Elevated soluble platelet glycoprotein VI is a useful marker for DVT in postoperative patients treated with edoxaban

Prevention of deep vein thrombosis (DVT) is important in patients undergoing major orthopedic surgery. Although the detection of an elevated D-dimer level is useful for predicting DVT, it is not efficacious in postoperative patients being treated with anti-Xa agents. The soluble platelet glycoprotein VI (sGPVI) level is a marker of activated platelets, but not bleeding. Therefore, sGPVI levels are usually examined as a predictor of DVT in such patients. In the present study, 83 orthopedic patients were treated with 30 mg of edoxaban for prophylaxis of DVT. Fourteen patients developed DVT and 17 patients discontinued the prophylaxis due to decreased hemoglobin levels. Plasma levels of sGPVI in the patients were significantly higher after surgery than before surgery. On day 1, the sGPVI levels increased, while the platelet counts decreased. There were no significant differences in D-dimer, soluble fibrin, or FDP levels in orthopedic patients with and without DVT before surgery and on days 1, 4, and 8. Plasma sGPVI levels were significantly higher in the patients with DVT than in those without DVT on days 1 and 4. Plasma levels of D-dimer were significantly higher in patients with withdrawal than in those without. However, there were no significant differences in sGPVI levels between those with and without withdrawal. As D-dimer levels are known to increase in patients with withdrawal, this parameter is not useful for evaluating the risk of DVT in these patients. In contrast, the sGPVI level is not increased in those with withdrawal and may therefore be useful for evaluating the risk of DVT in postoperative patients treated with an anticoagulant.

The relationships among hemostatic markers, the withdrawal of fondaparinux due to a reduction in hemoglobin and deep vein thrombosis in Japanese patients undergoing major orthopedic surgery

BACKGROUND

The relationships among the hemostatic markers, the development of deep vein thrombosis (DVT) and the withdrawal of fondaparinux due to a reduction in the hemoglobin levels were examined.

METHODS

Two-hundred twenty-one Japanese patients who underwent major orthopedic surgery and were treated with 1.5mg of fondaparinux instead of 2.5mg of fondaparinux were studied. Forty-seven of 221 patients discontinued fondaparinux treatment (withdrawal group) and 37 patients developed DVT.

RESULTS

The age, frequency of total knee arthroplasty (TKA), withdrawal of fondaparinux, reduction of hemoglobin and the plasma levels of soluble fibrin (SF), D-dimer and fibrinogen and fibrin degradation product (FDP) on day 1 after the operation were significantly higher in the patients with DVT. Elevated SF, D-dimer or FDP levels were associated with the risk for DVT. The age, frequency of TKA or DVT, anti-Xa activity and the creatinine, FDP and D-dimer levels were significantly higher in the withdrawal group. An anti-Xa level >0.33 mg/l and an elevated D-dimer or FDP level were associated with the risk of withdrawal.

CONCLUSION

The age and SF levels, TKA and withdrawal of fondaparinux were related to the risk of DVT, and the anti-Xa activity, creatinine level and DVT were related to the risk of withdrawal of fondaparinux due to a reduction in hemoglobin.

Monitoring for anti-Xa activity for prophylactic administration of Fondaparinux in patients with artificial joint replacement

The efficacy of measuring anti-Xa activity was evaluated in major orthopedic surgery patients receiving thrombo-prophylaxis with Fondaparinux. Although 98 orthopedic patients including those receiving total hip replacement (THR) and total knee replacement (TKR) were treated with 1.5 mg of Fondaparinux for prophylaxis of deep vein thrombosis (DVT). Sixteen patients developed DVT, but none was associated with a fatal pulmonary embolism. There was a wide range of anti-Xa activity, but there were no patients with less than 0.15 mg/l or more than 0.90 mg/l. Anti-Xa activity gradually increased from days 1 to 8 and showed no significant difference between patients with and without DVT. Anti-Xa activity was correlated with weight, height, body mass index, and antithrombin activity. Postoperative plasma levels of D: -dimer and soluble fibrin (SF) were markedly high, and those were significantly reduced at days 1 and 4 of treatment with Fondaparinux. Plasma levels of SF were significantly reduced at days 8 and 15, but D: -dimer was not. These findings suggested that there was continued thrombin generation after the injection of Fondaparinux until day 8 and secondary fibrinolysis occurred on day 8. In conclusion, 1.5 mg of Fondaparinux may not be sufficient for the prophylaxis of silent DVT, but it was found to be useful for that of fatal pulmonary embolism. Consequently, monitoring anti-Xa activity may be unnecessary for the administration of Fondaparinux at such doses.