The utility of a second head CT scan after a negative initial CT scan in head trauma patients on new direct oral anticoagulants (DOACs).

BACKGROUND: New direct oral anticoagulants (DOACs) are commonly used in the management of atrial fibrillation and VTE. Currently, there is no strong evidence to support the current practice of routinely repeating computed tomography (CT) head in anticoagulated patients within 24 hours after their first negative CT scan to assess for new and delayed intracranial hemorrhage (ICH). Our hypothesis is that the vast majority will not have new CT scan findings of ICH and those who do would not require any further intervention. METHODS: This is retrospective cohort study. IRB approval was obtained. Subjects included adults age ≥ 18 taking DOACs who presented to our level III trauma center with confirmed or suspected blunt head trauma between August 2013 and October 2019 and received at least one head CT scans. RESULTS: 498 Patient encounters met inclusion criteria. Only 19 patients (3.8%) had positive traumatic ICH on the initial CT head. Those had a higher ISS. 420 out of 479 initial negative CT encounters received a second CT head. Only 2 (0.5%) had delayed positive second CT scan for ICH. 95%CI [0.06%, 1.7%] Patients who developed a new ICH on the second CT head after an initial negative CT scan had a lower Glasgow Coma Scale (GCS) on presentation and a higher ISS. None of those patients required neurosurgical intervention CONCLUSION: Our data suggests that the risk of developing a new or delayed traumatic ICH for patients on DOAC on a second CT head within 24 hours following an initial negative CT is very low and when present did not require neurosurgical intervention and thus does not support routinely obtaining a repeat CT head within 24 hours after a negative initial CT scan. Patients presenting with lower GCS and higher ISS had a higher chance of having a delayed ICH.