Delayed Administration of Apixaban and Rivaroxaban is Associated with Reduced Rates of Postoperative Bleeding Without Increasing Thromboembolic Risk Following Elective Total Hip Arthroplasty.

BACKGROUND

The optimal timing for initiation of anticoagulation using direct oral anticoagulants following total hip arthroplasty (THA) remains a subject of debate. While direct oral anticoagulants are effective prophylactic agents against venous thromboembolism (VTE), bleeding risks remain a concern. This study sought to compare the incidence of postoperative bleeding and thromboembolic complications following elective THA between patients receiving either apixaban or rivaroxaban on postoperative day (POD) zero versus one.

METHODS

A large national database was used to identify all patients who underwent primary THA between 2015 and 2023. Patients receiving either apixaban or rivaroxaban on POD zero were compared to patients who received the same anticoagulant on POD 1. The 90-day post-operative bleeding complications (e.g., acute anemia, transfusion, hematoma, and hemorrhage), as well as thromboembolic complications (e.g., deep venous thrombosis [DVT] and pulmonary embolism), were compared between the POD zero and one cohorts for each medication. Univariable analysis and multivariable regression were used to assess differences. In total, 112,555 primary THA patients were identified. Of the 58,281 rivaroxaban patients, 17,288 (29.7%) received anticoagulation on POD zero compared to 40,993 (70.3%) on POD one. Of the 54,274 patients receiving apixaban, 14,414 (26.6%) received anticoagulation on POD zero compared to 39,860 (73.4%) on POD one.

RESULTS

For both cohorts, patients receiving anticoagulation beginning on POD one had a reduced risk of acute anemia (rivaroxaban: adjusted odds ratio [aOR] 0.868, 95% CI [confidence interval]: 0.832 to 0.905, P < 0.001 | apixaban: aOR 0.771, 95% CI: 0.735 to 0.809, P < 0.001) and aggregate bleeding complications (rivaroxaban: aOR 0.867, 95% CI: 0.832 to 0.903, P < 0.001 | apixaban: aOR 0.767, 95% CI: 0.732 to 0.804, P < 0.001). Neither drug was associated with an increased risk of DVT or pulmonary embolism when administered on POD one versus POD zero.

CONCLUSIONS

Delayed administration of apixaban and rivaroxaban until POD one was associated with a reduced risk of postoperative anemia without an increased risk of thromboembolic complications in patients undergoing THA.