CAN THE RISK FOR ACUTE CARDIAC EVENTS IN ACUTE CORONARY SYNDROME BE INDICATED BY PLATELET MEMBRANE ACTIVATION MARKER P-SELECTIN

Background: P-selectin, an adhesion molecule of the selectin family, is expressed on the surface of activated thrombocytes by thrombin. The aim of the present study was to assess the predictive value of P-selectin (estimated by flow cytometric assay) for acute cardiac events in acute coronary syndrome. Methods: The study consisted of 48 patients with acute coronary syndrome and 30 healthy control subjects. After immediate fixation with 1% paraformaldehyde, 50 mu l of this aliquot was incubated with phycoerythrin-CD62-related antigen, and then measured by flow cytometry. The short-term clinical course of the patients was compared with their P-selectin values. Results: The average P-selectin values in the 30 healthy volunteers was 0.11 +/- 0.20% (range, 0.0-0.5%). Significant differences were observed between acute cardiac events in patients with unstable angina and high P-selectin values and those with normal P-selectin Values (chi(2)=4.3; P<0.05). Moreover, the angina patients who experienced acute cardiac events had significantly elevated P-selectin values (2.1 +/- 2.3%) compared with patients who did not experience acute cardiac events (0.3 +/- 0.4%, P<0.05). The P-selectin values were elevated in seven out of 24 patients who suffered acute myocardial infarction. Seven of the 14 patients with acute coronary syndromes and high P-selectin values required urgent percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG), or both, otherwise they developed extension of the infarction. However, only five of the 34 patients with normal P-selectin values required urgent PTCA or CABG. Significant differences were observed in acute cardiac events between the high P-selectin and normal P-selectin groups (chi(2)=4.8, P<0.05). Conclusion: High P-selectin values indicate activation of platelets and the risk of acute cardiac events in patients with acute coronary syndrome.