Management and Treatment of Spontaneous Coronary Artery Dissection (SCAD)
For patients with Spontaneous Coronary Artery Dissection (SCAD), a conservative medical approach is the preferred treatment strategy for most cases, with revascularization reserved only for patients with very high-risk features such as hemodynamic instability or left main/proximal two-vessel dissection with critical flow limitation. 1, 2
Diagnosis and Classification
- SCAD is defined as a non-atherosclerotic, non-traumatic separation of coronary arterial layers creating a false lumen and downstream myocardial ischemia 1, 2
- SCAD accounts for up to 4% of all acute coronary syndromes (ACS), but 22-35% of ACS in women <60 years 1
- Three angiographic types of SCAD exist 1:
- Type 1: Contrast dye staining with multiple radiolucent lumens
- Type 2: Long diffuse and smooth narrowing
- Type 3: Focal stenosis mimicking atherosclerosis
- Intracoronary imaging with optical coherence tomography (OCT) or intravascular ultrasound (IVUS) is recommended for unclear cases to confirm diagnosis 1, 2
Initial Management Approach
Conservative Management (First-Line for Most Patients)
- Conservative medical therapy is recommended for clinically stable patients without high-risk features 1, 2
- Monitor stable patients as inpatients for 3-5 days to observe for early complications 1, 2
- 90% of conservatively managed patients have an uneventful in-hospital course, though 10% may experience early SCAD progression requiring revascularization 3
Revascularization (Reserved for High-Risk Cases)
Consider immediate revascularization only for 1, 2:
- Hemodynamically unstable patients
- Ongoing ischemia despite medical therapy
- Left main or proximal two-vessel coronary dissection with critical flow limitation
Important caveat: PCI for SCAD has high procedural failure rates (53%) even in patients with preserved vessel flow, and does not protect against target vessel revascularization or recurrent SCAD 3
Medical Therapy
- Beta-blockers are strongly recommended as they have been associated with reduced risk of recurrent SCAD 1, 2
- Aggressive anti-hypertensive therapy is recommended as hypertension is an independent predictor of recurrent SCAD 1, 2
- Optimal antiplatelet therapy remains unclear, but most patients are discharged on dual antiplatelet therapy based on general ACS guidelines 4
Algorithm for Management of Acute SCAD
Assess clinical stability and risk features 1, 2:
- If hemodynamically unstable or with ongoing ischemia: Consider revascularization
- If stable: Proceed with conservative management
For conservative management 1, 2:
- Hospital admission for 3-5 days
- Beta-blocker therapy
- Blood pressure control
- Monitor for complications
For patients requiring revascularization 1, 2:
- PCI for focal, accessible lesions with ongoing ischemia
- CABG for left main or multivessel involvement, especially when PCI is technically challenging
Long-term Management and Follow-up
- Continue beta-blocker therapy long-term 1, 2
- Maintain aggressive blood pressure control 1, 2
- Consider coronary CT angiography (CCTA) for follow-up in patients with persistent or recurrent symptoms 2
- Be aware that recurrent SCAD can occur (even in different coronary territories) 5
Special Considerations
- SCAD predominantly affects women (>90% of cases), particularly those under 60 years 1, 6
- Associated conditions include fibromuscular dysplasia, pregnancy, and history of anxiety/depression 1, 6
- Stress management is important as emotional/physical stress can precipitate SCAD 7
Common Pitfalls to Avoid
- Attempting PCI in all SCAD cases - high failure rate (53%) and may worsen dissection 3
- Discharging patients too early - observe for 3-5 days due to risk of early progression 1, 2
- Missing the diagnosis - SCAD Type 3 can mimic atherosclerotic disease; consider intracoronary imaging when unclear 1
- Failing to screen for associated conditions like fibromuscular dysplasia 6