When to start aspirin (acetylsalicylic acid) in patients with ischemic stroke complicated by intracranial bleed?

When to Start Aspirin After Ischemic Stroke Complicated by Intracranial Hemorrhage

In patients with ischemic stroke complicated by intracranial hemorrhage, aspirin can probably be restarted within 3-7 days for non-lobar hemorrhages with strong indications (such as recent acute coronary syndrome or coronary stents), but should be delayed for a minimum of 4-6 weeks for lobar hemorrhages or when indications are less compelling. 1

Critical Decision Framework

Immediate Management (First 24-48 Hours)

• Do NOT start aspirin within 24 hours if the patient received IV thrombolysis (rtPA) due to increased risk of serious intracranial bleeding complications 2
• Brain imaging must first exclude intracranial hemorrhage before any aspirin administration 2, 3
• For uncomplicated ischemic stroke (without hemorrhagic transformation), aspirin 160-325 mg should be initiated within 24-48 hours of stroke onset 2, 4

Risk Stratification for Hemorrhagic Complications

High-Risk Features for ICH Recurrence:

• Lobar location of the intracranial hemorrhage 1
• Older age 1
• Presence and number of microbleeds on gradient echo MRI 1
• Apolipoprotein E ε2 or ε4 alleles 1

Strength of Indication for Aspirin:

• Strong indications: Recent acute coronary syndrome, coronary stents, high-risk coronary disease, documented high thrombotic risk 1
• Weaker indications: Primary prevention, stable coronary disease without recent events 1

Timing Algorithm Based on Clinical Scenario

Non-Lobar ICH with Strong Antiplatelet Indication

• Restart aspirin at 3-7 days post-ICH if the patient is clinically stable 1
• This applies when there are compelling cardiovascular indications that outweigh bleeding risk 1

Lobar ICH or Moderate Indication

• Delay aspirin for minimum of 4-6 weeks after the hemorrhagic complication 1
• Consider longer delays if multiple microbleeds are present on MRI 1

Mechanical Heart Valve Patients

• Timing should be individualized with cardiology consultation, as anticoagulation (not aspirin) may be needed much earlier 1
• For patients without mechanical heart valves, avoidance of oral anticoagulation for at least 4 weeks might decrease ICH recurrence risk 1

Dosing Considerations When Restarting

• Loading dose: 160-325 mg aspirin when initiating therapy 2, 4, 5
• Maintenance dose: 50-100 mg daily for long-term secondary prevention 4, 5, 6
• Lower maintenance doses (75-100 mg daily) have similar efficacy to higher doses with fewer gastrointestinal side effects 4

Critical Pitfalls to Avoid

The most dangerous error is premature aspirin administration:

• Starting aspirin within 24 hours of thrombolytic therapy significantly increases intracranial hemorrhage risk 2
• Urgent anticoagulation in patients with moderate-to-severe strokes carries high risk of serious intracranial hemorrhagic complications 2

Aspirin-naïve patients have higher bleeding risk:

• Major/life-threatening bleeding on aspirin plus clopidogrel occurred in 4.8% of aspirin-naïve patients versus 0.5% in prior-aspirin patients (90-day risk) 7
• This is particularly relevant when considering dual antiplatelet therapy in the acute phase 7

Evidence Quality

The recommendation for delaying aspirin after hemorrhagic transformation carries Class IIa (Level of Evidence B) from the American Heart Association/American Stroke Association, indicating moderate-quality evidence that benefits probably outweigh risks 1. The timing recommendations are based on balancing the proven benefit of aspirin in preventing recurrent ischemic events (preventing about 10 deaths and recurrent strokes per 1,000 patients treated) 8 against the increased bleeding risk in patients with recent intracranial hemorrhage 1.