What are the theoretical risks of long-term dual antiplatelet therapy (DAPT) in a patient with a history of Spontaneous Coronary Artery Dissection (SCAD) event 10 years prior, currently being treated for acute stroke?

From the Guidelines

There are theoretical risks with being on dual antiplatelet therapy (DAPT) for acute stroke 10 years after a spontaneous coronary artery dissection (SCAD) event, and the decision to continue DAPT should be individualized based on the patient's specific stroke etiology, recurrence risk, and bleeding risk profile. Long-term DAPT, typically consisting of aspirin (81-325 mg daily) plus a P2Y12 inhibitor like clopidogrel (75 mg daily), carries an increased risk of bleeding complications, including gastrointestinal bleeding, intracranial hemorrhage, and major bleeding events, as noted in the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack 1. This risk increases with age and duration of therapy. For most patients who had a SCAD event 10 years ago, extended DAPT beyond the initial 6-12 months is generally not recommended unless there are specific ongoing risk factors, as suggested by the 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease 1. The bleeding risk typically outweighs the antithrombotic benefit after the initial recovery period.

Some key points to consider when deciding on DAPT include:

• The patient's specific stroke etiology and recurrence risk
• The patient's bleeding risk profile
• The duration of DAPT, with most guidelines recommending short-term DAPT (usually 21-90 days) followed by monotherapy
• Regular reassessment of the risk-benefit ratio, particularly in patients with a remote history of SCAD who may no longer derive significant benefit from aggressive antiplatelet therapy, as noted in the 2023 systematic review and synthesis of global stroke guidelines 1.

It's also important to consider the latest guidelines and studies, such as the 2024 standards of care in diabetes, which suggest that the length of treatment with dual antiplatelet therapy should be determined by an interprofessional team approach that includes a cardiovascular or neurological specialist 1. Ultimately, the decision to continue DAPT should be made on a case-by-case basis, taking into account the individual patient's unique risk factors and medical history.

From the Research

Theoretical Risks of Dual Antiplatelet Therapy

Theoretical risks associated with dual antiplatelet therapy for acute stroke, particularly 10 years out from a Spontaneous Coronary Artery Dissection (SCAD) event, include:

• Increased risk of major bleeding, particularly when the treatment is extended for greater than 30 days 2
• Higher risk of hemorrhagic complications when compared to other dual antiplatelet regimens 2
• Harmful association of more potent antiplatelet therapy and anticoagulation with adverse cardiovascular outcomes 3
• Increased risk of recurrent SCAD, with ticagrelor combined with aspirin being associated with a higher risk of SCAD recurrence 3

Considerations for Long-Term Dual Antiplatelet Therapy

Considerations for long-term dual antiplatelet therapy include:

• 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
• The use of dual antiplatelet therapy with aspirin and clopidogrel may be beneficial in reducing the risk of recurrent stroke, but it also increases the risk of major bleeding events 4
• The duration of dual antiplatelet therapy should be carefully considered, with some studies suggesting that short-term therapy (10-21 days) may be sufficient for high-risk transient ischemic attack or minor ischemic stroke 5

Patient-Specific Factors

Patient-specific factors that may influence the decision to use dual antiplatelet therapy include:

• History of stroke, which may increase the risk of recurrent SCAD and major adverse cardiovascular events 3
• Presence of fibromuscular dysplasia, which may increase the risk of SCAD recurrence 3
• Genetic polymorphisms associated with a slow bioactivation of clopidogrel, which may affect the efficacy and safety of dual antiplatelet therapy 2