Is a patient with a history of subarachnoid hemorrhage (SAH) and currently on dual antiplatelet therapy (aspirin and clopidogrel) following stenting of an aneurysm eligible for thrombolysis if they develop an acute ischemic stroke?

Thrombolysis Eligibility Post-Aneurysm Stenting in SAH Patients

Yes, the patient is eligible for thrombolysis despite recent SAH and dual antiplatelet therapy, as current stroke guidelines indicate that the benefit of thrombolysis likely outweighs the small increased risk of intracranial hemorrhage in patients on antiplatelet therapy. 1

Key Decision Framework

Primary Consideration: Secured Aneurysm Status

• Once the aneurysm is secured with stenting, the risk of rebleeding is substantially reduced, making thrombolysis a viable option 2
• The critical factor is that the aneurysm has been treated and secured, not the timing since SAH 2

Evidence Supporting Thrombolysis on DAPT

Guideline Position:

• Current stroke guidelines estimate that the small increased risk of intracranial hemorrhage in antiplatelet drug users is outweighed by larger benefits from thrombolysis, resulting in overall net improvement in functional outcomes 1
• The European Heart Journal task force explicitly states this applies even to patients on dual antiplatelet therapy, though the risk is "probably higher" than with single antiplatelet therapy 1

Quantified Risk Data:

• Patients on aspirin and clopidogrel have a 4.1% risk of symptomatic ICH (SITS-MOST criteria) compared to 1.1% in antiplatelet-naïve patients 3
• Using broader ECASS II criteria, the risk increases to 13.4% versus 4.1% 3
• However, multivariable analysis shows no significant increase in mortality or poor functional outcome regardless of antiplatelet status 3

Clinical Algorithm for Decision-Making

Step 1: Confirm Aneurysm Security

• Verify the aneurysm has been successfully stented (endovascular or surgical treatment completed) 2
• Ensure no evidence of ongoing hemorrhage on non-contrast CT 1

Step 2: Assess Stroke Eligibility Criteria

• Confirm acute ischemic stroke within thrombolysis window 1
• Exclude intracranial hemorrhage with non-contrast CT 1
• Evaluate standard contraindications (excluding antiplatelet therapy, which is NOT a contraindication) 3

Step 3: Proceed with Thrombolysis

• Administer IV tissue plasminogen activator per standard protocols 1
• Temporarily hold antiplatelet agents during acute thrombolysis 1
• Resume antiplatelet therapy after confirming no hemorrhagic transformation on follow-up imaging 1

Management of Antiplatelet Therapy Peri-Thrombolysis

Immediate Actions:

• Put aspirin and clopidogrel on hold at time of thrombolysis 1
• Administer IV t-PA per standard dosing 1

Post-Thrombolysis Resumption:

• Obtain brain MRI to exclude hemorrhagic transformation 1
• If no hemorrhage: Resume clopidogrel 75 mg daily (no loading dose needed if recently loaded for stenting) 1
• Consider discontinuing aspirin temporarily or permanently depending on bleeding risk and stent type 1
• The mandatory DAPT duration for intracranial stents (minimum 4 weeks for bare-metal, 6-12 months for drug-eluting) must still be respected 2, 4

Critical Caveats and Pitfalls

Common Misconception to Avoid:

• Do NOT withhold thrombolysis solely because the patient is on DAPT - this is explicitly not a contraindication despite increased bleeding risk 3
• The absolute excess of symptomatic ICH (1.4-2.1%) is small compared to the proven benefit of thrombolysis in randomized trials 3

Heightened Monitoring Required:

• Patients on aspirin plus clopidogrel require more vigilant neurological monitoring post-thrombolysis given the 2.11-fold increased risk of symptomatic ICH by ECASS II criteria 3
• Early recognition of hemorrhagic transformation is essential 1

Balancing Stent Thrombosis Risk:

• The risk of stent thrombosis from interrupting DAPT must be weighed, but brief interruption (24-48 hours) for thrombolysis is acceptable given the acute stroke emergency 1, 2
• Resume antiplatelet therapy as soon as hemorrhagic transformation is excluded 1

Special Considerations for SAH Context

SAH-Specific Factors:

• The Canadian Stroke Best Practice guidelines do not specifically contraindicate thrombolysis in patients with prior SAH once the aneurysm is secured 1
• Long-term aspirin use after SAH with aneurysm treatment is associated with shorter hospital stays and lower rates of complications, particularly in endovascularly treated patients 5
• Neither aspirin nor anticoagulant use were associated with differential mortality after SAH in nationwide analyses 5