Antiplatelet drugs and intraoperative haemorrhage Current literature demonstrates that there is less risk involved in maintaining anti-aggregant therapy (which might imply to transfuse more the patients), than in stopping it, which then increases dangerously the risk of coronary thrombosis. Aspirin, as a secondary preventive drug, should not be interrupted. Clopidogrel is essential for protection against thrombosis in areas where the endothelium is not intact. Unless there is a high hemorrhagic risk in closed cavities (intracranial surgery), clopidogrel should not be interrupted. Furthermore, any surgical intervention increasing the coagulability of the platelets, it seems particularly dangerous to stop such medication perioperatively.