The Clinical Analysis Of Low-intensity Anticoagulation Therapy After Heart Valve Replacement

Objective: To explore the efficacy and safety of low-intensity anticoagulation therapyby investigating the clinical application of low-intensity anticoagulation treatmentwith warfarin and early anticoagulation complications, after prosthetic heart valvereplacement.Methods:273patients received oral warfarin for low-anticoagulant treatment afterprosthetic heart valve replacement in Fujian Provincial Hospital from October2010toOctober2011were enrolled in this study, the clinical data and medications were alsorecorded. Oral anticoagulant therapy started after surgical drainage removal. After48-72h postoperation, all patients received postoperative oral anticoagulation therapywhich based on a low standard of international normalized ratio(PT-INR,1.4-2.0;AVR1.4-1.8, MVR/TVR/DVR1.6-2.0), all patients received a dosage of1.5-3.0mg/dwarfarin at the first time, and mechanical valve replacement requires lifelong oralwarfarin and3months for bioprosthetic heart valves. Warfarin was administered tomaintain the PT-INR within the assigned range. The follow-up includedcommunication, PT-INR values(PT-INR values measured in the other hospitalsincluded) and warfarin dosage via telephone calls and out-patient review, whichstarted when patients took warfarin, ended in March2012. Echocardiography and CTscan rows if necessary.Results:268patients were followed up with the follow-up rate98.2％(268/273) forthe median13months (range6-17months). The average PT-INR was1.76±0.32, andwarfarin dose was2.52±0.97mg/d. During follow-up,5bleeding events and2throm-boembolic complication occurred. The linearized rates of anticoagulation-relatedthromboembolism was2patients0.68per100patient-years (%/pt-y) and hemorrhagewas5patients1.7%/pt-y. The incidence of total complications (i.e., combinedthromboembolism and hemorrhages) was2.4%/pt-y. All of them were mechanicalvalve replacement surgery and thromboembolic complication occurred to patientswho were atrial fibrillation in preoperative diagnosis. Within the target PT-INR1.4- 2.0one case of bleeding and no thromboembolic events occurred. However, there wasa significant between the early and late periods of follow-up（P＜0.05）,earlyanticoagulation (<3months) complications incidence Included4bleeding(1.5%) and1thromboembolism (0.37%). Bleeding rather than thromboembolism was the majorcomplication after postoperation in this study.Conclusion: For Chinese patients with prosthetic heart valve, anticoagulation-relatedbleeding and thromboembolism are the principal complications. The incidence ofbleeding is much higher than that of thromboembolism, and the low-anticoagulation(PT-INR1.4-2.0) can remarkably decrease hemorrhagic events with no increasethrombolic events. Moreover, early postoperative anticoagulation after prostheticvalve implantation was associated with a higher incidence of thromboembolism andpostoperative bleeding complications，and the PT-INR was most unstable relatively inthe first three months after surgery, So re-examination in this period for the patientsafter the operation is vitally important.