Characteristics and Outcomes of Traumatic Acute Subdural Hematoma in Elderly Patients Receiving Antithrombotic Therapy: A Single-Center Retrospective Cohort Study

Background: Antithrombotic therapy is a risk factor for subdural hematoma after head injury. Methods: We retrospectively studied 180 consecutive patients with traumatic acute subdural hematoma. Results: The median age was 81 years, 68 (38%) were female, and 44% were on antithrombotic therapy. In the antithrombotic therapy group, the patients were significantly older (84, 77–88 vs. 78, 74–84, p value = 0.00104), and the proportion of minor injury was significantly higher (83% vs. 61%, p value = 0.00178). Poor clinical outcomes were not significantly different between the groups (44% vs. 41%; p value = 0.762). In multivariable logistic regression analysis adjusted for age and sex, poor outcomes (42%) were associated with the first Glasgow coma scale scores (OR 0.73, 95% CI 0.65–0.82, p value < 0.001) and the first CT findings (OR 4.9, 95% CI 1.98–11.8, p value < 0.001), but not with antithrombotic therapy (OR 1.48, 95% CI 0.61–3.60, p value = 0.390). Of the 97 patients treated conservatively for more than 2 weeks, surgical intervention in the chronic phase was higher in the antithrombotic therapy group (16% vs. 1.9%; p value = 0.0230). The timing of re-administration did not correlate with the incidence of chronic surgical intervention (within 2 weeks: 18%; over 2 weeks: 9.1%; p value = 0.663). Conclusions: The proportion of minor injury was significantly higher in the antithrombotic therapy group than in the non-medication group. Antithrombotic therapy was not associated with poor outcome but correlated with the increased risk of surgical intervention in the chronic phase.