Effects of unfractionated heparin and glycoprotein IIb/IIIa antagonists versus bivalirdin on myeloperoxidase release from neutrophils.

UNLABELLED OBJECTIVES The objective of this study was to determine whether adjunctive therapy during percutaneous coronary intervention (PCI) affects markers of systemic inflammation or platelet activation. Despite different mechanisms of action, direct-thrombin inhibition with bivalirudin during PCI provided similar protection from periprocedural and chronic ischemic complications as compared with unfractionated heparin (UFH) plus planned use of GPIIb/IIIa antagonists in the REPLACE-2 and ACUITY trials. METHODS AND RESULTS Patients undergoing nonurgent PCI of a native coronary artery were randomized to receive adjunctive therapy with bivalirudin or UFH+eptifibatide. Interleukin (IL)-6 and C-reactive protein (CRP) transiently increased in both groups after PCI. In the UFH+eptifibatide, but not the bivalirudin group, myeloperoxidase (MPO) levels were elevated 2.3-fold above baseline (P=0.004) immediately after PCI. In an in vitro assay, heparin and to a lesser extent enoxaparin, but not bivalirudin or eptifibatide, stimulated MPO release from and binding to neutrophils and neutrophil activation. A mouse model of endoluminal femoral artery denudation was used to investigate further the importance of MPO in the context of arterial injury. CONCLUSIONS Adjuvant therapy during PCI may have undesired effects on neutrophil activation, MPO release, and systemic inflammation.