What is the recommended duration and dosage of Dual Antiplatelet Therapy (DAPT) with aspirin and clopidogrel for patients post-stroke?

From the Guidelines

The recommended duration of Dual Antiplatelet Therapy (DAPT) with aspirin and clopidogrel for patients after an ischemic stroke is typically 21-90 days, after which patients should continue with a single antiplatelet agent long-term. The standard dosage is aspirin 81-100 mg daily combined with clopidogrel 75 mg daily 1. This short-term DAPT regimen is most beneficial when initiated within 24 hours of symptom onset for patients with minor stroke or high-risk TIA.

Key Considerations

• The initiation of DAPT should ideally occur within 12-24 hours of symptom onset, after an intracranial hemorrhage is ruled out on neuroimaging studies 1.
• A single loading dose of aspirin (160-325 mg) and clopidogrel (300 mg) should be used at the beginning of DAPT therapy for minor ischemic stroke or high-risk TIA 1.
• For patients with mild-moderate ischemic stroke or high-risk TIA, DAPT with aspirin and ticagrelor may be considered for 30 days, followed by long-term single antiplatelet therapy 1.

Patient Selection

• Patients with certain comorbidities like recent major bleeding, severe liver disease, or those on anticoagulation may not be suitable candidates for DAPT.
• The decision to extend DAPT beyond 90 days should be made on a case-by-case basis, considering the individual patient's risk of recurrent stroke and bleeding 1.

Mechanism of Action

• The combination of aspirin and clopidogrel works by inhibiting platelet aggregation through two different mechanisms: aspirin blocks the cyclooxygenase pathway while clopidogrel inhibits the ADP receptor pathway, providing more complete platelet inhibition than either agent alone.

Long-term Management

• After the initial DAPT period, patients should generally continue on either aspirin or clopidogrel alone indefinitely for secondary stroke prevention, as the risk of recurrent stroke remains elevated 1.

From the Research

Indications for DAPT Therapy Post-Stroke

The recommended duration and dosage of Dual Antiplatelet Therapy (DAPT) with aspirin and clopidogrel for patients post-stroke vary depending on the individual patient's condition and risk factors.

• DAPT with aspirin and clopidogrel is recommended for patients with minor acute non-cardioembolic stroke or high-risk transient ischemic attack (TIA) for a short-term period of 21-30 days 2, 3.
• For patients with large vessel intracranial atherosclerotic disease, DAPT for 90 days, followed by aspirin monotherapy, is suitable for secondary stroke prevention 2.
• The choice between different antiplatelets and anticoagulants for prevention of ischemic stroke depends on the underlying stroke mechanism, cytochrome P450 2C19 polymorphisms, bleeding risk profile, compliance, drug tolerance, and drug resistance 2.
• Short-term DAPT appears to be superior to prolonged DAPT in reducing the risk of ischemic stroke recurrence, but it also increases the risk of major bleeding 3, 4.
• The efficacy and safety of DAPT with clopidogrel and aspirin have been shown to be consistent when initiated within 72 hours after symptom onset, with a similar increase in the risk of moderate-to-severe bleeding 5.

Dosage and Duration

• The dosage of clopidogrel is typically 300 mg loading dose on day 1, followed by 75 mg daily, and aspirin 100 to 300 mg on the first day and then 100 mg daily 5.
• The duration of DAPT therapy can range from 21-30 days to 90 days, depending on the individual patient's condition and risk factors 2, 3, 5.

Safety and Efficacy

• DAPT with aspirin and clopidogrel has been shown to reduce the risk of recurrent stroke, but it also increases the risk of major bleeding 2, 3, 4.
• The combination of cilostazol and clopidogrel has been shown to significantly reduce the recurrence of ischemic stroke without increasing the bleeding risk in noncardioembolic, high-risk patients 6.