The Current Role of Glycoprotein IIb/ IIIa Inhibitors in Percutaneous Coronary Intervention*

The central role of platelets in acute coronary syndromes (ACS) and percutaneous coronary interventions (PCI) is well appreciated. The various platelet activation mechanisms finally lead to the expression and activation of surface glycoprotein IIb/ IIIa receptors that mediate platelet aggregation and thrombus formation. Glycoprotein IIb/IIIa inhibitors (GPIs) are the most potent antiplatelet agents and their role in ACS treatment and PCI has been dominant in the recent past. The advent of stents and thienopyridines minimized ischemic complications and in parallel the role of GPIs in low risk PCI. Despite being effective in decreasing PCI-related ischemic complications, the major drawback of GPI use is a relative increase of hemorrhagic complications that can unfavorably affect prognosis. The availability of bivalirudin, which is regarded as an equally effective but safer antithrombotic agent when compared to the combination of heparin and GPIs, despite an ongoing controversy, has also led to a decrease of GPI use in PCI for ACS. Finally the advent of novel potent antiplatelet agents (prasugrel, ticagrelor and soon cangrelor) further contained GPI use in patients with ischemic – thrombotic risk that clearly exceeds bleeding risk and mainly for bail-out in case of a thrombotic event during PCI. A concise overview of accumulated data regarding optimal use of GPIs as determined by large clinical trials and recent guidelines is herein attempted. I N t r O D U c t I O N The glycoprotein IIb/IIIa receptor is an integrin, a heterodimer consisting of αIIb and β3 subunits, which mediates the final common pathway of platelet aggregation. Glycoprotein IIb/IIIa inhibitors (GPIs) compete with fibrinogen and von Willebrand factor for glycoprotein IIb/IIIa binding and thus interfere with platelet cross-linking and platelet-derived thrombus formation (Fig. 1). Due to this mechanism of action, GPIs are very effective in inhibiting platelets and three parenteral GPIs with different pharmacologic features have been approved for clinical use: abciximab, eptifibatide, and tirofiban (Table 1). revIew Department of Cardiology, Evagelismos Hospital, Athens, Greece HOSPITAL CHRONICLES 2016, 11(2): 85–97