Impact of Oral Anticoagulation and Adenosine Diphosphate Inhibitor Therapies on Short-term Outcome of Traumatic Brain Injury

Abstract

Objective: Usage of oral anticoagulants (OAC) or adenosine diphosphate inhibitors (ADPi) is known to increase the risk of bleeding. We aimed to investigate the impact of OAC and ADPi therapies on short-term outcomes after traumatic brain injury (TBI). Methods: All adult patients hospitalized for TBI in Finland during 2005–2018 were retrospectively studied using a combination of national registries. Usage of pharmacy-purchased OACs and ADPis at the time of TBI was analyzed with the pill-counting method (Social Insurance Institution of Finland). The primary outcome was 30-day case-fatality (Finnish Cause of Death Registry). The secondary outcomes were acute neurosurgical operation (ANO) and admission duration (Finnish Care Register for Health Care). Baseline characteristics were adjusted with multivariable regression including age, sex, comorbidities, skull or facial fracture, OAC/ADPi treatment, initial admission location, and the year of TBI admission. Results: The study population included 57,056 persons (mean age 66 years) of whom 0.9% used direct oral anticoagulants (DOAC), 7.1% Vitamin K antagonists (VKA), and 2.3% ADPis. Patients with VKAs had higher case-fatality than patients without OAC (15.4% vs. 7.1%; adjHR 1.35, CI 1.23–1.48; pConclusion: Preinjury use of VKA is associated with increases in short-term mortality and in need for ANOs after TBI. DOACs are associated with lower fatality than VKAs after TBI. ADPis were not independently associated with the outcomes studied. These results point to relative safety of DOACs or ADPis in patients at risk of head trauma and encourage to choose DOACs when oral anticoagulation is required. Classification of evidence: This study provides Class II evidence that among adults with TBI, mortality was significantly increased in those using VKAs but not in those using DOACs or ADPis.