Guidelines for Restarting Aspirin After Subdural Hemorrhage
After a subdural hemorrhage, aspirin should be restarted approximately 4 weeks after the bleeding has stabilized, with consideration for earlier restart (2-3 weeks) if follow-up imaging shows stability. 1
Timing of Aspirin Resumption
The decision to restart aspirin after a subdural hemorrhage requires careful consideration of both hemorrhagic and thromboembolic risks:
Initial Management
- For patients who develop subdural hemorrhage (SDH), all anticoagulants and antiplatelets should be discontinued during the acute period for at least 1-2 weeks after the hemorrhage 2
- Immediate reversal of anticoagulation effect is necessary if the patient was on anticoagulants 1
Recommended Waiting Period
- Wait approximately 4 weeks after surgical removal or stabilization of a traumatic subdural hematoma before restarting aspirin 1
- Consider earlier restart (2-3 weeks) if follow-up imaging shows stability of the hematoma 1
- For patients with high cardiovascular risk, the waiting period may need to be shortened to balance thromboembolic risk 3
Monitoring After Restarting Aspirin
- Close clinical monitoring is recommended for the first 2-4 weeks after restarting aspirin 1
- Follow-up imaging should be performed 2-4 weeks after restarting aspirin to assess for recurrent bleeding 1
- Serial CT scans at 24 hours, 7-10 days, and 30 days are strongly recommended, with immediate repeat imaging for any neurological deterioration 1
Special Considerations
High Cardiovascular Risk Patients
- For patients with high cardiovascular risk (e.g., recent coronary stenting), the decision to restart aspirin may need to be made earlier to prevent thrombotic events 2
- The 2017 ESC guidelines suggest that the balance between ischemic and bleeding risks must be carefully weighed in each individual case 2
Recent Research Findings
- A 2025 randomized clinical trial (SECA trial) found that continuing aspirin during the perioperative phase of chronic subdural hematoma treatment did not significantly increase recurrence rates compared to discontinuation (13.9% vs 9.5%) 4
- This suggests that the risk of recurrent bleeding with aspirin may be lower than previously thought 4
Risk Assessment
Factors Increasing Hemorrhagic Risk
- Asian race/ethnicity and low body mass index are associated with heightened risk of intracerebral hemorrhage with low-dose aspirin 5
- Lobar hemorrhages or microbleeds suggesting cerebral amyloid angiopathy on MRI may indicate higher risk for recurrent hemorrhage 2
Factors Increasing Thromboembolic Risk
- Recent coronary stenting, especially drug-eluting stents
- History of stroke or transient ischemic attack
- Atrial fibrillation
- Mechanical heart valves
Preventive Measures During the Waiting Period
- Consider mechanical thromboprophylaxis with intermittent pneumatic compression during the waiting period 1
- Pharmacological thromboprophylaxis is recommended within 24 hours after bleeding has been controlled 1
- Maintain platelet count above 50×10^9/L during the acute phase 1
Common Pitfalls to Avoid
- Restarting aspirin too early (within 1 week) may increase risk of hematoma expansion
- Delaying aspirin restart too long in high cardiovascular risk patients may lead to preventable thrombotic events
- Failing to obtain follow-up imaging before restarting aspirin
- Not considering patient-specific factors that may alter the risk-benefit ratio
By following these guidelines and carefully monitoring patients after restarting aspirin, clinicians can optimize outcomes by balancing the risks of recurrent hemorrhage against the benefits of preventing thromboembolic events.