Atrial fibrillation is the most common sustained cardiac arrhythmia. Prevalence and incidence of atrial fibrillation increase with age. Much of the morbidity and mortality associated with atrial fibrillation is due to thromboembolic complications, mainly involving the cerebrovascular system and resulting in ischemic stroke. The limitation of current anticoagulation with vitamin K antagonists suggests the need of new anticoagulant strategies or new anticoagulant drugs with more favorable safety profiles that do not require coagulation monitoring or dose adjustment. Dual antiplatelet therapy in prevention of thromboembolic complications in patients with atrial fibrilla tion was evaluated in the prospective ACTIVE trials. ACTIVE-A trial compared clopidigrel plus aspirin with aspirin alone in patients with atrial fibrillation who were at increased risk for stroke and for whom therapy with vitamin K antagonist was considered unsuitable. In suitable patients for anticoagulant therapy with vitamin K antagonists ACTIVE-W trial compared aspirin plus clopidogel with adjusted dose of warfarin. In patients with atrial fibrillation who undergo percutaneous coronary intervention with stent implantation triple therapy remains problematic (aspirin + clopidogrel + warfarin).
KEYWORDS: atrial fibrillation, antithrombotic therapy, acetylsalicylic acid, clopidogrel, vitamin K antagonists