Critical SCAD genes identified

Critical genes identified behind the biggest cause of heart attacks for women aged under 50

30 May 2022

Scientists at the Victor Chang Cardiac Research Institute have significantly advanced the understanding of what causes Spontaneous Coronary Artery Dissection or SCAD.

SCAD is an increasingly recognised cause of heart attack that primarily affects younger women who are often fit and healthy. 

Until recently, little was known about what causes SCAD, but new research published in Nature Genetics has revealed there are at least 16 different genes associated with the disease, with one gene called PHACTR1 thought to be a key driver.

The Institute was part of a global collaboration that examined data from nearly 2000 SCAD patients.

They discovered the genes involved in causing SCAD are mainly implicated in forming the matrix or scaffolding around the cells forming coronary arteries, as well as a gene involved in blood clotting. A deficiency in this clotting factor is thought to increase the likelihood of a spontaneous bleed into the artery wall, which reduces blood flow as it expands and leads to a SCAD heart attack. 

“We have performed the largest study to date aimed at understanding the genetic basis of SCAD, discovering multiple genetic regions that confer susceptibility to SCAD. People who develop SCAD have subtle genetic changes that affect their blood vessels, putting them at a greater risk of a catastrophic tear or a spontaneous bleed involving the wall of the heart arteries.

"We now have a much clearer picture of the genetic risk of SCAD and how it is related to other cardiovascular diseases. Understanding these mechanisms should lead to new approaches to its management and treatment," said the Institute’s Associate Professor Eleni Giannoulatou who, together with the Institute’s Professors Robert Graham and Jason Kovacic led the Australian arm of the study.

The researchers also discovered that high blood pressure is likely to be causal for SCAD.

Professor Graham added: “Keeping your blood pressure under control is good for everyone, but we have shown that it is vital for SCAD patients who have a 20 per cent chance of having another SCAD heart attack without warning. 

“Until recently, SCAD was considered a rare disease, with little known about its causes. We are now getting closer to developing preventative treatments and providing genetic diagnosis for families affected by SCAD, which is a huge turnaround.”

The international consortium of researchers is from France, England, the US, and Australia. Notably, Professor Jason Kovacic, Executive Director of the Victor Chang Cardiac Research Institute, was also the lead investigator from one of the US sites in this study, the Icahn School of Medicine at Mount Sinai in New York.

SCAD Facts

• 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 to hospital 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.
• SCAD heart attack survivors have around a 20% chance of having another attack.
• It is the most common cause of heart attack associated with pregnancy.
• Nine out of 10 people who have a SCAD heart attack are women.
• SCAD 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.
• 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.

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For all media enquiries and interview requests, please contact:

Julia Timms
Head, Media & Communications
j.timms@victorchang.edu.au
0457 517 355