Spontaneous Coronary Artery Dissection: Symptoms, Types, Causes and Treatment

Spontaneous Coronary Artery Dissection (SCAD) is an often under-recognized and misunderstood cause of acute coronary syndromes (ACS), including heart attack and sudden cardiac death. Unlike classic atherosclerotic heart disease, SCAD typically affects younger women without traditional risk factors. Over the past decade, awareness, diagnosis, and research into SCAD have increased, but many questions remain about its presentation, underlying causes, classification, and optimal management. This article will guide you through the key symptoms, types, underlying causes, and current treatment options for SCAD, providing an up-to-date, evidence-based overview.

Symptoms of Spontaneous Coronary Artery Dissection

When it comes to SCAD, the range of symptoms can be broad and sometimes misleading. Because the artery tear can restrict or block blood flow to the heart, symptoms often mimic those of more common heart attacks. Understanding these symptoms is crucial for early recognition and prompt care—especially in young, otherwise healthy individuals.

Symptom	Description	Frequency/Association	Source(s)
Chest pain	Sudden, severe, often radiating	Most common presenting symptom	2 3 5 10
Palpitations	Sensation of rapid or fluttering heartbeat	Frequently reported	5
Dyspnea	Shortness of breath	Sometimes present	5 10
Nausea/vomiting	May accompany chest pain	Occasionally reported	5 10
Syncope	Fainting or near-fainting	In severe or sudden cases	1 10
Sudden death	Cardiac arrest, often in severe cases	Rare but possible	1 3 10

Table 1: Key Symptoms

The Most Common Presentations

SCAD most frequently presents as sudden chest pain, which may radiate to the arm, neck, or back. The pain is often severe and indistinguishable from a classic heart attack. Palpitations, or the feeling of a rapid or irregular heartbeat, are also common and may heighten anxiety in affected individuals. Some patients also experience shortness of breath, nausea, or vomiting, which can further complicate the clinical picture and lead to misdiagnosis as gastrointestinal or anxiety-related issues 2 3 5 10.

Severe and Atypical Manifestations

In more severe cases, especially when a large part of the heart is deprived of blood, patients may faint (syncope) or, rarely, experience sudden cardiac arrest or sudden death 1 3 10. These life-threatening symptoms underscore the importance of recognizing SCAD early, even in patients who lack traditional cardiac risk factors.

Patterns and Who Is at Risk

• SCAD is a leading cause of heart attack in young to middle-aged women, often those with few or no classic cardiovascular risk factors 5 6 9 10.
• Symptoms can occur at rest or be triggered by emotional or physical stress.
• The clinical presentation is highly variable and can range from asymptomatic (discovered incidentally) to severe, life-threatening events 1 5 10.

Types of Spontaneous Coronary Artery Dissection

SCAD is not a one-size-fits-all diagnosis. Advances in imaging and research have revealed distinct types, each with unique features and implications for treatment and outcomes.

Type	Key Features	Diagnostic Methods	Source(s)
Type 1	Visible arterial wall "flap" and double lumen	Angiography, OCT, IVUS	1 7 8 9
Type 2	Long segment of diffuse, smooth narrowing	Angiography, OCT, IVUS	7 8 9
Type 3	Focal, tubular stenosis mimicking atherosclerosis	OCT, IVUS (needed for clarity)	8 9

Table 2: SCAD Types and Diagnostic Tools

Classic Angiographic Types

Type 1: Intimal Tear with Double Lumen

This classic form is characterized by a visible tear in the inner lining of the artery, seen as a "flap" on angiography. Blood enters the wall of the artery, creating a true and a false lumen (channel). This type is relatively straightforward to diagnose with standard coronary angiography but is less common than previously thought 1 7 8 9.

Type 2: Diffuse Smooth Narrowing

Type 2 SCAD is defined by a long, smooth, and often subtle narrowing of the artery, sometimes extending for over 20 millimeters. Unlike Type 1, no clear flap is seen. This type is the most common SCAD pattern and may be easily missed or mistaken for other causes of vessel narrowing unless advanced imaging (like OCT or IVUS) is used 7 8 9.

