By Melanie Hinze
CT coronary artery calcium scoring should be considered as part of the heart health check for patients with intermediate cardiovascular disease (CVD) risk and a family history of early onset coronary artery disease (CAD), according to research published in the Medical Journal of Australia.
The study recruited 1059 participants, aged 40 to 70 years, who had a family history of early onset CAD and a five-year Australian CVD risk (ACVDR) of 2 to 15%. Participants were recruited from seven Australian hospitals between October 2016 and January 2019.
Non-zero coronary artery calcium scores were evident in 45% of participants. Of 151 participants with calcium scores of 100 or more, 77% were deemed to be at low cardiovascular risk by Australian guidelines. And 19% of participants deemed to be of intermediate risk by Australian guidelines were actually shown to have zero calcium scores.
‘Coronary artery calcium scores could be used to re-classify risk in one-half of our sample, and could change decisions about statin treatment in 41%,’ the study authors wrote.
‘A 5-year predicted ACVDR of 5% for symptomatic atherosclerotic disease may be a suitable threshold for referring patients for coronary artery calcium scoring,’ they concluded.
Commenting on the findings, Associate Professor Karam Kostner, Director of Cardiology at the Mater Hospital Brisbane and Associate Professor of Medicine at the University of Queensland, Brisbane, said, ‘Traditional risk scores are not very accurate in people who have one very prominent risk factor such genetically high cholesterol and this is exactly where calcium scoring can help in risk prediction’.
He said this was an important study that showed imaging methods such as CT could be used to detect CAD early.
‘Since we have very cheap and effective therapies to treat risk factors such as high cholesterol and blood pressure, this approach could prevent many heart attacks and strokes,’ he added.
Professor Kostner said that the only downside to this approach was that calcium was often not present in individuals aged younger than 35 years, even when they had very high cholesterol. ‘However, they will often have soft plaque in their coronary arteries that should also be treated,’ he said. ‘There are also other imaging methods such as carotid ultrasound and CT angiography that may be utilised in this group.’
Med J Aust 2020; 213: 170-177.