New test to catch 'silent' cases of heart disease in Australia

A new test is being trialled by general practitioners in the hope of catching "silent" cases of heart disease.

One Australian has a heart attack every nine minutes and 19 Australians die every day from them, according to Dr Gemma Figtree, an Interventional Cardiologist at Royal North Shore Hospital.

But patients with no obvious risk factors, such as high cholesterol and blood pressure, make up around a quarter of heart attacks.

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Ian Devlin is lucky to be alive after having a big heart attack at the age of 54, where the blockage was in such a deadly location in his artery, it's known as the widowmaker.

"Two o'clock in the morning, sharp pain in the middle of my chest, and I thought I had indigestion so toughed it out for 30 seconds," Devlin said. 

"There's a 10 per cent survival rate, so I was in the 10 per cent."

Devlin wasn't considered at risk of a heart attack as he has no history of high blood pressure, cholesterol or diabetes.

"I was as fit as a fiddle," he said.

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In a mission to identify "silent" cases like Devlin's, several GP clinics are recruiting patients for a new study.

"As we've got better at treating traditional risk factors in the community, we see that up to 25 per cent of our heart attack patients here at Royal North Shore hospital actually don't have traditional risk factors," Figtree said.

The study will consist of 1000 patients altogether. Dr Amy Ho, a GP at Our Medical in Crows Nest, will have 250 of those patients.

"I'm hoping to fix the problem before the problem actually happens," Ho said. 

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Patients considered to be at low or medium risk of having a heart attack within five years will be asked to have a blood test that will screen for about a million genetic variants shown to be linked to coronary artery disease (CAD).

"That test flags them potentially as being at higher risk than we otherwise considered using traditional factors," Figtree said.

Those who are flagged will be referred to a CT scan that measures the amount of calcified plaque in the heart.

"The plaque itself can actually be treated using traditional medical treatments we already have that we're not getting to these patients," Figtree added.

Experts have formed a not-for-profit company called CAD Frontiers to help save more lives and are applying for a $50 million grant through the Medical Research Future Fund to develop new blood biomarkers for early detection and novel treatments.