When can aspirin (acetylsalicylic acid) be restarted after an intracranial hemorrhage (ICH) in a patient with a history of cardiovascular disease or stroke?

When to Restart Aspirin After Intracranial Hemorrhage

Aspirin can be safely restarted beyond 24 hours after ICH symptom onset in patients with cardiovascular indications, with the RESTART trial demonstrating no increased risk of recurrent ICH and potential reduction in major adverse cardiovascular events. 1, 2

Immediate Management

• Discontinue aspirin immediately upon diagnosis of ICH 3
• Aspirin should be stopped as soon as possible to prevent hematoma expansion 1
• Note that prior aspirin use at ICH onset is associated with increased mortality (RR 2.5) and hematoma enlargement, making immediate cessation critical 4

Standard Timing for Aspirin Resumption

General Population (24-48 Hours)

• For acute ischemic stroke patients, aspirin is recommended within 24-48 hours after stroke onset 1
• For ICH patients with cardiovascular indications, aspirin can be restarted beyond 24 hours after ICH symptom onset 5, 2
• The 2023 guidelines support antiplatelet therapy resumption beyond 24 hours in patients with prior indications 2

Evidence-Based Safety Data

• The RESTART trial (537 patients, 2019) showed that resuming antiplatelet therapy after ICH did not increase recurrent ICH risk (adjusted HR 0.51,95% CI 0.25-1.03) 1
• Observational studies demonstrate lower ischemic events (RR 0.61) with no difference in hemorrhagic events (RR 0.84) when aspirin is resumed 1
• A Chinese cohort study found no increased recurrent ICH risk with aspirin use (22.7 vs 22.4 per 1,000 patient-years, p=0.70) 6

Risk Stratification Algorithm

High-Risk Hemorrhagic Features (Consider Delaying or Avoiding)

• Lobar ICH location - highest recurrence risk, likely indicates cerebral amyloid angiopathy 5
• Elderly patients with lobar ICH - AHA/ASA recommends avoiding long-term antiplatelet therapy in this population 5
• Multiple microbleeds on gradient echo MRI - predicts 9.3% ICH risk on antithrombotics versus 1.3% without 5
• Uncontrolled hypertension - independent predictor for recurrent ICH (HR 2.0) 6
• Age >60 years - independent predictor for recurrent ICH (HR 2.0) 6

High Thrombotic Risk (Favor Earlier Restart at 24 Hours)

• Recent acute coronary syndrome or unstable angina 6
• Recent coronary stent placement (especially drug-eluting stents <12 months) 6
• High CHADS₂ score ≥4 for atrial fibrillation patients 3
• Prior ischemic stroke 3

Pre-Restart Requirements

Before restarting aspirin at any timepoint:

• Obtain repeat brain imaging (CT or MRI) to confirm hemorrhage stability and absence of expansion 5
• Ensure adequate blood pressure control with target <130/80 mmHg long-term 5
• Document absence of new microbleeds if MRI available 5

Special Populations

Lobar ICH/Cerebral Amyloid Angiopathy

• Aspirin monotherapy appears generally safe even in cerebral amyloid angiopathy patients and can be restarted beyond 24 hours 5, 2
• However, AHA/ASA guidelines recommend avoiding long-term antiplatelet therapy after lobar ICH in elderly patients due to high rebleeding risk 5
• Consider left atrial appendage closure as alternative for atrial fibrillation patients who cannot restart antiplatelets 5

Patients on Dual Antiplatelet Therapy

• For patients previously on aspirin plus clopidogrel, consider aspirin monotherapy only after ICH 5
• Dual antiplatelet therapy reduces stroke risk by 20% but increases bleeding risk, requiring careful individualization 7

Common Pitfalls to Avoid

• Do not restart aspirin in patients with IV thrombolysis until >24 hours post-treatment 1
• Do not assume all ICH patients should avoid aspirin indefinitely - the RESTART trial refutes this concern 1
• Do not restart without repeat imaging - hemorrhage stability must be confirmed 5
• Do not ignore blood pressure control - uncontrolled hypertension doubles recurrent ICH risk 6

Alternative Strategies

• Aspirin monotherapy is preferred over dual antiplatelet therapy after ICH for most indications 5
• Left atrial appendage closure is viable for atrial fibrillation patients unable to restart any antithrombotic 5
• For patients with standard aspirin indications who restart therapy, combined vascular event rates are lower (52.4 vs 112.8 per 1,000 patient-years, p=0.04) 6