Aspirin 300 mg Prior to Thrombectomy is NOT a Contraindication
Aspirin 300 mg administered prior to mechanical thrombectomy is not a contraindication and is actually recommended in acute ischemic stroke management, though timing relative to thrombolysis requires consideration. 1
Evidence-Based Recommendations
For Acute Ischemic Stroke Patients
Aspirin (160-300 mg) is recommended within 24-48 hours after acute ischemic stroke onset, with Class I, Level A evidence from the American Heart Association/American Stroke Association guidelines 1
For patients receiving IV thrombolysis (alteplase), aspirin is generally delayed until 24 hours post-thrombolysis, but may be considered earlier when concomitant conditions provide substantial benefit or withholding poses substantial risk 1
Aspirin should NOT be used as a substitute for mechanical thrombectomy in otherwise eligible patients (Class III: No Benefit) 1
Intraprocedural Aspirin During Emergent Stenting
When emergent carotid or extracranial stenting is required during thrombectomy, intraprocedural intravenous aspirin (250-500 mg) appears safe and beneficial:
A 2024 registry study of 102 patients requiring emergent extracranial stenting during thrombectomy found that intraprocedural IV aspirin (500 mg) was associated with greater NIHSS improvement (median 8 vs 3 points, p=0.003) without significantly increased symptomatic intracranial hemorrhage (4% vs 17%) 2
Even when combined with IV thrombolysis, intraprocedural aspirin showed greater NIHSS improvement and lower mortality without increased bleeding 2
A 2023 matched case-control study of 70 patients with tandem occlusions treated with acute carotid stenting plus aspirin (250 mg IV bolus) during thrombectomy showed similar rates of symptomatic ICH compared to isolated intracranial occlusions treated without aspirin (OR 3.06,95% CI 0.66-14.04, p=0.150) 3
Pre-Stroke Aspirin Use
- Patients already on low-dose aspirin (75-100 mg) prior to stroke who undergo thrombectomy have better outcomes: A 2025 multinational study showed pre-stroke low-dose aspirin was associated with improved functional independence (mRS 0-2: OR 1.89,95% CI 1.14-3.12) and reduced 90-day mortality (OR 0.56,95% CI 0.32-1.00) without increased symptomatic ICH 4
Key Clinical Distinctions
Aspirin is NOT a Contraindication When:
- Given as standard acute stroke treatment (160-300 mg within 24-48 hours) 1
- Administered intraprocedurally during emergent stenting (250-500 mg IV) 2, 3
- Patient is already on chronic low-dose aspirin therapy 4
Timing Considerations:
For patients receiving IV thrombolysis: Aspirin is typically delayed 24 hours post-thrombolysis, but emerging evidence suggests intraprocedural use during emergent stenting may be safe even in thrombolysed patients 2
For mechanical thrombectomy alone (without thrombolysis): Aspirin 300 mg can be given before or during the procedure, particularly if stenting is anticipated 2, 3
Common Pitfalls to Avoid
Do not withhold aspirin thinking it is contraindicated for thrombectomy - this is not supported by current guidelines 1
Do not use aspirin as a substitute for thrombectomy in eligible patients - mechanical recanalization remains the primary treatment 1
Do not rigidly apply the 24-hour post-thrombolysis aspirin delay when emergent stenting is required during thrombectomy, as intraprocedural aspirin appears safe and beneficial in this specific scenario 2
Supporting Evidence from Other Contexts
The safety profile of aspirin 300 mg is well-established in cardiovascular interventions. For percutaneous coronary intervention, higher aspirin doses (300-325 mg) are specifically recommended for patients not already taking aspirin immediately before procedures 1. This supports the safety of this dose in the acute thrombectomy setting.