2025 Southeastern Residency Conference

Title: Evaluation of Direct Oral Anticoagulant Utilization for Venous Thromboembolism Treatment in Obese Spinal Cord Injury Rehabilitation Patients


Authors: Bryce Lackey, Virginia Montgomery, Dina Nakhleh, Raeda Anderson, Chloe Sellers, Carly B. Warner 


Background: Venous thromboembolism (VTE) is a continuous risk for hospitalized patients. Trauma, hypercoagulability, and sedentary lifestyle can increase risk of VTE due to venostasis and clotting factor proliferation. Each of these factors occurs following a spinal cord injury (SCI). Direct oral anticoagulants (DOAC) represent the mainstay of guideline recommended treatment for VTE.  Literature on DOAC use in obesity is evolving, but guidance is limited for DOAC use in patients with both SCI and obesity. This study aims to evaluate DOAC use for VTE treatment in patients with SCI and obesity.  


Methods: A retrospective, single center, cohort study was performed of obese SCI rehabilitation inpatients treated for VTE with a DOAC between July 1, 2019, and July 31, 2024.  The primary objective evaluated the effectiveness of DOAC therapy at preventing recurrent VTE.  Secondary objectives determined the frequency of anticoagulation interruptions, compared rates of VTE recurrence between American Spinal Injury Association (ASIA) scores (ASIA A, B, C, D, and E), and described bleeding events requiring blood transfusions.  For patients meeting inclusion criteria, data collected included: baseline characteristics, select past medical history, body mass index (BMI), weight, level of SCI, ASIA impairment scale, DOAC regimen, and type of VTE.  Patients were evaluated for whether the initial VTE happened prior to admission or at Shepherd Center, and the subsequent initiation of the DOAC regimen.  Those less than 18 years of age, with an indication for anticoagulation other than VTE, or a history of bariatric surgery were excluded.  Data was analyzed using descriptive statistics. Normally distributed data was analyzed via crosstabulations, chi-squared, and gamma tests.  This study was approved by the Institutional Review Board.


Results: The population included 72 patients with an average weight of 110.5kg and BMI of 34.7kg/m2. Average age was 43 years with 83% male and 60% quadriplegic. Patients were treated with apixaban (n=66, 92%) and rivaroxaban (n=6, 8%). Recurrent VTE occurred in eight patients (11%), including three recurrent VTEs while actively on a DOAC regimen.  A DOAC interruption occurred in 25 patients (35%) including five who experienced a recurrent VTE.  A majority of patients (n=39, 54%) had their initial VTE prior to admission and most (n=27) were admitted on a DOAC.  The remaining 33 patients (46%) had their initial VTE while admitted with ten of those patients started on a DOAC within 24 hours of their VTE.  There was no significant association between ASIA scores and the likelihood of having a recurrent VTE (p = 0.194).  There were six patients who required a blood transfusion, and four of those six patients had an accompanying blood hemoglobin level < 7mg/dL.  


Conclusions: This study explores important efficacy and safety outcomes regarding DOAC utilization in obese spinal cord injury patients. The rates of recurrent VTE, interruptions in DOAC therapy, and major bleeding suggest room for optimization in DOAC utilization.  Further research, including multi-center and randomized controlled trials, is needed to validate the findings of this study.