An artery blocker is a type of medication that works to prevent the formation of blood clots. It does this by inhibiting the activity of certain enzymes in the body, which can lead to the formation of clots. The term 'CLOT' is used to describe the process of blood clotting, which can be dangerous if it occurs in an artery. The most common form of artery blocker is aspirin, which is used to reduce the risk of stroke and heart attack. Other medications, such as warfarin, may also be prescribed to help prevent the formation of clots.