PLATELET MEMBRANE ACTIVATION MARKERS ARE PREDICTIVE FOR INCREASED RISK OF ACUTE ISCHEMIC EVENTS AFTER PTCA

Background. We wished to investigate whether platelet activation is related to the clinical outcome during the 24 hours immediately after elective percutaneous transluminal coronary angioplasty (PTCA). Methods and Results. In 102 patients with high-grade coronary stenosis admitted for elective PTCA, preprocedural platelet activation was characterized by flow cytometric measurement of the proteins CD62, CD63, and thrombospondin expressed on the platelet surface membrane. The prevalence of acute ischemic events during the 24 hours immediately after the procedure was then related to the pre-PTCA platelet activation status. Fifty-six patients were classified as ''nonactivated,'' whereas 46 patients showed an increased percentage of activated platelets. Two patients developed acute occlusion (1.96%) and four patients high-grade restenosis (3.92%), as confirmed by second-look coronary angiography. All events occurred in patients classified as ''activated'' (six of 46, or 13%). None of these patients received beta-blocker medication, which was associated with lower expression of platelet membrane activation markers. In the nonactivated patient group, no clinical events were found (0 of 56, or 0%). This difference in prevalence is significant (p=0.007). Conclusions. We conclude that analysis of platelet membrane activation markers may help to predict an increased risk of acute ischemic events after angioplasty.