High-density lipoprotein-cholesterol and not HbA1c was directly related to cardiovascular outcome in PROactive.

AIM: In PROactive, pioglitazone reduced the incidence of death, myocardial infarction and stroke, and significantly improved HbA1c, systolic blood pressure (SBP), triglycerides and high-density lipoprotein (HDL)-cholesterol relative to placebo. As these glycaemic and lipid parameters are major cardiovascular (CV) risk factors, we assessed their separate contribution to the reduced incidence of CV outcomes. METHODS: Patients (n = 5238) with type 2 diabetes and macrovascular disease were randomized to 45 mg pioglitazone or placebo. Relationships among treatment, outcome (time to first event of all-cause mortality, myocardial infarction and stroke) and 10 laboratory measurements and vital signs were investigated using log-linear models. Continuous variable measurements (percent changes from baseline to average of all postbaseline values prior to censoring) were made discrete by categorizing into tertiles. Log-linear models were fitted to multiway tables of discrete data and analysis of deviance used to summarize sources of variation in the data. RESULTS: Although pioglitazone treatment was associated with a decrease in HbA1c and an increase in HDL-cholesterol (HDL-C), only the change from baseline HDL-C predicted the outcome (χ(2) = 28.89, p < 0.0001). No other variables, including HbA1c, triglycerides and systolic blood pressure, showed significant direct associations with outcome. When the analysis was extended to include baseline statin use, this was associated with an improved outcome independently of HDL-C changes. CONCLUSIONS: This post hoc analysis suggests that HDL-C, but probably not HbA1c, is a driver of pioglitazone's favourable influence on CV outcome.

Management and outcome of patients with atrial fibrillation during acute myocardial infarction: the GUSTO-III experience. Global use of strategies to open occluded coronary arteries.

OBJECTIVE: To investigate the use of antiarrhythmic agents and electrical cardioversion in the management of patients with atrial fibrillation complicating acute myocardial infarction, and their relation to 30 day and one year mortality. DESIGN: Prospective study of 1138 patients with atrial fibrillation from the GUSTO-III trial. INTERVENTIONS: Of the 1138 study patients, 317 (28%) received antiarrhythmic treatment, including class I antiarrhythmic agents (12%), sotalol (5%), and amiodarone (15%); electrical cardioversion was attempted in 116 (10%). RESULTS: Sinus rhythm was restored in 72% of patients receiving class I antiarrhythmic agents, 67% of those receiving sotalol, 79% of those receiving amiodarone, and 64% of those having electrical cardioversion. After adjusting for baseline characteristics and complications occurring before the onset of atrial fibrillation, there was no difference among the treatment groups in the incidence of sinus rhythm at the time of discharge or before deterioration to hospital death. However, the use of class I antiarrhythmic drugs or sotalol was associated with a lower unadjusted 30 day and one year mortality. After adjustment for baseline factors and pre-atrial fibrillation complications, the odds ratios for 30 day and one year mortality were 0.42 (95% confidence interval (CI) 0.19 to 0.89) and 0.58 (95% CI 0.33 to 1.04) with class I agents, and 0.31 (95% CI 0.07 to 1.32) and 0.31 (95% CI 0.09 to 1.02) with sotalol. In contrast, there was no association between the use of amiodarone or electrical cardioversion and 30 day or one year mortality. CONCLUSIONS: There was a strong trend towards lower mortality associated with the use of class I antiarrhythmic agents or sotalol in managing patients with atrial fibrillation after acute myocardial infarction. Randomised trials are indicated.

Availability of on-site catheterization and clinical outcomes in patients receiving fibrinolysis for ST-elevation myocardial infarction.

