From the Guidelines
Dual antiplatelet therapy (DAPT) is recommended after a transient ischemic attack (TIA), particularly in the early high-risk period, for a duration of 21-90 days, as it reduces the risk of recurrent stroke. The standard regimen consists of aspirin (81-325 mg daily) plus clopidogrel (75 mg daily) for this period, with the greatest benefit occurring in the first 21 days 1. After this initial period, patients typically transition to single antiplatelet therapy (usually aspirin alone) for long-term secondary prevention. This approach is especially important for patients with high-risk features such as multiple TIAs, significant carotid stenosis, or a high ABCD2 score.
Key Considerations
- The rationale behind DAPT is that it provides more potent platelet inhibition through complementary mechanisms of action, significantly reducing the risk of recurrent stroke during the vulnerable early period when risk is highest.
- However, DAPT carries an increased bleeding risk compared to single antiplatelet therapy, which is why it's generally limited to the short term.
- Patients should be monitored for bleeding complications while on DAPT, and those with high bleeding risk may require a shorter duration or alternative approaches.
Evidence Summary
- A 2021 guideline from the American Heart Association/American Stroke Association recommends DAPT for patients with noncardioembolic ischemic stroke or TIA, initiated early and continued for 21 to 90 days, followed by single antiplatelet therapy 1.
- The benefits and risks of DAPT versus single antiplatelet therapy for secondary stroke prevention were systematically reviewed, concluding that DAPT is more effective for reducing recurrent ischemic stroke when initiated soon after high-risk TIA or minor stroke, but carries a higher risk of bleeding 1.
- The optimal timing, duration, and patient selection for DAPT require further research to maximize the risk-benefit ratio 1.
From the Research
Dual Antiplatelet Therapy (DAPT) After TIA
- DAPT with aspirin and another antiplatelet agent such as clopidogrel or ticagrelor has been shown to be effective in preventing recurrent strokes after minor ischemic stroke or transient ischemic attack (TIA) 2, 3, 4.
- Short-term DAPT (21-30 days) is more effective than single antiplatelet therapy (SAPT) in patients with minor acute non-cardioembolic stroke or high-risk TIA 2.
- However, prolonged DAPT can increase bleeding risks without additional benefit 2, 5.
- The choice of DAPT regimen, including the duration of treatment, should be individualized based on the patient's underlying stroke mechanism, bleeding risk profile, and other factors 2, 6.
Comparison of DAPT Regimens
- Both clopidogrel and aspirin, and ticagrelor and aspirin, are superior to aspirin alone in preventing recurrent stroke and death 3, 4.
- There is no statistically significant difference between clopidogrel and aspirin, and ticagrelor and aspirin, in terms of efficacy 3, 4.
- However, ticagrelor and aspirin may be associated with a higher risk of major bleeding, including intracranial bleeding 4.
Duration of DAPT
- Short-term DAPT (≤3 months) appears to be superior to prolonged DAPT (≥1 year) in terms of efficacy and safety 5.
- Short-term DAPT significantly reduces the risk of ischemic stroke recurrence and major vascular events, without increasing the risk of intracranial hemorrhage 5.
- Prolonged DAPT reduces the risk of ischemic stroke recurrence and major vascular events, but increases the risk of major bleeding and intracranial hemorrhage 5.