Systematic Review and Meta-Analysis: Is Pre-Injury Antiplatelet Therapy Associated with Traumatic Intracranial Hemorrhage?

The objective of this systematic review and meta-analysis is to evaluate whether the pre-injury use of antiplatelet therapy (APT) is associated with increased risk of traumatic intracranial hemorrhage (tICH) on CT scan. PubMed, Medline, Embase, Cochrane Central, reference lists, and national guidelines on traumatic brain injury were used as data sources. Eligible studies were cohort studies and case-control studies that assessed the relationship between APT and tICH. Studies without control group were not included. The primary outcome of interest was tICH on CT. Two reviewers independently selected studies, assessed methodological quality, and extracted outcome data. This search resulted in 10 eligible studies with 20,247 patients with head injury that were included in the meta-analysis. The use of APT in patients with head injury was associated with significant increased risk of tICH compared with control (odds ratio [OR] 1.87, 95% confidence interval [CI] 1.27-2.74). There was significant heterogeneity in the studies (I-2 84%), although almost all showed an association between APT use and tICH. This association could not be established for patients receiving aspirin monotherapy. When considering only patients with mild traumatic brain injury (mTBI), the OR is 2.72 (95% CI 1.92-3.85). The results were robust to sensitivity analysis on study quality. In summary, APT in patients with head injury is associated with increased risk of tICH; this association is most relevant in patients with mTBI. Whether this association is the result of a causal relationship and whether this relationship also exists for patients receiving aspirin monotherapy cannot be established with the current review and meta-analysis.