Randomized controlled study on the prophylaxis of venous thromboembolism events in patients undergoing total knee arthroplasty: comparison of aspirin and rivaroxaban

Abstract

Background: The aim of this prospective randomized trial was to compare the prevalence of thromboembolic events with two oral pharmacologic agents, aspirin and rivaroxaban, for the prevention of venous thromboembolism after total knee arthroplasty (TKA) in a Korean population. In addition, bleeding complications were evaluated.

Methods: Between October 2014 and December 2015, 156 patients (119 primary TKAs) were enrolled for the randomized controlled trial. Group A consisted of 61 patients (78 TKAs) who were allocated to receive 300 mg aspirin, while Group R consisted of 58 patients (78 TKAs) who were allocated to receive 10 mg of the factor Xa inhibitor rivaroxaban. To detect venous thromboembolism, multidetector computed tomography was performed on postoperative day 10.

Results: Out of 78 TKAs in each group, 28 (35.9%) had developed VTE in Group A, compared with 4 (5.1%) in Group R (P < 0.001). The prevalence of pulmonary embolism was 20.5% for Group A and 5.1% for Group R (P = 0.004). There were three pulmonary embolisms in the central portion of the pulmonary artery in Group A, compared with none at this location in Group R. Seven cases of pulmonary embolism coexisted with deep vein thrombosis of the lower extremities in Group A, whereas only one case of a pulmonary embolism coexisted with deep vein thrombosis in Group R. Wound complications requiring hematoma evacuation, cessation of pharmacologic agents, or surgical management did not occur in either of the groups.

Conclusions: The prevalence of thromboembolic events after TKA was significantly higher in patients who received aspirin than in those who received rivaroxaban. Among patients who had developed pulmonary embolism in the aspirin group, there was a stronger tendency for the embolism to involve a more central portion of the pulmonary artery and to coexist with DVT of the lower extremities. There were no cases of wound complications requiring evacuation of hematoma in either group, and no patients required cessation of pharmacologic agents or surgical management.