What is Spontaneous Coronary Artery Dissection (SCAD)?
Spontaneous coronary artery dissection (SCAD) is a rare but serious condition that results when an inner layer of one of the blood vessels in the heart tears. Blood seeps between the artery layers, forms a blockage and can slow or block blood flow to the heart, causing angina, heart attack, abnormalities in heart rhythm or sudden death.
Women in their 40s and 50s are most at risk of SCAD, although it can occur at any age and also in men. The majority of people who develop SCAD are often healthy with no known risk factors of heart disease such as high blood pressure, diabetes or high blood cholesterol.
In the video below, SCAD is explained by Cardiologist, Professor Bob Graham.
What are the symptoms of SCAD?
Signs and symptoms of spontaneous coronary artery dissection (SCAD) may vary from mild discomfort in the chest to common heart attack warning signs. If you experience any of the below, it is best to seek medical advice immediately:
- A rapid heartbeat or fluttery feeling in your chest
- Chest pain
- Dizziness
- Nausea
- Pain in your arms, shoulders or jaw
- Shortness of breath
- Sweating
- Unusual or extreme tiredness
What are the causes of SCAD?
Spontaneous coronary artery dissection (SCAD) is a very rare condition and not enough medical research has been done into the disease, so the causes are largely unknown. However, it is likely a combination of factors and causes that can trigger SCAD. These include:
- Blood vessel changes
- Sex hormone changes
- Blood volume changes
- Changes in women related to pregnancy or menopause
- For men and women, extreme exertion and extreme stress appear to play a role
- Having fibromuscular dysplasia (FMD) – which is a closely related blood vessel disorder. About half of SCAD sufferers also have FMD
How is SCAD diagnosed?
To diagnose spontaneous coronary artery dissection (SCAD), your doctor may order the following tests after reviewing your symptoms:
- Coronary angiogram
- Intravascular ultrasound
- Optical coherence tomography
- CT scans
A major challenge in diagnosing SCAD is getting health care practitioners to see beyond the young, seemingly healthy individual, as they are not stereotypical patients at risk of a heart attack.
How is SCAD treated?
The goal of treatment for spontaneous coronary artery dissection (SCAD) is to restore blood flow to the heart. Treatment plans will depend on the severity of your condition including the size and location of the tear. Treatments may include:
- Inserting a stent to hold the artery open
- Surgery to bypass the damaged artery
- Medications such as aspirin, blood-thinning drugs, blood pressure drugs or medications to control chest pain, cholesterol drugs, beta blockers
- Checking and monitoring weaknesses in other blood vessels
- Cardiac rehabilitation programs
Ideally, cardiac rehabilitation for a SCAD should be started a few weeks after leaving hospital. Don't worry if you or the patient has been out of hospital for longer than this, one should still go to cardiac rehab to get benefits. When deciding on a start date, the cardiac rehab staff will consider your heart condition and medical history. Fortunately, SCADs all heal within 30-35 days, but light rehab can be started before this. Be sure to inform the rehab staff that you've had a SCAD heart attack and not a traditional one, as the rehab program needs to be modified accordingly.
How do you prevent SCAD?
Because there has been very little research into spontaneous coronary artery dissection (SCAD) and the causes are still unknown, there is no scientifically proven way to prevent SCAD from occurring.
It is best to keep your heart healthy and follow advice regarding general heart disease prevention, such as:
- Regular exercise, starting with daily walking
- Eat a healthy diet
- Not smoking
- Moderate alcohol consumption
- Manage stress levels
- Control blood pressure, blood cholesterol and sugar levels
How prevalent is SCAD in the population?
SCAD is responsible for approximately 25% of heart attacks in women under the age of 50. It is the most common cause of heart attack associated with pregnancy.
What research is being done into SCAD?
The Victor Chang Cardiac Research Institute is leading Australia's first research program into Spontaneous Coronary Artery Dissection (SCAD).
Previously SCAD was thought to be a rare disease, but recently it has been found to be the cause of 2-4% of all cases presenting with acute coronary syndrome (ACS) such as a heart attack.
Research suggests it also accounts for up to 24% of cases of heart attack in women under the age of 50.
Genetic research
The Victor Chang Cardiac Research Institute has assembled the largest SCAD cohort in Australia, which currently includes more than 500 angiographically-verified SCAD patients, to investigate the genetic underpinnings and pathophysiology of SCAD, and many other aspects of this disease.
PHACTR1 gene
The Institute helped identify the first ever gene to be linked to SCAD – PHACTR1. This gene has been identified as having one of the strongest genetic associations with SCAD.
The Institute’s Executive Director, Professor Jason Kovacic, was involved in discovering that the PHACTR1 gene is also linked to the related condition fibromuscular dysplasia.
Studies have shown that increased levels of PHACTR1 are linked to SCAD. It is hoped that by better understanding the function of the PHACTR1 gene, researchers at the Institute may be able to uncover how to control the gene to treat and potentially prevent diseases such as SCAD.
SCAD and connective tissue disorders
The Institute has also been involved in research that has identified genetic links between SCAD and connective tissue disorders (such as Ehlers Danlos syndrome).
Further genes involved in SCAD
Through international research collaborations, the Institute has identified at least 16 different genes involved in SCAD.
Psychosocial research
Together with Dr Barbara Murphy and Prof Alun Jackson from the Australian Centre for Heart Health, we are investigating the psychosocial consequences of SCAD.
Our collective research has shown that anxiety, stress, and depression are more common in women after a SCAD heart attack than a traditional heart attack.
In particular, research has highlighted lack of information on SCAD as a contributor to emotional distress among patients diagnosed with SCAD.
Other research
ANZ-SCAD Registry
Together with A/Prof Sarah Zaman, Westmead Applied Research Centre, the Institute is also involved in developing the ANZ-SCAD registry, which includes patients with SCAD from across 15-30 sites in Australia and New Zealand.
This registry allows researchers to better understand clinical presentation, management and outcomes – including acute deterioration and recurrence – for patients with SCAD.
iSCAD Registry
The Victor Chang Cardiac Research Institute’s SCAD scientists have become the first research team outside of the USA to join the iSCAD Registry – the International SCAD registry. This registry is a global collaboration of researchers and patients investigating the features and pathophysiology of SCAD.
Stem cells
A human-induced pluripotent stem cell (hiPSC) bank has been generated from patients who have survived an episode of SCAD, as well as age and gender-matched healthy controls.
Since coronary artery samples cannot be obtained from SCAD survivors to study its pathology, these stem cell lines have been used to generate blood vessel cells as a model of SCAD to understand its pathophysiology at the cellular level.
Treatment
The Institute has submitted a grant application as the Australian contingent of the first international randomised, controlled trial of SCAD management (the APT-SCAD trial) involving over 2,500 SCAD survivors from 190 centres in 10 countries. This trial will test if moderate - as compared to intensive - blood thinning treatment improves outcomes and reduces major adverse cardiovascular events, including bleeding and recurrences, in SCAD patients.
If successful, the Institute will be the coordinator of the Australian arm of this study, which will involve 200 SCAD patients.
The result of this application will be announced by late 2023.
SCAD survivor stories
Read these amazing stories from SCAD heart patients from all around Australia.
How can I participate in the SCAD Research?
If you are an Australian SCAD survivor and would like to be involved in the Australian first research program at the Victor Chang Institute, please email scad@victorchang.edu.au
A Facebook group has been set up, especially for Australian SCAD survivors and is a great support network.
