Bivalirudin preferred for PCI in AMI with or without ST-elevation
MedWire News: A head-to-head comparison of a combination of abciximab and unfractionated heparin (UFH) versus bivalirudin in patients with acute non-ST-segment elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention (PCI) shows that the efficacy of the two therapies are virtually identical.
Primary and secondary efficacy endpoints were not significantly different between the treatment groups, but bivalirudin was significantly better in the secondary safety endpoint of major bleeding, at 2.6% versus 4.6% with abciximab/UFH (p=0.02).
"These findings, along with those reported for STEMI, show that bivalirudin might be the preferred drug in patients undergoing PCI for an acute myocardial infarction, with or without ST-segment elevation," said lead author Adnan Kastrati (Deutsches Herzzentrum, Munich, Germany), speaking at the American Heart Association Scientific Sessions in Orlando, Florida.
Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment 4 (ISAR-REACT 4) was designed to answer a question not satisfactorily addressed by the 2006 Acute Catheterization and Urgent Intervention Triage Strategy trial (ACUITY): whether the combination of the glycoprotein IIb/IIIa inhibitor abciximab plus UFH could be equal or superior in efficacy to the direct thrombin inhibitor bivalirudin in patients with NSTEMI undergoing PCI.
The investigators enrolled 1721 patients from the ages of 19 through 80 years who had unstable angina within the preceding 48 hours, elevated levels of the cardiac biomarkers troponin or CK-MB, and coronary stenoses requiring PCI. The study was powered to detect a 30% reduction with abciximab/UFH in a composite endpoint of death, large myocardial infarction, or urgent target vessel revascularization within 30 days of PCI. Patients with STEMI within 48 hours of symptoms onset were excluded, as were those with cardiogenic shock, active bleeding or a bleeding diathesis, a planned staged PCI within 30 days, glomerular filtration rate <30 mL/min or creatine >30 mg/L, or who had recently received coumarin, a glycoprotein IIb/IIIa inhibitor, unfractionated or low molecular weight heparin, or bivalirudin.
Immediately before PCI, patients were randomly assigned in a double-blind fashion to receive either a bolus infusion of abciximab 0.25 mg/kg followed by a 12-hour infusion, plus a bolus dose of UFH 70 U/kg, or a bolus of bivalirudin 0.75 mg/kg followed by an infusion of 1.75 mg/kg for the duration of PCI. All patients also received 600 mg clopidogrel.
There were no significant between-group differences in the primary endpoint among all patients, at 10.9% and 11.0% for patients given abciximab/UFH and bivalirudin, respectively (p=0.94). The corresponding rates of the secondary endpoint of death, any MI, or urgent target vessel revascularization, were 12.8% and 13.4%, respectively (p=0.76). There were also no between-group differences among subsets of patients grouped by age, gender, diabetes status, body mass index, glomerular filtration rate, or troponin T values.
The safety analysis, however, showed that the incidence of major bleeding was significantly higher among patients treated with abciximab/UFH. The incidence of Thrombolysis in Myocardial Infarction (TIMI) major bleeding was similar (p=0.61), but TIMI minor bleeding occurred significantly more in the abciximab group (7.7 vs 4.3%, p=0.003).
By Neil Osterweil