Outdated heart advice ‘risks lives’, cardiologists say

Experts have issued a plea for an overhaul of Australia’s outdated guidelines on screening for cardiovascular disease, which fail to detect many patients at risk of having a sudden heart attack.

Top cardiologists are calling for new national guidelines on cardiovascular disease to recommend the widespread adoption of a test known as a CT scan calcium score. Picture: iStock

The nation’s leading heart disease institutes have issued a plea for an overhaul of Australia’s outdated guidelines on screening for cardiovascular disease, which fail to detect hundreds of thousands of patients at risk of having a sudden heart attack.

Top cardiologists are calling for new national guidelines on cardiovascular disease to recommend the widespread adoption of a test known as a CT scan calcium score, which can detect heart disease in those who “sit under the radar” of risk calculators but have plaque in their arteries despite being asymptomatic.

The Cardiac Society of Australia and New Zealand has joined with the Baker Heart and Diabetes Institute and the Victor Chang Cardiac Research Institute in backing the push for a lowering of the threshold for coronary calcium scoring, which is commonly recommended at a much lower threshold of risk for patients in other countries.

Calcium scoring is measured using a CT scan of the heart to see how much calcium is visible in the walls of the arteries.

Some people will have a score of zero indicating there is no ­calcified plaque despite having high blood pressure and cholesterol, while others who are not deemed at risk by current assessment measures may have plaque and already have heart disease.

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Coronary artery calcium scoring is not covered by Medicare, so the cost of the test is an out-of-pocket expense, and the cost varies across the country but is on average around $200.

The prestigious medical organisations have weighed in on the issue following the publication of an academic paper in the Medical Journal of Australia which called for CVD prevention guidelines for people at intermediate risk of heart disease to be revised to include coronary artery calcium scoring in assessing for eligibility of statin treatment.

The paper comes a year after Melbourne cardiologists Brett Forge and Richard Harper brought national attention to coronary artery calcium scoring following the death of Shane Warne by saying such sudden heart attacks were largely preventable if CT scanning was used. Coronary heart disease is Australia’s No.1 killer, taking 50 lives every day.

Dr Forge said some researchers had estimated Australia’s current risk assessment guidelines miss 45 per cent of people who are going to have cardiac coronary events, while many others deemed at risk may have recorded a zero calcium score and were therefore unnecessarily taking statins. “There’s a lot of medicalisation that can be prevented,” Dr Forge said.

A lead author of the MJA paper, the Baker Institute’s director Thomas Marwick, said CAC score testing was cost-effective as proven in the research, which was based on a randomised controlled trial. The paper was accompanied by an editorial in the journal that declared “the time has come to eliminate cost and access as barriers to broader adoption of CAC screening by aggressively campaigning for widespread, inexpensive CAC scanning”.

“Most other OECD countries have moved in the direction of these tests and this risk assessment process,” Professor Marwick said. “I don’t know of any place that has been so slow adopting this as we have.

“The reality is we are under treating at the moment. We have a primary prevention system that’s not working effectively.”

The controversy comes as doctors throughout the country raise the alarm that Medicare funding for Heart Health Checks, which have been performed on almost half a million Australians in the past four years, is not guaranteed beyond the end of June.

US guidelines recognise the value of coronary artery calcium scores for guiding treatment of people at intermediate risk of cardiovascular events. But Australian guidelines do not mention the test.

Cardiac Society president Stephen Nicholls, a world-renowned cardiologist who is also program leader of the Victorian Heart Hospital and was a co-author of the MJA paper, said the latest clinical trial data strengthened the case for wider adoption of CAC scoring.

“What we know is that if you put calcium scoring aside, the kind of risk scores that we currently use in the clinic are not perfect,” Professor Nicholls said. “So we end up labelling a lot of people as either low or moderate risk who actually end up having a heart attack event. And not everyone who is high risk is actually going to have an event.

“We’ve seen clinical trial after clinical trial that show higher risk patients should be more intensively treated with regard to their cholesterol and yet we haven’t updated guidelines for the better part of a decade.”

Victor Chang Cardiac Research Institute executive director Jason Kovacic said Australia currently did a “below average” job on screening.

“I think CT screening is something we definitely do need to seriously consider bringing into our guidelines and funding models.”

National guidelines on absolute cardiovascular disease risk date from 2012 and are currently being updated. The Heart Foundation of Australia, which publishes the guidelines, says risk will be better calibrated and the new guidelines would “bring Australia to the forefront of heart disease prevention globally”.

“There is indeed a role for calcium scoring in risk prevention, and we are pleased to say that calcium scoring is being strongly considered in the new Guideline,” said the foundation’s chief medical adviser Garry Jennings. “I think everyone in the field would agree that coronary calcium scoring has got a role to play,” said the foundation’s chief medical adviser Garry Jennings. “But it’s got to be used appropriately. It’s got to be used in the right group.”

The new guideline is due to launch in June.