Mark B. Effron

Randomized, Placebo-Controlled Trial of Platelet Glycoprotein IIb/IIIa Blockade With Primary Angioplasty for Acute Myocardial Infarction

Background—The benefit of catheter-based reperfusion for acute myocardial infarction (MI) is limited by a 5% to 15% incidence of in-hospital major ischemic events, usually caused by infarct artery reocclusion, and a 20% to 40% need for repeat percutaneous or surgical revascularization. Platelets play a key role in the process of early infarct artery reocclusion, but inhibition of aggregation via the glycoprotein IIb/IIIa receptor has not been prospectively evaluated in the setting of acute MI. Methods and Results—Patients with acute MI of <12 hours’ duration were randomized, on a double-blind basis, to placebo or abciximab if they were deemed candidates for primary PTCA. The primary efficacy end point was death, reinfarction, or any (urgent or elective) target vessel revascularization (TVR) at 6 months by intention-to-treat (ITT) analysis. Other key prespecified end points were early (7 and 30 days) death, reinfarction, or urgent TVR. The baseline clinical and angiographic variables of the 483 (242 placeb...

Facilitated PCI in Patients with ST-Elevation Myocardial Infarction

BACKGROUND We hypothesized that percutaneous coronary intervention (PCI) preceded by early treatment with abciximab plus half-dose reteplase (combination-facilitated PCI) or with abciximab alone (abciximab-facilitated PCI) would improve outcomes in patients with acute ST-segment elevation myocardial infarction, as compared with abciximab administered immediately before the procedure (primary PCI). METHODS In this international, double-blind, placebo-controlled study, we randomly assigned patients with ST-segment elevation myocardial infarction who presented 6 hours or less after the onset of symptoms to receive combination-facilitated PCI, abciximab-facilitated PCI, or primary PCI. All patients received unfractionated heparin or enoxaparin before PCI and a 12-hour infusion of abciximab after PCI. The primary end point was the composite of death from all causes, ventricular fibrillation occurring more than 48 hours after randomization, cardiogenic shock, and congestive heart failure during the first 90 days after randomization. RESULTS A total of 2452 patients were randomly assigned to a treatment group. Significantly more patients had early ST-segment resolution with combination-facilitated PCI (43.9%) than with abciximab-facilitated PCI (33.1%) or primary PCI (31.0%; P=0.01 and P=0.003, respectively). The primary end point occurred in 9.8%, 10.5%, and 10.7% of the patients in the combination-facilitated PCI group, abciximab-facilitated PCI group, and primary-PCI group, respectively (P=0.55); 90-day mortality rates were 5.2%, 5.5%, and 4.5%, respectively (P=0.49). CONCLUSIONS Neither facilitation of PCI with reteplase plus abciximab nor facilitation with abciximab alone significantly improved the clinical outcomes, as compared with abciximab given at the time of PCI, in patients with ST-segment elevation myocardial infarction. (ClinicalTrials.gov number, NCT00046228 [ClinicalTrials.gov].)

Emergency Administration of Abciximab for Treatment of Patients With Acute Ischemic Stroke: Results of an International Phase III Trial Abciximab in Emergency Treatment of Stroke Trial (AbESTT-II)

Background and Purpose— A previous randomized, placebo-controlled, double-blind study suggested that abciximab may be safe and effective in treatment of acute ischemic stroke. The current phase 3 study was planned to test the relative efficacy and safety of abciximab in patients with acute ischemic stroke with planned treatment within 5 hours since symptoms onset. Methods— An international, randomized, placebo-controlled, double-blind phase 3 trial tested intravenous administration of abciximab in 2 study cohorts using stratification variables of time since onset and stroke severity. The planned enrollment was 1800 patients. The primary cohort enrolled those patients who could be treated within 5 hours of onset of stroke. A companion cohort enrolled patients that were treated 5 to 6 hours after stroke as well as a smaller cohort of patients who could be treated within 3 hours of stroke present on awakening. The primary efficacy measure was the dichotomous modified Rankin Scale score at 3 months as adjusted to the baseline severity of stroke among subjects in the primary cohort. The primary safety outcome was the rate of symptomatic or fatal intracranial hemorrhage that occurred within 5 days of stroke. Results— The trial was terminated prematurely after 808 patients in all cohorts were enrolled by recommendation of an independent safety and efficacy monitoring board due to an unfavorable benefit-risk profile. At 3 months, approximately 33% of patients assigned placebo (72/218) and 32% of patients assigned abciximab (71/221; P=0.944) in the primary cohort were judged to have a favorable response to treatment. The distributions of outcomes on the modified Rankin Scale were similar between the treated and control groups. Within 5 days of enrollment, ≈5.5% of abciximab-treated and 0.5% of placebo-treated patients in the primary cohort had symptomatic or fatal intracranial hemorrhage (P=0.002). The trial also did not demonstrate an improvement in outcomes with abciximab among patients in the companion and wake-up cohorts. Although the number of patients was small, an increased rate of hemorrhage was noted within 5 days among patients in the wake-up population who received abciximab (13.6% versus 5% for placebo). Conclusions— This trial did not demonstrate either safety or efficacy of intravenous administration of abciximab for the treatment of patients with acute ischemic stroke regardless of end point or population studied. There was an increased rate of symptomatic or fatal intracranial hemorrhage in the primary and wake-up cohorts.

