C. Cohan1, G. Beattie1, D. Dominguez1, M. Cochran1, B. Palmer1, G. P. Victorino1 1University of California San Francisco – East Bay,Department Of Surgery,Oakland, CA, USA
Introduction: Guidelines regarding management of patients on anticoagulation suffering from mild blunt traumatic brain injury (TBI) are unclear. Repeat CT head (CTH) is commonly performed on anticoagulated patients after an initial negative CTH to assess for delayed intracranial hemorrhage (ICH-d). The reported incidence of ICH-d in anticoagulated patients is 0.51-6%. Current literature focuses on patients taking prehospital warfarin. Since approval of several novel oral anticoagulants (NOACs) including rivaroxaban, apixaban, and dabigatran, there has been a steady increase in trauma patients presenting on these medications. The rate of ICH-d in this patient population is unknown. We hypothesized that the incidence of ICH-d in patients on NOACs would be low, similar to patients on warfarin, and that routine repeat CTH after initial negative CTH in patients on NOACs is not indicated.
Methods: We performed a retrospective chart review of all adult patients on anticoagulation presenting to our level I trauma center for blunt trauma between February 2016 and May 2018. We excluded patients who had a positive initial CTH, who did not have a repeat CTH within 24 hours of initial scan, or who had a GCS <13 on arrival. CTH was repeated 4-12 hours after initial CTH. Clinical outcomes including ICH-d, discharge GCS, neurosurgical intervention, readmission, and death were assessed. Comparisons were made using a chi squared test or ANOVA. Data are presented as mean ± standard error of the mean.
Results: A total of 218 patients met inclusion criteria with an average initial GCS of 14.7 ± 0.03. The following groups were evaluated: warfarin only (n=133), NOAC only (n=68), and anticoagulation (warfarin or NOAC)-ASA combination regimen (n=17). The average INR for each group was 2.7 ± 0.24, 1.4 ± 0.03, and 2.2 ± 0.26, respectively (p<0.01). Average age in years for each group was 78.3 ± 1.1, 75.7 ± 0.86, and 72.9 ± 3.0, respectively (p=0.2). The overall incidence of ICH-d after initial negative CTH was 2.5%. The incidence in the NOAC only group was 1.5% (1/68) vs. 2.3% (3/133) in the warfarin only group, (p=0.71). In the warfarin group, 66% (2/3) of patients with ICH-d had a supratherapeutic INR on presentation. There were no ICH-d events in the anticoagulation-ASA combination group.
Conclusion: To our knowledge, this is the largest study of patients on novel anticoagulants to assess ICH-d in mild TBI. We found that the incidence rates of ICH-d are similar between patients taking NOACs and warfarin. In the one patient with ICH-d on novel anticoagulation, no neurosurgical intervention, decline in GCS, readmission or death occurred. Our findings suggest there is no indication for repeat imaging in patients on novel anticoagulation presenting with mild TBI. Limiting unnecessary imaging in this substantial and growing population may save time, reduce costs, and improve allocation of resources.