Comparison of outcomes in non-head injured trauma patients using pre-injury warfarin or direct oral anticoagulant therapy

Background: Patients on prehospital anticoagulation with warfarin or direct oral anticoagulants (DOACs) represent a vulnerable subset of the trauma population. While protocolized warfarin reversal is widely available and easily implemented, prehospital anticoagulation with DOAC is cost prohibitive with only a few reversal options. This study aims to compare hospital outcomes of non-head injured trauma patients taking pre-injury DOAC versus warfarin.

Methods: A retrospective cohort study at a level 1 trauma center was performed. All adult trauma patients with pre-injury anticoagulation admitted between January 2015 and December 2018, were stratified into DOAC-using and warfarin-using groups. Patients were excluded if they had traumatic brain injury (TBI). Univariate and multivariable analyses were performed. Outcomes measures included in-hospital mortality, blood transfusion requirements, ICU length of stay (LOS), hospital LOS and discharge disposition.

Results: 374 non-TBI trauma patients on anticoagulation were identified, of which 134 were on DOACs and 240 on warfarin. Patients on DOACs had a higher ISS (9 [IQR, 9-10] vs. 9 [IQR, 5-9]; p<0.001), and lower admission INR values (1.2 [IQR, 1.1-1.3] vs 2.4 [IQR, 1.8-2.7]; p<0.001) than warfarin users. Use of reversal agents was higher in warfarin users (p<0.001). Relative to warfarin, DOAC users did not differ significantly with respect to hospital mortality (OR 0.47, 95% CI [0.13-1.73]). Multivariable analysis (not possible for mortality) did not show significant difference for RBC transfusion requirements (OR 0.92 [0.51-1.67]), ICU LOS (OR 1.08 [0.53-2.19]), hospital LOS (OR 1.10 [0.70-1.74]) or discharge disposition (OR 0.56 [0.29-1.11]) between the groups.

Conclusion: Despite lower reversal rates and higher ISS, non-TBI trauma patients with pre-injury DOAC use had similar outcomes as patients on pre-injury warfarin. There may be equipoise to have larger, prospective studies evaluating the comparative safety of DOACs and warfarin in the population prone to low energy fall type injuries.