Arterial calcification is a stable marker of advanced vascular disease. High coronary artery calcification scores are recognised as an indicator of future cardiovascular risk and increasingly used to guide patient management and to prompt better adherence to frontline medications.
However, the prognostic importance of vascular calcification in other beds such as the abdominal aorta is relatively underexplored. Abdominal aortic calcification (AAC) is commonly seen when imaging the abdominal or lumbar spine regions in older individuals and those with diabetes and chronic kidney disease. Modifiable risk factors for AAC include smoking, a sedentary lifestyle, poor diet, dyslipidaemia, poor glycaemic control and impaired kidney function.
The research
We undertook a systematic review and meta-analysis that identified 52 observational studies of 36,092 individuals to determine the long-term risk of future cardiovascular events and prognosis in people with AAC.
In studies with participants recruited from the general population, people with any or more extensive AAC had approximately twice the risks of future CVD events, fatal CVD events and dying from any cause than those with no or less extensive AAC. We also found the more extensive the AAC, the higher the risk of future clinical events.
Importantly, when pooling the adjusted risk estimates from these studies, these increased CVD risks attributable to AAC were similar even after accounting for traditional CVD risks factors such as high blood pressure, smoking and lipid profiles. In people with chronic kidney disease, those with any or more extensive AAC had almost four times the risk of cardiovascular events compared to those with no or less extensive AAC.
The findings of this study demonstrate that the presence and extent of AAC can serve as an “early warning” for patients and their GPs on the risk of future cardiovascular events.
A 74-year-old community participant told us: “I think anyone my age would want to know (their AAC). I came away with; okay I have an issue to sort out … I’ve got a challenge and so I’m very grateful to know (my AAC).
So how can we use this information?
Widely accessible bone density machines can quickly and cheaply capture images for AAC assessment at a fraction of the radiation dose of alternative imaging modalities such as computed tomography.
We are currently undertaking a world-first, 12-week randomised controlled trial in 300 older men and women in Perth. Our aim is to determine whether providing AAC information and results to individuals and their GPs leads to positive lifestyle changes as well as improved uptake and adherence to cardiovascular medications.
The ultimate goal is to develop the evidence that providing AAC information to GPs and their patients can prevent future clinical cardiovascular disease events such as heart attacks and strokes. That is, early detection of high-risk individuals will ultimately lead to fewer heart attacks and strokes.
In summary, fortuitous identification of abdominal aortic calcification may serve as an early warning sign of future clinical cardiovascular disease risk. Consistent reporting and conveying these results to GPs and patients may improve existing public health and primary prevention strategies for cardiovascular disease.
Key messages
- AAC is commonly observed on abdominal and lumbar spine imaging but its clinical importance for future cardiovascular risk has been unclear.
- AAC presence was associated with an increased risk of cardiovascular events and deaths in people with no known CVD
- Providing these results to the patient without known CVD may prompt positive behaviour changes.
– References available on request
Author competing interests – the author has been involved in the research described