From the Guidelines
The recommended dual antiplatelet therapy (DAPT) regimen for patients following an ischemic stroke typically consists of aspirin 81-325 mg daily plus clopidogrel 75 mg daily for 21-90 days, with the shorter duration (21 days) generally preferred to minimize bleeding risks. This regimen should be initiated within 24 hours of symptom onset for maximum benefit, as supported by the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline from the American Heart Association/American Stroke Association 1. After the initial DAPT period, patients should transition to single antiplatelet therapy (usually aspirin 81 mg daily or clopidogrel 75 mg daily) for long-term secondary prevention. For patients with minor stroke or high-risk TIA, early DAPT has been shown to significantly reduce the risk of recurrent stroke compared to aspirin alone, with the greatest benefit occurring in the first few weeks after the initial event, as noted in the 2021 guideline 1 and the 2023 systematic review and synthesis of global stroke guidelines on behalf of the World Stroke Organization 1. The mechanism involves more complete platelet inhibition through blocking multiple pathways of platelet activation, thereby reducing the formation of arterial thrombi. Important considerations include:
- Assessing bleeding risk before initiating therapy
- Avoiding DAPT in patients with hemorrhagic transformation
- Ensuring proper medication adherence through patient education about the importance of not missing doses, as highlighted in the 2021 guideline 1 and other studies 1. It is also worth noting that the optimal combination of medications, timing of initiation, and duration of DAPT are areas of ongoing research, as discussed in the 2021 guideline 1.
From the Research
Dual Antiplatelet Therapy Regimens
- The recommended dual antiplatelet therapy (DAPT) regimen for patients post ischemic stroke includes aspirin plus clopidogrel or aspirin plus ticagrelor 2, 3, 4.
- Aspirin plus clopidogrel is superior to antiplatelet monotherapy in secondary stroke prevention when used in patients with mild noncardioembolic stroke or high-risk transient ischemic attack 2, 3.
- Aspirin plus ticagrelor is also superior to aspirin monotherapy for the prevention of recurrent ischemic stroke, although this combination is associated with a higher risk of hemorrhagic complications when compared to other dual antiplatelet regimens 2, 4.
Benefits and Risks of DAPT
- DAPT reduces the risk of recurrent stroke by 26% (RR: 0.74; 95% CI: 0.67-0.83; p < 0.00001) and major adverse cardiovascular events (MACE) by 24% (RR: 0.76; 95% CI: 0.68-0.84; p < 0.00001) compared to aspirin monotherapy 3.
- However, DAPT is associated with a significantly increased risk of moderate or severe bleeding (RR: 1.88; 95% CI: 1.10-3.23; p = 0.02) compared to aspirin alone 3, 5.
- The risk of bleeding is higher with ticagrelor and aspirin compared to clopidogrel and aspirin, although both regimens have higher rates of major hemorrhage than aspirin alone 4.
Patient-Specific Considerations
- The specific antiplatelet regimen should be individualized based on the stroke characteristics, time from symptom onset, and patient-specific predisposition to develop hemorrhagic complications 2.
- Patients with symptomatic intracranial stenosis may benefit from aggressive medical management in addition to dual antiplatelet therapy up to 90 days 2.
- Patients who carry CYP2C19 genetic polymorphisms associated with a slow bioactivation of clopidogrel may benefit from short-term treatment with aspirin plus ticagrelor instead of aspirin plus clopidogrel 2.