What is SCAD?

These are some common questions about SCAD. To see the answer, click on the question.

What is SCAD?

Spontaneous Coronary Artery Dissection (SCAD) is a relatively rare and poorly understood acute coronary event which typically affects a younger, otherwise healthy population. Based on available medical literature:

  • The average age of a SCAD patient is about 42 years but it can occur in people as young as their early 20’s.
  • SCAD is more than twice as common in women as in men.
  • Approximately 70% of SCAD cases occur in women under age 50 years with as many as one-third of those cases occurring in the post-partum period.

SCAD occurs when a split or separation suddenly develops between the layers of the wall of one of the blood vessels (artery) that provides blood flow to the heart. The space between the layers of the artery wall may fill with blood, causing a hematoma, which may reduce or block blood flow through the artery; or a flap of loose tissue from the dissection may create a blockage.

If not diagnosed and treated quickly, SCAD may lead to a heart attack, sudden cardiac arrest/sudden cardiac death (SCD) or other complications such as life-threatening arrhythmias.
This video, from MAYO CLINIC, MEDICAL edge, shows an animation of a dissection.

What is the history of SCAD?

SCAD was first described by H.C. Pretty in 1931 when his case study titled “Dissecting aneurysm of a coronary artery in a woman aged 42” was published in The British Medical Journal. His findings were the result of a post mortem examination performed on a woman he attended the previous day for severe stomach vomiting. In her right coronary artery, Pretty found “marked atheroma, with dissecting aneurysm, which had evidently ruptured during the last sudden and violent retching attack.”

Some classify SCAD as an “orphan” condition, and as such, it has received less attention and has been less well studied than other types of heart attack. What we know about SCAD is based largely on autopsy reports, individual case reports of survivors, and reports published in medical journals of series of patients who were treated at individual medical centers. These reports all have small numbers and as a result, it has not been feasible to get an accurate assessment of how common SCAD is (disease prevalence), the causes, prognosis, recurrence rate or the optimal management.

More recently, greater awareness of SCAD and increased frequency of diagnosis suggest that this rare condition may be more prevalent than previously believed. The medical community has much to learn about treatment and prevention of this potentially fatal cardiovascular event.
For more in-depth information, take a look at our Notes from the Research Team.

What causes SCAD?

The exact cause of Spontaneous Coronary Artery Dissection (SCAD) is unknown, but it is probably a combination of factors.

SCAD may result from blood vessel changes, sex hormone changes, blood volume changes, and other changes in women related to pregnancy or menopause. In both men and women, extreme exertion appears to play a role.

With these differences between men and the majority of women who experience SCAD related to hormonal changes, it is possible that the disease processes and prognosis for SCAD are gender specific as well.

What are the risk factors for SCAD?

Spontaneous Coronary Artery Dissection (SCAD) usually occurs in people who do not have traditional cardiovascular risk factors for build-up of plaques in the arteries (atherosclerosis) such as high cholesterol, high blood pressure and diabetes. Researchers have identified several diseases and conditions as being associated with SCAD, but the vast majority of cases occur in people with no known risk factors or underlying condition and are called “idiopathic.”

The suspected associated conditions or potential triggers for SCAD include:

  • Pregnancy – hormonal and hemodynamic changes are suspected of playing a role
  • Hormonal therapy – related to IVF treatments and menopause
  • Connective tissue disorders – such as Ehlers-Danlos Type IV (Vascular Type) and Marfan Syndrome are thought to affect artery walls resulting in greater susceptibility to dissection
  • Fibromuscular dysplasia (FMD) – a condition which causes arteries to narrow
  • Extreme physical activity
  • Cocaine abuse – artery spasms are thought to cause dissection

Can the risk of SCAD be reduced?

