Épidémiologie des accidents hémorragiques survenant chez les patients sous antivitamine K

Oral anticoagulation is widely used to prevent thrombotic events, especially in case of atrial fibrillation, prosthetic heart valve and venous thromboembolic disease. Antivitamin K (AVK) remains the only oral anticoagulation available. Bleedings are the most feared complication of AVK. Major bleeding occurs with an annual incidence of 10 %, and 1 % for fatal bleeding. The most frequent location of bleeding is the gastrointestinal tractus, although intracranial haemorrhages are associated with a poor prognosis. Risk factors for bleeding under AVK are advanced age (more than 75 years old), over therapeutic INR (more than 5) and started treatment (in the first 3 months). One of the major keys to optimize the treatment is the evaluation of the severity of the bleeding. Recent French guidelines will be helpful to graduate the importance of haemorrhage.