AIMS: To compare management and clinical outcomes in hospitals stratified by the availability of on-site catheterization in InTIME-II, a multicentre trial comparing alteplase with lanoteplase for acute myocardial infarction. METHODS AND RESULTS: We studied 15,078 patients enrolled in 35 countries and 855 hospitals. Thirty-one percent of hospitals had 24-h, 25% day-only, and 44% no on-site catheterization facilities. Rates of cardiac angiography (57%, 38%, 26%) and revascularization (37%, 21%, 17%) were higher in hospitals with increasing access to on-site facilities(P<0.0001). The presence of a 24-h on-site facility was the strongest predictor of angiography during the index admission (odds ratio 4.17, 95% CI 3.85-4.54). There were no major differences in patient outcomes at 30 days when hospitals were stratified by availability of on-site catheterization. Adjusted 1-year mortality was similar between groups of hospitals (odds ratio for day-only 0.94 [0.80-1.09] and odds ratio for no availability 0.95 [0.83-1.10] compared to hospitals with 24-h facilities). CONCLUSIONS: There is a marked variation in procedure use by the availability of on-site catheterization with no major differences in patient outcomes. There is a need for additional randomized trials in the current era to address both the appropriate selection of patients and timing of invasive procedures in ST-elevation acute myocardial infarction.

Geographic variation in patient and hospital characteristics, management, and clinical outcomes in ST-elevation myocardial infarction treated with fibrinolysis. Results from InTIME-II.

AIMS: We examined the geographic variations in InTIME-II, a randomized double-blind trial comparing alteplase with lanoteplase for myocardial infarction. METHODS AND RESULTS: We compared baseline characteristics, management, and outcomes in four regions (Western Europe, Eastern Europe, North America, and Latin America) and in countries with historically different management approaches (Germany vs the U.K., the U.S. vs Canada). Thirty-day mortality in Western Europe, Eastern Europe, North America and Latin America was 6.7%, 7.3%, 5.7%, 10.1%, P<0.0001. Adjusted mortality for Europe was intermediate between North America and Latin America (odds ratios (OR) [95% confidence intervals (CI)] compared to Western Europe: North America 0.84 [0.67-1.0], Eastern Europe 1.2 [1.0-1.4], and Latin America 1.8 [1.3-2.7]). Revascularization rates varied 10-fold but did not explain regional mortality differences. Germany and the U.K. had similar adjusted 1-year mortality (OR for the U.K. 1.16 [0.92-1.5]), although invasive procedures were four- to 10-fold more common in Germany. Similarly the U.S. and Canada had equal adjusted 1-year mortality (OR for Canada 0.85 [0.61-1.17]) despite three-fold higher use of invasive procedures in the U.S. CONCLUSIONS: Significant geographic variations in practice and adjusted mortality following fibrinolysis persist despite recent guidelines. These findings have important implications in the design and interpretation of international studies, identify under- and over-utilized therapies, and support further study of treatments with marked worldwide variations.

Open multicentre study of the P2T receptor antagonist AR-C69931MX assessing safety, tolerability and activity in patients with acute coronary syndromes.

Platelet aggregation is the central process in the pathophysiology of acute coronary syndromes. ADP contributes to thrombosis by activating platelets, and AR-C69931MX is a specific antagonist of this process acting at the P2T receptor. At 5 hospitals, 39 patients with unstable angina or non-Q wave myocardial infarction, who were receiving aspirin and heparin, were administered intravenous AR-C69931MX with stepped dose increments over 3 h to a plateau of either 2 microg/kg/min for 21 h (Part 1; n = 12) or up to 69 h (Part 2; n = 13) or 4 microg/kg/min for up to 69 h (Part 3: n = 14). Safety parameters, platelet aggregation (PA) induced by ADP 3 micromol/L (impedance aggregometry), bleeding time (BT) and plasma concentrations of AR-C69931XX were assessed. AR-C69931MX was well tolerated. 33 patients completed the study. There were no deaths at 30 days and no serious adverse events attributed to AR-C69931MX. Trivial bleeding (56%) was common. At 24 h, mean inhibition of PA was 96.0 +/- 8.6, 94.9 +/- 14.4 and 98.7 +/- 2.1% and BT was 9.5 +/- 8.4, 14.0 +/- 9.7 and 16.0 +/- 11.1 min for Parts 1, 2 and 3 respectively. At 1 h post-infusion, mean inhibition of PA was 36.2 +/- 39.2, 20.7 +/- 25.9 and 40.7 +/- 36.7% respectively. 90% patients had a plasma half-life for AR-C69931XX of <9 min. In conclusion, AR-C69931MX is a potent, short-acting platelet ADP receptor antagonist suitable for further studies as an antithrombotic agent.

Lower-dose heparin with fibrinolysis is associated with lower rates of intracranial hemorrhage.

