Comparison of clinical trials with glycoprotein IIb-IIIa inhibitors in the management of acute coronary syndromes

Inhibitors of the platelet receptor glycoprotein (GP) IIb-IIa represent an important advance in the management of patients with unstable angina or non-Q-wave myocarbial infarction, known collectively as non-ST-segment elevation acute coronary syndromes (ACS). Clinical trials with three GP IIb- IIIa inhibitors have all demonstrated significant therapeutic benefits with this drug class. However, due to substantial differences in trial design (e.g., entry criteria and management strategies employed), achieving optimal results with GP IIb-IIIa inhibitors in clinical practice requires careful examination and a full understanding of these differences. In the CAPTURE trial with abciximab, patients were eligible for enrollment if they had angina that was refractory to heparin and nitrates, and if diagnostic catherization demonstrated that their culprit lessions were suitable for angioplasty, which was performed in all patients 18-24 hours after randomization. The PRISM-PLUS study with tirofiban hydrochloride enrolled patients with very-high risk electrocardiographic (ECG) changes, and diagnostic catherization was carried out in 90% of patients of 48-96 hours after randomization. In the PURSUIT trial with eptifibatide, ECG and other eligibility requirements were less stringent, and the use and timing of invasive procedures were left to the discretion of the physician. Other significant study differences pertain to the use of heparin, minimal duration of study drug infusion, and the adjudication of endpoint and data analysis. The PURSUIT results are applicable to the broadest population of patients with non-ST-segment elevation ACS, as well as to the full spectrum of clinical management strategies.