P-selectin expression, platelet aggregates, and platelet-derived microparticle formation are increased in peripheral arterial disease

Platelet volume has been reported to be increased in vascular disease. Ther efore, we studied the relationship of mean platelet volume and platelet cou nt as well as flow cytometrically measured platelet size and platelet funct ion in 50 patients with peripheral arterial disease and 50 healthy voluntee rs. Platelet activation was measured by P-selectin expression analysis on r esting and on stimulated platelets, and the determination of platelet aggre gates and platelet-derived microparticles using flow cytometry. P-Selectin expression on platelets was significantly elevated in patients suffering fr om peripheral arterial disease (all P < 0.0001). Platelet aggregates (P < 0 .0001) and platelet-derived microparticles (P < 0.0001) were significantly higher in the patient group compared with controls, whereas mean platelet v olume and platelet count showed no significant differences. Platelet count was inversely related to mean platelet volume in patients and controls (r = -0.43, P < 0.001). The present study supports the hypothesis of platelet h yperreactivity and circulating activated platelets in peripheral arterial d isease. Mean platelet volume, and platelet count cannot be used as predicti ve markers for platelet activation in peripheral arterial disease patients. Blood Coagul Fibrinolysis 11:723-728 (C) 2000 Lippincott Williams & Wilkin s.