ro-48-3657 and Angina--Unstable

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

Topics: Acetates; Angina, Unstable; Biphenyl Compounds; Cost-Benefit Analysis; Eptifibatide; Female; Humans; Male; Oximes; Peptides; Piperidines; Platelet Aggregation Inhibitors; Pyrrolidines; 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

Aspirin lowers risks of death and myocardial infarction in patients with acute coronary syndromes. Intravenous glycoprotein IIb/IIIa receptor antagonists further reduce the rates of ischaemic events in these patients, but the efficacy of long-term oral glycoprotein IIb/IIIa receptor blockade has not been established. We tested whether the oral glycoprotein IIb/IIIa receptor antagonist sibrafiban would prevent more cardiovascular events than aspirin, when given within 7 days of, and sustained for 90 days after, an acute coronary syndrome event.. 9233 patients who had stabilised after an acute coronary syndrome event were randomly assigned aspirin (80 mg orally twice daily) or low-dose or high-dose sibrafiban. Sibrafiban doses (3.0 mg, 4.5 mg, or 6.0 mg) were based on a model accounting for weight and serum creatinine and designed to achieve at least 25% steady-state inhibition of platelet aggregation (low dose) or at least 50% inhibition (high dose). The primary endpoint was the composite of death, non-fatal infarction or reinfarction, or severe recurrent ischaemia at 90 days. Analysis was by intention to treat.. The 90-day rate of the primary endpoint did not differ significantly between the groups assigned aspirin (302 [9.8%]), low-dose sibrafiban (310 [10.1%]; odds ratio 1.03 [95% CI 0.87-1.21]), and high-dose sibrafiban (303 [10.1%]; 1.03 [0.87-1.21]). The groups did not differ significantly in the rates of the component events or secondary efficacy endpoints. Major bleeding was more common with high-dose sibrafiban (171 [5.7%]) than with aspirin (120 [3.9%]) or low-dose sibrafiban (159 [5.2%]).. Sibrafiban showed no additional benefit over aspirin for secondary prevention of major ischaemic events after an acute coronary syndrome, and was associated with more dose-related bleeding.

Topics: Administration, Oral; Aged; Angina, Unstable; Aspirin; Double-Blind Method; Female; Humans; Male; Middle Aged; Odds Ratio; Oximes; Piperidines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Recurrence

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

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: Angina, Unstable; Aspirin; Double-Blind Method; Humans; Oximes; Piperidines; Platelet Aggregation Inhibitors; Randomized Controlled Trials as Topic

Topics: Angina, Unstable; Anti-Inflammatory Agents; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Coronary Disease; Humans; Inflammation; Methylprednisolone; Oximes; Piperidines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Randomized Controlled Trials as Topic

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