GP IIb/IIIa antagonists in ACS

By competing with fibrinogen and vWF for GP IIb/IIIa binding, GP IIb/IIIa antagonists inhibit platelet aggregation. Three approved parenteral GP IIb/IIIa antagonists for clinical use are abciximab, eptifibatide, and tirofiban.In older studies, including the landmark trial of EPIC, in high-risk patients undergoing balloon angioplasty, those randomized to abciximab bolus and infusion, had a 35% lower rate of death, MI, or unplanned urgent revascularization at 30 days. Similarly in the EPILOG trial a significant reduction in the incidence of death or MI in patients treated with abciximab was reported. In the two important randomized trials, EPISTENT and ESPRIT on patients undergoing coronary stenting the superior efficacy of GP IIb/IIIa antagonists were established.Subsequently, however, it was shown that GP IIb/IIIa inhibitors may no longer benefit patients if they had been pretreated with high-dose clopidogrel, particularly those with stable CAD or in the absence of elevated cardiac enzymes.In ISAR-REACT and ISAR-SWEET trials GP IIb/IIIa inhibitors had no clinical benefit in low- to intermediate-risk patients pretreated with clopidogrel. However, in the ISAR-REACT 2 trial benefit of GP IIb/IIIa inhibitors in pretreated patients with clopidogrel was detected on those patients who presented with elevated troponin.In EARLY-ACS trial, upstream IIb-IIIa inhibitors, compared with provisional therapy were associated with similar rate of primary endpoint and higher rate of bleeding complications.Overall, in the modern era of interventional cardiology using high p2y12 dosing regimens, GP IIb/IIIa inhibition should be reserved for high-risk patients with ACS and elevated cardiac biomarkers only for bailout purposes if there is evidence of no-reflow or a thrombotic complication. (IIa indication in ESC guidelines-2017).In the large (AIDA-STEMI) trial, intracoronary administration of abciximab was not superior to IV route.