[Effect of different duration of clopidogrel pretreatment on platelet activation in patients undergoing stenting].

Objective: To investigate the effect of two clopidogrel pretreatment duration on platelet activation in patients undergoing stenting.
Methods: From July 2006 to December 2007 40 elective carotid or vertebral artery stenting patients were assigned into two groups: Group A (n = 24) initiated clopidogrel (75 mg/d) > or = 5 d before stenting; group B (n = 16) initiated 3 - 4 days. Platelet-monocyte aggregates and fibrinogen receptors analyzed by flow cytometric, and platelet aggregation tests using optical aggregometry, as well as serum soluble CD40 ligand quantified by enzyme-linked immunosorbent assay were assessed in peripheral blood samples obtained immediately before and at 0.5, 18 h and 6 d after stenting.
Results: Platelet-monocyte aggregates, fibrinogen receptors and serum soluble CD40 ligand were higher in group B than in group A (14.59% vs 8.70%, P = 0.012; 4.87% vs 2.42%, P = 0.024; 5.79 microg/L vs 2.64 microg/L, P = 0.020) at 18 h after stenting. Serum soluble CD40 ligand was higher in group B than in group A (0.49 microg/L vs 0.31 microg/L, P = 0.033) at 0.5 h after stenting.
Conclusions: Premedication before stenting with clopidogrel 75 mg/d merely 3 - 4 d may be insufficient to achieve adequate platelet inhibition, whereas clopidogrel initiated at least 5 d could obtain preferable clinical antiplatelet efficacy.