Effect of Pre-Management Antithrombotic Agent Use on Outcome after Traumatic Acute Subdural Hematoma in the Elderly: A Systematic Review

Traumatic acute subdural hematomas (ASDH) are common in elderly patients (age ≥65 years) and are associated with a poorer prognosis compared with younger populations. Antithrombotic agent (ATA) use is also common in the elderly; however, the influence that pre-morbid ATA has on outcome in ASDH is poorly understood. We hypothesized that pre-morbid ATA use significantly worsens outcomes in elderly patients presenting with traumatic ASDH. English language medical literature was searched for articles relating to ATA use in the elderly with ASDH. Data were collated and appraised where possible. Analyses of study bias were performed. Twelve articles encompassing 2038 patients were included; controls were poorly described in the included studies. Pre-morbid ATA use was seen in 1042 (51.1%) patients and 18 different ATA combination therapies were identified, with coumarins being the most common single agent used. The newer direct oral anticoagulants were evaluated in only two studies. ATA use was associated with a lower presenting Glasgow Coma Scale (GCS) score but not hematoma volume on computed tomography (CT) or post-operative hematoma re-accumulation. No studies connected ATA use with patient outcomes without the presence of confounders and bias. Reversal strategies, bridging therapy, recommencement of ATA, and comparison groups were poorly described; accordingly, our hypothesis was rejected. ATA reversal methods, identification of surgical candidates, optimal surgery methods, and when or whether ATA should be recommenced following ASDH resolution remain topics of debate. This study defines our current understanding on this topic, revealing clear deficiencies in the literature with recommendations for future research.