Because the causes of SCAD are unknown at this point, there is no scientifically validated way to reduce the risk of SCAD occurring. To help keep your heart healthy, follow advice regarding coronary artery disease prevention in general. In other words, exercise regularly, eat a healthful diet, eliminate risk factors such as smoking and excessive alcohol, and control your blood pressure and stress level. As with all heart health, “know your numbers” and discuss the best options for you with your health care professional.

What are the symptoms of SCAD?

Symptoms vary widely in SCAD cases, with some reporting mild discomfort to others experiencing “classic heart attack symptoms.” If you’re experiencing symptoms including chest pain, shortness of breath or other signs of a heart attack, you need emergency diagnosis and treatment.

The spectrum of clinical presentation can range from chest pain symptoms alone to heart attack (e.g. ST-elevation myocardial infarction, “STEMI”, the type that warrants urgent treatment), ventricular fibrillation and sudden death. A single coronary artery could be involved or multiple.

SCAD is known to occur both during exercise and at rest.

How is SCAD diagnosed?

Spontaneous Coronary Artery Dissection (SCAD) is principally diagnosed with invasive coronary angiography. You may hear this called an angiogram, or some call it a heart cath. However, SCAD might not be visible on an angiogram because, although the test will clearly identify a narrowing or blockage in the artery, it does not allow physicians to see the actual vessel walls or their structure. Additional imaging modalities such as intravascular ultrasound (IVUS), optical coherence tomography (OCT) and CT angiography (non-invasive) may also be ordered by your doctor.

One of the biggest challenges in diagnosing SCAD is getting health care professionals to see past the young, seemingly healthy individual before them and take steps to determine the correct diagnosis. Even the patients themselves and family members may not suspect a young, healthy person could be experiencing a cardiac event such as a heart attack. Yet in the case of SCAD, it is urgent to get the patient to cardiac catheterization lab to undergo an angiography as soon as possible. “Time is muscle,” when it comes to heart attack.

Sadly, like many with heart disease, some SCAD patients have initially been sent away from the ER with a diagnosis of a panic attack or a gastric problem only to return with more severe symptoms – this delay can be fatal.

Read more about tests and diagnostic procedures here.

How is SCAD treated?

The best treatment strategy for acute SCAD remains undetermined and may vary according to type and severity. At this point in time, each case has had to be treated based on the treating medical team’s “best medical judgment,” rather than experience or clinical trial results. Some patients have favorable outcomes with conservative management using monitoring and medications only, while others undergo Percutaneous Coronary Intervention (PCI), otherwise known as stents, or open heart Coronary Artery Bypass Graft (CABG) surgery.
Early treatment can prevent or limit damage to the heart muscle. Acting fast, at the first symptoms of heart attack, can save your life. Time is muscle!

Drugs such as antiplatelets (aspirin and clopidogrel), anticoagulants (heparin, coumadin), nitrates (nitroglycerine), beta blockers (bisoprolol, metoprolol) and ACE inhibitors (ramipril, lisinopril) will most likely be administered and some may be prescribed for life. The decision to thrombolyse (dissolve blood clots) may enable flow to be re-established; however, there is also the risk that thrombolysis may aggravate bleeding and the dissection.

Following hospital discharge, enrolling in a cardiac rehabilitation program is a very important step in the recovery process – both physically and emotionally. Cardiac rehab nurses are well equipped to advise regarding diet and exercise and the sessions help to rebuild confidence after what can be an extremely frightening experience.

A good diet, plenty of rest, stress reduction, realizing your limitations, help and support from loved ones, listening to your body, and a carefully controlled exercise program are all key factors for healing and recovery. Seek advice from your health care professional to develop a comprehensive plan.

Will I die from SCAD?

Spontaneous Coronary Artery Dissection (SCAD) is an emergency which requires urgent treatment and is sometimes fatal.

The overall prognosis is unknown but the medical literature indicates that prognosis is typically good for those who survive the initial event. Recent case review and research reports the outcome of SCAD to be more favorable, with one review suggesting a survival rate of 82%. (The earliest reported literature on SCAD stated a mortality rate of 70%. Unfortunately, this statistic is the one found most often when a patient does an initial Google search of SCAD!)

