What is the treatment for Spontaneous Coronary Artery Dissection (SCAD)?

Treatment of Spontaneous Coronary Artery Dissection (SCAD)

Conservative medical management is the preferred initial approach for clinically stable SCAD patients, with beta-blockers and aggressive blood pressure control as the cornerstone of therapy, reserving revascularization only for hemodynamically unstable patients or those with left main/proximal two-vessel dissection. 1, 2

Acute Management Strategy

For Clinically Stable Patients

• Conservative therapy is strongly recommended as the first-line approach for all hemodynamically stable patients without high-risk anatomic features 1, 2
• Monitor as inpatient for 3-5 days to observe for early complications including dissection extension, recurrent ischemia, or hemodynamic deterioration 1, 2
• Conservative management avoids the technical challenges and complications associated with PCI in SCAD, where stenting can propagate the dissection or cause iatrogenic injury 3

Indications for Revascularization

Revascularization should be considered only in these specific scenarios:

• Hemodynamic instability (cardiogenic shock, sustained ventricular arrhythmias) 1, 2
• Left main coronary dissection with critical flow limitation 1, 2
• Proximal two-vessel dissection with ongoing ischemia 1, 2
• Actively ongoing ischemia despite medical management 1

Choice of revascularization approach:

• PCI if technically feasible for focal, accessible lesions 2
• CABG for left main or multivessel involvement, especially when PCI is technically challenging 1, 2
• Meta-analysis demonstrates revascularization as first-line treatment increases target vessel revascularization risk by 6.3% compared to conservative management 3

Medical Therapy

Beta-Blockers (Strongly Recommended)

• Beta-blockers are the most important medication for SCAD patients and should be initiated in all patients unless contraindicated 2, 4, 5
• Reduce risk of recurrent SCAD with hazard ratio of 0.36 (64% risk reduction) in multivariate analysis 5
• Continue long-term indefinitely to prevent recurrence 2, 4
• Provide dual benefit of reducing arterial wall stress and migraine prophylaxis in affected patients 6

Aggressive Blood Pressure Control

• Hypertension is an independent predictor of recurrent SCAD (hazard ratio 2.46) and must be aggressively treated 2, 4, 5
• Target normal blood pressure using ACE inhibitors, ARBs, or non-dihydropyridine calcium channel blockers 4
• Aggressive anti-hypertensive therapy reduces arterial wall stress and dissection propagation 2, 4

Antiplatelet Therapy

• Aspirin monotherapy is generally safe and recommended for conservatively managed patients without high-risk angiographic features 7, 8
• Dual antiplatelet therapy (DAPT) with aspirin plus clopidogrel:
  • Required for 12 months if stent placed 7, 8
  • May be given short-term (1 month) followed by aspirin monotherapy in conservatively managed patients 8
• Avoid potent P2Y12 inhibitors (ticagrelor, prasugrel) as they may increase bleeding risk into the intramural hematoma 7

Medications to AVOID

• Fibrinolytics are absolutely contraindicated - can propagate intramural hematoma 7, 8
• Anticoagulants should be avoided - risk of hematoma expansion 7, 8
• Glycoprotein IIb/IIIa inhibitors are contraindicated - bleeding risk 8
• Triptans should be avoided in patients with migraine due to vasoconstrictive effects 6

Additional Cardiovascular Medications

• RAAS inhibitors, mineralocorticoid antagonists, and diuretics should be used only if left ventricular ejection fraction is reduced below 50% or heart failure symptoms present 7, 8
• Statins may be considered for pleiotropic properties despite lack of firm evidence, though not routinely recommended without left ventricular dysfunction 7, 8

Management of Recurrent Chest Pain After SCAD

New Acute Coronary Syndrome Presentation

• Urgent evaluation per standard ACS guidelines with ECG, troponin monitoring, and imaging 1
• Differential diagnosis includes SCAD progression, recurrent SCAD, stenosis, or thrombosis 1

Stable Angina Symptoms

• Evaluate with stress imaging (echocardiography, cardiac MRI, or nuclear perfusion) 1
• If high-risk anatomy or compelling clinical scenario, consider coronary imaging as initial approach 1
• Abnormal stress test warrants medical management optimization and consideration of coronary CT angiography 1, 2

Atypical Symptoms

• Evaluate for non-cardiac causes and address symptom triggers 1
• Consider healing SCAD, coronary vasospasm, or endothelial dysfunction as differential diagnoses 1
• Medical management for post-SCAD chest pain without obstructive disease includes long-acting nitrates, calcium channel blockers, or ranolazine 1

Screening for Associated Conditions

Fibromuscular Dysplasia (FMD)

• FMD is present in up to 72% of SCAD patients and requires systematic screening 4, 6
• Vascular imaging from brain to pelvis should be considered in all SCAD patients 1
• Annual non-invasive imaging of carotid arteries is reasonable initially, with less frequent follow-up once stability confirmed 4
• Platelet inhibitor medication is beneficial for carotid FMD to prevent thromboembolism 4
• Revascularization is NOT recommended for asymptomatic carotid FMD regardless of stenosis severity 4

Intracranial Aneurysm Screening

• Intracranial aneurysms present in 14-23% of SCAD patients 1
• Screening warranted given overlap with FMD, vascular Ehlers-Danlos syndrome, Loeys-Dietz syndrome, and polycystic kidney disease 1

Special Populations

Pregnancy-Associated SCAD

• Hormonal therapy is absolutely contraindicated in patients who develop SCAD during pregnancy 8
• Future pregnancy is strongly discouraged in this population 8
• Exogenous hormones should be avoided in all SCAD patients 1

Women with Heavy Menstrual Bleeding

• Consider second-generation endometrial ablation techniques over hormonal therapy given need to avoid exogenous hormones 1
• Low-dose progestin intrauterine devices may be considered if shown effective 1

Long-Term Follow-Up

• Recurrent SCAD occurs in 10.4% of patients at median 3.1-year follow-up 5
• Overall major adverse cardiac event rate is 19.9% long-term (death 1.2%, recurrent MI 16.8%, stroke/TIA 1.2%, revascularization 5.8%) 5
• Stress management techniques are essential as SCAD is often precipitated by emotional or physical stress 2, 4, 6
• Continue beta-blocker therapy indefinitely for recurrence prevention 2, 4
• Coronary CT angiography may be used for follow-up imaging in patients with persistent or recurrent symptoms 2

Key Clinical Pitfalls to Avoid

• Do not perform routine PCI - technical failure rates are high and conservative management has equivalent mortality and MI rates with lower TVR rates 3
• Do not use fibrinolytics even if STEMI presentation - this is a contraindication specific to SCAD 7, 8
• Do not overlook blood pressure control - hypertension more than doubles recurrence risk 5
• Do not discontinue beta-blockers - they provide the strongest evidence for recurrence prevention 5