Abstract

Stroke is the most dangerous complication in patients with atrial fibrillation. Approximately 20% of patients with ischemic stroke have atrial fibrillation. For prevention of ischeamic events, K antagonists (VKA) and aspirin are widely used in patients with atrial fibrillation (AF).
However, treatment with anticoagulants increases the risk of various haemorrhagia complicatons. Meta-analyses have revaled the increase of relative risk of haemorrhage in patients treated with VKA 2.4% compared with placebo.
In many treatment protocols the optimal value of INR in patients treated with VKA is between 2–3. When VKA  are prescribed, regular monitoring of INR is necessary. VKA have many interactions with other drugs and different food products.
However, a large number of patients remain untreated. The inconvenience of monitoring and frequent dose adjustments, combined with fear of major haemorrhage associated with VKAs, contribute to their underuse.
New antithrombotic drugs have the potential to simplify management of patients with AF, and may soon enter the market for prophylaxis of stroke in these patients. The direct thrombin inhibitor ximelagatran is likely to be the first available alternative to warfarin. Studies with  idraparinux are under way and trials evaluating orally active factor Xa inhibitors are likely to follow soon. The availability of these new agents has the potential to  increase the use of anticoagulation therapy in patients with AF, thereby reducing morbidity and mortality from stroke.