Type 3: Focal Tubular Stenosis

This type appears as a short segment of narrowing that closely resembles atherosclerotic plaque. It is the most difficult to distinguish from classic coronary artery disease and often requires advanced imaging for a definitive diagnosis 8 9.

Diagnostic Tools

• Coronary Angiography: The initial test for most cases, though it may miss subtle or ambiguous cases, especially Types 2 and 3 8 9.
• Optical Coherence Tomography (OCT) and Intravascular Ultrasound (IVUS): These intracoronary imaging techniques provide high-resolution images, helping to clarify ambiguous findings, differentiate SCAD from plaque rupture, and guide management 1 7 8.
• Non-invasive Imaging: Techniques like multidetector computed tomography (MDCT) may be used for follow-up but are less useful acutely 1.

Overlapping and Secondary Forms

• Primary SCAD: Occurs without a precipitating event or external injury.
• Secondary Dissection: Can result from extension of an aortic dissection or as a complication of medical procedures, trauma, or surgery 1.

Causes of Spontaneous Coronary Artery Dissection

SCAD is a multifactorial condition. Unlike classic heart attacks, which are usually due to cholesterol-laden plaque buildup, SCAD is not caused by atherosclerosis. Instead, it often results from a combination of genetic susceptibility, hormonal influences, vascular abnormalities, and acute triggers.

Cause/Factor	Description	Associated Groups	Source(s)
Female sex/hormones	Predominantly affects young to middle-aged women	Peripartum, postpartum	5 6 9 10 11
Fibromuscular dysplasia (FMD)	Non-atherosclerotic vascular disease	Many SCAD patients	5 7 9 10
Genetic predisposition	Risk loci and connective tissue gene variants	Family history, syndromes	9 12 15
Emotional/physical stress	Triggering events leading to arterial stress	Acute onset	5 9 10
Hormonal therapy/pregnancy	Hormone changes, fertility treatment	Pregnancy, HRT users	9 10
Connective tissue disorders	E.g., Marfan, Ehlers-Danlos syndromes	Rare, but higher risk	5 9 12
Sympathomimetic drugs	Stimulants, recreational drugs	Occasional cases	5
Unknown	No clear risk factor (idiopathic cases)	Many cases	10 12

Table 3: Main Causes and Risk Factors

Who Gets SCAD?

SCAD is most commonly seen in women (up to 90% of cases in some studies), mainly between ages 44 and 53, with little or no traditional cardiovascular risk factors like high cholesterol or smoking 5 6 9 10. However, it is increasingly recognized that men and older adults can also be affected 6 9 10.

Predisposing Medical Conditions

• Fibromuscular Dysplasia (FMD): A non-atherosclerotic, non-inflammatory arterial disease that causes abnormal cell growth in arterial walls. Nearly half of SCAD patients have signs of FMD, suggesting a strong association 5 7 9 10.
• Connective Tissue Disorders: Rarely, conditions such as Marfan syndrome or Ehlers-Danlos syndrome, which weaken arterial walls, are implicated 5 9 12.

Genetic and Hormonal Factors

Recent genetic studies have identified specific gene variants associated with increased SCAD risk, often related to connective tissue integrity and vascular health 12. The strong female predominance and association with pregnancy, postpartum periods, and hormonal therapies (including fertility and hormone replacement treatments) point to a hormonal influence 9 10 12.

Triggers and Acute Events

• Physical stress: Intense exercise, heavy lifting, or labor during childbirth can precipitate SCAD.
• Emotional stress: Sudden psychological distress can trigger an episode.
• Sympathomimetic drugs: Use of stimulant medications or recreational drugs has been linked to some cases 5 9 10.

Idiopathic Cases

Despite investigations, many cases have no identifiable risk factor or trigger and are considered idiopathic. The interplay between genetic background, vessel vulnerability, and environmental triggers is still the subject of ongoing research 10 12.

Treatment of Spontaneous Coronary Artery Dissection

Managing SCAD is fundamentally different from treating typical heart attacks caused by atherosclerosis. The unique nature of SCAD, including fragile blood vessels and the potential for healing without intervention, means careful consideration must be given to each patient.

