Risk of delayed intracranial haemorrhage after an initial negative CT in patients on DOACs with mild traumatic brain injury

Background: Repeat head CT in patients on direct oral anticoagulant therapy (DOACs) with minor traumatic brain injury (MTBI) after an initial CT scan without injury on arrival in the Emergency Department (ED) is a common clinical practice but is not based on clear evidence. Aim: To assess the incidence of delayed intracranial haemorrhage (ICH) in patients taking DOACs after an initial negative CT and the association of clinical and risk factors presented on patient arrival in the ED. Methods: This retrospective multicentre observational study considered patients taking DOACs undergoing repeat CT after a first CT free of injury for the exclusion of delayed ICH after MTBI. Timing between trauma and first CT in the ED and pre- or post-trauma risk factors were analysed to assess a possible association with the risk of delayed ICH. Results: A total of 1426 patients taking DOACs were evaluated in the ED for an MTBI. Of these, 68.3% (916/1426) underwent a repeat CT after an initial negative CT and 24 h of observation, with a rate of delayed ICH of 1.5% (14/916). Risk factors associated with the presence of a delayed ICH were post-traumatic loss of consciousness, post-traumatic amnesia and the presence of a risk factor when the patient presented to the ED within 8 h of the trauma. None of the patients with delayed ICH at 24-h repeat CT required neurosurgery or died within 30 days. Conclusions: Delayed ICH is an uncommon event at the 24-h control CT and does not affect patient outcome. Studying the timing and characteristics of the trauma may indicate patients who may benefit from more in-depth management.