In a female patient with a thalamic stroke 4 years ago who is taking low‑dose aspirin (ecospirin) and now has an unruptured intracranial aneurysm, should aspirin be continued?

Should Aspirin Be Continued in a Patient with Prior Thalamic Stroke Who Now Has an Unruptured Intracranial Aneurysm?

Continue the aspirin (ecospirin) for secondary stroke prevention in this patient with a history of thalamic stroke and a newly discovered unruptured intracranial aneurysm. The evidence demonstrates that aspirin does not increase aneurysm rupture risk and may actually reduce it, while discontinuation would expose her to unacceptable recurrent stroke risk.

Evidence Supporting Aspirin Continuation

The most recent and highest-quality evidence comes from a 2021 prospective multicenter cohort study of 1,866 patients with ischemic cerebrovascular disease harboring unruptured intracranial aneurysms <7 mm. This study found that aspirin use was associated with a lower incidence rate of aneurysm rupture (0.06 per 100 person-years) compared to no aspirin (0.39 per 100 person-years), and multivariate analysis showed aspirin was independently associated with reduced rupture risk 1.

• A 2018 experimental study in mice demonstrated that aspirin (10 mg/kg) significantly reduced aneurysm rupture from 80% to 31% (p<0.05) without affecting aneurysm formation rates, suggesting a protective mechanism against rupture 2.

• The 2021 human cohort study provides Class III evidence that aspirin does not increase rupture risk in patients with small unruptured aneurysms and ischemic cerebrovascular disease 1.

Secondary Stroke Prevention Imperative

For patients with prior ischemic stroke, aspirin provides critical protection against recurrent vascular events that far outweighs theoretical aneurysm concerns:

• Aspirin 75-100 mg daily is the established first-line recommendation for long-term secondary stroke prevention after non-cardioembolic ischemic stroke 3, 4.

• Discontinuing aspirin in patients with established cerebrovascular disease exposes them to up to 10.2% risk of acute cardiovascular syndromes, with acute cerebral events occurring an average of 14.3 ± 11.3 days after aspirin withdrawal 5.

• The 2011 AHA/ASA stroke prevention guidelines explicitly recommend antiplatelet therapy (aspirin 50-325 mg daily) for all patients with prior stroke or TIA unless contraindicated 3.

Recommended Management Algorithm

1. Continue aspirin at 75-100 mg daily for secondary stroke prevention 3, 4, 6.

2. Ensure aggressive blood pressure control to target <140/90 mm Hg (or <130/80 mm Hg if tolerated), as uncontrolled hypertension was the strongest predictor of aneurysm rupture in the 2021 cohort study 1, 6.

3. Determine aneurysm size and risk stratification:

• If aneurysm is <5 mm with controlled blood pressure: routine surveillance imaging every 6-24 months 3.
• If aneurysm is 5-7 mm with uncontrolled hypertension: this represents the highest-risk group requiring intensive surveillance, but aspirin should still be continued 1.
• If aneurysm is ≥7 mm: neurosurgical consultation for potential intervention, but aspirin continuation remains appropriate for stroke prevention 1.

4. Address modifiable risk factors including smoking cessation (if applicable), diabetes control, and lipid management with statin therapy 3.

Critical Contraindications to Aspirin (None Apply Here)

Aspirin should only be discontinued if the patient develops 6:

• Active gastrointestinal bleeding
• Documented aspirin allergy or hypersensitivity
• Severe bleeding disorder
• Clinically active hepatic disease

The presence of an unruptured intracranial aneurysm is NOT a contraindication to aspirin therapy.

Common Pitfall to Avoid

Do not discontinue aspirin out of unfounded fear of aneurysm rupture. The 2021 prospective study specifically demonstrated that patients in the high-risk group (aneurysms 5-7 mm with uncontrolled hypertension) who were not taking aspirin had the highest rupture rates, suggesting aspirin may be protective rather than harmful 1. Withdrawing aspirin would eliminate proven stroke protection while providing no benefit for aneurysm management.

Monitoring Strategy

• Continue aspirin 75-100 mg daily indefinitely 3, 4.
• Obtain baseline imaging (CT or MRI) to establish aneurysm size and characteristics 3.
• Schedule follow-up imaging in 6-12 months to assess stability, then every 6-24 months depending on size 3.
• Maintain blood pressure <140/90 mm Hg with antihypertensive therapy (ACE inhibitor or ARB preferred) 1, 6.
• Monitor for any new neurological symptoms that might indicate aneurysm growth or rupture 1.