Treatment Approach	When Used	Key Points	Source(s)
Conservative	Most SCAD cases	Medical therapy, observation	5 7 10 13
PCI (Stenting)	Ongoing ischemia, high-risk anatomy	Higher risk of complications	1 5 13 17
CABG (Bypass)	Failed PCI, left main/large vessel	Rare, for severe cases	1 5 13
Aspirin/Antiplatelets	Most receive aspirin; DAPT debated	DAPT may increase adverse events	5 14 16
Beta-blockers	Often prescribed	May lower recurrence risk	5 16
Cardiac Rehab	Post-event recovery	Tailored for SCAD patients	15
Follow-up	All patients	Regular imaging, risk factor mgmt	5 10 15

Table 4: SCAD Treatment Strategies

Conservative (Medical) Management

For the majority of SCAD patients, especially those who are stable and have preserved blood flow, conservative treatment is the preferred approach. The rationale is that many dissections will heal on their own, and invasive procedures may actually increase the risk of complications 5 7 10 13.

• Medications: Aspirin is nearly always prescribed, with or without a second antiplatelet agent (such as clopidogrel). However, recent registry data suggest that dual antiplatelet therapy (DAPT) may be linked with higher rates of adverse events compared to aspirin alone in conservatively managed patients 5 14.
• Beta-blockers: These medications, commonly used in heart disease, may help reduce the risk of recurrence and are often prescribed 5 16.
• Close observation: Patients are monitored for signs of worsening dissection or recurrent symptoms during hospitalization and follow-up.

Interventional Approaches

Percutaneous Coronary Intervention (PCI)

PCI, or stent placement, is reserved for patients with ongoing or severe ischemia, high-risk anatomy (such as left main artery involvement), or hemodynamic instability. However, PCI in SCAD is technically challenging and has a high rate of complications, including extension of the dissection and procedural failure 1 5 13 17.

• Studies show that up to 50% of PCI attempts in SCAD fail or result in complications, and PCI does not reduce the risk of recurrence compared to conservative therapy 13.
• In some regions, such as Japan, PCI is still used more frequently, but international consensus supports a conservative-first approach 17.

Coronary Artery Bypass Grafting (CABG)

CABG is rarely needed but may be considered if PCI fails or in cases involving critical vessels (e.g., left main artery) or extensive dissection 1 5 13.

Additional Therapies and Considerations

• Cardiac Rehabilitation: Tailored rehab programs support physical and emotional recovery, addressing unique SCAD patient needs 15.
• Follow-up: Regular follow-up with non-invasive imaging (such as MDCT or MRI) is recommended to monitor healing and assess for recurrence 5 10 15.
• Psychosocial Support: SCAD can have a significant emotional impact, and mental health support is important, especially for women who are at higher risk of depression and anxiety post-SCAD 9 15.

Ongoing Research

Large randomized trials, such as the BA-SCAD study, aim to clarify the best pharmacological strategies, including the duration of antiplatelet therapy and the use of beta-blockers in SCAD 16. The field is rapidly evolving, and future guidelines will be shaped by these studies.

Conclusion

Spontaneous Coronary Artery Dissection is a distinct and increasingly recognized cause of acute coronary syndrome, especially in young and middle-aged women without traditional risk factors. While research is ongoing, awareness, prompt recognition, and tailored management are crucial for optimal outcomes.

Key Takeaways:

• Symptoms are diverse but most often mimic classic heart attacks, with sudden chest pain, palpitations, and occasionally life-threatening events like cardiac arrest 1 2 3 5 10.
• Types of SCAD are defined by angiographic and imaging features, with Type 2 (diffuse narrowing) being the most common and often requiring advanced imaging for diagnosis 1 7 8 9.
• Causes are multifactorial, including female sex, hormonal changes, fibromuscular dysplasia, genetic predisposition, and stress triggers, though many cases remain idiopathic 5 6 9 10 12.
• Treatment is primarily conservative, with medical therapy and observation favored in stable patients. Invasive procedures are reserved for select high-risk cases due to increased complication rates 5 7 10 13 14 16 17.
• Ongoing follow-up and psychosocial support are vital for long-term well-being and monitoring of recurrence 5 9 10 15.

As research continues, the landscape of SCAD diagnosis and management will evolve, but the current evidence underscores the importance of a personalized, cautious approach.