Is dual antiplatelet therapy with Plavix (clopidogrel) and Aspirin (acetylsalicylic acid) indicated for a patient with a history of Spontaneous Coronary Artery Dissection (SCAD) and a recent acute striatocapsular infarct, or is monotherapy with Aspirin (acetylsalicylic acid) sufficient?

From the Guidelines

The second neurologist's decision to discontinue Plavix and maintain the patient on a single antiplatelet agent (aspirin) is likely more appropriate given the patient's history of spontaneous coronary artery dissection (SCAD) 10 years ago. This decision is supported by the fact that SCAD patients generally have a higher bleeding risk with dual antiplatelet therapy (DAPT), and the benefit of DAPT is most pronounced in the first 21 days after an acute ischemic stroke 1. Since this patient's stroke likely occurred more than 3 days ago (based on the initial ER visit with transient speech difficulty), the maximum benefit period for DAPT may have already passed. The risk-benefit ratio shifts toward single antiplatelet therapy in this scenario, especially with the SCAD history. Aspirin alone (typically 81-325mg daily) provides adequate secondary stroke prevention while minimizing bleeding risk, as recommended by the Canadian Stroke Best Practice Recommendations for acute antiplatelet therapy 1. This approach balances the need for stroke prevention with the patient's unique risk factors. However, the decision should be individualized based on the patient's complete vascular risk profile, the extent of the infarct, and ongoing monitoring for any new neurological symptoms. It's also worth noting that the 2018 ESC/EACTS guidelines on myocardial revascularization recommend life-long single antiplatelet therapy, usually aspirin, for patients with stable coronary artery disease, which may be relevant to this patient's SCAD history 1. In summary, the second neurologist's decision to discontinue Plavix is likely the most appropriate choice, given the patient's history and the current evidence-based guidelines. Key considerations in this decision include:

• The patient's history of SCAD and associated bleeding risk
• The timing of the stroke and the potential benefit of DAPT
• The need for individualized decision-making based on the patient's unique risk factors and vascular profile
• The recommendation for life-long single antiplatelet therapy in patients with stable coronary artery disease.

From the FDA Drug Label

The CAPRIE trial was a 19,185-patient, 304-center, international, randomized, double-blind, parallel-group study comparing clopidogrel (75 mg daily) to aspirin (325 mg daily) The trial’s primary outcome was the time to first occurrence of new ischemic stroke (fatal or not), new myocardial infarction (fatal or not), or other vascular death. The overall relative risk reduction (9. 8% vs 10.6%) was 8.7%, p=0.045. The CHARISMA trial was a 15,603 subject, randomized, double-blind, parallel group study comparing clopidogrel (75 mg daily) to placebo for prevention of ischemic events in patients with vascular disease or multiple risk factors for atherosclerosis The study failed to demonstrate a reduction in the occurrence of the primary endpoint, a composite of CV death, MI, or stroke.

The first neurologist is correct. Dual antiplatelet therapy with clopidogrel and aspirin may be beneficial in patients with acute ischemic stroke, as shown in the CAPRIE trial 2. The CHARISMA trial also suggests that clopidogrel plus aspirin may not be beneficial in patients with multiple risk factors or established vascular disease, but this does not directly apply to the patient's situation 2. The patient's prior SCAD history 10 years ago and the possible timing of the stroke do not provide a clear reason to discontinue clopidogrel. Caution should be exercised when making clinical decisions, and the benefits and risks of dual antiplatelet therapy should be carefully considered. Key points to consider include:

• The patient's recent ischemic stroke
• The potential benefits of dual antiplatelet therapy
• The patient's prior SCAD history and its potential impact on treatment decisions
• The need for careful consideration of the benefits and risks of treatment.

From the Research

Dual Antiplatelet Therapy in Stroke Patients

• The first neurologist recommends dual antiplatelet treatment with plavix and aspirin, which is supported by studies 3, 4, 5, 6, 7 that show dual antiplatelet therapy reduces the risk of recurrent stroke and combined vascular events in patients with acute ischemic stroke or transient ischemic attack.
• The second neurologist discontinues the plavix citing the patient's prior SCAD history 10 years ago and possible timing of this stroke occurring 3+ days ago, which may be a consideration for the risk of bleeding associated with dual antiplatelet therapy 4, 5, 6, 7.
• However, study 7 shows that dual antiplatelet treatment up to 72 hours after ischemic stroke leads to a lower risk of new stroke at 90 days than aspirin therapy alone, but is associated with a low but higher risk of moderate-to-severe bleeding.

Considerations for Dual Antiplatelet Therapy

• The patient's prior SCAD history 10 years ago may be a consideration for the risk of bleeding associated with dual antiplatelet therapy, but the current evidence suggests that the benefits of dual antiplatelet therapy may outweigh the risks in patients with acute ischemic stroke or transient ischemic attack 3, 4, 5, 6, 7.
• The timing of the stroke occurring 3+ days ago may also be a consideration, but study 7 shows that dual antiplatelet treatment initiated within 72 hours after stroke onset leads to a lower risk of new stroke at 90 days than aspirin therapy alone.
• The decision to use dual antiplatelet therapy should be individualized based on the patient's specific characteristics, including their stroke history, risk of bleeding, and other medical conditions 6.

Risks and Benefits of Dual Antiplatelet Therapy

• Dual antiplatelet therapy is associated with a higher risk of major bleeding compared to monotherapy 4, 5, 6, 7.
• However, the benefits of dual antiplatelet therapy in reducing the risk of recurrent stroke and combined vascular events may outweigh the risks in patients with acute ischemic stroke or transient ischemic attack 3, 4, 5, 6, 7.