Use of preinjury antiplatelet and oral anticoagulant agents on outcomes following blunt trauma in an Asian population: a 1:2 propensity score matched study.

Background: Bleeding is a feared complication of antiplatelets (APTs) and oral anti-coagulants (OACs) use. Asians are at higher risk of bleeding from APT/OAC compared to Western population. Our study aims to investigate the impact of preinjury APT/OAC use on outcomes of moderate to severe blunt trauma.

Methods: This is a retrospective cohort study from Jan 2017 - Dec 2019 of all patients with moderate to severe blunt trauma. A 1:2 propensity score matching (PSM) analysis was performed to address for confounding factors. Our primary outcome was in-hospital mortality. Our secondary outcomes were severity of head injury and need for emergency surgery within the first 24 hours.

Results: There were 592 patients (APT/OAC n=72, no APT/OAC n=520) included in our study. The median age was 74 years in APT/OAC and 58 years in no APT/OAC. PSM resulted in 150 patients (APT/OAC n=50, no APT/OAC n=100). In the PSM cohort, more patients with APT/OAC use had ischemic heart disease (76% vs 0%, P<0.001). APT/OAC use was independently associated with higher in-hospital mortality (22.0% vs 9.0%, Odds ratio (OR) 3.00, 95% Confidence interval (CI): 1.05, 8.56, P=0.040) Severity of head injury (abbreviated injury scale in APT/OAC: 3.33 ± 1.53, vs 2.97 ± 1.43, P=0.380) and need for emergency surgery (APT/OAC 16.2% vs 11.0%, P=0.434) was comparable between APT/OAC and no APT/OAC.

Conclusions: Preinjury APT/OAC use was associated with higher in-hospital mortality. Severity of head injury and need for emergency surgery within 24 hours from admission were comparable between APT/OAC use and no APT/OAC use.