What is the optimal timing to repeat a CT brain scan for a patient with acute ischemic stroke who is previously on apixaban (eliquis)?

Timing to Repeat CT Brain for Acute Ischemic Stroke Patients Previously on Apixaban

For acute ischemic stroke patients previously on apixaban, obtain a repeat CT brain scan at 24 hours after the initial stroke event, regardless of clinical stability, before initiating any anticoagulation or antiplatelet therapy for secondary stroke prevention. 1, 2

Standard 24-Hour Follow-Up Protocol

• All acute ischemic stroke patients require a repeat CT or MRI brain scan at 24 hours after the initial stroke event, even if clinically stable. 1, 2
• This 24-hour follow-up scan is mandatory before starting anticoagulants or antiplatelet agents for secondary stroke prevention. 1, 2
• The follow-up imaging serves to detect hemorrhagic transformation, assess infarct progression, and confirm the diagnosis. 1, 2

If Thrombolysis Was Administered

• The same 24-hour repeat imaging protocol applies to patients who received thrombolytic therapy. 1
• Neurological assessments should be performed every 15 minutes during the tPA infusion, every 30 minutes for the next 6 hours, then hourly until 24 hours after treatment. 1
• The 24-hour CT scan is required before starting anticoagulants or antiplatelet agents for secondary stroke prevention. 1

Emergency Repeat CT Indications

Obtain immediate repeat CT scanning for any neurological deterioration, regardless of the time since initial imaging. 3, 1, 2

• Emergency repeat CT is indicated for:
  • Any decline in level of consciousness 1
  • Worsening NIHSS score by ≥4 points from baseline 1
  • New or worsening brainstem signs 3
  • Any neurological deterioration whatsoever 3, 1

Special Considerations for Patients Previously on Apixaban

• Patients on anticoagulants like apixaban have a 3-fold increased risk of hemorrhage progression (26% vs 9%) compared to non-anticoagulated patients. 3
• If the initial CT shows intracranial hemorrhage, plan for follow-up imaging within 24 hours to assess for hemorrhage progression. 3
• The presence of any intracranial hemorrhage on initial CT requires neurosurgical consultation and consideration of anticoagulation reversal with andexanet alfa (specific reversal agent for apixaban) or prothrombin complex concentrate if unavailable. 3

Imaging Modality Selection

• CT head without IV contrast is usually preferred for follow-up due to its quick repeatability and ease of comparison to prior examinations. 2
• MRI is more accurate for detecting chronic intracerebral hemorrhage and small intraventricular hemorrhages but is not required for routine follow-up. 2
• There is no role for IV contrast in CT evaluation of evolving or subacute infarct. 2

Common Pitfalls to Avoid

• Do not delay the 24-hour follow-up CT scan, as this postpones initiation of secondary stroke prevention measures. 1, 2
• Do not rely solely on clinical examination without follow-up imaging, as this may miss asymptomatic hemorrhagic transformation. 1
• Do not delay emergency repeat imaging when neurological deterioration occurs, regardless of time since initial scan. 3, 1
• Failing to consider the patient's anticoagulation status may lead to underestimating hemorrhage progression risk. 3