and were more likely to have coronary stenting. Elevated cTnI was associated with nonsignificantly higher risks of the primary end point (11.5% vs. 8.7%; p = 0.15) and of death (1.8% vs. 0.4%; p = 0.4) and a significantly higher risk of death or infarction (10.6% vs. 4.2%; p = 0.005). This pattern was more pronounced for patients who became positive only after PCI: primary end point, 20.7% vs. 10.1% for patients who remained negative after PCI (p = 0.05); death, 5.2% vs. 0% (p = 0.02); death or infarction, 18.1% vs. 4.1% (p = 0.007).. Elevated cTnI, often observed after PCI in patients with ACS, is associated with worse 90-day clinical outcomes. This marker, therefore, is a useful prognostic indicator in such patients.

Topics: Angina, Unstable; Angioplasty, Balloon, Coronary; Aspirin; Biomarkers; Creatine Kinase; Creatine Kinase, MB Form; Disease-Free Survival; Female; Heart Diseases; Humans; Isoenzymes; Male; Middle Aged; Myocardial Infarction; Oximes; Piperidines; Platelet Aggregation Inhibitors; Prognosis; Prospective Studies; Sensitivity and Specificity; Stents; Troponin I

This study was designed to determine the magnitude and time course of platelet activation during therapy of acute coronary syndromes with an oral platelet antagonist.. Platelet activation and aggregation are central to the pathogenesis of the acute coronary syndromes (ACS). However, few data are available on levels of platelet activation over time in patients with ACS, especially in the setting of chronic glycoprotein (GP) IIb/IIIa inhibition.. The Thrombolysis in Myocardial Infarction (TIMI) 12 trial was a phase II, double-blind trial evaluating the effects of sibrafiban, an oral, selective antagonist of the platelet glycoprotein IIb/IIIa receptor in patients stabilized after an ACS. A subset of 90 of the 329 patients in the study had measurement of platelet activation as assessed by the expression of platelet associated P-Selectin on days 0, 7 and 28. Platelet activation was measured in blood samples that were fixed either immediately (spontaneous activation) or after 5 minute incubation with 0, 1 microM or 5 microM ADP in order to assess platelet responsiveness to very low or moderate stimulation.. At baseline there was a significant elevation of spontaneous platelet activation as compared to samples obtained from normal donors or from patients who did not have acute coronary syndromes (ACS patients 27.6+/-18.7%, Normal controls 8.5+/-4.4%, Patient controls 10.9+/-7.1%, p < 0.005 for both). In addition, there was a significant decrease in the levels of platelet activation with time during the 28 days of treatment with sibrafiban. Nevertheless, even on day 28, the TIMI-12 patients continued to show elevated platelet activation in comparison to the control groups (p < 0.05 for both).. These results suggest that platelets remain activated long after clinical stabilization post ACS. Although platelet activation decreased after one month of oral GPIIb/IIIa inhibition, levels remained higher than normal, suggesting the need for long-term antiplatelet therapy following ACS.

Topics: Administration, Oral; Adult; Aged; Angina, Unstable; Blood Platelets; Double-Blind Method; Electrocardiography; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Infarction; Oximes; P-Selectin; Piperidines; Platelet Activation; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Thrombolytic Therapy; Treatment Outcome

Recent trials reveal no benefit and possible harm from chronic hormone replacement therapy (HRT). Less is known about intermediate-term outcomes associated with HRT use in the setting of acute coronary syndromes (ACS).. To examine the prevalence of HRT use and relationships with intermediate-term outcomes among women with ACS, we classified as HRT users or nonusers 4029 postmenopausal women (age > 50 years or postmenopausal by case report form) randomized in the Sibrafiban versus Aspirin to Yield Maximum Protection from Ischemic Heart Events Post-Acute Coronary Syndromes (SYMPHONY) and 2nd SYMPHONY trials. Outcomes included 90-day and 1-year death and 90-day stroke, death, or myocardial infarction (MI); death, MI, or stroke; and death, MI, or severe recurrent ischemia (SRI).. HRT use was 13% overall and varied by region (Asia, 0%; Eastern Europe, 0.2%; Latin America, 0.8%; Western Europe, 4%; Australia/New Zealand, 12%; Canada, 14%; United States, 24%); estrogen-only regimens were most common (90%). HRT users were younger, had higher estimated creatinine clearance, more frequently were smokers and had prior revascularization, but less frequently had diabetes, prior angina, or heart failure. Unadjusted 90-day and 1-year mortality rates were lower among HRT users (hazard ratios [95% CI] 0.48 [0.23-0.98] and 0.35 [0.18-0.68], respectively) but after multivariable adjustment, were not significantly different. Ninety-day stroke and composite end points did not differ between HRT users and nonusers.. HRT use (predominantly estrogen-only) was low among patients with ACS but varied by region and was not associated with improved intermediate-term outcomes. These results are consistent with the absence of benefit from HRT use (combination or estrogen only) in previous studies in more stable populations.

