Do patients with lacunar stroke require Aspirin (ASA) as part of secondary prevention?

From the Guidelines

Patients with lacunar stroke should receive aspirin (ASA) as part of secondary prevention, with a recommended dose guided by weight-based considerations, such as 75-100 mg for patients weighing <70 kg and higher doses for those >70 kg. The use of ASA in secondary prevention for lacunar stroke is supported by studies such as the ESPS2 trial, which showed that aspirin alone is more effective than placebo in reducing recurrent stroke 1. Additionally, a pooled analysis of trials in patients with lacunar stroke suggested that any of the evaluated antiplatelet agents, including aspirin, were similarly effective compared with placebo 1.

Key considerations for ASA use in lacunar stroke secondary prevention include:

• Assessing for aspirin allergies or contraindications such as active bleeding, recent major bleeding, or severe thrombocytopenia
• Monitoring for potential side effects, including gastrointestinal bleeding
• Evaluating the need for dual antiplatelet therapy (DAPT) in certain cases, although the 2021 guideline from the American Heart Association/American Stroke Association recommends single antiplatelet therapy (SAPT) for those who do not meet DAPT clinical criteria 1

The mechanism of action of aspirin, through the inhibition of platelet aggregation by irreversible inhibition of cyclooxygenase-1, is crucial in preventing recurrent strokes by reducing the formation of platelet-rich thrombi in cerebral vessels, which is particularly relevant in lacunar strokes resulting from small vessel disease affecting penetrating arteries in the brain. The choice of aspirin dosing may be guided by recent patient-level pooled analyses, although these have primarily been performed in the context of primary prevention 1.

From the Research

Lacunar Stroke and Aspirin for Secondary Prevention

• Lacunar strokes account for approximately 25% of ischemic strokes, and the optimal antiplatelet regimen for secondary prevention remains unclear 2.
• Studies have shown that any single antiplatelet agent, including aspirin, is associated with a significant reduction in the recurrence of any stroke and ischemic stroke compared to placebo 2.
• The addition of clopidogrel to aspirin did not significantly reduce the risk of recurrent stroke and increased the risk of bleeding and death in patients with recent lacunar strokes 3, 4.
• Low-dose acetylsalicylic acid (ASA) has been established as effective for secondary prophylaxis after ischemic cerebrovascular events, including lacunar strokes, with a dose of 100 mg per day being sufficient to reduce the incidence of further stroke, myocardial infarction, and death due to cardiovascular causes 5.
• A multicenter prospective cohort study found that aspirin significantly reduced stroke recurrence in patients with lacunar stroke, with a hazard ratio of 0.67 (95% CI 0.45-0.99) 6.

Key Findings

• Aspirin is effective in reducing the risk of recurrent stroke in patients with lacunar stroke 2, 6.
• Dual antiplatelet therapy with aspirin and clopidogrel does not confer a clear benefit over monotherapy with aspirin alone in patients with lacunar stroke 2, 3, 4.
• The risk of major hemorrhage is increased with dual antiplatelet therapy compared to aspirin alone 3, 4.

Implications for Secondary Prevention

• Aspirin can be considered as part of secondary prevention for patients with lacunar stroke, given its efficacy in reducing the risk of recurrent stroke 2, 6.
• The decision to use aspirin should be individualized, taking into account the patient's risk factors and medical history 5.