The impact of preinjury anticoagulants and prescription antiplatelet agents on outcomes in older patients with traumatic brain injury.

BACKGROUND: Anticoagulants and prescription antiplatelet (ACAP) agents widely used by older adults have the potential to adversely affect traumatic brain injury (TBI) outcomes. We hypothesized that TBI patients on preinjury ACAP agents would have worse outcomes than non-ACAP patients.

METHODS: This was a 5.5-year retrospective review of patients 55 years and older admitted to a Level I trauma center with blunt force TBI. Patients were categorized as ACAP (warfarin, clopidogrel, dipyridamole/aspirin, enoxaparin, subcutaneous heparin, or multiple agents) or non-ACAP. ACAP patients were further stratified by class of agent (anticoagulant or antiplatelet). Initial and subsequent head computerized tomographic results were examined for type and progression of TBI. Patient preadmission living status and discharge destination were identified. Primary outcome was in-hospital mortality. Secondary outcomes were progression of initial TBI, development of new intracranial hemorrhage (remote from initial), and the need for an increased level of care at discharge.

RESULTS: A total of 353 patients met inclusion criteria: 273 non-ACAP (77%) and 80 ACAP (23%). Upon exclusion of three patients taking a combination of agents, 350 were available for advanced analyses. ACAP status was significantly related to in-hospital mortality. After adjustment for patient and injury characteristics, anticoagulant users were more likely than non-ACAP patients to show progression of initial hemorrhage and develop a new hemorrhagic focus. However, compared with non-ACAP users, antiplatelet users were more likely to die in the hospital. Among survivors to discharge, anticoagulant users were more likely to be discharged to a care facility, but this finding was not robust to adjustment.

CONCLUSION: Older TBI patients on preinjury ACAP agents experience a comparatively higher rate of inpatient mortality and other adverse outcomes caused by the effects of antiplatelet agents. Our findings should inform decision making regarding prognosis and caution against grouping anticoagulant and antiplatelet users together in considering outcomes.

LEVEL OF EVIDENCE: Therapeutic study, level IV.