Mixed Findings for Prehospital Bivalirudin in Primary PCI

Since completion of the HORIZONS AMI trial (NEJM JW Cardiol May 21 2008), prehospital antithrombotic treatment, radial access, and novel antiplatelet therapies have become widespread in percutaneous coronary intervention (PCI) for ST-segment-elevation myocardial infarction. In a new, manufacturer-sponsored, randomized, open-label, multicenter, European trial, investigators compared outcomes in 2218 adults (median age, 62; 24% women) who received bivalirudin or heparin and optional glycoprotein (GP) IIb/IIIa inhibitors (used in 69%) during transport for primary PCI. The primary outcome was a composite of death and major bleeding unrelated to coronary artery bypass grafting at 30 days. Major bleeding was defined as any intracranial, retroperitoneal, or intraocular hemorrhage; a decrease in hemoglobin (≥4 g/dL with — or ≥3 g/dL without — an overt source); or an event leading to reintervention or transfusion.

The primary outcome occurred in 5.1% of bivalirudin patients and 8.5% of heparin patients (relative risk, 0.60; P=0.001). The difference was driven by a reduction in protocol-defined major bleeding from 6.0% to 2.6%, mostly at nonaccess sites; cardiac and noncardiac mortality were similar in both groups. Transfusions were reduced with bivalirudin from 3.9% to 2.1%, but major bleeding defined by Thrombolysis in Myocardial Infarction criteria did not differ significantly between the two groups. Acute stent thrombosis occurred more frequently with bivalirudin (1.6%) than with heparin and optional GP IIb/IIIa inhibitors (0.5%; RR, 2.89; P=0.02), at a median time of 2.3 hours after PCI. The results were similar in many prespecified subgroup comparisons, including by access site (radial, 46%) and P2Y₁₂ inhibitor (novel agents, >50%).