Postoperative D-dimer as a signal of venous thromboembolism in patients receiving Edoxaban after hip or knee arthroplasty.

BACKGROUND: Edoxaban is the only direct-acting oral anticoagulant (DOAC) indicated for preventing venous thromboembolism (VTE) in patients undergoing arthroplasty and can be administered for a short period (1-2 weeks). The dosage of edoxaban is set according to renal function and the presence or absence of concomitant medications with P-glycoprotein inhibitory effects. However, a small number of patients still develop VTE after lower-extremity orthopedic surgery (LE-OS), despite edoxaban administration. This single-center, exploratory cohort study retrospectively investigated patients prescribed edoxaban after LE-OS in order to explore the potential of D-dimer as a signal of VTE. METHODS: Of the 1,457 patients who received edoxaban after total hip arthroplasty or total knee arthroplasty between January 2016 and December 2020, 1,244 who cleared the exclusion criteria were divided into the non-VTE group (1,219 patients) and VTE group (25 patients). To reduce bias in VTE occurrence, patient age, sex, body weight, serum creatinine, edoxaban underdosing, previous thromboembolism, bed rest duration ≥ 48 h, and blood transfusion were matched using propensity score matching (PSM). We compared the routinely measured D-dimer values of blood samples collected on postoperative day 7 among non-VTE and VTE groups using the Mann-Whitney U test. RESULTS: After PSM, there were 23 patients in each of the non-VTE and VTE groups. The median (interquartile range) D-dimer value on postoperative day 7 was 6.2 (4.2-8.1) µg/mL in the non-VTE group and 9.6 (6.3-12.4) µg/mL in the VTE group (p = 0.005). CONCLUSIONS: This retrospective exploratory study demonstrated that D-dimer values in patients receiving edoxaban after LE-OS may serve as a signal for VTE occurrence.