A pharmacodynamic comparison of prasugrel vs. high-dose clopidogrel in patients with type 2 diabetes mellitus and coronary artery disease: results of the Optimizing anti-Platelet Therapy In diabetes MellitUS (OPTIMUS)-3 Trial

Aims Patients with diabetes mellitus (DM) have increased platelet reactivity and reduced platelet response to clopidogrel compared with patients without DM. Prasugrel, a more potent antiplatelet agent, is associated with greater reductions in ischaemic events compared with clopidogrel, particularly in patients with DM. The aim of this study was to perform serial pharmacodynamic assessments of prasugrel with high-dose clopidogrel in patients with DM. Methods and results Optimizing anti-Platelet Therapy In diabetes MellitUS (OPTIMUS)-3 was a prospective, randomized, double-blind, crossover study in patients with type 2 DM and coronary artery disease (CAD). Patients (n= 35) were randomly assigned to either prasugrel 60 mg loading dose (LD)/10 mg maintenance dose (MD) or clopidogrel 600 mg LD/150 mg MD over two 1-week treatment periods separated by a 2-week washout period. Platelet function was assessed by VerifyNow® P2Y12 assay, light transmission aggregometry, and vasodilator-stimulated phosphoprotein phosphorylation at 0, 1, 4, and 24 h and 7 days. Greater platelet inhibition by VerifyNow® P2Y12 was achieved by prasugrel compared with clopidogrel at 4 h post-LD (least squares mean, 89.3 vs. 27.7%, P< 0.0001; primary endpoint). The difference in platelet inhibition between prasugrel and clopidogrel was significant from 1 h through 7 days (P < 0.0001). Similar results were obtained using all other platelet function measures. Prasugrel resulted in fewer poor responders at all time points irrespective of definition used. Conclusion In patients with type 2 DM and CAD, standard-dose prasugrel is associated with greater platelet inhibition and better response profiles during both the loading and maintenance periods when compared with double-dose clopidogrel. Clinical trial identifier: www.clinicaltrials.gov—NCT00642174

Increased Platelet Inhibition After Switching From Maintenance Clopidogrel to Prasugrel in Patients With Acute Coronary Syndromes: Results of the SWAP (SWitching Anti Platelet) Study

OBJECTIVES The objective was to evaluate the pharmacodynamic response of switching patients on maintenance phase clopidogrel therapy after an acute coronary syndrome (ACS) to prasugrel. BACKGROUND Prasugrel P2Y(12) receptor blockade is associated with greater pharmacodynamic platelet inhibition and reduction of ischemic complications compared with that of clopidogrel in ACS patients undergoing percutaneous coronary intervention. The pharmacodynamic effects of switching patients during maintenance phase clopidogrel therapy after an ACS event to prasugrel are unknown. METHODS The SWAP (SWitching Anti Platelet) study was a phase 2, multicenter, randomized, double-blind, double-dummy, active-control trial. After a run-in of daily open-label clopidogrel 75 mg with aspirin therapy for 10 to 14 days, patients were randomly assigned to 1 of the following 3 treatments: placebo loading dose (LD)/clopidogrel 75 mg maintenance dose (MD), placebo LD/prasugrel 10 mg MD, or prasugrel 60 mg LD/10 mg MD. Platelet function was evaluated at 2 h, 24 h, 7 days, and 14 days using light transmittance aggregometry, VerifyNow P2Y(12) assay, and vasodilator-stimulated phosphoprotein phosphorylation. RESULTS A total of 139 patients were randomized, of whom 100 were eligible for analysis. Maximum adenosine diphosphate-induced platelet aggregation (20 μM) by light transmittance aggregometry at 1 week (primary end point) was lower after prasugrel MD compared with clopidogrel MD (41.1% vs. 55.0%, p < 0.0001), and was also lower in the prasugrel LD+MD group compared with clopidogrel MD (41.0% vs. 55.0%, p < 0.0001). At 2 h, a prasugrel LD resulted in higher platelet inhibition compared with the other regimens. Similar results were found using light transmittance aggregometry with 5 μM adenosine diphosphate, VerifyNow P2Y(12), and vasodilator-stimulated phosphoprotein phosphorylation assays. CONCLUSIONS For patients receiving maintenance clopidogrel therapy after an ACS event, switching from clopidogrel to prasugrel is associated with a further reduction in platelet function by 1 week using prasugrel MD or within 2 h with the administration of a prasugrel LD. (A Pharmacodynamic Comparison of Prasugrel [LY640315] Versus Clopidogrel in Subjects With Acute Coronary Syndrome Who Are Receiving Clopidogrel [SWAP]; NCT00356135).

