Serial change in platelet activation markers with aspirin and clopidogrel after acute ischemic stroke.
OBJECTIVE
Antiplatelet drugs are widely used for secondary prevention after cerebral ischemia of noncardioembolic origin and different antiplatelet drugs exert different pharmacologic effects. This study investigated differences in platelet activation markers in patients taking either aspirin or clopidogrel after acute ischemic stroke.


METHODS
A prospective randomized case-control study evaluated 70 patients with noncardioembolic stroke treated with either aspirin (100 mg/d) or clopidogrel (75 mg/d) after acute ischemic stroke. Platelet activation markers (CD62P, CD63, and CD40L) were measured by flow cytometry at different time points (<48 hours and days 7, 30, and 90 after stroke). The markers were also evaluated in 30 at-risk control subjects.


RESULTS
Ischemic stroke patients had significantly increased circulating CD62P, CD63, and CD40L in the acute stage compared with the control group. Levels of CD62P, CD63, and CD40L were more significantly reduced in the clopidogrel group than in the aspirin group in the first week after stroke. Furthermore, differences in CD62P and CD63 levels were significant even at 1 month after stroke.


CONCLUSIONS
Patients treated with clopidogrel have lower platelet activity than those taking aspirin after acute ischemic stroke. The stronger effect of clopidogrel is notable 1 week after stroke and persists for at least 1 month. Further large-scale trials are warranted to clarify optimal treatment.
Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Taiwan.
Nai-Wen
NW
Tsai
Wen-Neng
WN
Chang
Chen-Fu
CF
Shaw
Chung-Ren
CR
Jan
Hsueh-Wen
HW
Chang
Chi-Ren
CR
Huang
Shang-Der
SD
Chen
Yao-Chung
YC
Chuang
Lian-Hui
LH
Lee
Cheng-Hsien
CH
Lu
D000368:Aged; D015703:Antigens, CD / Q000097:blood*; D001241:Aspirin / Q000627:therapeutic use*; D002545:Brain Ischemia / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D016022:Case-Control Studies; D000077144:Clopidogrel; D004311:Double-Blind Method; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011446:Prospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
D015703:Antigens, CD; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin