Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with increased risk for ischemic stroke or systemic artery embolization. Evidences from meta-analysis found that the vitamen K antagonists (VKAs) reduced the relative risk of is chemic stroke by 62% compared with placebo. However, there were lots of limitations for long term warfarin (VKA) therapy, including frequent monitoring of INR, drug or food interactions, and bleeding complications as well. Therefore, data from the Taiwanese population study had demonstrated that there were a low prescription rate of VKAs for AF patients and the annual stroke for AF still remained high.

A new oral drug of direct thrombin inhibitor- Dabigatran which has been evaluated in RE-LY study with promising results in stroke prevention. In patients with AF, dabigatran given at a dose of 110 mg BID was associated with rates of stroke and systemic embolism that were similar to warfarin, as well as lower rates of major hemorrhage. At a dose of 150 mg BID was associated with lower rates of stroke and systemic embolism in comparison to the warfarin therapy. A remarkable reduction of hemorrhagic stroke or intracranial bleeding was found among patient taking Dabigatran, either 110mg or 150mg BID, in comparison with those who were on warfarin therapy. Data from the RE-LY study provided us a new option for the stroke prevention in patients with atrial fibrillation.