BACKGROUND: The optimal heparin dose as an adjunct to fibrinolysis and its role in causing intracranial hemorrhage (ICH) is unclear. METHODS: We reviewed the heparin regimens and rates of ICH in 3 sets of recent fibrinolytic trials: (1) studies with accelerated recombinant tissue plasminogen activator (TPA, alteplase) plus intravenous heparin, in which the heparin regimen was changed during the course of the trial; (2) phase III trials with accelerated TPA plus intravenous heparin; and (3) trials of new single-bolus fibrinolytic agents. RESULTS: Lower rates of ICH were observed among studies of accelerated TPA that reduced the heparin dose mid-trial (TIMI 9A --> 9B: 1.87% --> 1.07%, GUSTO-IIa --> IIb: 0.92% --> 0.71%, TIMI 10B: 2.80% --> 1.16%). Rates of ICH with accelerated TPA gradually increased from GUSTO-I (0.72%) in 1990 to 1993 to ASSENT-2 (0.94%) in 1997 to 1998. However, this trend was reversed in InTIME-II, which used the lowest heparin dose and most aggressive activated partial thromboplastin time monitoring and observed an ICH rate of 0.64% with accelerated TPA. Lower ICH rates were also observed when the heparin dose was reduced with single-bolus tenecteplase (TNK-TPA) and lanoteplase. CONCLUSIONS: Nonrandomized comparisons with accelerated TPA suggest that lower doses of intravenous heparin are associated with lower rates of ICH. This observation also appears to apply to single-bolus TNK-TPA and novel plasminogen activator. A lower-dose, weight-adjusted heparin regimen (60 U/kg bolus; maximum, 4000 U; 12 U/kg per hour infusion; maximum, 1000 U/h) with earlier monitoring of activated partial thromboplastin time is currently recommended in the revised American College of Cardiology/American Heart Association myocardial infarction guidelines and should be used in clinical practice.

Effect of lipid-lowering therapy on early mortality after acute coronary syndromes: an observational study.

BACKGROUND: Lipid-lowering agents are known to reduce long-term mortality in patients with stable coronary disease or significant risk factors. However, the effect of lipid-lowering therapy on short-term mortality immediately after an acute coronary syndrome has not been determined. We did an observational study using data from two randomised trials to investigate this issue. METHODS: We used data from the GUSTO IIb and PURSUIT trials to compare all-cause mortality among patients with acute coronary syndromes who were discharged on lipid-lowering agents (n=3653) with those who were not (n=17,156). A propensity analysis was done to adjust for presumed selection biases in the prescription of lipid-lowering agents. FINDINGS: Lipid-lowering therapy was associated with a smaller proportion of deaths at 30 days (17 [0.5%] vs 179 [1.0%], hazard ratio 0.44 [95% CI 0.27-0.73], p=0.001) and at 6 months (63 [1.7%] vs 605 [3.5%], 0.48 [0.37-0.63], p<0.0001). After adjustment for the propensity to be prescribed lipid-lowering agents and other potential confounders, prescription of a lipid-lowering agent at discharge remained associated with a reduced risk of death at 6 months (0.67 [0.48-0.95], p=0.023). INTERPRETATION: Prescription of a lipid-lowering drug at hospital discharge was independently associated with reduced short-term mortality among patients after an acute coronary syndrome.

Association of white blood cell count with increased mortality in acute myocardial infarction and unstable angina pectoris. OPUS-TIMI 16 Investigators.

We observed in a study of 7,651 patients with acute coronary syndromes that a white blood cell (WBC) count of > 10,000 was associated with increased 30-day and 10-month mortality (6.2% vs 3.2% to 3.6% for WBC count < 10,000; p < 0.000). With its simplicity and widespread availability, WBC count could serve as a simple, inexpensive, new tool for risk stratification in acute coronary syndromes.

Therapeutic value of eptifibatide at community hospitals transferring patients to tertiary referral centers early after admission for acute coronary syndromes. PURSUIT Investigators.

