ROLE OF ACTIVATION-DEPENDENT PLATELET MEMBRANE-GLYCOPROTEINS IN DEVELOPMENT OF SUBACUTE OCCLUSIVE CORONARY STENT THROMBOSIS

Background Platelets have an important role in coronary thrombosis. Me thods We studied 151 consecutive patients undergoing implantation of P almaz-Schatz stents because of suboptimal results after coronary ballo on angioplasty treated by intense anticoagulation. Surface exposure of the constitutively expressed glycoprotein complex IIb-IIIa (CD41), P- selectin (CD62P) and of the GPIIb-IIIa complex activated exposure (of ligand-induced binding site-1) were determined, in addition to platele t count and plasma fibrinogen, before and daily for 12 days after sten ting in peripheral venous blood samples. Results Six of 151 patients ( 3.9%) developed subacute stent thrombosis within the first week after stenting. The relative risk of stent thrombosis was 18.5-fold for pati ents with enhanced GPIIb-IIIa surface expression (P< 0.003; 95% confid ence interval 2.1 to 163.1) before stent placement. In the period afte r stenting, platelet activation occurred, with an increase in fibrinog en receptor activity and P-selectin degranulation above pre-stent valu es (P< 0.01), In logistic regression analysis, GPIIb-IIIa before stent ing emerged as a risk factor for stent thrombosis, independent of the activational status of platelets, platelet count or fibrinogen levels (P< 0.02). However, after stenting, P-selectin surface expression acqu ired prognostic importance for stent thrombosis (P < 0.05). Conclusion We conclude that changes in platelet membrane glycoproteins are of pr ognostic value in predicting subacute stent thrombosis.