Abstract:

Objective To study the changes of coagulation-related monitoring indicators in elderly patients with acute venous thromboembolism（VTE） after taking rivaroxaban，and to investigate the appropriate indicators for monitoring the anticoagulation strength and safety of rivaroxaban. Methods Totally，50 elderly patients with acute venous thromboembolism，including 21 males and 29 females，aged（84.25±3.28） years，from Drum Tower Hospital of Nanjing University Medical School from April 2019 to December 2021，were enrolled. Rivaroxaban（10 mg） was administered orally to patients，and the changes on anti-factor Ⅹa activity，coagulation six indicators and coagulation factor activity for VTE patients were observed before and after dosing. Bleeding risk was predicted with related indicators using receiver operating characteristic（ROC） curve. Results Compared with those before taking rivaroxaban，anti-factor Ⅹa activity was higher（P<0.01），prothrombin time（PT），international normalized ratio（INR） and activated partial thromboplastin time（APTT） were higher（P<0.01），and the levels of coagulation factors（Ⅱ，Ⅴ，Ⅶ，Ⅷ，Ⅸ，Ⅹ，Ⅺ and Ⅻ） showed a decreasing trend（P<0.01）. ROC curve analysis showed that PT was a moderate predictor of bleeding risk，and the area under curve was 0.81 [95% confidence interval（CI） 0.66-0.95]. Conclusions PT can be used not only as a preliminary indicator for anticoagulation monitoring with rivaroxaban，but also it has high predictive role for bleeding risk.

Key words: Rivaroxaban, Acute venous thromboembolism, Anti-factor Ⅹa, Coagulation routine test, Coagulation factor