Platelet activation in embolic and preembolic status of patients with nonrheumatic atrial fibrillation.
OBJECTIVE
Information on platelet activation possibly associated with a preembolic or embolic status in nonrheumatic atrial fibrillation (AF) with special regard to the role of platelet membrane activation markers (P-selectin and CD63).


METHODS
The study included 60 patients with nonrheumatic AF; 28 of them had a history of an embolic event. The age-matched control group consisted of 28 healthy subjects (13 men and 15 women).


METHODS
Patients underwent transesophageal echocardiography to detect eventual intracardiac thrombus or spontaneous echo contrast that would represent a preembolic status. Blood samples were taken from all persons to evaluate markers for platelet activation under these conditions.


RESULTS
Measurements of hematologic variables did not differ significantly between normal subjects and patients presenting with AF but no preembolic or embolic status. Elevated concentrations of fibrinogen were significantly related to the presence of left atrial spontaneous echo contrast. The amount of circulating platelets expressing P-selectin and CD63 was significantly higher in the patients positive for both spontaneous echo contrast and left atrial thrombus or embolic events. Furthermore, in these groups, significantly more leukocyte-platelet conjugates were present.


CONCLUSIONS
Platelet activation indicated by platelet membrane activation markers occurs in embolic and preembolic status of patients with nonrheumatic AF.
Pongratz
G
G
Department of Internal Medicine, University of Erlangen, Germany.
Brandt-Pohlmann
M
M
Henneke
K H
KH
Pohle
C
C
Zink
D
D
Gehling
G
G
Bachmann
K
K
D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D001281:Atrial Fibrillation / Q000097:blood* / Q000150:complications; D001792:Blood Platelets / Q000737:chemistry; D017548:Echocardiography, Transesophageal; D004617:Embolism / Q000097:blood* / Q000209:etiology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D019007:P-Selectin / Q000032:analysis; D015539:Platelet Activation; D010980:Platelet Membrane Glycoproteins / Q000032:analysis; D060149:Tetraspanin 30
D015703:Antigens, CD; C554586:CD63 protein, human; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30