What Is Spontaneous Coronary Artery Dissection

Introduction

What is spontaneous coronary artery dissection? Our hearts rely on a network of blood vessels called coronary arteries to supply them with the essential oxygen and nutrients they need. However, these arteries can sometimes experience a rare and often unexpected condition known as Spontaneous Coronary Artery Dissection (SCAD). Although it is a rare condition, it can be incredibly serious and sometimes fatal if left untreated, so it is vital that we understand more about it and how it presents in order to have the best possible chance of recognising it.  

Definition of SCAD

SCAD is a rare heart condition where a tear occurs within one or more of the arteries supplying the heart, the coronary arteries.  

The coronary arteries are vessels that deliver oxygen-rich blood and nutrients to the heart muscle. There are two main arteries: the left coronary artery (LCA) and the right coronary artery (RCA). These branch off and, in turn, supply different areas of the heart. 

With SCAD, a sudden tear forms in the innermost layer of a coronary artery, creating a false path where blood can flow. The blood builds up and eventually causes an obstruction within the artery. This blockage can slow down or even stop the normal flow of blood in the artery, which can lead to chest pain, heart attacks, or, in severe cases, sudden cardiac death.¹ 

SCAD most commonly affects women in their 40s and 50s, although it is still possible to develop this condition in people of any age or gender. 

Risk factors and prevalence 

The exact cause of SCAD is not known. However, the tear in the wall is thought to be due to weakening of the artery wall itself. There are several factors thought to increase the risk of this weakening:²  

• Fibromuscular Dysplasia: An abnormal growth or development of the muscle cells in the arterial walls. 
• Genetic Predisposition: Inherited traits may play a role in making individuals susceptible to SCAD. Specific genes or genetic variations may play a role in the weakening of the arterial walls.
• Connective Tissue Disorders: Ehlers-Danlos and Marfan syndromes are most commonly associated with SCAD, as they can affect the structural integrity of the arteries, making them more prone to dissection.
• Illegal Drug Use: Substance abuse, particularly the use of cocaine, can be a contributing factor in damaging the arterial walls. Cocaine use can lead to severe vasoconstriction (narrowing of blood vessels), increased blood pressure, and inflammation, all of which can weaken the arteries and predispose them to SCAD.
• Uncontrollable high blood pressure: Uncontrolled high blood pressure, or hypertension, places chronic strain on the arterial walls. Over time, this increased pressure can lead to arterial weakening, making individuals more susceptible to SCAD.
• Recent childbirth: There are cases of SCAD in women who have recently given birth, thought to be due to the hormonal changes and stress on the arteries themselves 
• Extreme Stress: Extreme stress, whether stemming from physical exertion or overwhelming emotional distress, can be a triggering factor for SCAD. Stress can lead to changes in blood pressure and heart rate, increasing the strain on the arterial walls and potentially precipitating a dissection.

SCAD can affect people of any age, gender, or background, but it is more common in women, especially those who are young or in the postpartum period. Hormonal changes, like those occurring during pregnancy, may contribute to the vulnerability of the arterial walls. Overall, SCAD is rare, but its occurrence is likely under-reported.

Signs, symptoms, and diagnosis

Presentation of SCAD

SCAD presents with a range of symptoms which are similar to those of a heart attack. 

People with SCAD may experience: 

• Severe chest pain is often described as crushing or squeezing, radiating into the arms, neck, jaw, or back.  
• Shortness of breath 
• Excessive sweating 
• Nausea 
• Extreme fatigue.

It is important to note that SCAD symptoms can vary depending on the person, with some people experiencing less common or milder signs, making it a challenging condition to identify solely based on symptoms. 

Diagnosis

Doctors will conduct various tests to diagnose SCAD and distinguish it from other heart-related conditions.  

The first tests bedside tests are: 

• Electrocardiogram (ECG) - a way to monitor the heart’s electrical activity 
• Echocardiogram - an ultrasound bedside scan of the heart 
• Troponins – a cardiac enzyme which is raised when the heart muscle is damaged, which can be tested through a blood test 

One important diagnostic tool is coronary angiography, where a special dye is injected into the coronary arteries, allowing physicians to visualise any tears in the arteries on imaging.³ 

Other more specialist imaging techniques like intravascular ultrasound (IVUS) or optical coherence tomography (OCT) may be used to provide more detailed views of the affected arteries. 

Early diagnosis of SCAD is essential to initiate prompt and appropriate treatment. Recognising SCAD early ensures that healthcare providers can take necessary measures to restore proper blood flow to the heart muscle, alleviate symptoms, and minimise the risk of further complications. Delayed or missed diagnosis can lead to more severe consequences and may affect the overall prognosis. Therefore, if someone experiences symptoms suggestive of a heart issue, seeking immediate medical attention is of utmost importance.

Complications and prognosis

When a dissection occurs, it obstructs the flow of blood to the heart muscle, which can result in heart attacks (myocardial infarctions).⁴ Additionally, SCAD can lead to abnormal heart rhythms (arrhythmias), heart failure, or even cardiac arrest.

Patients with SCAD may also be at risk of developing long-term issues, such as recurrent SCAD, atherosclerosis (hardening of the arteries), and post-traumatic stress disorder due to the traumatic experience of the initial event.

The short-term and long-term prognosis for individuals with SCAD can vary widely. In the immediate aftermath of a SCAD event, some people may recover fully with proper medical intervention. However, others may face a more challenging road to recovery, and s in the long term, the risk of future cardiac events remains a concern for some SCAD patients. 

However, with prompt medical management and lifestyle adjustments, many individuals can still lead fulfilling lives and reduce the risk of further complications.

Treatments

Medical management

Medications, such as antiplatelet drugs and beta-blockers, are often prescribed to manage blood clot formation and lower blood pressure. Medical procedures like angioplasty may be performed for more severe cases to widen the affected artery, and stent placement may be considered to keep the artery open.⁵ Treatment choice depends on the SCAD's location and severity and the patient's baseline health.

What works for each person is different. Factors like the location of the dissection, the extent of damage, and the presence of underlying health conditions influence treatment decisions. 

Lifestyle

Beyond medical interventions, lifestyle changes are fundamental in managing SCAD. These changes include adopting a heart-healthy diet, exercising regularly, stopping smoking, and finding ways to lower stress. Furthermore, patients require ongoing monitoring to track their heart health, assess the effectiveness of treatment, and detect potential complications or recurrences early. Combining medical treatment with proactive lifestyle adjustments, as well as further services such as cardiac rehabilitation service to help with support and physical therapy, will help you manage your health as best as possible post-SCAD.

Recent advances and research

Studies have explored potential causes, risk factors, and optimal treatment approaches.⁶ Furthermore, advances in imaging techniques have enhanced our understanding of the condition, enabling better diagnosis and targeted interventions.⁷ These studies aim to refine treatment protocols, discover underlying genetic factors, and develop improved diagnostic methods. With each discovery, we move closer to enhancing the management and outcomes for individuals with SCAD.

Summary

Spontaneous Coronary Artery Dissection is a rare but serious condition that affects the heart's blood vessels. By understanding its causes, symptoms, and available treatments, we can better support those affected. Encouraging ongoing research and promoting awareness about SCAD is vital for improving outcomes and enhancing the quality of life for individuals with this condition. If you suspect any heart-related symptoms, seeking medical attention promptly can significantly improve your health and well-being.