OBJECTIVES: We aimed to evaluate the benefits of the glycoprotein (GP) IIb/IIIa antagonist, eptifibatide, after patients with acute coronary syndromes (ACS) were admitted to hospitals that approach revascularization for ACS through early transfer to tertiary referral centers. BACKGROUND: Across a variety of hospital settings, GP IIb/IIIa inhibition, after patients were admitted to the hospital for non-ST segment elevation ACS, is associated with a reduction in death or myocardial infarction (MI) before and during a percutaneous coronary intervention. METHODS: The outcomes of 429 patients from 153 sites in the Platelet glycoprotein IIb/IIIa in unstable angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial, who were transferred during study drug infusion ("transfer patients"), were compared with those of 1,987 patients who either remained in the hospital at those sites or were transferred after study drug termination ("nontransfer patients"). RESULTS: The baseline characteristics of transfer and nontransfer patients were similar. Patients receiving eptifibatide were transferred less frequently than those receiving placebo (16% vs. 20%, p = 0.014). Transfer patients underwent more procedures and experienced a greater 30-day incidence of death or MI, as compared with nontransfer patients (21% vs. 12%, p = 0.001). Eptifibatide was associated with a reduction in death or MI through 30 days, independent of transfer status (2.5% absolute reduction), as well as for those transferred (5.5% absolute reduction). CONCLUSIONS: For patients with ACS admitted to community hospitals, eptifibatide is associated with a reduced need for transfer and improved clinical outcomes.

Safety and preliminary efficacy of one month glycoprotein IIb/IIIa inhibition with lefradafiban in patients with acute coronary syndromes without ST-elevation; a phase II study.

AIMS: Oral glycoprotein IIb/IIIa inhibitors might enhance the early benefit of an intravenous agent and prevent subsequent cardiac events in patients with acute coronary syndromes. We assessed the safety and preliminary efficacy of 1 month treatment with three dose levels of the oral GP IIb/IIIa blocker lefradafiban in patients with unstable angina or myocardial infarction without persistent ST elevation. METHODS: The Fibrinogen Receptor Occupancy STudy (FROST) was designed as a dose-escalation trial with 20, 30 and 45 mg lefradafiban t.i.d. or placebo. Five hundred and thirty-one patients were randomized in a 3:1 ratio to lefradafiban or placebo in a double-blind manner. Efficacy was assessed by the incidence of death, myocardial infarction, coronary revascularization and recurrent angina. Safety was evaluated by the occurrence of bleeding classified according to the TIMI criteria and by measuring clinical laboratory parameters. RESULTS: There was a trend towards a reduction in cardiac events with lefradafiban 30 mg when compared with placebo and lefradafiban 20 mg. The benefit was particularly apparent in patients with a positive (> or = O.1 ng. ml(-1)) troponin I test at baseline and less so in those with a negative test result. In patients receiving lefradafiban, the cardiac event rate decreased with increasing minimal levels of fibrinogen receptor occupancy. There was a dose-dependent increase in the incidence of bleeding: the composite of major or minor bleeding occurred in 1% of placebo patients, 5% of patients receiving lefradafiban 20 mg and in 7% of patients receiving 30 mg, with an excessive risk (15%) in the 45 mg group which resulted in early discontinuation of this dose level. Gingival and arterial or venous puncture site bleedings were most common and accounted for more than 60% of all haemorrhagic events. There was an increased incidence of neutropenia (neutrophils <1. 5 x 10(9)/l) in the lefradafiban groups (5.2% vs 1.5% in the placebo group), which did not result from bone marrow depression but rather from a reversible redistribution of neutrophils by margination or clustering. CONCLUSION: One month's treatment with the oral glycoprotein IIb/IIIa inhibitor lefradafiban in patients with unstable angina and myocardial infarction without persistent ST elevation resulted in a decrease in cardiac events with lefradafiban 30 mg and a dose-dependent increase in haemorrhagic events. The observed favourable trend towards a reduction in cardiac events in patients with elevated troponin levels requires confirmation in a large clinical trial.

New atrial fibrillation after acute myocardial infarction independently predicts death: the GUSTO-III experience.

