The Relative Effects of Abciximab and Tirofiban on Platelet Inhibition and C-Reactive Protein during Coronary Intervention

Volume 22 - Issue 1 - January, 2010
Posted on: 1/7/10
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Pages:

2 - 6

Author(s):

Adam J. Saltzman, MD, Roxana Mehran, MD, W. Craig Hooper, PhD*, Jeffrey W. Moses, MD,
Giora Weisz, MD, Michael B. Collins, MD, Alexandra J. Lansky, MD, Edward M. Kreps, MD,
Martin B. Leon, MD, Gregg W. Stone, MD, George Dangas, MD

ABSTRACT: Background. We sought to compare the efficacy of tirofiban and abciximab on platelet inhibition as well as their effects of platelet inhibition on C-reactive protein levels during percutaneous coronary intervention (PCI). Methods. Using a randomized, double-blind study design, 95 consecutively eligible patients were randomized to receive either tirofiban or abciximab before undergoing native coronary artery revascularization with a stent. Clinical endpoints were death, nonfatal MI, target vessel revascularization (TVR) with coronary artery bypass grafting or PCI within 30 days of the study procedure. The medications were compared for differences in platelet aggregation as measured by a rapid function platelet assay, as well as measurements of the inflammatory marker C-reactive protein (CRP) at frequent intervals following drug administration during PCI. Results. A total of 95 patients were randomized to abciximab (n = 44) or tirofiban (n= 51). There was no significant difference in platelet aggregation documented throughout the procedure (10-, 20-, 30-, 45-minute time points). In diabetic patients abciximab had significantly lower platelet inhibition as compared to tirofiban at 10 minutes (84.17 ± 8.28% vs. 90.40 ± 5.79%; p = 0.0097). Using a Spearman correlation coefficient model, hs-CRP demonstrated an inverse relationship with platelet inhibition over time (-0.7307, p=0.0002) in patients treated with abciximab. Conclusion. There is no major difference in platelet inhibition between tirofiban and abciximab during PCI. In this study, tirofiban showed a greater inhibition in diabetic subsets at the first time point within PCI. Platelet inhibition may be inversely related to the levels of CRP during PCI.

J INVASIVE CARDIOL 2010;22:2–6

Key words: glycoprotein IIb/IIIa receptor antagonists,
platelet inhibition, inflammation, percutaneous coronary intervention

Several randomized trials have studied the use of glycoprotein (GP) IIb/IIIa platelet inhibitors in unstable angina/non-Q-wave myocardial infarction (MI) and in the cardiac catheterization laboratory.1–9 Results from a multicenter study demonstrated that a high degree of platelet inhibition during percutaneous coronary intervention (PCI) was associated with less major adverse cardiac events (MACE).10 Although all GP IIb/IIIa inhibitors have been reported to produce > 80% inhibition of platelet aggregation ex vivo and in vitro, the in vivo degree of GP IIb/IIIa inhibition and platelet aggregation during the PCI itself have not been well studied.

The aim of this study was to compare the efficacy of abciximab (a noncompetitive inhibitor of fibrinogen binding) (Reo-Pro, Eli Lilly and Company, Indianapolis, Indiana) and tirofiban (a competitive inhibitor of fibrinogen binding) (Aggrastat, Merck, White House Station, New Jersey), both in combination with heparin, in inhibiting platelet aggregation and inflammatory marker fluctuation during the duration of the PCI procedure in patients undergoing urgent PCI for unstable angina as well as elective PCI.

Methods