What is the role of Dual Antiplatelet Therapy (DAPT) in managing Transient Ischemic Attack (TIA)?

From the Guidelines

For patients with transient ischemic attack (TIA), dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is recommended for 21-90 days following the event, followed by single antiplatelet therapy long-term. This approach is based on the most recent and highest quality evidence from the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack 1. The guideline suggests that starting short-term DAPT followed by long-term single antiplatelet therapy (SAPT) is preferred compared to SAPT alone for patients with mild stroke or high-risk TIA, especially when evaluated early after the onset of their stroke.

The benefits of short-term DAPT in reducing the risk of early recurrent stroke are well-established 1. However, beyond 90 days after stroke, DAPT is associated with an increased risk of bleeding and no benefit in long-term reduction of recurrent stroke risk 1. Therefore, long-term DAPT is not recommended due to the increased bleeding risk without additional benefit in stroke prevention beyond the initial high-risk period.

Key points to consider when implementing DAPT for TIA patients include:

• Initiation of DAPT within 24 hours of symptom onset for maximum benefit
• Typical regimen includes aspirin 81mg daily plus clopidogrel 75mg daily
• DAPT should be continued for 21-90 days, followed by single antiplatelet therapy indefinitely for secondary stroke prevention
• The risk of bleeding should be considered and weighed against the potential benefits of DAPT, especially in older patients and those with more severe stroke 1

Overall, the current evidence supports the use of short-term DAPT for TIA patients, followed by long-term single antiplatelet therapy, to optimize the balance between reducing recurrent stroke risk and minimizing bleeding complications 1.

From the Research

TIA and DAPT

• The use of Dual Antiplatelet Therapy (DAPT) with clopidogrel and aspirin in patients with Transient Ischemic Attack (TIA) has been studied in several clinical trials 2, 3.
• These studies have shown that DAPT can provide greater protection against subsequent stroke than monotherapy, with a significant reduction in the risk of recurrent stroke and ischemic stroke 2, 3.
• However, DAPT is also associated with an increased risk of bleeding, including intracranial bleeding and major bleeding 2, 3.
• The optimal duration of DAPT in patients with TIA is still unclear, but short-duration DAPT (≤ 1 month) started during the early acute ischemic phase may be associated with less bleeding and greater reduction of recurrent strokes compared to monotherapy 2.
• Current guidelines recommend the use of DAPT in patients with high-risk TIA, defined as a score ≥ 4 on the ABCD2 instrument, who do not have severe carotid stenosis or atrial fibrillation 4.
• The diagnosis and management of TIA is a medical emergency, and urgent assessment and treatment can prevent up to 80% of recurrent strokes 5, 6.

Clinical Outcomes

• The clinical outcomes of patients with TIA treated with DAPT have been studied in several clinical trials, including the risk of recurrent stroke, ischemic stroke, major adverse cardiovascular events (MACE), and bleeding 2, 3.
• The results of these studies have shown that DAPT can reduce the risk of recurrent stroke and MACE, but may increase the risk of bleeding 2, 3.
• The number needed to harm for DAPT in patients with TIA has been estimated to be 258 for intracranial bleeding and 113 for major bleeding 2.

Guidelines and Recommendations

• Current guidelines recommend the use of DAPT in patients with high-risk TIA, defined as a score ≥ 4 on the ABCD2 instrument, who do not have severe carotid stenosis or atrial fibrillation 4.
• The guidelines also recommend the use of anticoagulation for atrial fibrillation, carotid revascularization for symptomatic carotid artery stenosis, and vascular risk factor reduction strategies in patients with TIA 4, 6.
• The diagnosis and management of TIA is a medical emergency, and urgent assessment and treatment can prevent up to 80% of recurrent strokes 5, 6.