1.How do I need anticoagulation after valve replacement? Lifetime anticoagulation therapy is required after mechanical valve replacement, which means taking warfarin; if there is no atrial fibrillation (AF) after biological valve replacement, patients need anticoagulation therapy for 6 months; if there is AF after biological replacement, lifelong anticoagulation therapy is required. 2, the dosage of warfarin is recommended to start with a small dose, the general recommended dose is 2.5-3mg, then regular blood test anticoagulation check, according to the test results to adjust the dosage of warfarin. 3, anticoagulation laboratory test refers to the regular review of prothrombin time, prothrombin activity, international normalized ratio (INR). Since the results of the first two tests are not very stable, the current adjustment of anticoagulant drugs is mainly based on the international normalized ratio (INR). 4. The international normalized ratio (INR) in the general population is generally around 0.8-1.2; post-valve replacement patients need to increase the INR to between 1.8-2.2 by taking warfarin. In the case of post-tricuspid valve replacement patients, INR values need to be maintained between 2.0 and 3.0. When INR is lower than 1.8, increase warfarin by 1/4 tablet based on yesterday’s dosage; when INR is greater than 2.5, reduce warfarin by 1/4 tablet based on yesterday’s dosage; when INR is greater than 3.0, stop the drug once on the same day, review the drug the next day, and then decide the dosage according to the examination results. 5. It takes about 3 days for warfarin to take full effect, so the INR value checked on the same day reflects the efficacy of the oral warfarin taken 3 days ago. The INR needs to be rechecked frequently in the early days after discharge, and should be measured at least twice in the first week; it can be reduced to about once in the second and third weeks; later, as the INR becomes stable, the number of measurements will be gradually reduced; even for patients with stable INR, it is recommended to recheck the INR once every 1-2 months. 6.Warfarin needs to be taken once a day, and it is recommended that the time of taking the drug and the time of INR testing be relatively fixed.