Role of activation-dependent platelet membrane glycoproteins in development of subacute occlusive coronary stent thrombosis

Background Platelets have an important role in coronary thrombosis. Methods We studied 151 consecutive patients undergoing implantation of Palmaz-Schatz stents because of suboptimal results after coronary balloon 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 platelet count and plasma fibrinogen, before and daily for 12 days after stenting 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 patients with enhanced GPIIb-IIIa surface expression (P< 0.003; 95% confidence interval 2.1 to 163.1) before stent placement. In the period after stenting, platelet activation occurred, with an increase in fibrinogen receptor activity and P-selectin degranulation above pre-stent values (P< 0.01), In logistic regression analysis, GPIIb-IIIa before stenting 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 acquired prognostic importance for stent thrombosis (P < 0.05). Conclusion We conclude that changes in platelet membrane glycoproteins are of prognostic value in predicting subacute stent thrombosis.