A dedicated anticoagulation clinic does not improve postoperative management of warfarin after total joint arthroplasty

Abstract

BackgroundPeriprosthetic joint infections (PJIs) are devastating complications. Excessive anticoagulation with warfarin is an independent risk factor for PJIs. The use of a dedicated anticoagulation clinic to improve warfarin management has not been proven.MethodsBetween 2006 and 2014, we identified 92 patients who were placed on postoperative warfarin, and later developed PJI. These patients were compared to 313 patients who underwent total joint arthroplasty placed on warfarin without developing PJI. Patients were included if they had no history of a venous thromboembolic event, were warfarin naive, and enrolled in the anticoagulation clinic. A univariate analysis compared independent variables, and statistical analysis was performed using Student's t-test and Pearson chi-square test for continuous and categorical variables.ResultsThirty-six PJI patients and 297 control patients met the inclusion criteria. The venous thromboembolism rate was 2.1%. At discharge, 82% of all patients were subtherapeutic. Patients were within their target international normalized ratio (INR) range 26.7% of the time. The mean INR in the initial postoperative period for the PJI group was 1.46 and 1.29 in the control group (P < .001). In the acute postoperative period, 13.3% of the knee PJI group were therapeutic or supratherapeutic compared with 3.5% in the knee control group (P = .002).ConclusionsDespite utilization of a dedicated anticoagulation clinic, patients were only within their target INR range 27% of the time. Total knee arthroplasty patients who developed a PJI were more likely to be therapeutic or supratherapeutic in the initial postoperative period. Consequently, the risks associated with warfarin as a venous thromboembolism prophylaxis may outweigh the potential benefits.

Prevention of thrombotic complications in patients in the postoperative period of total hip and knee arthroplasty: efficacy and safety

“…В настоящее время варфарин для первичной профилактики тромбозов и тромбоэмболий после выполнения ЭТС и ЭКС применяется редко. Данные о его назначении описаны лишь в немногочисленных исследованиях [41][42][43][44]. В представленных работах варфарин не продемонстрировал преимущества, и его применение было связано с большим риском развития кровотечений и осложнений.…”

The Current Status of Venous Thromboembolism Prophylaxis Following Total Joint Arthroplasty

“…35 Additionally, patient compliance and laboratory monitoring programs have also come under scrutiny with regard to improving the efficacy, and the safety profiles of using warfarin as the principal chemoprophylaxis following total joint arthroplasty. 36,37 Cho et al reported equal efficacy with improved bleeding risks using lower dose of warfarin (lower international normalized ratio: INR= 1.5 to 2.5) over a four week course. 38 There is increasing evidence-based data supporting the use of aspirin following total joint arthroplasty.…”