PLATELET ACTIVATION IN EMBOLIC AND PREEMBOLIC STATUS OF PATIENTS WITHNONRHEUMATIC ATRIAL-FIBRILLATION

Study objective: Information on platelet activation possibly associate d with a preembolic or embolic status in nonrheumatic atrial fibrillat ion (AF) with special regard to the role of platelet membrane activati on markers (P-selectin and CD63). Study population: The study included 60 patients with nonrheumatic AF; 28 of them had a history of an embo lic event. The age-matched control group consisted of 28 healthy subje cts (13 men and 15 women). Interventions: Patients underwent transesop hageal echocardiography to detect eventual intracardiac thrombus or sp ontaneous echo contrast that would represent a preembolic status. Bloo d samples were taken from all persons to evaluate markers for platelet activation under these conditions. Results: Measurements of hematolog ic variables did not differ significantly between normal subjects and patients presenting wifh AF but no preembolic or embolic status. Eleva ted concentrations of fibrinogen were significantly related to the pre sence of left atrlal spontaneous echo contrast. The amount of circulat ing platelets expressing P-selectin and CD63 was significantly higher in the patients positive for both spontaneous echo contrast and left a trial thrombus or embolic events. Furthermore, in these groups, signif icantly more leukocyte-platelet conjugates were present. Conclusion: P latelet activation indicated by platelet membrane activation markers o ccurs in embolic and preembolic status of patients with nonrheumatic A F.