BACKGROUND: Atrial fibrillation (AF) or flutter occurring after myocardial infarction may occur alone or in association with other complications. Whether the arrhythmia portends a poor prognosis independent of other complications with contemporary therapy is unknown. METHODS AND RESULTS: As part of the Global Use of Strategies To Open occluded coronary arteries (GUSTO-III) trial, we evaluated whether postinfarction complications were associated with the subsequent development of AF and whether AF independently predicted death over periods of 30 days and 1 year. Information including exact timing was collected on deaths and major in-hospital postinfarction complications up to 30 days. Of the 13,858 patients with sinus rhythm at enrollment, 906 later had AF or flutter and 12, 952 did not. We compared outcomes between these 2 groups, adjusting for differences in baseline characteristics and prefibrillation complications. Worsening heart failure, hypotension, third-degree heart block, and ventricular fibrillation were independent predictors of new-onset AF. The unadjusted odds ratio (OR) for death among patients with versus those without AF was 2.74 (95% confidence interval [95% CI], 2.56-3.34). After adjusting for baseline differences, the OR was reduced to 1.63 (95% CI, 1.31-2.02). Adjustment for other in-hospital complications before the onset of AF further reduced the OR to 1.49 (95% CI, 1.17-1.89). CONCLUSIONS: Atrial fibrillation or flutter occurs secondary to other postinfarction complications but independently portends a worse prognosis. Prevention and management may improve outcome.

Oral glycoprotein IIb/IIIa inhibition with orbofiban in patients with unstable coronary syndromes (OPUS-TIMI 16) trial.

BACKGROUND: Although intravenous glycoprotein IIb/IIIa inhibitors are beneficial in patients with acute coronary syndromes, prolonged oral IIb/IIIa inhibition might provide an additional reduction in recurrent events. METHODS AND RESULTS: Investigators at 888 hospitals in 29 countries enrolled 10 288 patients with acute coronary syndromes, which was defined as ischemic pain at rest within 72 hours of randomization, associated with positive cardiac markers, electrocardiographic changes, or prior cardiovascular disease. Patients received aspirin and were randomized to receive, for the duration of the trial, (1) 50 mg of orbofiban twice daily (50/50 group), (2) 50 mg of orbofiban twice daily for 30 days followed by 30 mg of orbofiban twice daily (50/30 group), or (3) a placebo. The primary composite end point was death, myocardial infarction, recurrent ischemia requiring rehospitalization, urgent revascularization, or stroke. The trial was terminated prematurely because of an unexpected increase in 30-day mortality in the 50/30 orbofiban group. Mortality through 10 months was 3.7% for the placebo group versus 5.1% in the 50/30 group (P=0.008) and 4.5% in the 50/50 group (P=0.11). There were no differences in the primary end point (22.9%, 23.1%, and 22.8%, for the placebo, 50/30, and 50/50 groups, respectively). Major or severe bleeding (but not intracranial hemorrhage) was higher with orbofiban; it occurred in 2. 0%, 3.7% (P=0.0004), and 4.5% (P<0.0001) of patients, respectively. Exploratory subgroup analyses found that patients who underwent percutaneous coronary intervention had a lower mortality and a significant reduction in the composite end point (P=0.001) with orbofiban. CONCLUSIONS: -Fixed-dose orbofiban failed to reduce major cardiovascular events and was associated with increased mortality in this broad population of patients with acute coronary syndromes; however, a benefit was observed among patients who underwent percutaneous coronary intervention.

Predictors of outcome in patients with acute coronary syndromes without persistent ST-segment elevation. Results from an international trial of 9461 patients. The PURSUIT Investigators.

BACKGROUND: Appropriate treatment policies should include an accurate estimate of a patient's baseline risk. Risk modeling to date has been underutilized in patients with acute coronary syndromes without persistent ST-segment elevation. METHODS AND RESULTS: We analyzed the relation between baseline characteristics and the 30-day incidence of death and the composite of death or myocardial (re)infarction in 9461 patients with acute coronary syndromes without persistent ST-segment elevation enrolled in the PURSUIT trial [Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin (eptifibatide) Therapy]. Variables examined included demographics, history, hemodynamic condition, and symptom duration. Risk models were created with multivariable logistic regression and validated by bootstrapping techniques. There was a 3.6% mortality rate and 11.4% infarction rate by 30 days. More than 20 significant predictors for mortality and for the composite end point were identified. The most important baseline determinants of death were age (adjusted chi(2)=95), heart rate (chi(2)=32), systolic blood pressure (chi(2)=20), ST-segment depression (chi(2)=20), signs of heart failure (chi(2)=18), and cardiac enzymes (chi(2)=15). Determinants of mortality were generally also predictive of death or myocardial (re)infarction. Differences were observed, however, in the relative prognostic importance of predictive variables for mortality alone or the composite end point; for example, sex was a more important determinant of the composite end point (chi(2)=21) than of death alone (chi(2)=10). The accuracy of the prediction of the composite end point was less than that of mortality (C-index 0.67 versus 0.81). CONCLUSIONS: The occurrence of adverse events after presentation with acute coronary syndromes is affected by multiple factors. These factors should be considered in the clinical decision-making process.

