April 2025
Study supports use of coronary artery calcium score in CVD primary prevention strategies
By Rebecca Jenkins
Combining coronary artery calcium (CAC) scoring with a CVD prevention strategy can limit plaque progression in intermediate-risk patients with a family history of coronary artery disease (CAD), Australian research shows.
It was known that CAC scoring could provide prognostic information, especially in patients at intermediate risk for CAD; however, no randomised trial had tested the benefit of combining a CAC score with a primary prevention strategy, the study authors led by researchers from the Baker Heart and Diabetes Institute, Melbourne, wrote in JAMA.
The authors recruited asymptomatic people from the community aged 40 to 70 years who had a first-degree relative with CAD onset at younger than 60 years old or a second-degree relative with onset at younger than 50 years for the prospective, randomised, open-blinded end-point clinical trial in seven hospitals across Australia.
At a screening visit, researchers established that the participants did not satisfy the contemporary criteria for statin use, then those participants assessed as being at intermediate risk of CAD based on the Australian risk calculator progressed to CAC scoring.
A total of 449 participants (mean age 58 years) with a CAC score greater than 0 and less than 400 were randomised to usual or CAC score-informed care, which included 40 mg of atorvastatin.
In the final analysis of 365 eligible patients, the CAC score-informed group showed a sustained reduction in total and LDL-cholesterol (LDL-C) levels at three years.
The mean achieved LDL-C level was 2.0 mmol/L (79 mg/dL) in the CAC-score informed group, of whom 84 individuals achieved LDL-C levels less than 1.8 mmol/L (70mg/dL), compared with only six individuals in the usual care group, of whom three had been started on a statin by their physician.
Plaque volume increased in both groups after three years; however, there was significantly less progression of total, noncalcified, and fibrofatty and necrotic core plaque volume in the CAC-score informed group compared with the usual care group.
‘These results may support the use of the CAC score to inform the use of more intensive preventive strategies to intermediate-risk patients,’ the authors concluded.
Commenting on the findings, Professor Len Kritharides, Professor in Medicine at The University of Sydney and Group Leader of the Atherosclerosis Laboratory at the ANZAC Research Institute, Sydney, said the reduction in LDL-C in the active treatment group was clinically meaningful and its significance was supported by the changes in coronary plaque composition.
Although the study was unable to show plaque reduction, Professor Kritharides noted that decreased progression was still a very important outcome.
‘The balance between regression and progression can depend on many things, including the extent to which LDL-C is lowered, the age of the subjects studied and the chronicity of the atherosclerotic disease,’ he said.
‘We can speculate that the same study design may have seen regression in a younger cohort and with more potent LDL-C lowering therapies.’
Professor Kritharides said the findings suggested CAC could be used more syste matically to refine risk calculations for individual patients. However, there were currently no widely supported guidelines outlining when CAC should be performed. Additionally, as CAC was not supported by Medicare, patients faced an outofpocket expense, which was a disincentive.
‘The take-home message is that both medical and patient engagement for the prevention of coronary events can be strengthened by having personalised CAC data showing subclinical atherosclerosis. If in doubt, look,’ he said.
‘Further research should formalise CAC utilisation strategies and should identify if and when CT coronary angiography might also be appropriate in defined populations.’