Retrospective Evaluation of Postoperative Bleeding Events in Patients Receiving Rivaroxaban After Undergoing Total Hip and Total Knee Arthroplasty: Comparison with Clinical Trial Data

Study ObjectiveAlthough data from the Regulation of Coagulation in Orthopedic Surgery to Prevent Deep Venous Thrombosis and Pulmonary Embolism (RECORD) 1-4 trials have shown a similar postoperative bleeding risk between rivaroxban and enoxaparin in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), anecdotal observations from local institutions have suggested that postoperative bleeding rates seemed higher in patients who received rivaroxaban than those reported in the RECORD trials. Thus, the objective of this pilot study was to assess postoperative bleeding events observed in clinical practice in patients receiving rivaroxaban after undergoing THA and TKA and to compare their results with those published in the RECORD trials. DesignRetrospective cohort study with a comparator group of patients from the RECORD 1-4 trials. SettingTwo institutions within a regional health care system. PatientsFour hundred forty adults who received at least one dose of rivaroxaban 10mg daily after undergoing THA or TKA in the two institutions between August 2011 and October 2013 (cohort group), and 6183 patients who received rivaroxaban in the RECORD 1-4 trials (comparator group). Measurements and Main ResultsPostoperative bleeding was assessed in the cohort patients versus the patients in the RECORD trials. The primary outcome, occurrence of any postoperative bleeding, was a composite of major and clinically relevant nonmajor bleeding as defined in the RECORD trials. Any postoperative bleeding occurred in 6.8% of the cohort patients versus 3.2% of the RECORD trial patients (p<0.0001); 1.4% of the cohort patients versus 0.38% of the RECORD trial patients suffered a major bleed (p=0.013). Within defined major bleeding, bleeding leading to reoperation and clinically overt extrasurgical site bleeding resulting in either a hemoglobin level decrease of at least 2g/dl or transfusion of 2 units or greater of packed red blood cells were reported in 0.68% versus 0.19% (p=0.073) and 0.68% versus 0.13% (p=0.032), respectively, of the cohort patients versus the RECORD trial patients. ConclusionOverall, any postoperative bleeding in the cohort patients occurred significantly more frequently than that observed in the RECORD trial patients. The major bleeding rate was also significantly higher in the cohort patients, influenced by higher rates of bleeding leading to reoperation and clinically overt extrasurgical site bleeding resulting in either a hemoglobin decrease of at least 2g/dl or transfusion of two units or greater of packed red blood cells. These findings from our pilot study are thought provoking and, thus, invite further investigation.