From the Guidelines
Dual antiplatelet therapy is indicated for patients with minor ischemic stroke or high-risk transient ischemic attack, particularly in the early period after the event when the risk of recurrence is highest, as recommended by current guidelines 1. The primary indication for dual antiplatelet therapy is to reduce the risk of recurrent stroke in patients with minor ischemic stroke or high-risk transient ischemic attack (TIA).
- The standard dual antiplatelet therapy regimen consists of aspirin 81-325 mg daily plus a P2Y12 receptor antagonist, such as clopidogrel 75 mg daily, initiated within 24 hours of symptom onset and continued for a short period, typically 21-90 days.
- For loading doses, aspirin 325 mg and clopidogrel 300-600 mg can be given initially.
- After this short-term dual antiplatelet therapy period, patients typically transition to single antiplatelet therapy (usually aspirin or clopidogrel alone) for long-term secondary prevention.
- Dual antiplatelet therapy is particularly beneficial for patients with large artery atherosclerosis, such as intracranial or extracranial stenosis. However, dual antiplatelet therapy is generally not recommended for cardioembolic strokes (where anticoagulation is preferred) or for hemorrhagic strokes. The benefit of dual antiplatelet therapy comes from the complementary mechanisms of action - aspirin inhibits thromboxane A2-dependent platelet activation while the P2Y12 receptor antagonist blocks ADP-mediated platelet aggregation, providing more comprehensive platelet inhibition than either agent alone. This enhanced antiplatelet effect must be balanced against the increased bleeding risk, which is why dual antiplatelet therapy is typically limited to a short duration in the highest risk period after stroke, as supported by recent guidelines 1.
From the FDA Drug Label
1.2 Recent MI, Recent Stroke, or Established Peripheral Arterial Disease 14.2 Recent Myocardial Infarction, Recent Stroke, or Established Peripheral Arterial Disease 14.3 No Demonstrated Benefit of Clopidogrel plus Aspirin in Patients with Multiple Risk Factors or Established Vascular Disease
The indications of dual antiplatelet therapy in stroke are not explicitly stated for dual therapy, but the label mentions the use of clopidogrel for patients with Recent Stroke.
- The label does mention the use of clopidogrel in patients with Recent Stroke.
- However, it also states that there is No Demonstrated Benefit of Clopidogrel plus Aspirin in certain patient populations. The use of dual antiplatelet therapy in stroke patients may be considered on a case-by-case basis, but the label does not provide clear guidance on this topic 2.
From the Research
Indications of Dual Antiplatelet Therapy in Stroke
- Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is commonly used in patients with acute coronary syndrome (ACS) to reduce cardiovascular event rates 3.
- In patients with minor stroke or high-risk transient ischemic attack, DAPT with P2Y12 inhibitors (clopidogrel/ticagrelor) and aspirin reduces the risk of stroke recurrence by 24% compared to aspirin alone 4.
- However, DAPT is associated with an increased risk of severe or moderate bleeding, particularly with treatment durations over 21 days or with the use of ticagrelor 4.
Patient Selection for Dual Antiplatelet Therapy
- Patients at high risk of bleeding, such as those with a history of bleeding, diabetes, or low body weight, may require shorter durations of DAPT (3-6 months) 3.
- Patients with a history of stroke or transient ischemic attack should avoid prasugrel due to an increased risk of cerebrovascular events 3.
- Ticagrelor monotherapy may be a suitable alternative for patients who cannot complete a course of dual antiplatelet therapy, with a lower risk of cardiovascular events compared to clopidogrel monotherapy 5.
Duration and Choice of Antiplatelet Therapy
- The optimal duration of DAPT beyond 1 year is not well established, and recommendations vary according to the risk of bleeding 3.
- High-potency DAPT with aspirin and prasugrel or ticagrelor may be considered for patients with a low risk of bleeding, while shorter durations of DAPT may be reasonable for patients with a high risk of bleeding 6.
- Aspirin and ticagrelor for 3 months, followed by aspirin and clopidogrel for the remaining duration, may be an optimal strategy for treating post-percutaneous coronary intervention patients with ACS 6.