Dual Antiplatelet Therapy for Coronary Artery Dissection
For patients with spontaneous coronary artery dissection (SCAD), dual antiplatelet therapy (DAPT) should consist of aspirin plus clopidogrel, while avoiding more potent P2Y12 inhibitors like ticagrelor and prasugrel. 1
Recommended DAPT Regimen
Initial Therapy
- First-line recommendation:
Duration of Therapy
- If stent was placed during PCI: Continue DAPT for 12 months 1
- If conservatively managed without stenting: Consider aspirin monotherapy if no high-risk angiographic features (thrombus burden, critical stenosis, decreased coronary flow) 1
Rationale for Clopidogrel Over More Potent P2Y12 Inhibitors
The pathophysiology of SCAD differs significantly from atherosclerotic coronary artery disease:
- SCAD involves intimal tear and intramural hematoma formation
- More potent P2Y12 inhibitors (ticagrelor, prasugrel) may increase bleeding risk and potentially worsen intramural hematoma 1
Important Considerations and Precautions
Medications to Avoid in SCAD
- Avoid fibrinolytic agents and anticoagulants as they may promote hematoma propagation 1
- Avoid prasugrel and ticagrelor despite their superiority in typical ACS scenarios 1
Additional Pharmacotherapy
- Beta-blockers are recommended to prevent SCAD recurrence 1
- For patients with reduced ejection fraction (<50%) or heart failure symptoms:
- Consider ACE inhibitors, ARBs, mineralocorticoid antagonists, and loop diuretics 1
Special Situations
Perioperative Management
If surgery is required while on DAPT:
- For non-urgent surgery: Consider delaying procedure until completion of necessary DAPT duration
- For urgent surgery: Clopidogrel should be stopped 5-7 days before surgery if possible, while continuing aspirin 4
- For emergency surgery: Proceeding with continued DAPT may be necessary despite increased bleeding risk 4
Monitoring
- Regular assessment of bleeding risk
- Evaluation for signs of SCAD recurrence or extension
Evidence Limitations
It's important to note that SCAD-specific randomized controlled trials for antiplatelet therapy are lacking. Current recommendations are based primarily on observational studies, expert consensus, and extrapolation from general ACS guidelines with modifications based on SCAD's unique pathophysiology 1, 5.
The European Society of Cardiology guidelines for general ACS recommend DAPT for 12 months, but these were not specifically developed for SCAD patients 2, 3.