What are the indications for aspirin therapy in patients with a history of stroke?

From the Guidelines

Aspirin therapy is recommended for secondary prevention in patients with a history of ischemic stroke or transient ischemic attack (TIA) at a dose of 75-100 mg once daily. This recommendation is based on the American College of Chest Physicians evidence-based clinical practice guidelines 1. The guidelines suggest that aspirin, clopidogrel, aspirin/extended-release dipyridamole, or cilostazol are all acceptable options for initial therapy in patients with noncardioembolic ischemic stroke or TIA.

Key Points

• Aspirin therapy should be initiated as soon as possible after the event and continued indefinitely unless contraindicated 1.
• The selection of an antiplatelet agent should be individualized on the basis of patient risk factor profiles, tolerance, and other clinical characteristics 1.
• Patients with a history of ischemic stroke or TIA and atrial fibrillation should be treated with oral anticoagulation instead of aspirin or combination therapy with aspirin and clopidogrel 1.
• Patients should be monitored for gastrointestinal bleeding, particularly those with a history of peptic ulcer disease, and concomitant use of proton pump inhibitors may be considered in high-risk individuals.

Important Considerations

• Aspirin is not recommended for patients with hemorrhagic stroke or those with aspirin allergy or other contraindications such as active bleeding disorders.
• The addition of aspirin to clopidogrel increases the risk of hemorrhage and is not routinely recommended for ischemic stroke or TIA patients 1.
• For patients who have an ischemic stroke while taking aspirin, there is no evidence that increasing the dose of aspirin provides additional benefit 1.

From the Research

Indications for Aspirin Therapy in Patients with a History of Stroke

Aspirin is widely used for the prevention of recurrent stroke in patients with transient ischemic attack (TIA) and ischemic stroke of arterial origin 2. The indications for aspirin therapy in patients with a history of stroke include:

• Prevention of recurrent stroke in patients with TIA and ischemic stroke of arterial origin 2
• Primary prevention of ischemic stroke in women 3
• Secondary prevention of ischemic stroke in patients with noncardioembolic ischemic stroke or TIA 3
• Treatment of acute ischemic stroke 4

Aspirin Dosing for Stroke Prevention

The optimal dose of aspirin for stroke prevention varies depending on the indication:

• Low-dose aspirin (50-81 mg daily) may be insufficient for some indications 4
• Acute ischemic stroke treatment requires 160-325 mg of aspirin 4
• Atrial fibrillation and carotid arterial disease require daily doses of 325 and 81-325 mg of aspirin, respectively 4
• Combination therapy with clopidogrel and aspirin may provide greater protection against subsequent stroke than aspirin alone in patients with minor ischemic stroke or high-risk TIA 5

Benefits and Risks of Aspirin Therapy

Aspirin therapy has been shown to be effective in preventing ischemic stroke, but it also carries a risk of bleeding complications:

• Aspirin reduces the risk of ischemic stroke in patients with TIA and ischemic stroke of arterial origin 2
• Aspirin is associated with a small reduction in ischemic strokes in women 3
• The risk of bleeding complications increases with higher doses of aspirin 6
• Combination therapy with clopidogrel and aspirin does not increase the risk of hemorrhage in patients with minor ischemic stroke or high-risk TIA 5