Risk of significant traumatic brain injury in adults with minor head injury taking direct oral anticoagulants: a cohort study and updated meta-analysis

Abstract

Background: Patients taking direct oral anticoagulants (DOACs) commonly undergo CT head imaging after minor head injury, regardless of symptoms or signs. However, the risk of intracranial haemorrhage (ICH) in such patients is unclear, and further research has been recommended by the UK National Institute for Health and Care Excellence head injury guideline group.

Methods: An observational cohort study was performed in the UK South Yorkshire major trauma centre between 26 June and 3 September 2018. Adult patients taking DOACs with minor head injury were prospectively identified, with case ascertainment supplemented by screening of radiology and ED information technology systems. Clinical and outcome data were subsequently collated from patient records. The primary endpoint was adverse outcome within 30 days, comprising: neurosurgery, ICH or death due to head injury. A previously published meta-analysis was updated with the current results and the findings of other recent studies.

Results: 148 patients with minor head injury were included (GCS 15, n=107, 72%; GCS 14, n=41, 28%). Patients were elderly (median 82 years) and most frequently injured from ground level falls (n=142, 96%). Overall risk of adverse outcome was 3.4% (5/148, 95% CI 1.4% to 8.0%). Five patients had ICH, of whom one died within 30 days. One patient was treated with prothrombin complex concentrate but no patient received critical care management or underwent neurosurgical intervention. Updated random effects meta-analysis, including the current results and two further recent studies, showed a weighted overall risk of adverse outcome of 3.2% (n=29/787, 95% CI 2.0% to 4.4%).

Conclusions: The risk of adverse outcome following mild head injury in patients taking DOACs appears low. These findings would support shared patient-clinician decision making, rather than routine imaging, following minor head injury while taking DOACs.

Keywords: CT/MRI; clinical; head; imaging; research; trauma.