Is there evidence to support the use of Ticagrelor (a P2Y12 inhibitor) in patients with Spontaneous Coronary Artery Dissection (SCAD)?

Ticagrelor Use in Spontaneous Coronary Artery Dissection (SCAD)

Ticagrelor should not be used in patients with Spontaneous Coronary Artery Dissection (SCAD) as it is associated with increased risk of major adverse cardiovascular events and SCAD recurrence. 1

Evidence Against Ticagrelor in SCAD

The most recent evidence strongly discourages the use of ticagrelor in SCAD patients:

• The Australian-New Zealand SCAD cohort study (2025) demonstrated that ticagrelor combined with aspirin was independently associated with higher rates of major adverse cardiovascular events (MACE) (adjusted HR 1.8) and SCAD recurrence (adjusted HR 2.6) compared to less potent antiplatelet regimens 1

• Current evidence suggests SCAD is primarily caused by intramural bleeding, and more potent antiplatelet therapy may worsen outcomes by promoting hematoma propagation 2

• The 2024 ESC guidelines for chronic coronary syndromes do not recommend ticagrelor for SCAD patients, instead suggesting less potent antiplatelet options 3

Recommended Antiplatelet Approach for SCAD

For Conservatively Managed SCAD:

• First-line therapy: Single antiplatelet therapy with aspirin only, particularly for patients without high-risk angiographic features 2
• If DAPT is needed: Use aspirin plus clopidogrel rather than potent P2Y12 inhibitors 2

For SCAD Treated with Stent Implantation:

• First-line DAPT: Aspirin plus clopidogrel for 12 months 2
• Avoid: Potent P2Y12 inhibitors like ticagrelor and prasugrel 2

Pathophysiological Rationale

The mechanism of SCAD differs fundamentally from atherosclerotic coronary artery disease:

• SCAD involves an intramural hematoma that propagates within the arterial wall, creating a false lumen 2
• Potent antiplatelet agents like ticagrelor may increase bleeding into the false lumen, worsening the dissection 2, 1
• This contrasts with atherosclerotic disease where platelet inhibition reduces thrombotic complications

Important Considerations

• Fibrinolytic agents and anticoagulants should be strictly avoided in SCAD as they may favor hematoma propagation 2
• Beta-blockers should be used in SCAD patients to prevent recurrence 2
• The optimal duration of antiplatelet therapy remains uncertain, but generally follows standard post-ACS timelines (typically 12 months) 2

Clinical Decision Algorithm for SCAD Antiplatelet Management

1. Confirm SCAD diagnosis (angiography with or without intravascular imaging)
2. Determine management strategy:
   • Conservative management (preferred when possible)
   • PCI (only if ongoing ischemia, hemodynamic instability, or left main involvement)
3. Select antiplatelet regimen:
   • For conservative management: Aspirin monotherapy or aspirin plus clopidogrel
   • For PCI with stenting: Aspirin plus clopidogrel for 12 months
4. Avoid ticagrelor, prasugrel, fibrinolytics, and anticoagulants
5. Add beta-blockers for all SCAD patients to prevent recurrence

In conclusion, the evidence does not support the use of ticagrelor in SCAD patients, and current guidelines recommend using less potent antiplatelet regimens to minimize the risk of hematoma propagation and recurrence.