Topics: Aged; Aspirin; Attitude to Health; Coronary Disease; Estrogen Replacement Therapy; Female; Global Health; Humans; Middle Aged; Myocardial Infarction; Odds Ratio; Oximes; Piperidines; Platelet Aggregation Inhibitors; Postmenopause; Prevalence; Randomized Controlled Trials as Topic; Surveys and Questionnaires; Survival Analysis; Time Factors; Treatment Outcome; Women's Health

The secondary prevention benefit of therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) has been clearly demonstrated; however, the role of early initiation of statins after acute coronary syndromes (ACSs) is unknown.. To evaluate the association of early statin initiation (< or = 7 days) after ACS with 90-day and 1-year outcomes.. Observational cohort from databases of 2 randomized clinical trials, SYMPHONY and 2nd SYMPHONY.. Nine hundred thirty-one clinical centers in 37 countries.. A total of 12,365 ACS patients randomized from August 1997 to August 1999 who were not taking statins prior to the index ACS and who either started statin therapy early (median, 2.0 [interquartile range, 1.0-3.1] days after ACS; n = 3952) or survived more than 5 days after ACS and never received statin therapy (n = 8413).. Ninety-day incidence of death; death or myocardial infarction (MI); and death, MI, or severe recurrent ischemia; as well as 1-year incidence of death.. Ninety-day and 1-year unadjusted mortality comparison suggested early statin benefit (1.2% for early statins vs 2.1% for no statins; hazard ratio [HR], 0.58; 95% confidence interval [CI], 0.42-0.81 for 90-day comparisons and 2.3% for early statins vs 4.4% for no statins; HR, 0.52; 95% CI, 0.40-0.68 for 1-year comparison). However, no benefit was evident for 90-day death or MI (6.5% vs 6.9%; HR, 0.95; 95% CI, 0.82-1.11) or death, MI, or severe recurrent ischemia (9.2% vs 8.9%; HR, 1.04; 95% CI, 0.92-1.18). After propensity and covariate adjustment, there were no 90-day or 1-year differences between the early-statin group and the no-statin group. The 90-day adjusted HR for death was 1.08 (95% CI, 0.75-1.56); for death or MI, 1.08 (95% CI, 0.91-1.29); and for death, MI, or severe recurrent ischemia, 1.15 (95% CI, 0.99-1.34). One-year mortality-adjusted HR was 0.99 (95% CI, 0.73-1.33). Among 2711 patients with core laboratory lipid analysis, early statin was associated with higher adjusted risk for death or death or MI at cholesterol levels below treatment guidelines but was more favorable at higher levels.. In this study, there was no relationship between early initiation of statin therapy and improved outcomes although our subset analysis suggests that outcomes after early statin initiation may vary with cholesterol levels. Confirmation of early treatment effects of statins on outcomes awaits the results of adequately powered randomized clinical trials.

Topics: Acute Disease; Aged; Angina, Unstable; Aspirin; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lipoproteins; Male; Middle Aged; Myocardial Infarction; Oximes; Piperidines; Platelet Aggregation Inhibitors; Proportional Hazards Models; Randomized Controlled Trials as Topic; Survival Analysis; Treatment Outcome

Topics: Administration, Oral; Aspirin; Death, Sudden, Cardiac; Humans; Myocardial Infarction; Oximes; Piperidines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Risk Factors

Despite progress, atherosclerotic vascular disease remains a major cause of morbidity and mortality. Intravenous therapy with platelet glycoprotein (GP) IIb/IIIa receptor antagonists improves outcome in patients with acute coronary syndromes (ACS). Whether potent long-term antiplatelet therapy with oral GP IIb/IIIa antagonists will further improve outcome at a dose that is tolerable in long-term treatment is unknown.. SYMPHONY (Sibrafiban versus aspirin to Yield Maximum Protection from ischemic Heart events post-acute cOroNary syndromes) was a randomized, double-blind, aspirin-controlled trial with 2 concentration regimens of sibrafiban, an oral peptidomimetic GP IIb/IIIa antagonist, for long-term treatment instead of aspirin in patients after an ACS. Patients were eligible for SYMPHONY if they presented within 7 days of an ACS (>/=20 minutes of ischemic symptoms), had been clinically stable for at least 12 hours, and met one of the following inclusion criteria: ST-segment depression or elevation of at least 0.5 mm or new left bundle branch block with the ACS or elevated creatinine kinase MB more than the upper limit of normal and >3% of total creatine kinase or, if creatine kinase MB was not measured, an elevated level of troponin T or I. Approximately 9000 patients post ACS were randomized 1:1:1 to treatment with either aspirin (80 mg every 12 hours) or high-dose or low-dose sibrafiban every 12 hours. Assignment of tablet strength (3, 4.5, or 6 mg) within the sibrafiban arms was based on body weight and renal function to achieve a target steady-state plasma concentration. The duration of study drug therapy was 90 days. Patients who had intracoronary stenting during the course of the study initially received a blinded stent medication assignment for 2 to 4 weeks based on their initial randomization as follows: aspirin/ticlopidine 250 mg twice daily, low-dose sibrafiban/ticlopidine placebo twice daily, and high-dose sibrafiban/ticlopidine placebo twice daily. After the second interim safety assessment by the Data and Safety Monitoring Board the stent regimen for the low-dose group was modified to include ticlopidine 250 mg twice daily.. The primary efficacy end point of SYMPHONY was the 90-day incidence of a composite of all-cause mortality, myocardial infarction or reinfarction, and severe recurrent ischemia. A clinical events classification committee was established to determine the end points of reinfarction and severe recurrent ischemia. The primary safety end points were the incidence of major bleeding or minor bleeding and the combined incidence of major and minor bleeding. Bleeding classification was done by computer algorithm. Tolerability was assessed by the rate of study drug discontinuation from bleeding.

Topics: Angina, Unstable; Aspirin; Clinical Trials, Phase III as Topic; Double-Blind Method; Humans; Myocardial Infarction; Oximes; Piperidines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Prodrugs; Randomized Controlled Trials as Topic; Research Design; Syndrome; Treatment Outcome