Low-dose aspirin for prevention of stroke in low-risk patients with atrial fibrillation: Japan Atrial Fibrillation Stroke Trial.
OBJECTIVE
Although the efficacy of anticoagulant therapy for primary prevention of stroke in patients with nonvalvular atrial fibrillation (NVAF) has been established, efficacy of antiplatelet therapy for low-risk patients is disputable in Japanese patients because of the frequent hemorrhagic complications. We examined the efficacy and safety of aspirin therapy in Japanese patients with NVAF in a prospective randomized multicenter trial.


METHODS
Patients with NVAF were randomized to an aspirin group (aspirin at 150 to 200 mg per day) or a control group without antiplatelet or anticoagulant therapy. Primary end points included cardiovascular death, symptomatic brain infarction, or transient ischemic attack.


RESULTS
A total of 426 patients were randomized to aspirin group and 445 to no treatment. The trial was stopped earlier because there were 27 primary end point events (3.1% per year; 95% CI, 2.1% to 4.6% per year) in the aspirin group versus 23 (2.4% per year; 95% CI, 1.5% to 3.5% per year) in the control group, suggesting a low possibility of superiority of the aspirin treatment for prevention of the primary end point. In addition, treatment with aspirin caused a marginally increased risk of major bleeding (7 patients; 1.6%) compared with the control group (2 patients; 0.4%; Fisher exact test P=0.101).


CONCLUSIONS
For prevention of stroke in patients with NVAF, aspirin at 150 to 200 mg per day does not seem to be either effective or safe. Further prospective studies are needed to determine the best preventive therapy for cerebrovascular events in Japanese patients with NVAF.
Sato
Hiroshi
H
Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan. satoz@medone.med.osaka-u.ac.jp
Ishikawa
Kinji
K
Kitabatake
Akira
A
Ogawa
Satoshi
S
Maruyama
Yukio
Y
Yokota
Yoshiyuki
Y
Fukuyama
Takaya
T
Doi
Yoshinori
Y
Mochizuki
Seibu
S
Izumi
Tohru
T
Takekoshi
Noboru
N
Yoshida
Kiyoshi
K
Hiramori
Katsuhiko
K
Origasa
Hideki
H
Uchiyama
Shinichiro
S
Matsumoto
Masayasu
M
Yamaguchi
Takenori
T
Hori
Masatsugu
M
D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000628:therapy*; D002561:Cerebrovascular Disorders / Q000628:therapy; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000517:prevention & control*; D013927:Thrombosis / Q000628:therapy; D016896:Treatment Outcome
D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin