Incidence of intracranial bleeding in mild traumatic brain injury patients taking oral anticoagulants: a systematic review and meta-analysis

Background: Traumatic brain injury (TBI) is one of the leading causes of disability and death worldwide. Most TBI cases occur in older people, because they are at a higher risk of accidental falling. As the population ages, the use of anticoagulants is increasing. Some serious complications of TBI, such as intracranial hemorrhage (ICH), may occur even in mild cases. According to the current guidelines regarding managing mild TBI patients, a CT head scan is recommended for all patients receiving anticoagulation. We aim to assess the incidence of ICH in patients with mild TBI taking oral anticoagulants. Methods: Our systematic review and meta-analysis were performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. The protocol was registered in PROSPERO (CRD42024503086). Twenty-eight studies evaluating patients with a mild TBI from ten countries with a total sample size of 11,172, 5671 on DOACs, and 5501 on VKAs were included in our meta-analysis. Results: The random-effects overall incidence of ICH among oral anticoagulated patients with mild TBI was calculated to be 9.4% [95% CI 7.2–12.1%, I² = 89%]. The rates of immediate ICH for patients taking DOACs and VKAs were 6.4% and 10.5%, respectively. The overall rate of immediate ICH in anticoagulated mild TBI patients was 8.5% [95% CI 6.6–10.9%], with a high heterogeneity between studies (I² = 88%). Furthermore, the rates of delayed ICH in patients with mild TBI taking DOACs and VKAs were 1.6% and 1.9%, respectively. The overall incidence of delayed ICH among oral anticoagulated mild TBI patients was 1.7% [95% CI 1–2.8%, I² = 79%]. The overall rate of ICH among mild TBI patients taking DOAC was calculated to be 7.3% [95% CI 5.2–10.3%], with significant heterogeneity between studies (I² = 79%). However, the overall ICH rate is higher in patients who take only VKAs 11.3% [95% CI 8.6–14.7%, I² = 83%]. Patients on DOACs were at lower risk of ICH after mild TBI compared to patients on VKAs (OR = 0.64, 95% CI 0.48–0.86, p < 0.01, I² = 28%). Conclusion: Our meta-analysis confirms the need for performing brain CT scan in patients with mild TBI patients who receive oral anticoagulants before injury. Due to limited data, further multi-center, prospective studies are warranted to confirm the true incidence of traumatic ICH in patients on anticoagulants.