Atrial fibrillation and anticoagulation therapy: different race, different risk, and different management?

摘要

A trial fibrillation (AF) is the most frequent sustained cardiac arrhythmia. The current prevalence in the general population is 0.5-1%, and goes up to 8% in people older than 80 years. AF is associated with increased risk of thromboembolic events. In fact, stroke rates in patients with nonvalvular AF are 2-7-fold higher than in those without AF. This risk increases up to 17-fold in patients with AF and rheumatic heart disease. Only antithrombotic drags have been shown to reduce death rates associated with AF. Vitamin K antagonists (VKAs) have been used for decades to prevent embolisms in patients with AF.Currently, the worldwide target international normalized ratio (INR) to prevent ischaemic stroke in these patients ranges from 2 to 3, but in clinical practice, less than 60% of patients achieve this universal therapeutic range. Multiple interactions with other drugs, and the need for careful monitoring of the INR, might explain this poor therapeutic control. Furthermore, patients receiving VKAs are at risk of severe hemorrhages (including intracranial hemorrhage). Interestingly enough, ethnic differences in the risk of intracranial hemorrhage among patients with AF and VKAs have been described. According to these studies, Asian people appear to require a lower daily dose of VKAs to maintain the INR in the target range