RESUMO
We should offer anticoagulation (INR 2-3) to patients with atrial fibrilation and valvular disease. We should also anticoagulate patients with high risk cardioembolic nonvalvular atrial fibralation like: 1-Prior stroke, transient ischemic attack or peripheral embolia. 2-Diabetes. 3-Sistolic hypertension > 160 mmHg. 4- Recent heart failure. 5- Age > 75 years and female gender. We should not offer anticoagulant therapy to patients with lone atrial fibrilation and also to patients with low cardioembolic risk atrial fibrilation and high risk or bleeding like: 1- prior gastrointestinal bleeding. 2- Hemorragic disease. 3-Prior compliance to anticoagulant treatment. 4- Cormobid severe disease. In this patients we may use aspirin 325 mg daily. Advanced age is not a contraindication to anticoagulation but it could justify more frequent blood test controls