ANTIPLATELET EFFECT OF TICLOPIDINE AFTER CORONARY STENTING

Objectives. This study sought to investigate the contribution of ticlo pidine to the inhibition of platelet activation after coronary stent p lacement. Background. After coronary stenting, antiplatelet therapy wi th aspirin and ticlopidine improves stent patency compared with antico agulation, However, the specific role of ticlopidine has not been eluc idated. Methods. After successful coronary stent placement, we randomi zed 22 patients to receive ticlopidine and aspirin (ticlopidine group) and 25 to receive aspirin alone (aspirin group). Surface expression o n platelets of the activated fibrinogen receptor and of P-selectin was assessed by flow cytometry. Results. In the aspirin group the percent of platelets with activated fibrinogen receptors increased between da ys 1 and 5 (p = 0.001), whereas there were no substantial changes in t he ticlopidine group, The percent of P-selectin-positive platelets did not change significantly in the aspirin group but decreased in the ti clopidine group (p = 0.019). At day 5 after the intervention, the perc ent of platelets with activated fibrinogen receptors in the ticlopidin e group was significantly lower (median [interquartile range]: 8.5 [3. 1 to 17.8] vs. 18.1 [8.5 to 35.5], p = 0.025), and there was a trend t o fewer P-selectin-positive platelets than in the aspirin group (5.8 [ 3.4 to 9.5] vs, 8.8 [4.0 to 15.8], p = 0.073). Conclusions. Combined a ntiplatelet therapy with ticlopidine plus aspirin is superior to treat ment with aspirin alone in suppressing platelet activation after coron ary stenting. (C) 1997 by the American College of Cardiology.