When should low‑dose aspirin (81 mg daily) be restarted after an intracerebral hemorrhage?

Restarting Aspirin After Intracerebral Hemorrhage

For patients with intracerebral hemorrhage who have a clear indication for antiplatelet therapy (such as prior cardiovascular disease or stroke prevention), resuming low-dose aspirin is reasonable and may improve survival, with current guidelines supporting restart beyond 24 hours after ICH symptom onset. 1

Timing of Aspirin Resumption

The optimal timing remains uncertain, but aspirin can be restarted within days to weeks after ICH onset based on individual risk assessment. 1

• Early restart (>24 hours): Guidelines from the UK and Ireland indicate that antiplatelet treatment may be considered beyond 24 hours after ICH symptom onset in patients who were taking antithrombotics for prevention of occlusive vascular events. 1

• Chinese guidelines suggest aspirin monotherapy can be restored within a few days from ICH onset, though acknowledge the best timing is unclear. 1

• The RESTART trial, which forms the basis for current recommendations, showed no significant increase in recurrent ICH risk with antiplatelet resumption, and actually demonstrated reduced major adverse cardiovascular events (adjusted HR 0.65,95% CI 0.44-0.95). 1

Risk-Benefit Assessment

Clinicians must weigh the baseline risks of recurrent ICH against occlusive vascular events when deciding on aspirin restart. 1

Factors Favoring Aspirin Resumption:

• Prior indication for antiplatelet therapy (history of ischemic stroke, coronary artery disease, or other atherosclerotic disease) 1
• Patients who were on antithrombotic therapy before the ICH appear to have improved survival with aspirin resumption (adjusted HR 0.56,95% CI 0.39-0.80). 2
• Observational data suggest low-dose aspirin after ICH is associated with 32% improved survival (adjusted HR 0.68,95% CI 0.53-0.88). 2

Factors Requiring Caution:

• Age >65 years may be associated with increased ICH risk when using aspirin. 3
• Concurrent anticoagulant use increases ICH risk and requires careful consideration. 3
• ICH location and mechanism should inform decision-making, though specific data stratifying risk by these factors remain limited. 1

Current Guideline Recommendations

Multiple international guidelines (USA, Canada, UK, China) now support aspirin resumption with Level B evidence, indicating it is "reasonable" for appropriate patients. 1

• The 2022 AHA/ASA guideline states that resumption of antiplatelet therapy may be reasonable for prevention of thromboembolic events based on consideration of benefit and risk. 1
• Canadian guidelines indicate resuming antiplatelet therapy is reasonable in patients with continued indication. 1
• All guidelines emphasize that the decision should account for individual patient risks of both recurrent ICH and thromboembolic events. 1

Critical Caveats

• Discontinuation of aspirin after ICH in patients who were previously on it is associated with decreased survival (adjusted HR 1.54,95% CI 1.21-1.97), suggesting harm from stopping in appropriate candidates. 2
• The evidence base has limitations: Most data come from the RESTART trial, which was a pilot-phase RCT with imprecise effect estimates due to relatively small sample size, and enrolled primarily UK patients. 1
• Monotherapy is preferred over dual antiplatelet therapy when restarting. 1

Practical Algorithm

1. Confirm the patient has a clear indication for antiplatelet therapy (prior ischemic stroke, coronary disease, peripheral arterial disease). 1
2. Wait at least 24 hours after ICH symptom onset before considering restart. 1
3. Assess high-risk features: age >65 years, need for concurrent anticoagulation, ICH location (lobar vs deep). 3, 1
4. For patients with prior antiplatelet indication and no high-risk features: restart low-dose aspirin (81 mg daily) within days to weeks. 1, 2
5. For patients with high-risk features: consider delaying restart or enrollment in clinical trials if available. 1