[Prevention of thromboembolism in atrial fibrillation of non-valvular etiology].

Atrial fibrillation is an independent risk factor for cerebral and systemic embolism. The risk increases with the patient's age and the presence of other risk factors: hypertension, diabetes, cardiac failure, prior transient ischemic attacks or embolic stroke. Risk stratification is of essential importance to allow the choice of the most suitable prophylaxis with antithrombotic drugs for the individual patient. On the basis of the results of controlled clinical trials, it is possible to suggest the following guidelines: a) in patients at low risk (< 65 years, with no other risk factor) the drug of first choice should be acetylsalicylic acid; b) in patients at high risk (> 65 years, with one or more risk factors) the drugs of first choice are oral anticoagulants, given at doses that prolong the prothrombin time to INR values of 2-3; c) in patients at high risk with contraindications to oral anticoagulants, acetylsalicylic acid or indobufen (shown to be as effective as oral anticoagulants in patients with prior transient ischemic attacks or stroke) should be considered.