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.