Baseline platelet aggregation and major receptor expression predict subsequent activity following thrombolysis for acute myocardial infarction

Abstract

The early identification of patients with heightened platelet activity for aggressive antiplatelet regimens represents a critical clinical issue in acute myocardial infarction (AMI) therapy. We sought to determine whether the degree of pre-reperfusion platelet function is related to subsequent activity following thrombolysis. Platelets were investigated at baseline and at 24 h following thrombolytic therapy by aggregometry, and flow cytometry in 19 AMI patients enrolled in the GUSTO-III trial. Regression analysis revealed a significant correlation for 5 microM ADP (r2 = 0.529), 10 microM ADP (r2 = 0.445), thrombin (r2 = 0.226), collagen (r2 = 0.568), and ristocetin-induced aggregation (r2 = 0.964). Platelet expression linearly correlated for GPIIb/IIIa (r2 = 0.337), P-selectin (r = 0.817), PECAM-1 (r2 = 0.586), and the vitronectin receptor (r2 = 0.634). The data suggest that the baseline characteristics predict future platelet activity, and may prospectively identify patients who will benefit most from antiplatelet strategies after coronary thrombolysis.