Benefits and Risks of Abciximab Use in Primary Angioplasty for Acute Myocardial Infarction The Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) Trial

Background—Trials of platelet glycoprotein IIb/IIIa inhibitors as adjuncts to primary percutaneous coronary intervention for acute myocardial infarction (MI) have shown improved early clinical and angiographic outcomes with treatment. However, variations in trial designs, modest sample sizes, and limited long-term follow-up have precluded these studies from being definitive. Methods and Results—As a prespecified secondary analysis of the CADILLAC trial, we compared early and late outcomes by abciximab assignment among 2082 patients randomized in an open-label, 2×2 factorial-design trial of primary stenting versus angioplasty and abciximab treatment (n=1052) versus no abciximab treatment (n=1030). Baseline characteristics were balanced between groups. Abciximab treatment was associated with a significant reduction in the composite end point of death, MI, ischemia-driven target-vessel revascularization (TVR), or disabling stroke at 30 days (4.6% versus 7.0%; relative risk, 0.65; 95% CI, 0.46 to 0.93; P =0.01). Subacute thrombosis also was significantly reduced with abciximab treatment. At 12 months, however, rates of the composite end point did not differ significantly (18.4% for controls versus 16.9% for abciximab-treated patients; relative risk, 0.92; 95% CI, 0.76 to 1.10; P =0.29), reflecting a decrease in the relative difference in TVR rates (ie, no effect of abciximab on reducing restenosis). In an angiographic substudy (n=656), myocardial salvage, restenosis, and infarct-artery reocclusion at 7 months were unaffected by abciximab treatment. There was no significant interaction between stenting and abciximab treatment. Conclusions—Adjunctive abciximab treatment during primary percutaneous coronary intervention significantly enhanced 30-day event-free survival, predominantly by reducing ischemia-driven TVR. Abciximab treatment did not affect the composite end point at 1 year, reflecting a lack of effect on restenosis.

Effects of Integrelin, a Platelet Glycoprotein IIb/IIIa Receptor Antagonist, in Unstable Angina A Randomized Multicenter Trial

BACKGROUND Although aspirin is beneficial in patients with unstable angina, it is a relatively weak inhibitor of platelet aggregation. The effect of Integrelin, which inhibits the platelet fibrinogen receptor glycoprotein (GP) IIb/IIIa, on the frequency and duration of Holter ischemia was evaluated in 227 patients with unstable angina. METHODS AND RESULTS Patients received intravenous heparin and standard ischemic therapy and were randomized to receive oral aspirin and placebo Integrelin; placebo aspirin and low-dose Integrelin. 45 micrograms/kg bolus followed by a 0.5 microgram.kg-1. min-1 continuous infusion; or placebo aspirin and high-dose Integrelin, 90 micrograms/kg bolus followed by a 1.0-microgram.kg-1, min-1 constant infusion. Study drug was continued for 24 to 72 hours, and Holter monitoring was performed. Patients randomized to high-dose Integrelin experienced 0.24 +/- 0.11 ischemic episodes (mean +/- SEM) on Holter lasting 8.41 +/- 5.29 minutes over 24 hours of study drug infusion. Patients randomized to aspirin experienced a greater number (1.0 +/- 0.33, P < .05) and longer duration (26.2 +/- 9.8 minutes, P = .01) of ischemic episodes than the high-dose Integrelin group. There was no evidence of rebound ischemia after withdrawal of study drug. In 46 patients, platelet aggregation was rapidly inhibited by Integrelin in a dose-dependent fashion. The number of clinical events was small, and there were no bleeding differences in the three treatment arms. CONCLUSIONS Intravenous Integrelin is well tolerated, is a potent reversible inhibitor of platelet aggregation, and added to full-dose heparin reduces the number and duration of Holter ischemic events in patients with unstable angina compared with aspirin.