Cigarette smoking status and outcome among patients with acute coronary syndromes without persistent ST-segment elevation: effect of inhibition of platelet glycoprotein IIb/IIIa with eptifibatide. The PURSUIT trial investigators.

BACKGROUND: Studies have shown that cigarette smokers constitute a substantial proportion of patients with acute coronary syndromes (ACS) and have platelet-rich coronary thrombi. We characterized the influence of smoking status on outcome of patients with ACS without persistent ST-segment elevation and tested the hypothesis that selective inhibition of the platelet glycoprotein IIb/IIIa receptor with eptifibatide would improve outcomes among cigarette smokers. METHODS: The study population included patients enrolled in the PURSUIT trial (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy) with known smoking status presenting with ischemic chest pain

Geographic variability in outcomes within an international trial of glycoprotein IIb/IIIa inhibition in patients with acute coronary syndromes. Results from PURSUIT.

AIMS: Variations in outcome of patients from different geographic regions have been observed in many large international trials. We analysed the factors that might contribute to the geographic variations in patient outcome and treatment effect as observed in the PURSUIT trial. METHODS: In PURSUIT, 9461 patients with acute coronary syndromes without persistent ST-elevation were randomized to the platelet inhibitor eptifibatide or placebo for 72 h in 27 countries in four geographic regions: Western (n=3697) and Eastern Europe (n=1541) as well as North (n=3827) and Latin America (n=396). The primary end-point was the 30-day composite of death or myocardial infarction. In the initial univariate analysis, the treatment effect appeared greater in N. America than in W. Europe, while no benefit was apparent in L. America and E. Europe. However, the confidence intervals were wide and overlapping. To study these differences, a subdivision in an early and late patient outcome and treatment effect was made. Accordingly, we analysed the rate of death or infarction at 72 h censored for percutaneous coronary intervention and the rate between 3 and 30 days, respectively. Additional analyses were performed with different definitions of myocardial infarction using progressively higher thresholds of CK(-MB) elevation. Multivariable analysis was used to evaluate the relation between region and outcome and to determine the adjusted odds ratios for the eptifibatide treatment effect. RESULTS: Major differences in baseline demographics were apparent among the four regions; in particular, more patients from E. Europe had characteristics associated with impaired outcome. Interventional treatment also varied considerably, with more patients from N. America undergoing revascularization. Despite differences in the 72 h event rate, eptifibatide showed a consistent trend towards a reduction in the composite end-point among all four regions and for all definitions of infarction. Relative reductions ranged from 17-42% in W. Europe, 23-35% in N. America, 0-33% in E. Europe, and 55-82% in L. America. After multivariable adjustment, the pattern of benefit with eptifibatide was consistent among the regions. In patients undergoing percutaneous coronary intervention during study drug infusion in W. Europe (n=266) and N. America (n=931), the relative reduction in myocardial infarction during medical therapy ranged from 56-75% in W. Europe and 14-67% in N. America, while the reduction in procedure-related events ranged from 12-44% and 25-61% for different definitions of infarction. After multivariable adjustment neither benefit nor rebound were apparent after study drug discontinuation, or after 3 days in all regions, except in L. America. In general, the differences in outcome and treatment effect were greatest when the protocol definition of myocardial infarction (CK(-MB) >1 upper normal limit) was applied. Under stricter definitions, these differences became smaller and disappeared with the investigator's assessment. CONCLUSION: The analysis suggests that the apparent differences in patient outcome and eptifibatide treatment effect can be explained largely by differences in baseline demographics and adjunctive treatment strategies as well as by the methodology of myocardial infarction definition and the adjudication process.

Early percutaneous coronary intervention, platelet inhibition with eptifibatide, and clinical outcomes in patients with acute coronary syndromes. PURSUIT Investigators.

