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

Background. We wished to investigate whether platelet activation is re lated to the clinical outcome during the 24 hours immediately after el ective percutaneous transluminal coronary angioplasty (PTCA). Methods and Results. In 102 patients with high-grade coronary stenosis admitte d for elective PTCA, preprocedural platelet activation was characteriz ed by flow cytometric measurement of the proteins CD62, CD63, and thro mbospondin expressed on the platelet surface membrane. The prevalence of acute ischemic events during the 24 hours immediately after the pro cedure was then related to the pre-PTCA platelet activation status. Fi fty-six patients were classified as ''nonactivated,'' whereas 46 patie nts showed an increased percentage of activated platelets. Two patient s developed acute occlusion (1.96%) and four patients high-grade reste nosis (3.92%), as confirmed by second-look coronary angiography. All e vents occurred in patients classified as ''activated'' (six of 46, or 13%). None of these patients received beta-blocker medication, which w as associated with lower expression of platelet membrane activation ma rkers. In the nonactivated patient group, no clinical events were foun d (0 of 56, or 0%). This difference in prevalence is significant (p=0. 007). Conclusions. We conclude that analysis of platelet membrane acti vation markers may help to predict an increased risk of acute ischemic events after angioplasty.