Coronary Artery Dissection

Coronary artery dissection is a tear in the wall of a heart artery that can happen suddenly and without warning, most often affecting younger women who may have no traditional risk factors for heart disease.

Table of contents

• What is Spontaneous Coronary Artery Dissection?
• Who is Affected?
• Causes and Risk Factors
• Symptoms and Warning Signs
• Diagnosis
• Treatment Options
• Living with Coronary Artery Dissection
• Related Conditions

What is Spontaneous Coronary Artery Dissection?

spontaneous coronary artery dissection, SCAD

Spontaneous coronary artery dissection (SCAD) is an emergency condition that occurs when a tear forms in the wall of a heart artery^[1]. The heart receives its own supply of blood from blood vessels called the coronary arteries. Each coronary artery has a wall made up of three thin layers of tissue. When a tear or separation develops inside this artery wall, blood can pool between the layers^[6].

This trapped blood can lead to the formation of a blood clot, which may partially or completely block blood flow to the heart^[6]. The buildup of blood between the layers causes the artery to bulge inward, which blocks or slows blood flow to your heart^[3]. The condition is called “spontaneous” because it happens without warning and is not caused by trauma, medical procedures, or the rupture of fatty buildup that typically causes heart attacks in older adults^[4].

SCAD can slow or block blood flow to the heart, causing a heart attack, heart rhythm problems, or in severe cases, sudden death^[1]. The main mechanism differs from typical heart attacks, which are usually caused by fatty deposits called plaque that rupture inside an artery. In SCAD, patients often have fragile arterial walls with no fatty deposits or calcium buildup, which means the dissection can spread more extensively^[9].

Who is Affected?

SCAD most commonly affects women in their 40s and 50s, though it can occur at any age and can also occur in men^[1]. Medical experts consider SCAD to be an underdiagnosed condition. It may account for up to 4% of all cases of acute coronary syndrome (a sudden reduction of blood flow to the heart) and affects 1 in 4 women who are younger than 50^[3].

The condition is an important cause of heart attacks in young women, responsible for up to 25% of all cases in women under 50 years of age^[9]. Around 10% of patients affected by SCAD are male^[7]. People who have SCAD often don’t have risk factors for heart disease, such as high blood pressure, high cholesterol, or diabetes^[1].

Causes and Risk Factors

Experts aren’t sure exactly why SCAD occurs. Many people who develop this artery tear are younger and physically active, and they don’t have a known history of heart disease^[3]. The true cause of SCAD may be multifactorial, involving a combination of factors including gender, hormone secretion, genetic predisposition, environmental and emotional triggers, or underlying blood vessel problems^[17].

The trigger is thought to be either a tear in the inner lining of the artery or bleeding from small blood vessels within the artery wall, resulting in a blood-filled bruise called an intramural hematoma. The buildup of this bruise causes the dissection to spread^[9].

SCAD is more likely to occur in people who have recently given birth. It is also more common around the time of menstruation or during the years after menopause. These risk factors suggest that fluctuations in female hormones may play a role^[3]. Around 10% of patients have their SCAD around the time of pregnancy, with some studies reporting that SCAD causes 21 to 27% of heart attacks during pregnancy and 50% of heart attacks that occur after giving birth^[7].

In men, arterial tears most often occur after strength training or lifting a heavy object. The physical exertion may cause the tear^[3]. In rare instances, the force of severe vomiting or coughing may cause the artery wall to tear^[3].

People with certain conditions may be more prone to coronary artery dissection. These conditions include:

• Fibromuscular dysplasia (FMD), an abnormality found within arteries^[3]
• Connective tissue diseases like Marfan syndrome^[3]
• Dangerously high blood pressure^[3]
• Hypothyroidism, or an underactive thyroid gland^[3]
• Inflammatory diseases like lupus, multiple sclerosis, and sarcoidosis^[3]
• Substance use disorder^[3]
• Extreme physical exertion or extreme emotional stress^[6]

Symptoms and Warning Signs

Lack of blood flow from SCAD can cause a heart attack or a type of chest pain called unstable angina, a dangerous form of chest pain that increases your risk of heart attack^[3]. SCAD is a medical emergency. You should call emergency services (911 in the United States) if you experience heart attack symptoms, even if you think you aren’t at risk of a heart attack^[1].

Symptoms of SCAD can include:

• Chest pain or pressure^[1]
• Pain in the arms, shoulders, back, or jaw^[1]
• Shortness of breath^[1]
• Unusual sweating or a cold sweat^[1]
• Extreme tiredness^[1]
• Upset stomach or nausea^[1]
• A rapid heartbeat or fluttery feeling in the chest^[1]
• Feeling dizzy or fainting^[1]

Anyone experiencing an acute onset of these symptoms should call emergency services immediately, as they could indicate the early stages of spontaneous coronary artery dissection, a heart attack, or another serious heart-related condition^[6].

Diagnosis

SCAD is usually diagnosed in an emergency setting. You may be asked questions about your personal and family medical history, and tests will be done to check your heart^[10]. Diagnosing SCAD requires a high level of suspicion for young patients presenting with signs of a heart attack^[16].

Tests to diagnose SCAD are similar to tests used to detect a heart attack and may include:

Blood tests. Certain heart proteins slowly leak into the blood after heart damage from a heart attack. Blood tests can check for these proteins, and other blood tests may also be done^[10].

Electrocardiogram (ECG or EKG). This quick test checks the heart’s electrical activity and can show how fast or slowly the heart is beating. Changes in the pattern can suggest a heart problem^[10].

