After valve replacement, the contact between the prosthetic valve and blood can easily cause platelet coagulation and the formation of thrombus, and in serious cases, thrombus may be dislodged, leading to organ vascular embolism such as cerebral embolism and lower extremity artery embolism; thrombus occurring in the annulus may jam the prosthetic valve leaflet and prevent the valve from opening, leading to heart failure or sudden death. Therefore, postoperative anticoagulation is mandatory for both mechanical and biologic valves. Mechanical valves should be anticoagulated for life, while biological valves should be anticoagulated for 3-6 months, with appropriate extension of anticoagulation time for those with atrial fibrillation, and discontinuation of the medication under the guidance of the physician. The anticoagulation should be monitored regularly during the course of medication and adjusted in a timely manner. Insufficient anticoagulation can easily lead to thromboembolism and other bad consequences, while too much anticoagulation can lead to bleeding, such as nosebleed, dental bleeding, hematuria, menstruation and so on. Therefore, anticoagulation is a life-threatening issue, and must be handled in close cooperation with medical personnel. The main anticoagulants available are warfarin. Your doctor will make appropriate adjustments for you during your hospitalization and will make recommendations upon discharge, such as the dose of medication and the timing of testing. However, the sensitivity of anticoagulants varies from patient to patient, so regular blood tests for prothrombin time and activity are required. The normal value of prothrombin time is 12-14 seconds, and the activity is above 80%. After valve replacement, the prothrombin time should be maintained at 1.5-2.0 times the normal value (usually 19-24 seconds) or an activity of 35%-45%. The WHO (World Health Organization) now advocates an international standard for oral anticoagulant testing, the international normal ratio (INR). The INR should be controlled between 2 and 3 after valve replacement. Prothrombin time or activity should be tested regularly after each dose adjustment according to the physician’s recommendation. If bleeding tendencies or signs of cerebral infarction occur while taking the medication, prompt medical attention should be sought. Another issue that should be noted after discharge from the hospital is that food, medications and other diseases also have a degree of influence on the anticoagulant effect. For example, some foods rich in vitamin K can reduce the effect of anticoagulants, including spinach cauliflower and peas. However, as long as a balanced diet and regular, regular reviews can be adjusted to the anticoagulant dose, there is no need to purposely favor a certain food or fasting. Drugs that enhance the effect of anticoagulant drugs include aspirin, chloramphenicol, metronidazole, salicylates, phenibut, etc., while drugs that reduce the effect of anticoagulant drugs include bilirubin, rifampin and estrogen, etc.