The purpose of antithrombotic
therapy is not to recanalyze obstruction but to prevent propagation of
thrombus and reocclusion by rethrombosis in the brain arteries. There is no evidence of
heparin or
heparinoid to improve long-term outcome, although
anticoagulant therapy might be indicated for
stroke associated with coagulation activation such as progressing
stroke, basilar artery
thrombosis,
cardioembolic stroke at high risk, coagulopathy, and
arterial dissection. In patients with nonvalvular
atrial fibrillation, there is no evidence of immediate anticoagulation with
heparin to improve long-term outcome, which is rather contraindicated for large hemispheric
stroke, and it is recommended to start
warfarin directly in the safety issue.
Aspirin is recommended in the guidelines of many countries, although the efficacy is modest. A clinical trial of the
GP IIb/IIIa inhibitor
abciximab, which is a more potent
antiplatelet agent than
aspirin, had recently been conducted, although it was stopped because of the concern on the safety. Clinical trials of dual antiplatelet
therapy with
aspirin and another
antiplatelet agent are ongoing to compare efficacy and safety with
aspirin monotherapy in Japan and overseas.