Anticoagulation after prosthetic valve replacement requires appropriate anticoagulation measures depending on the valve being replaced and the comorbidities. To achieve anticoagulation safely and effectively, it is important to understand the techniques and methods of anticoagulation. Why should valve replacement patients be treated with anticoagulation? Because the artificial valve (biological valve or mechanical valve) is not the body’s own group, blood is easy to coagulate in and around the artificial valve, causing thrombosis and affecting the function of the artificial valve, and if the thrombus is dislodged, it can also cause vascular embolism (brain embolism, lower limb artery embolism, etc.), which is very harmful to people. Therefore, anticoagulation therapy is required for all valve replacement patients to prevent thrombosis. Biologic valve replacements generally require anticoagulation for only three months after surgery, while those with atrial fibrillation require anticoagulation for six months; mechanical valve replacements require lifelong anticoagulation. How are patients with valve replacements anticoagulated? What are the anticoagulation criteria? The main method of anticoagulation is oral anticoagulation tablets. Commonly used anticoagulants include Warfarin tablets. Oral anticoagulation tablets are usually started after the chest drain is removed after surgery or 48 hours after surgery. In order not to overdose or underdose the anticoagulant, blood is drawn periodically after surgery to check the prothrombin time (PT) and the international normalized ratio (INR). This test reflects the effect of the amount of medication used on the coagulation effect, with PT around 18-24 seconds and INR 1.8-2.5. Commonly used anticoagulants The drugs that can be used for postoperative anticoagulation after valve replacement are: warfarin, new anticoagulation tablets, and heparin. Aspirin can also be used as an adjunctive anticoagulant. The most commonly used is the oral formulation of warfarin. Because of the long half-life of warfarin, if secondary surgery or other procedures other than cardiac surgery are required, heparin may be temporarily substituted by intravenous or subcutaneous injection during discontinuation of warfarin. Warfarin usage is once daily, and the daily dosing time can be fixed at 8:00 p.m. Always remember to take your medication on time each day. Adjustment of anticoagulant dose Due to individual differences, the amount of anticoagulant used after valve replacement varies from person to person. Some patients require 7 mg of warfarin daily, while others require only 0.5 mg. However, most patients use about 3 mg of warfarin per day. Warfarin dosage is relatively stable for each individual, with some fluctuations observed over time, but the range of fluctuation is not significant. Each patient should figure out his or her anticoagulant dose as soon as possible and have regular lab tests to adjust it appropriately. After discharge from the hospital, the patient should be given the initial dose of anticoagulation, and be tested every 3-5 days, and learn to adjust the dosage according to the anticoagulation standard, and after the anticoagulation is more stable (about one month), the patient can be tested once a week. -After the anticoagulation is more stable (about one month), the test can be done once a week. Anticoagulation therapy after valve replacement is very important and is arguably the key to ensuring good valve function. Patients must pay attention to it and learn to read the labs as soon as possible and adjust their own medications with reference to anticoagulation criteria to improve their quality of life. Anticoagulation therapy is not difficult and should not be seen as a burden by the patient, but rather as a meal that is necessary for their daily life. If there is any doubt about anticoagulation therapy, especially in the first 1-2 months after discharge, if you are not sure how to adjust anticoagulation medication, you should consult with your doctor promptly. What should I do if I need to have a tooth extraction or other surgery after a flap replacement? It is best to have extractions or other procedures after valve replacement when your heart function is in good condition. If you are on long-term anticoagulation, you should suspend anticoagulation for two days prior to surgery to prevent post-operative bleeding, or for emergency surgery, special hemostasis and anti-bleeding treatment is required. Your surgeon will carefully stop the bleeding during the procedure, and you can continue anticoagulation 24 to 48 hours after the procedure when there is no blood leakage. What about anticoagulation in female patients with excessive menstruation? Generally speaking, anticoagulation therapy has little effect on menstruation. Even if your menstruation is slightly more or longer than before, you do not have to deal with it as long as it is not serious. If there is a significant increase in menstrual flow, the amount of anticoagulant can be reduced during menstruation and resumed after menstruation. If menstrual disorders and bleeding continue after anticoagulation therapy, you should visit a gynecologist and take menstrual regulating drugs to stop bleeding. In addition, women of childbearing age should pay attention to contraception during anticoagulation therapy to avoid the risk of increased bleeding from abortion. The effect of drugs (the use of the following drugs need to pay attention to detect changes in anticoagulation indicators) drugs that increase the effect of anticoagulant drugs: broad-spectrum antibiotics can reduce the production of vitamin K by intestinal bacteria; aspirin, Antomin, sulfonamides, propofol, etc. can compete with warfarin for plasma protein binding sites, so that the free drug concentration of the latter increases; liquid paraffin can reduce the absorption of vitamin K; chloramphenicol, metronidazole, methotrexate Metformin, alcohol, etc. can inhibit the enzymes that degrade warfarin, so that the concentration of warfarin increases relatively; phenytoin sodium, toluenesulfonylurea has the same metabolic pathway; aspirin and acetaminophen have anticoagulant synergistic effects; salicylates, pautazone, chlorpromazine, benadryl, etc. have the effect of interfering with platelet function; quinidine, thyroxine, phenylethylenediamine, and antamine have enhanced anticoagulant effects. Drugs that reduce the anticoagulant effect: abciximide can bind to anticoagulants in the intestine; hypnotics, rifampin, and ashwagandine have the effect of increasing the activity of enzymes in the liver and accelerating the metabolism of warfarin; estrogen and oral contraceptives can increase the level of clotting factors in the blood. The effect of other diseases: diarrhea, vomiting can affect the absorption of drugs; heart failure or primary liver disease can reduce vitamin K synthesis reduction, while reducing the metabolic rate of warfarin, so that warfarin dosage is reduced.