Postoperative antithrombotic therapy The early postoperative antithrombotic therapy will be based on intravenous bolus of 100 mg aspirin given 6 h after the arrival in intensive care unit, as previously described. The day after surgery, enoxaparin 40 mg will be given once daily subcutaneously. The perioperative blood transfusion will be done according to the French National recommendations (9). In patients preoperatively treated by combined antiplatelet therapy, clopidogrel will be re-introduced the day after the surgery.