Clinical Presentation, Treatment, and Outcome of Nontraumatic Subarachnoid Hemorrhage in Patients with Preceding Antithrombotic Therapy.

With the aging of the population, the number of people taking antithrombotic drugs is increasing. Few reports have described the clinical presentation, treatment, and outcomes of nontraumatic subarachnoid hemorrhage (SAH) in patients with preceding antithrombotic therapy. This study included 459 patients with nontraumatic SAH who had been treated between April 2009 and May 2021. Overall, 39 of the 459 patients with aneurysmal SAH were on antithrombotic therapy before ictus (8.5%). Therefore, we classified patients into two groups: Group A (n = 39), patients with preceding antithrombotic therapy and Group B (n = 420), patients without preceding antithrombotic therapy. Hunt and Kosnik (H&K) grade on admission was significantly higher in Group A than in Group B (p = 0.02). Patients in Group A more frequently received endovascular treatment. The rate of endovascular therapy for symptomatic vasospasm after SAH was significantly lower in Group A (2.6%) than in Group B (15.5%; p = 0.03). The outcomes at 3 months after onset were significantly poorer in Group A patients than in Group B patients (p = 0.03). Patients with preceding antithrombotic drugs tended to be at greater risk of unfavorable outcomes, but this difference was not significant in the univariate analysis. In the multivariate analysis, patient age, H&K grade ≥4, and subdural hematoma remained as risk factors for poor outcomes; however, preceding use of antithrombotic drugs was not a significant risk factor.