Prosthetic valves have been continuously updated and developed over the course of half a century of development and clinical application, with further improvements in hemodynamics, progressive increases in histocompatibility, and more accurate indicators of anticoagulation strength monitoring, but still do not fundamentally address the problems of thrombosis, thromboembolism, and bleeding associated with anticoagulation therapy. Warfarin is the main anticoagulant therapy after heart valve replacement and has proven efficacy, but the pharmacology is complex and the therapeutic window is narrow, and even small dose-response changes may lead to thrombosis or bleeding. Therefore, the range of safe anticoagulation intensities is small, and strict guidance of anticoagulation therapy by anticoagulation intensity criteria and regular monitoring of anticoagulation intensity are key factors in reducing anticoagulation complications. The intensity of anticoagulation therapy after prosthetic valve replacement is not consistent across countries, probably due to ethnic differences, differences in lifestyle and dietary structure, and differences in patient selection, definition of complications, and anticoagulation protocols among hospitals. Guidelines issued by the European Society of Cardiology recommend that anticoagulation intensity should be proportional to the risk of embolization, which is related to the type of implanted heart valve and individual differences. A variety of anticoagulation complications may occur in patients undergoing regular anticoagulation monitoring with INR, and the outcome of anticoagulation therapy after prosthetic valve replacement is not influenced solely by anticoagulation intensity; anticoagulation therapy is guided by anticoagulation intensity criteria, while also being sensitive to individual patient characteristics. Individualized anticoagulation therapy is a key factor in reducing anticoagulation complications. Several points should be noted: 1. Warfarin is almost completely metabolized by the liver, and the metabolites have weak anticoagulant effects and are mainly eliminated through the kidneys (very little goes into the bile), and only a very small amount is excreted from the urine in its original form; therefore, it is not necessary to adjust the dose of warfarin in patients with renal insufficiency. 2, warfarin therapy should be monitored daily at the beginning of the treatment until the INR is within the target range for two consecutive days, then monitored 2-3 times a week for 1-2 weeks, and gradually reduced to once every 4 weeks after stabilization. The safety and efficacy of warfarin therapy depends on maintaining the INR within the target range; the risk of bleeding increases sharply when the INR is above the upper target limit, and the risk of embolism increases when the INR is below the lower target limit. Re-monitoring is required when adjusting the dose. 3. Warfarin dose-response sometimes fluctuates greatly due to diet, drugs, alcohol, and other factors. The reality of “low anticoagulation levels” after valve surgery is not unrelated to the improvements in the manufacturing process of mechanical valves in recent years, as improvements in the structure of mechanical valve frames and advances in the coating process of valve leaflets have significantly improved the quality of prosthetic mechanical valves. At present, the actual clinical status of warfarin administration and INR after prosthetic valve replacement in heart valve surgery is at a low level, and the overall average INR level is below 2.5, with the incidence of thrombosis not higher than the international level and the rate of bleeding decreasing, so the level of “low anticoagulation” seems to be at a low level. The “low anticoagulation” level seems to have become the “consensus” in the industry. However, it should be noted that a consensus on “low anticoagulation” requires a process of evidence-based medical exploration, and domestic studies are still in single-center independent studies and mainly retrospective case reports, so we need to carefully conduct scientific evidence. In addition, in determining the intensity of postoperative oral warfarin anticoagulation therapy, how to monitor or what frequency to monitor INR is the correct monitoring method is still a clinical problem that needs to be solved, the frequency and monitoring method of postoperative INR in our country are not reasonable, the monitoring frequency is low, and there is a lack of home individualized monitoring equipment and conditions. There is no evidence of relevant indication medical studies and expert consensus, and these also lead to the correct determination of the intensity of appropriate anticoagulation therapy.