Acute and Delayed Intracranial Hemorrhage in Head-Injured Patients on Warfarin versus Direct Oral Anticoagulant Therapy

INTRODUCTION: Direct oral anticoagulant (DOAC) use for thrombosis treatment and prophylaxis is a popular alternative to warfarin. This study compares rates of traumatic intracranial hemorrhage (ICH) for patients on anticoagulant therapies and the effect of combined anticoagulant and antiplatelet therapies. METHODS: A retrospective observational study of trauma patients was conducted at two level I trauma centers. Patients aged ≥18 years with preinjury use of an anticoagulant (warfarin, rivaroxaban, apixaban, or dabigatran) who sustained a blunt head injury within the past day were included. Patients were evaluated by head CT to evaluate for ICH. RESULTS: Three hundred and eighty-eight patients were included (140 on warfarin, 149 on a DOAC, and 99 on combined anticoagulant and antiplatelet therapies). Seventy-nine patients (20.4%) had an acute ICH, while 16 patients (4.1%) had a delayed ICH found on routine repeat CT. Those on combination therapy were not at increased risk of acute ICH (relative risk [RR] 0.90, confidence interval [CI]: 0.56–1.44; P > 0.5) or delayed ICH (RR 2.19, CI: 0.84–5.69; P = 0.10) compared to anticoagulant use only. Those on warfarin were at increased risk of acute ICH (RR 1.75, CI: 1.10–2.78, P = 0.015), but not delayed ICH (RR 0.99, CI 0.27–3.59, P > 0.5), compared to those on DOACs. No delayed ICH patients died or required neurosurgical intervention. CONCLUSION: Patients on warfarin had a higher rate of acute ICH, but not delayed ICH, compared to those on DOACs. Given the low rate of delayed ICH with no resultant morbidity or mortality, routine observation and repeat head CT on patients with no acute ICH may not be necessary.