What are the typical symptoms, diagnostic criteria, and work‑up for spontaneous coronary artery dissection (SCAD) in otherwise healthy adults, especially women aged 30–55?

Spontaneous Coronary Artery Dissection: Symptoms and Diagnostic Criteria

Clinical Presentation

SCAD typically presents as acute coronary syndrome with chest discomfort and elevated cardiac biomarkers, occurring predominantly in young to middle-aged women (30-55 years) without traditional cardiovascular risk factors. 1

Typical Symptoms

• Chest pain or discomfort is the most common presenting symptom, indistinguishable from other causes of acute coronary syndrome 1
• Symptoms may range from unstable angina to ST-elevation myocardial infarction 2
• Cardiogenic shock, ventricular arrhythmias, and cardiac arrest can occur, particularly in pregnancy-associated SCAD 3
• Sudden cardiac death is a recognized but less common presentation 2

Key Demographic and Clinical Context

• Over 90% of SCAD cases occur in women 4
• SCAD accounts for 22-35% of acute coronary syndromes in women under 60 years of age 1, 4
• Patients are typically otherwise healthy without traditional cardiovascular risk factors (no diabetes, hyperlipidemia, smoking) 1, 5
• Emotional or physical stress often precedes the event 4, 6
• Pregnancy and peripartum period represent high-risk windows 4

Diagnostic Criteria and Angiographic Classification

Angiographic Types (Primary Diagnostic Method)

SCAD is diagnosed by invasive coronary angiography, which reveals three distinct angiographic patterns: 1

• Type 1: Contrast dye staining of the arterial wall with multiple radiolucent lumens (pathognomonic appearance of intimal tear with double lumen) 1
• Type 2: Long, diffuse, smooth narrowing of the coronary artery (most common pattern, caused by intramural hematoma)
  • Type 2A: Stenosis >50% (obstructive)
  • Type 2B: Stenosis <50% (non-obstructive) 1
• Type 3: Focal or tubular stenosis mimicking atherosclerosis (most challenging to diagnose) 1

Advanced Imaging for Diagnostic Confirmation

When angiographic findings are equivocal, intracoronary imaging with optical coherence tomography (OCT) or intravascular ultrasound (IVUS) can definitively demonstrate intramural hematoma or double lumen 1. This may be fundamental to making a proper diagnosis, particularly for Type 3 SCAD 1.

Important caveat: Coronary computed tomography angiography (CCTA) may miss SCAD, so a negative CCTA should not exclude the diagnosis 1.

Diagnostic Work-Up Algorithm

Initial Evaluation

• ECG and cardiac biomarkers (troponin) in all patients presenting with chest pain 1
• Invasive coronary angiography remains the gold standard for diagnosis 1
• Administer intracoronary nitrates before final angiographic interpretation to exclude vasospasm 1

When Diagnostic Uncertainty Exists

If angiography is inconclusive, consider: 1

• OCT or IVUS if technically feasible and safe (preferred for definitive diagnosis)
• CT coronary angiography, especially for proximal lesions
• Repeat coronary angiography at 6-8 weeks to document healing or evolution
• CT or MR angiography of extracoronary vascular beds to screen for fibromuscular dysplasia 1

Screening for Associated Conditions

Up to 72% of SCAD patients have fibromuscular dysplasia (FMD), making systematic screening essential: 4, 5

• Non-invasive vascular imaging (CT or MR angiography) of renal, carotid, and iliac arteries to detect FMD 1, 7
• Screen for connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome, systemic lupus erythematosus) 4
• Assess for pregnancy status in women of childbearing age 4
• Evaluate for hypertension, as it predicts recurrent SCAD 1, 4

High-Risk Features Requiring Urgent Evaluation

• Left main coronary artery dissection 1
• Proximal two-vessel dissection 1
• Hemodynamic instability or ongoing ischemia 1
• Pregnancy-associated SCAD (higher complication rates) 8, 3

Common Diagnostic Pitfalls

• Misdiagnosis as atherosclerotic ACS in young women, leading to inappropriate aggressive intervention 1
• Failure to recognize Type 3 SCAD which mimics atherosclerosis and requires high index of suspicion 1
• Overlooking SCAD in the differential when young women present with chest pain due to sex bias in cardiac investigations 1
• Performing PCI without recognizing SCAD, which has high technical failure rates and can extend the dissection 8, 3