Coronary Artery Dissection (SCAD)

What happens in SCAD

The coronary artery wall has three layers. In SCAD, either a tear in the inner lining or a bleed within the wall creates a pocket of blood (an intramural hematoma). This pushes inward and narrows or blocks the artery, reducing blood flow to part of the heart muscle and causing a heart attack.

SCAD differs from the usual cause of heart attacks, atherosclerosis, where cholesterol plaque builds up and ruptures. People with SCAD often have normal cholesterol, no diabetes and no smoking history.

Who gets SCAD

• About 90% of people with SCAD are women.
• Most are 30 to 60 years old.
• SCAD causes a substantial share of heart attacks in women under 50, and it is the most common cause of heart attack linked to pregnancy.

Associated factors and triggers

• Fibromuscular dysplasia (FMD): an abnormal growth of cells in artery walls, found in many SCAD patients, often in the kidney, neck or brain arteries
• Pregnancy and the postpartum period, especially the first weeks after birth
• Hormonal factors, including hormone therapy and fertility treatment
• Intense physical exertion, such as heavy weightlifting or extreme endurance exercise
• Extreme emotional stress
• Inherited connective tissue disorders: Ehlers-Danlos syndrome, Marfan syndrome, Loeys-Dietz syndrome
• Stimulant drugs, including cocaine and amphetamines
• Inflammatory conditions in some cases

Coronary artery dissection can also occur from chest trauma or as a complication of heart catheterization, or as an extension of an aortic dissection, but these are not spontaneous.

Symptoms

Symptoms are those of a heart attack:

• chest pain, pressure, tightness or heaviness
• pain in the arms, shoulders, back, neck or jaw
• shortness of breath
• sweating
• nausea or vomiting
• unusual tiredness
• dizziness or fainting
• a racing heart

Some people have cardiac arrest as the first sign. Because patients are often young women without risk factors, symptoms are sometimes dismissed as anxiety or indigestion. Chest pain in a young woman, especially around pregnancy, deserves an ECG and troponin test.

Diagnosis

• ECG and troponin blood test: show heart muscle damage.
• Coronary angiography: dye injected into the coronary arteries under X-ray. SCAD has characteristic appearances, such as a long, smooth narrowing.
• Intravascular imaging (OCT or IVUS) in uncertain cases, used with caution.
• Coronary CT angiography for follow-up in some patients.
• Screening for fibromuscular dysplasia with CT or MR angiography from head to pelvis, recommended after SCAD.
• Genetic testing when a connective tissue disorder is suspected.

Treatment

Most SCAD tears heal naturally over weeks to months, and procedures can make the dissection worse. So treatment is usually conservative:

• hospital monitoring for several days, because the dissection can extend
• beta blockers, which may reduce recurrence
• aspirin and sometimes a second antiplatelet medicine for a period
• medicines for heart function if the heart muscle was damaged
• blood pressure control
• stenting or bypass surgery only when blood flow is severely compromised, symptoms continue, or the patient is unstable

Statins are not routinely given unless there is another reason, such as high cholesterol.

Recovery and living after SCAD

• Cardiac rehabilitation is safe and strongly recommended. It rebuilds fitness and confidence.
• Exercise is encouraged, but avoid extreme exertion, very heavy lifting, straining with your breath held, and competitive or intense endurance sports. Ask your cardiologist for personal limits.
• Many patients experience anxiety, depression or post-traumatic stress. Counseling and peer support groups help.
• Avoid stimulant drugs and discuss hormone therapy with your doctor.
• Pregnancy after SCAD carries risk of recurrence and needs specialist advice before conception.

Outlook

Survival after SCAD is generally good. However, SCAD can recur, in roughly 1 in 10 people within several years and more over the long term. Controlling blood pressure, beta blockers and avoiding triggers may lower that risk. Long-term follow-up with a cardiologist familiar with SCAD is recommended.

Frequently asked questions

What is spontaneous coronary artery dissection?

SCAD is a tear or bleed in the wall of a coronary artery that happens without trauma. Blood collects within the artery wall and blocks blood flow to the heart, causing a heart attack. It mostly affects women aged 30 to 60, often without usual heart risk factors.

What causes SCAD?

The exact cause is unknown. It is linked to fibromuscular dysplasia, pregnancy and the postpartum period, hormonal factors, extreme physical or emotional stress, connective tissue disorders and stimulant drugs. Many people have more than one factor.

What are the symptoms of SCAD?

Symptoms are the same as a heart attack: chest pain or pressure, pain spreading to the arm, back or jaw, shortness of breath, sweating, nausea, dizziness and fatigue. Call 911 for these symptoms, even if you are young, healthy or recently pregnant.

How is SCAD treated?

Most cases are treated with medicines and monitoring, because the artery usually heals on its own within weeks to months. Beta blockers and antiplatelet medicines are common. Stents or bypass surgery are used only when blood flow is severely reduced or symptoms continue.

Can SCAD happen again?

Yes. SCAD recurs in a minority of people, roughly 1 in 10 over several years. Blood pressure control, beta blockers, avoiding extreme exertion and stimulants, and careful planning around pregnancy may reduce the risk. Regular cardiology follow-up is important.