How long will it take for my SCAD to heal? How will I know when it has healed?

The time for a dissected artery, or arteries, to heal will vary from person to person. Some case studies in the medical literature report spontaneous healing within the first few days, often noted on a follow-up angiography. There is growing belief, however, that SCAD patients should only undergo repeat angiography in emergency circumstances due to the risk of worsening the dissection, disrupting the healing process, or causing a new dissection during the procedure.

It is not uncommon for a SCAD patient to experience ongoing chest pain or other symptoms. Sometimes this may be related to the surgical treatment (stenting or bypass grafting). Some SCAD patients develop scar tissue in the artery related to stents. For those being treated with medication and monitoring, it may be helpful for their cardiologist to adjust their dosages. Other patients are left with varying degrees of heart failure as a result of damaged heart muscle.

Be sure to talk to your health care professional if you are worried about any ongoing symptoms.

How can I cope with my SCAD diagnosis?

First, take comfort that you are not alone. Breathe! A common saying of heart disease patients is finding their “new normal” which means you have to re-learn what is now normal for your body to feel. Many SCAD patients describe feeling frightened by every sensation, questioning whether another SCAD is about to happen. They experience a loss of confidence in their body, which takes time to return. Some of the medications, and combinations of medications that SCAD patients are prescribed can have side effects, and it may be hard to know whether a symptom is caused by medications, the original dissection, the resulting cardiac event, or from the treatments of stents or surgery. Not all medications are right for every patient, and you may have to work with your doctor to get the right combination and dosages that work best for you.

The following methods may help you to find and adjust to your “new normal”:

  • Find a doctor you like. You may not find a local doctor experienced in caring for SCAD patients but it is important to find a doctor who will do more than tell you how “rare” or “unique” you are!
  • Participate in research. The Mayo Clinic studies are open to patients globally. Take a look at the Research section for more information.
  • Exercise. Talk to your doctor and cardiac rehabilitation nurses about an appropriate exercise plan.
  • Engage in enjoyable activities. Life doesn’t have to stop after a SCAD event but the adjustments vary from person to person. Listen to your body.
  • Reduce stress. Stress is not a direct risk factor for cardiovascular disease but it may contribute to your risk level. Many SCAD patients describe experiencing extreme stress prior to their SCAD events.
  • Connect with others. Don’t let yourself become isolated; pick up the phone, send an email, write a letter, join a group! Above all, don’t wait for family and friends to call first. To find an online or in-person support community, see the Support & Additional Info section.
  • Seek counseling to supplement medical treatment. The emotional toll of a heart attack can be so severe that an estimated 1 in 8 patients who survive the experience develop post-traumatic stress disorder (PTSD), a condition that doubles the risk of experiencing additional severe heart disease.
  • Learn all you can about SCAD and the medications you take. Knowledge is power, and continuous learning keeps you empowered, informed and in control. Keep checking the Voices of SCAD and In the News sections for the latest.
  • Ask your doctors any questions you may have and be your own advocate!

Will SCAD happen again?

Spontaneous Coronary Artery Dissection (SCAD) can recur; up to 17% of patients experience two or more events. However, there is limited data on recurrence rate and the time between SCAD events varies greatly in the known case studies from a few days to years apart.

Are my family members at risk of SCAD too?

It is well documented that if coronary disease runs in your immediate family (parents and/or siblings), you need to take more care managing your risk factors. Spontaneous Coronary Artery Dissection (SCAD) is a form of heart disease but it is not known whether there is a genetic link in the same way as traditional heart disease. A hereditary factor has been discussed in some cases in the medical literature but there has been no research – yet. The development of a DNA bio bank for SCAD patients and close relatives by the Mayo Clinic is the first step toward identifying potential genetic factors.