Initial Management of SCAD with FMD
For patients with spontaneous coronary artery dissection (SCAD) and fibromuscular dysplasia (FMD), conservative medical management is the preferred initial approach for clinically stable patients, with beta-blockers and aggressive blood pressure control as the cornerstone of therapy. 1
Immediate Assessment and Stabilization
Conservative management is recommended for clinically stable patients without high-risk features, avoiding revascularization unless absolutely necessary 1. Monitor these patients as inpatients for 3-5 days to observe for early complications 1.
Indications for Revascularization (PCI or CABG)
Proceed with revascularization only if:
- Hemodynamic instability is present 1
- Left main or proximal two-vessel coronary dissection with critical flow limitation exists 1
Important caveat: PCI in SCAD carries high technical failure rates due to the non-atherosclerotic nature of the disease, and stenting can propagate dissection 2, 3. If revascularization is necessary, consider PCI for focal accessible lesions or CABG for left main/multivessel involvement 1.
Medical Therapy
Beta-Blockers (First-Line)
Beta-blockers are strongly recommended as they reduce the risk of recurrent SCAD 1, 4. This is particularly important given that FMD is associated with SCAD in up to 72% of cases 4, and beta-blockers provide dual benefit for both conditions.
Aggressive Blood Pressure Control
Aggressive anti-hypertensive therapy is essential, as hypertension is an independent predictor of recurrent SCAD 1, 4. Use ACE inhibitors, ARBs, or non-dihydropyridine calcium channel blockers (verapamil or diltiazem) to achieve normal blood pressure and reduce arterial wall stress 5.
Antiplatelet Therapy
Single antiplatelet therapy (SAPT) with aspirin (81-325 mg daily) is preferred over dual antiplatelet therapy (DAPT) for conservatively managed SCAD 6.
Key evidence:
- DAPT was independently associated with a 4.54-fold higher risk of 12-month major adverse cardiovascular events compared to SAPT in conservatively managed patients 6
- DAPT showed an 18.9% MACE rate versus 6.0% with SAPT at 12 months 6
- If PCI with stenting was performed, DAPT should be continued for 12 months 2, 3
Critical pitfall: Avoid potent P2Y12 inhibitors (ticagrelor, prasugrel) as they may increase bleeding risk into the false lumen 2. If DAPT is necessary, use aspirin plus clopidogrel 2.
Contraindicated Medications
Absolutely avoid:
- Fibrinolytic agents (can propagate hematoma) 2, 3
- Anticoagulants (can favor hematoma propagation) 2, 3
- Glycoprotein IIb/IIIa inhibitors 3
FMD-Specific Considerations
Surveillance for FMD
Annual non-invasive imaging of the carotid arteries is reasonable initially to detect changes in FMD extent or severity 5. Studies may be repeated less frequently once stability is confirmed 5.
Platelet inhibitor medication is beneficial for FMD of the carotid arteries to prevent thromboembolism, though optimal dosing is not established 5.
Revascularization for FMD
Revascularization is NOT recommended for asymptomatic FMD of a carotid artery, regardless of stenosis severity 5. Only consider carotid angioplasty with or without stenting if the patient develops retinal or hemispheric cerebral ischemic symptoms related to FMD 5.
Long-Term Management
- Continue long-term beta-blocker therapy to prevent SCAD recurrence 1, 4
- Consider coronary CT angiography for follow-up in patients with persistent or recurrent symptoms 1
- Implement stress management techniques, as SCAD is often precipitated by emotional or physical stress 4
- Avoid hormonal therapy if SCAD occurred during pregnancy, and discourage future pregnancy in this population 3
Special Monitoring
Given the strong association between SCAD and FMD (up to 72% of cases) 4, screen for extracoronary FMD in renal, carotid, and iliac arteries using non-invasive imaging or angiography 7. This is crucial for predicting possible SCAD recurrence and obtaining a definitive diagnosis 7.