From the Guidelines
After a suspected stroke, patients are typically advised to take aspirin indefinitely unless contraindicated, with the standard recommendation being 81-325 mg daily, as supported by the most recent guidelines from the World Stroke Organization 1. The treatment should begin as soon as possible after stroke symptoms appear, ideally within 24-48 hours, once hemorrhagic stroke has been ruled out by imaging. Some patients may initially receive a loading dose of 160-325 mg followed by the maintenance dose. This long-term aspirin therapy helps prevent recurrent strokes by inhibiting platelet aggregation, thereby reducing the formation of blood clots that could cause another stroke. Key considerations include:
- The dose of aspirin, with many clinicians preferring the lower dose of 81 mg (baby aspirin) for long-term use to minimize bleeding risks.
- The potential for alternative antiplatelet medications such as clopidogrel or a combination therapy, depending on the patient's specific risk factors, stroke type, and medical history, as outlined in the guidelines 1.
- The importance of not discontinuing aspirin without consulting a healthcare provider, as sudden cessation can potentially increase stroke risk. It's also worth noting that for patients with minor ischemic stroke or high-risk TIA, dual antiplatelet therapy with aspirin and clopidogrel may be recommended for a duration of 21-30 days, followed by antiplatelet monotherapy, as suggested by the Canadian Stroke Best Practice Recommendations 1. However, the most recent and highest quality study, the 2023 systematic review and synthesis of global stroke guidelines, supports long-term antiplatelet therapy with aspirin as the primary recommendation for secondary stroke prevention in patients with non-cardioembolic ischemic stroke or TIA 1.
From the Research
Duration of Aspirin Therapy after Suspected Stroke
- The duration of aspirin therapy after a suspected stroke is not explicitly stated in the provided studies, but we can infer some information from the study results.
- According to the study 2, short-term dual antiplatelet therapy with aspirin and clopidogrel is superior to antiplatelet monotherapy in secondary stroke prevention when used in patients with mild noncardioembolic stroke or high-risk transient ischemic attack, but dual therapy is associated with an increased risk of major bleeding, particularly when the treatment is extended for greater than 30 days.
- The study 3 suggests that dual antiplatelet therapy combining aspirin with dipyridamole or clopidogrel might be more effective in the acute and early chronic post-ischemic phase (i.e., first 90 days).
- The study 4 compared the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy for 30 days, but found that intensive antiplatelet therapy did not reduce the incidence and severity of recurrent stroke or TIA, but did significantly increase the risk of major bleeding.
Recommended Duration of Aspirin Therapy
- Based on the study 5, the appropriate dose for the primary and secondary prevention of stroke and MI is 160 mg/day, but the study does not specify the duration of therapy.
- The study 2 recommends long-term therapy with aspirin, clopidogrel, or aspirin plus extended-release dipyridamole for secondary stroke prevention in patients with noncardioembolic ischemic stroke, but does not specify the exact duration of therapy.
- The American Heart Association and other organizations recommend lifelong aspirin therapy for patients with a history of ischemic stroke or transient ischemic attack, unless there are contraindications 2, 3.