Effects of the Selective Estrogen Receptor Modulator Raloxifene on Coronary Outcomes in The Raloxifene Use for the Heart Trial: Results of Subgroup Analyses by Age and Other Factors

Background— The Raloxifene Use for The Heart (RUTH) trial showed that raloxifene, a selective estrogen receptor modulator, had no overall effect on the incidence of coronary events in women with established coronary heart disease or coronary heart disease risk factors. We provide detailed results of the effect of raloxifene on coronary outcomes over time and for 24 subgroups (17 predefined, 7 post hoc). Methods and Results— Postmenopausal women (n=10 101; mean age, 67 years) were randomized to raloxifene 60 mg/d or placebo for a median of 5.6 years. Coronary outcomes were assessed by treatment group in women with coronary heart disease risk factors and those with established coronary heart disease. Raloxifene had no effect on the incidence of coronary events in any subgroup except in the case of a post hoc age subgroup analysis using age categories defined in the Womens Health Initiative randomized trials. The effect of raloxifene on the incidence of coronary events differed significantly by age (interaction P=0.0118). The incidence of coronary events in women <60 years of age was significantly lower in those assigned raloxifene (50 events) compared with placebo (84 events; hazard ratio, 0.59; 95% confidence interval, 0.41 to 0.83; P=0.003; absolute risk reduction, 36 per 1000 women treated for 1 year). No difference was found between treatment groups in the incidence of coronary events in women ≥60 and <70 or ≥70 years of age. Conclusions— In postmenopausal women at increased risk of coronary events, the overall lack of benefit of raloxifene was similar across the prespecified subgroups.

Benefit of Facilitated Percutaneous Coronary Intervention in High-Risk ST-Segment Elevation Myocardial Infarction Patients Presenting to Nonpercutaneous Coronary Intervention Hospitals

OBJECTIVES We hypothesized that patients most likely to benefit would be those at high risk with a shorter duration of acute ischemia and who required transfer for percutaneous coronary intervention (PCI). BACKGROUND The FINESSE (Facilitated Intervention with Enhanced Reperfusion Speed to Stop Events) study failed to demonstrate an improvement in the 90-day composite clinical end point of early treatment with abciximab plus half-dose reteplase (combination-facilitated PCI) or abciximab alone. METHODS We performed a retrospective analysis of 2,452 patients in this double-blind, placebo-controlled study. Patients were stratified by Thrombolysis In Myocardial Infarction (TIMI) risk score for ST-segment elevation myocardial infarction (STEMI), presentation to a spoke (no PCI available) or hub site, and symptom-to-randomization time. Outcomes included the primary composite end point of death, ventricular fibrillation after 48 h, cardiogenic shock, and congestive heart failure through day 90 as well as 1-year mortality. RESULTS Mortality for all patients at 1 year was directly related to TIMI risk score (23 of 1,223 = 1.9% in patients with score <3 and 145 of 1,229 = 11.8% with score > or =3, p < 0.001). Patients with TIMI risk score > or =3 and presentation to a spoke site with a symptom-to-randomization time < or =4 h had significantly better 1-year survival if treated with combination-facilitated PCI (hazard ratio [HR]: 0.351, p = 0.01) as well as 90-day composite outcome (HR: 0.45, p = 0.009). A trend for improved survival was also observed in patients with TIMI score > or =3 and spoke site alone (HR: 0.549, p = 0.06). CONCLUSIONS Facilitation of PCI with a combination of abciximab and half-dose reteplase improved survival at 1 year in high-risk patients presenting to a spoke hospital with symptom-to-randomization time < or =4 h. Further prospective study of facilitated PCI in this subgroup of patients is warranted.

Abciximab and bleeding during coronary surgery: results from the EPILOG and EPISTENT trials ∗

BACKGROUND Abciximab during percutaneous coronary revascularization reduces ischemic complications, but concern exists regarding increased bleeding risk should emergency coronary surgical procedures be required. METHODS Outcomes were assessed among 85 patients who required coronary artery bypass grafting operations after coronary intervention in two randomized placebo-controlled trials of abciximab. Comparisons were made between patients in the pooled placebo and abciximab groups. RESULTS The incidence of coronary surgical procedures was 2.17% and 1.28% among patients randomized to placebo and abciximab, respectively (p = 0.021). Platelet transfusions were administered to 32% and 52% of patients in the placebo and abciximab groups, respectively (p = 0.059). Rates of major blood loss were 79% and 88% in the placebo and abciximab groups, respectively (p = 0.27); transfusions of packed red blood cells or whole blood were administered in 74% and 80% of patients, respectively (p = 0.53). Surgical reexploration for bleeding was required in 3% and 12% of patients, respectively. Death and myocardial infarction tended to occur less frequently among patients who had received abciximab. CONCLUSIONS Urgent coronary artery bypass grafting operations can be performed without an incremental increase in major hemorrhagic risk among patients on abciximab therapy.