What is the recommended duration of dual antiplatelet therapy (DAPT) after a stroke?

From the Guidelines

The recommended duration of dual antiplatelet therapy (DAPT) after a stroke is typically 21-30 days, with most guidelines suggesting a short course for minor strokes or high-risk TIAs. The standard DAPT regimen consists of aspirin (81-325 mg daily) plus clopidogrel (75 mg daily), with the aspirin often continued indefinitely after the DAPT period ends. For minor strokes or high-risk TIAs, DAPT 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 1. After completing the DAPT course, patients typically transition to single antiplatelet therapy (usually aspirin alone) for long-term secondary prevention. This approach balances the early benefit of more intensive platelet inhibition when the risk of recurrent stroke is highest against the increased bleeding risk with prolonged DAPT, as noted in a systematic review and synthesis of global stroke guidelines 1. The short-term DAPT strategy is supported by clinical trials showing that most of the benefit occurs in the first few weeks after the initial event, while the bleeding risk increases with longer duration therapy, as discussed in the benefits and risks of dual versus single antiplatelet therapy for secondary stroke prevention 1. Some key points to consider include:

• The exact duration of DAPT at which the risk of hemorrhage begins to outweigh the benefit of stroke prevention is unknown, but meta-analyses report as early as 21,30, or 90 days 1.
• Older patients and those with more severe stroke appear to be at higher risk of ICH with DAPT 1.
• Beyond 90 days after stroke, DAPT is associated with increased risk of bleeding and no benefit in long-term reduction of recurrent stroke risk, as stated in the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack 1. Overall, the decision to use DAPT should be based on individual patient risk factors and the potential benefits and risks of therapy, as recommended by the Canadian stroke best practice recommendations for acute stroke management 1.

From the Research

Duration of Dual Antiplatelet Therapy

The recommended duration of dual antiplatelet therapy (DAPT) after a stroke is a topic of ongoing research and debate.

• Studies have shown that short-term DAPT (up to 3 months) can reduce the risk of recurrent stroke and combined vascular events in patients with acute ischemic stroke or transient ischemic attack 2, 3, 4.
• However, DAPT is also associated with an increased risk of major bleeding, particularly when the treatment is extended for more than 30 days 3, 4, 5.
• The specific duration of DAPT may depend on the individual patient's risk factors and stroke characteristics, with some studies suggesting that DAPT may be beneficial for up to 90 days in patients with symptomatic intracranial stenosis 3.

Factors Influencing DAPT Duration

Several factors can influence the duration of DAPT, including:

• Stroke severity and type: Patients with mild noncardioembolic stroke or high-risk transient ischemic attack may benefit from short-term DAPT 3, 4.
• Patient-specific risk factors: Patients with a history of bleeding or those taking anticoagulant medications may require a shorter duration of DAPT 3.
• Genetic polymorphisms: Patients with CYP2C19 genetic polymorphisms associated with slow bioactivation of clopidogrel may benefit from alternative DAPT regimens, such as aspirin plus ticagrelor 3.

Comparison of DAPT Regimens

Different DAPT regimens have been compared in clinical trials, including:

• Aspirin plus clopidogrel versus aspirin alone: This combination has been shown to reduce the risk of recurrent stroke and combined vascular events, but is associated with an increased risk of major bleeding 2, 4, 5.
• Aspirin plus ticagrelor versus aspirin plus clopidogrel: This combination has been shown to be superior to aspirin monotherapy in preventing recurrent ischemic stroke, but is associated with a higher risk of hemorrhagic complications 3, 6.