Comparison of changes in circulating platelet-derived microparticles and platelet surface P-selectin expression after coronary stent implantation

Platelet-derived microparticles (PDMPs) are released from activated platelets and may participate in the inflammatory process in response to vessel wall injury. This study was designed to compare the clinical significance of circulating PDMPs with that of P-selectin on the platelet membrane surface. In 20 patients with stable angina undergoing coronary stent implantation, circulating PDMPs were serially measured by enzyme-linked immunosorbent assay, and P-selectin expression on the surface of platelets was simultaneously analyzed by flow cytometry. PDMPs increased 24–48 h after coronary stenting in the coronary sinus (8.7 ± 8.9 to 31.8 ± 19.8 U/ml, P < 0.001) with a maximum at 48 h. In contrast, the mean channel fluorescence intensity for P-selectin increased 15 min after coronary stenting in the coronary sinus (19.5 ± 5.6 to 25.2 ± 7.5, P < 0.01) and remained elevated for 48 h; the changes were less striking in peripheral blood. The relative increase in PDMPs was not correlated with the increase in P-sel...