Australia’s updated cardiovascular disease risk calculator is identifying substantially more Australians aged 45-74 as being at “intermediate” risk of heart attack and stroke, according to new analysis published in the Medical Journal of Australia.
The insights could provide patients and their GPs with a valuable opportunity to act early and prevent cardiovascular events.
Cardiovascular disease remains one of the leading causes of death in Australia, and blood pressure- and cholesterol-lowering medications, along with quitting smoking and improving diet, can substantially reduce the risk of having a heart attack or stroke.
In 2023, Australia updated its cardiovascular risk calculator to align with revised national guidelines for assessing the likelihood of heart attack and stroke. In the study, the updated calculator was compared to the previous one published in 2012.
Researchers from Australian National University (ANU) and QIMR Berghofer analysed data from more than 115,000 people aged 45 to 74 who had visited a GP between 2020 and 2022, none of whom had a history of heart disease or stroke.
Using the updated calculator, around one in 10 people (9.7 per cent) were found to be at high risk of a cardiovascular event within five years, meaning preventive medication would be routinely recommended. A further quarter (26.4 per cent) were classified as intermediate risk, where treatment should be considered, depending on individual circumstances. The remaining two-thirds (63.9 per cent) were at low risk.
QIMR Berghofer Cardiovascular Disease Prevention Team Head and Visiting Research Fellow at the ANU National Centre for Epidemiology and Population Health Dr Ellie Paige said the findings were crucial for better care.
“This is a marked shift from the old calculator, under which 17.6 per cent of people were classed as high risk and only 11.6 per cent as intermediate risk,” she said.
“Now, more than twice as many Australians fall into the intermediate category, where a conversation with a GP about treatment could save their life.”
The new calculator was built using contemporary data from more than 400,000 people and updated for the Australian population, replacing an outdated US-based equation that was known to generally overestimate risk in the broader Australian population and underestimate risk in Aboriginal and Torres Strait Islander peoples. It also factors in a wider range of information, including social disadvantage, use of heart medications and history of an irregular heartbeat (atrial fibrillation).
The result is a more accurate, up-to-date picture of an individual's risk, and one that flags many more people for a preventive conversation with a qualified health professional before they reach high risk.
The Heart Foundation’s guidelines encourage Aboriginal and Torres Strait Islander Australians aged 30 and over, and Australians aged 45 and over, to talk to their GP about having their cardiovascular risk checked using the updated calculator. People with diabetes aged over 35 should also consider discussing their health with a GP.
The Heart Foundation’s Chief Medical Advisor and study co-author, Professor Garry Jennings, called on health professionals to discuss the benefits of treatment for patients in the intermediate risk category, particularly those with additional risk-enhancing factors.
“Our message to clinicians is that the intermediate-risk category requires careful clinical judgement,” he said.
“For many patients, a conversation about medication alongside healthy lifestyle changes could help avoid serious cardiovascular events down the track.”
The updated guidelines allow GPs to increase or decrease a person's risk based on additional factors, such as family history of heart disease, coronary artery calcium score, or ethnicity.
Read the scientific paper here.