From the Guidelines
A computed tomography (CT) scan of the head is indicated for a patient with a minor head injury who is taking Clopidogrel (Plavix). This recommendation is based on the increased risk of intracranial bleeding associated with antiplatelet therapy, as highlighted in the 2023 clinical policy by the American College of Emergency Physicians (1). The policy emphasizes the importance of liberal use of neuroimaging in patients on anticoagulants or antiplatelet agents due to the higher incidence of significant intracranial injuries after blunt head trauma.
Key considerations for managing patients on Clopidogrel with minor head injuries include:
- Urgent CT head scan, ideally within 8 hours of the injury, but certainly within 24 hours
- Monitoring for neurological deterioration, including headache, vomiting, confusion, seizures, or focal neurological deficits while waiting for the scan
- Observation for at least 24 hours if possible, even if the initial CT is negative, due to the risk of delayed bleeding
- Discussion with the prescribing physician regarding the continued use of Clopidogrel, weighing the risk of thrombotic events against the risk of bleeding
- Consideration of reversal of antiplatelet effects in consultation with hematology in cases of confirmed intracranial hemorrhage
The 2021 update on ACR Appropriateness Criteria for head trauma (1) also supports the use of CT scans in patients with mild head trauma and coagulopathy, including those on antiplatelet therapy. However, the most recent and highest quality evidence from the 2023 clinical policy (1) takes precedence, emphasizing the need for a low threshold for imaging in patients on antiplatelet agents like Clopidogrel due to the potential for increased morbidity and mortality from intracranial hemorrhage.
From the Research
Indications for CT Scan in Minor Head Injury with Clopidogrel Use
- The use of Clopidogrel (Plavix) in patients with minor head injury is associated with an increased risk of intracranial hemorrhage, as evidenced by studies 2, 3, 4, 5, 6.
- A study published in 2014 found that patients on preinjury clopidogrel therapy were more likely to have progression on repeat head CT scan and require neurosurgical intervention 2.
- Another study from 2011 reported a high incidence of intracranial hemorrhage in patients with minor head injury taking anticoagulation or antiplatelet therapy, including clopidogrel, especially after loss of consciousness 3.
- The risk of intracranial hemorrhage after minor head trauma in patients with pre-injury use of clopidogrel was found to be significantly increased, with an odds ratio of 16.7 4.
- A retrospective observational study published in 2016 found that patients receiving warfarin or clopidogrel have approximately a 2.5% risk of delayed intracerebral hemorrhage after an initial normal head CT scan 5.
- A clinical prediction rule derived from a prospective observational study published in 2013 was unable to identify a subset of patients with mild head trauma and preinjury warfarin or clopidogrel use who are at low risk for immediate traumatic intracranial hemorrhage, suggesting the need for urgent and liberal cranial CT imaging in this patient population 6.
Key Findings
- Clopidogrel use is associated with an increased risk of intracranial hemorrhage after minor head injury.
- Patients on clopidogrel therapy are more likely to require repeat head CT scans and neurosurgical intervention.
- The risk of delayed intracerebral hemorrhage after an initial normal head CT scan is approximately 2.5% in patients receiving warfarin or clopidogrel.
- Clinical prediction rules are unable to identify patients at low risk for immediate traumatic intracranial hemorrhage, suggesting the need for liberal cranial CT imaging in patients with mild head trauma and preinjury warfarin or clopidogrel use.