Does Pre-existing Anticoagulation or Antiplatelet Therapy Increase the Risk of Traumatic Subarachnoid Hemorrhage Progression?

BACKGROUND: Isolated traumatic subarachnoid hemorrhage (tSAH) is a common finding in mild traumatic brain injury that often results in transfer to a tertiary center. Patients prescribed blood-thinning medications (BTs) are believed to be at higher risk of clinical or radiographic worsening. OBJECTIVE: To compare the rates of radiographic progression and need for neurosurgical intervention in patients with tSAH who are on anticoagulation (AC) and antiplatelet (AP) therapies with those who are not. METHODS: Analysis using a retrospective cohort design identified patients older than 18 years with isolated tSAH and a Glasgow Coma Scale of 15 on admission. Clinical information including use of BTs, administration of reversal agents, radiographic progression, and need for neurosurgical intervention was collected. Patients on BTs were divided into AP, AC, and AP/AC groups based on drug type. RESULTS: Three hundred eighty-four patients were included with 203 in the non-BT group and 181 in the BT group. Overall, 2.1% had worsening scans, and none required operative intervention. There was no difference in radiographic worsening between the non-BT and BT groups (2.4% vs 1.6%; P = 1.00). Crosswise comparison revealed no difference between the non-BT group and each BT subtype (AP, AP/AC, or AC). The non-BT group was more likely to have radiographic improvement than the BT group (45.8% vs 30.9%; P = .002). CONCLUSION: Neurologically intact patients on BTs with isolated tSAH are not at increased risk of radiographic progression or neurosurgical intervention. The presence of BTs should not influence management decisions for increased surveillance.