Objective To evaluate the quality of anticoagulant therapy in patients with mechanical prosthetic valve replacement during early period through time in therapeutic range(TTR) and fraction of time in therapeutic range(FTTR), and to provide an objective evidence for further improving quality of anticoagulant therapy. Methods All the patients were followed and registered in hospital and at outpatient clinic from July 2012 through April 2014, with a maximum of 6 months after surgery. Targeted international normalized rate (INR) was 1.60 to 2.20, acceptable INR was 1.50 to 2.30. And warfarin weekly dosage adjustment was used as the strategy of anticoagulation management. Adjusting the warfarin dosage when INR was beyond acceptable INR. Events of bleeding, thrombogenesis and thromboembolism, TTR and FTTR of these patients during the follow-up were collected to evaluate quality of anticoagulant therapy in these patients. Results A total 477 patients and 2 755 reports of INR values were included for data analysis. The follow-up time was 78 918 days. Values of INR varied from 0.92 to 7.72(1.83±0.64). Required weekly doses of warfarin in target INR and acceptable INR were 5.00–35.00(18.15±3.99) mg/week and 5.00–39.38(18.29±4.08) mg/week. TTR of target INR and acceptable INR was 36.85%(27 079.5 d/78 918.0 d) and 49.84% (39 331.5 d/78 918.0 d), respectively. FTTR of target INR and acceptable INR was 37.31% (1 028 times/2 755 times), 50.01% (1 378 times/2 755 times), respectively. TTR of target INR and acceptable INR was 46.04%(3 902.5 d/8 475.5 d), 59.49%(5 042 d/8 475.5 d) when the patients’ follow-up was up to six months and FTTR of target INR and acceptable INR value of these patients was 46.81%(206 times/440 times), 60.45%(266 times/440 times). During the follow-up, there were 3 thromboembolism events, 1 transient physical abnormal activity, and 1 thrombogenesis in the left atrium, and there was no bleeding and death events. Conclusion The strategy of anticoagulation management used in our study is reasonable. In order to further improve the patients’ quality of anticoagulant therapy, it is necessary to start anticoagulation after operation as soon as possible, to strengthen the education of patients with anticoagulant knowledge and to increase INR test frequency properly.
Objective Influence factors of the stable warfarin dose in the early period after mechanical prosthetic valve replacement were analyzed to guide the anticoagulation therapy for these patients. Methods A total of 288 patients within 6 months after mechanical prosthetic valve replacement in West China Hospital were followed up and registered at outpatient department from July 2012 to April 2014, including basic information (name, sex, age, height, weight, etc.), general clinical data (cardiac function, heart rate, surgery pattern, etc.) and related data about anticoagulation therapy. The target international standardized ratio (INR) range was 1.60 to 2.20 and the acceptable INR was 1.50 to 2.30. The sex, age, height, body weight, body mass index (BMI), body surface area (BSA) and related clinical factors were analyzed to find the relationship with the dose of warfarin. Results Sex was found to have a significant effect on the stable warfarin dose (P<0.05). Women needed a lower stable warfarin dose than men during the early anticoagulation therapy. There was no significant difference in the stable warfarin dose of patients with different ages, rhythms, NYHA classification, surgery pattern and diseases before operation; but the stable warfarin dose was lower in the patients with radiofrequency ablation during valve replacement procedures than the patients with single valve replacement (P<0.05). There was an association between age, height, weight, BMI, BSA and the stable warfarin dose withR2 of 1.2%, 3.2%, 3.5%, 1.1%, 4.2%, respectively and they could explain 6.1% of variability in warfarin dose. Conclusion During early anticoagulation therapy in patients with mechanical prosthetic valve replacement, it is necessary to consider the effects of various preoperative factors, drug factors and demographic factors on warfarin dose. Even though there is an association between age, height, weight, BMI, BSA and the stable warfarin dose, which can only explain 6.1% of variability in warfarin dose, thus cannot guide the postoperative anticoagulation of these patients.
The patients with mechanical prosthetic valve replacement need anticoagulant therapy for all their life. The incidence of thromboembolism and anticoagulation-related bleeding events still account for major postoperative complications after mechanical heart valve replacement. Most of the complications happen in the first half year after operation. Therefore, early anticoagulation therapy is very important. Of course, so far most guidelines focus stating their opinions on long-term anticoagulant therapy. However, there is no consensus about anticoagulant therapy in the early period of postoperation. In this review, we summarize early anticoagulant therapy of the patients with mechanical heart valve replacement through consulting domestic and abroad relevant research in recent years and give an overview of the present situations of early anticoagulant therapy.