What is the management approach for coronary artery dissection?

Management of Coronary Artery Dissection

Conservative management is the preferred first-line approach for clinically stable patients with spontaneous coronary artery dissection (SCAD), while revascularization should be reserved for patients with ongoing ischemia, hemodynamic instability, or left main/proximal two-vessel involvement. 1

Diagnosis and Initial Assessment

SCAD is characterized by a non-atherosclerotic separation of coronary arterial walls, creating a false lumen or intramural hematoma that compresses the true lumen and impairs blood flow. It predominantly affects women (>90% of cases), often without traditional cardiovascular risk factors 1.

Diagnostic approach:

• Coronary angiography is the primary diagnostic tool
• Three angiographic types of SCAD:
  • Type 1: Multiple radiolucent lumens or arterial wall contrast staining
  • Type 2: Diffuse stenosis of varying severity and length
  • Type 3: Focal stenosis mimicking atherosclerosis

When diagnostic uncertainty exists:

• Intracoronary imaging (OCT/IVUS) if feasible and safe
• CT coronary angiography for proximal lesions
• Consider screening for fibromuscular dysplasia (FMD) in other vascular beds

Management Algorithm

For Clinically Stable Patients:

• Conservative medical therapy is recommended 1, 2
• Monitor as inpatient for 3-5 days
• Medical therapy includes:
  • Aspirin for at least 12 months
  • Beta-blockers
  • Consider P2Y12 inhibitor (typically clopidogrel) for 1-12 months 1

For Patients with High-Risk Anatomy but Clinically Stable:

• Conservative therapy is still preferred if no ongoing ischemia 1
• For left main or severe proximal two-vessel dissection:
  • Consider CABG in selected cases, though conservative management may still be reasonable 1

For Patients with Ongoing Ischemia or Hemodynamic Instability:

• Consider PCI if technically feasible
• Urgent CABG if PCI not feasible or for left main involvement
• Decision based on technical considerations and local expertise 1

Revascularization Considerations

PCI in SCAD carries significant risks:

• High failure rate (approximately 50%)
• Risk of extending dissection
• Risk of iatrogenic dissection
• Potential for abrupt vessel closure during intervention 1

If PCI is performed:

• Should be done by experienced operators
• Use intravascular imaging to confirm true lumen
• Consider on-site surgical backup 3
• After stenting, dual antiplatelet therapy with aspirin and ticagrelor (or prasugrel) for one year followed by aspirin alone is recommended 1

Post-SCAD Management

For recurrent chest pain after SCAD:

• Evaluate for SCAD progression, recurrence, or thrombosis
• Consider stress imaging tests for stable symptoms
• Medical management for post-SCAD chest pain without obstructive disease may include long-acting nitrates, calcium channel blockers, or ranolazine 1

Prognosis and Follow-up

• Most patients who survive the acute phase are free from coronary events at 1 year 4
• Increased risk of recurrent dissections in other arteries several weeks after the first event 3
• Conservative therapy shows favorable outcomes with reduced risk of target vessel revascularization compared to initial revascularization strategy 2

Key Pitfalls to Avoid

1. Avoid thrombolytic therapy - can extend dissection and worsen outcomes
2. Avoid routine PCI when patient is stable with preserved coronary flow
3. Avoid intravascular imaging unless revascularization is already decided upon, as it may trigger abrupt vessel closure 1
4. Avoid overlooking FMD - present in up to 72% of SCAD cases 1
5. Avoid missing SCAD in young women - accounts for up to 24-35% of ACS in women ≤50 years 1

In summary, while SCAD management must consider individual clinical and anatomical factors, conservative medical therapy should be the default approach in stable patients, with revascularization reserved for those with ongoing ischemia or high-risk anatomy.