Long-term outcomes after traumatic brain injury in elderly patients on antithrombotic therapy

Elderly patients receiving antithrombotic treatment have a significantly higher risk of developing an intracranial hemorrhage when suffering traumatic brain injury (TBI), potentially contributing to higher mortality rates and worse functional outcomes. It is unclear whether different antithrombotic drugs carry a similar risk.

This study aims to investigate injury patterns and long-term outcomes after TBI in elderly patients treated with antithrombotic drugs.

The clinical records of 2999 patients ≥ 65 years old admitted to the University Hospitals Leuven (Belgium) between 1999 and 2019 with a diagnosis of TBI, spanning all injury severities, were manually screened.

A total of 1443 patients who had not experienced a cerebrovascular accident prior to TBI nor presented with a chronic subdural hematoma at admission were included in the analysis. Relevant clinical information, including medication use and coagulation lab tests, was manually registered and statistically analyzed using Python and R. In the overall cohort, 418 (29.0%) of the patients were treated with acetylsalicylic acid before TBI, 58 (4.0%) with vitamin K antagonists (VKA), 14 (1.0%) with a different antithrombotic drug, and 953 (66.0%) did not receive any antithrombotic treatment. The median age was 81 years (IQR = 11). The most common cause of TBI was a fall accident (79.4% of the cases), and 35.7% of the cases were classified as mild TBI. Patients treated with vitamin K antagonists had the highest rate of subdural hematomas (44.8%) (p = 0.02), hospitalization (98.3%, p = 0.03), intensive care unit admissions (41.4%, p < 0.01), and mortality within 30 days post-TBI (22.4%, p < 0.01). The number of patients treated with adenosine diphosphate (ADP) receptor antagonists and direct oral anticoagulants (DOACs) was too low to draw conclusions about the risks associated with these antithrombotic drugs.

In a large cohort of elderly patients, treatment with VKA prior to TBI was associated with a higher rate of acute subdural hematoma and a worse outcome, compared with other patients. However, intake of low dose aspirin prior to TBI did not have such effects. Therefore, the choice of antithrombotic treatment in elderly patients is of utmost importance with respect to risks associated with TBI, and patients should be counselled accordingly. Future studies will determine whether the shift towards DOACs is mitigating the poor outcomes associated with VKA after TBI.