Antiplatelet therapy is the cornerstone of treatment for patients with an acute coronary syndrome (ACS). However, patients presenting with possible ACS are a heterogeneous population, and there is a choice of many potential combination antiplatelet therapies, with aspirin, thienopyridines (eg, clopidogrel), and glycoprotein (GP) IIb/IIIa antagonists. The ISAR-REACT-2 trial investigated the optimal application of triple (aspirin + thienopyridine + GP IIb/IIIa inhibitor) versus dual (aspirin + thienopyridine) antiplatelet therapy for patients with ACS undergoing percutaneous coronary intervention. Abciximab was associated with a significant 25% relative reduction in risk for the 30-day combined endpoint of death, myocardial infarction, or urgent target vessel revascularization. All of this benefit was confined to the patients with elevated troponin levels. The data indicate that troponin can be used as a biomarker to identify patients most likely to benefit from the addition of a GP IIb/IIIa antagonist.