Increased baseline levels of platelet P-selectin, and platelet-endothelial cell adhesion molecule-1 in patients with acute myocardial infarction as predictors of unsuccessful thrombolysis.

Background: Platelets play a pivotal role in the pathogenesis of acute myocardial infarction and their activation can cause thrombolysis to fail.
Methods: Baseline aggregation of platelets and expression of major surface receptors measured by flow cytometry were compared with clinical outcome after thrombolysis for 23 patients enrolled in the GUSTO-III trial.
Results: Failure to reperfuse (n = 3) and recurrent ischemia (n = 2) were observed in five patients who subsequently underwent emergency angioplasty. These patients were treated later in their course of disease than were the 18 patients who were successfully reperfused and remained free of recurrent ischemia. Greater than normal expression of platelet P-selectin (33.7 +/- 1.1 versus 28.1 +/- 1.9, P = 0.01) and expression of platelet--endothelial cell adhesion molecule-1 (PECAM-1; (57.1 +/- 2.3 versus 50.2 +/- 2.8, P = 0.02) were observed in members of the group with recurrent ischemia or failed reperfusion.
Conclusion: Greater than normal baseline expression of P-selectin and PECAM-1 platelet receptors was correlated to delayed and unsuccessful coronary thrombolysis among patients presenting with acute myocardial infarction.