BACKGROUND: Platelet glycoprotein (GP) IIb/IIIa antagonists prevent the composite end point of death or myocardial infarction (MI) in patients with acute coronary syndromes. There is uncertainty about whether this effect is confined to patients who have percutaneous coronary interventions (PCIs) and whether PCIs further prevent death or MI in patients already treated with GP IIb/IIIa antagonists. METHODS AND RESULTS: PURSUIT patients were treated with the GP IIb/IIIa antagonist eptifibatide or placebo; PCIs were performed according to physician practices. In 2253 of 9641 patients (23.4%), PCI was performed by 30 days. Early (<72 hours) PCI was performed in 1228 (12.7%). In 34 placebo patients (5.5%) and 10 treated with eptifibatide (1.7%) (P=0.001), MI preceded early PCI. In patients censored for PCI across the 30-day period, there was a significant reduction in the primary composite end point in eptifibatide patients (P=0.035). Eptifibatide reduced 30-day events in patients who had early PCI (11.6% versus 16.7%, P=0.01) and in patients who did not (14.6% versus 15.6%, P=0.23). After adjustment for PCI propensity, there was no evidence that eptifibatide treatment effect differed between patients with or without early PCI (P for interaction=0.634). PCI was not associated with a reduction of the primary composite end point but was associated with a reduced (nonspecified) composite of death or Q-wave MI. This association disappeared after adjustment for propensity for early PCI. CONCLUSIONS: Eptifibatide reduced the composite rates of death or MI in PCI patients and those managed conservatively.

Risk stratification with a point-of-care cardiac troponin T test in acute myocardial infarction. GUSTOIII Investigators. Global Use of Strategies To Open Occluded Coronary Arteries.

Troponin T has been used successfully to risk stratify patients with acute coronary syndromes, but the utility of this approach using a rapid bedside assay in patients undergoing thrombolysis for ST-segment elevation acute myocardial infarction has not been assessed in a large population. We assessed whether a point-of-care, qualitative troponin T test at enrollment could independently risk-stratify patients randomized to receive alteplase or reteplase in the GUSTO-III trial. Complete troponin T data were available for 12,666 patients (84%) enrolled at 550 hospitals. The primary end point was mortality at 30 days, and the predictive ability of an elevated baseline troponin T level was analyzed (after adjustment for baseline characteristics) with multiple logistic regression. Patients with an elevated troponin T result at enrollment (8.9%) had significantly higher mortality at 30 days (unadjusted 15.7% vs 6.2% for negative patients; p = 0.001), which persisted even after adjustment for age, heart rate, location of infarction, Killip class, and systolic blood pressure. In a multivariable regression model, a positive troponin T result added independently to the prediction of 30-day mortality (chi-square 46, p = 0.001). A positive result with qualitative troponin T testing on admission is an independent marker of higher 30-day mortality. Troponin T testing could be a valuable addition to the evaluation strategy for patients with acute myocardial infarction.

A whole blood assay of inhibition of platelet aggregation by glycoprotein IIb/IIIa antagonists: comparison with other aggregation methodologies.

We have used a whole blood single-platelet counting assay (WB-SPC) that is sensitive to microaggregation for monitoring GPIIb/IIIa antagonists and have compared this with other methodologies. In vitro effects of the GPIIb/IIIa antagonist fradafiban on ADP-induced platelet aggregation were determined using WBSPC and PRP turbidimetry, comparing citrate and hirudin anticoagulation. Fradafiban was a more potent inhibitor of aggregation assessed by PRP turbidimetry compared to WBSPC. Citrate showed only a trend towards enhancing fradafiban potency (p = 0.087). Citrated blood from 8 patients with unstable angina, randomised to receive oral lefradafiban (the oral prodrug of fradafiban) or placebo, was studied before and during treatment using WBSPC, PRP turbidimetry, impedance aggregometry and Rapid Platelet Function Assay (RPFA, Accumetrics). RPFA, PRP turbidimetry and WBSPC measurements correlated well. Impedance aggregometry responses were oversensitive to GPIIb/IIIa blockade. WBSPC was most discriminating at high levels of inhibition and offered a rapid means of monitoring GPIIb/IIIa antagonist effect within the therapeutic range of inhibition.