Cardiac catheterization and coronary angiogram. This is the main test used to confirm SCAD. A thin, flexible tube called a catheter is inserted into a blood vessel, usually in the wrist or groin, and guided to the heart. A special dye is then injected through the catheter, and X-rays are taken to show blood flow through the coronary arteries^[10]. This test can reveal the characteristic appearance of a tear or dissection in the artery wall.

Intravascular imaging. If the coronary angiogram results are not clear, additional imaging using special instruments inside the blood vessels may be performed to get a closer look at the artery wall^[10].

Echocardiogram. This test uses sound waves to create moving pictures of your heart. It can show how well your heart is pumping and whether there are any areas of damaged heart muscle^[3].

It is important to recognize SCAD because patient characteristics and management differ substantially from typical heart attack cases caused by fatty plaque buildup^[9].

Treatment Options

The treatment approach for SCAD is different from treatment for typical heart attacks caused by blocked arteries from fatty buildup. SCAD is primarily managed with medication in clinically stable patients^[16]. Conservative medical management for stable patients with resolved symptoms is typical, as many dissections heal on their own over time^[13].

Conservative treatment is preferred for most stable patients without ongoing chest pain. However, patients with ongoing chest pain, evidence of continued lack of blood flow to the heart, elevation of the ST segment on their electrocardiogram, or unstable vital signs may need procedures to restore blood flow^[13]. Procedures to open or bypass the blocked artery may be necessary for a small percentage of patients^[13].

Emergency surgery should be considered for patients where the dissection involves the left main coronary artery, which supplies blood to a large portion of the heart^[13]. Attempts to treat dissected coronary arteries with stents or surgery can be very challenging and can sometimes result in poor outcomes^[13].

Medications commonly used in SCAD management include:

Antiplatelet therapy. In SCAD patients, antiplatelet therapy should be prescribed, especially dual antiplatelet therapy consisting of aspirin and clopidogrel. More potent blood thinners like ticagrelor and prasugrel should generally be avoided due to greater bleeding risk and potential to extend the dissection^[14].

Beta-blockers. These medications reduce stress on the artery wall by slowing the heart rate and lowering blood pressure. They are routinely given for SCAD, both during the emergency and for long-term management^[13].

Blood pressure medications. Medications that help control blood pressure may be given, especially when there is significant heart muscle damage after the heart attack^[13].

Important medications to avoid include:

• Thrombolytic therapy (clot-busting drugs) should be avoided for patients with SCAD, as these medications could favor spread of the blood-filled bruise in the artery wall^[14]
• Anticoagulants (blood thinners) are controversial and are typically discontinued once SCAD is detected to avoid extension of the bruise in the artery wall^[13]

Living with Coronary Artery Dissection

Most people make a very good recovery from SCAD. However, it’s important to understand that recovery is both a physical and emotional journey, and it’s going to take time^[18]. Anyone who has a major health event is likely to go through doubts and a range of emotions, and these are an important part of how you adapt and change to your circumstances^[18].

High rates of anxiety, depression, and post-traumatic stress disorder have been reported among SCAD patients. Seeking support from a mental health professional to help manage these symptoms is recommended^[20].

Physical activity. Regular moderate-intensity exercise likely outweighs the theoretical risk of another SCAD. However, strenuous exercise and straining associated with heavy lifting can result in a sudden increase in blood pressure and stress on blood vessels. It is recommended that patients avoid lifting or carrying heavy objects that require prolonged straining, extreme endurance training, and elite competitive sports^[20].

Physical activity recommendations should be individualized and take into consideration the patient’s baseline physical activity and fitness level^[20]. Light to moderate aerobic exercise for around 150 minutes per week is generally recommended^[19].

Patients should avoid yoga and Pilates moves that involve aggressive neck posturing or stretching, and should avoid all activities involving rapid acceleration and deceleration like bungee jumping, skydiving, or riding roller coasters^[19].

Cardiac rehabilitation. Participating in a supervised cardiac rehabilitation program can help with recovery and provide guidance on safe exercise^[16].

Lifestyle modifications. Quitting smoking is recommended to protect your heart and blood vessel system. There is no known association between diet and SCAD, but it is recommended that patients avoid excess caffeine and caffeinated energy drinks^[20]. Maintaining a healthy body weight, controlling cholesterol, managing blood glucose if diabetic, and getting seven to nine hours of sleep per night are all recommended^[19].

Screening for related conditions. Long-term management includes screening for fibromuscular dysplasia and other blood vessel abnormalities, as these conditions are often found together with SCAD^[16].

Follow-up imaging. Many patients receive follow-up coronary angiography or other imaging tests after about one year to check for healing of the dissection^[17].

Risk of recurrence. Recurrent SCAD events are possible, and patients must be followed closely. Anyone experiencing symptoms should seek immediate medical attention^[13].

Related Conditions

• Coronary arteries
• Heart

Several conditions are associated with an increased risk of SCAD:

Fibromuscular dysplasia (FMD) is an abnormality found within arteries, veins, or capillaries. This condition is commonly found in people who have had SCAD^[6].

Connective tissue disorders including Marfan syndrome, Ehlers-Danlos syndromes, and Loeys-Dietz syndrome affect the body’s connective tissues and can make blood vessel walls more fragile^[3].

Autoimmune diseases are conditions in which your immune system mistakenly attacks your body. Examples include lupus, rheumatoid arthritis, and scleroderma^[6].

SCAD can lead to complications including acute coronary syndrome, angina (chest pain), heart attack, heart failure, life-threatening heart rhythm problems, and in severe cases, sudden cardiac death^[3].