The new research could help GPs identify patients at risk of cardiovascular disease years before symptoms arise.
While much is known about the impact of coronary artery calcification as a predictor of future cardiovascular events, the prognostic importance of arteries outside the heart has been less clear. That is, until now.
A new international systemic review and meta-analysis of 52 studies, led by Edith Cowan University (ECU), has found that a build-up of calcium in the abdominal aortic could help clinicians identify patients at risk of future heart attack or stroke.
Specifically, the analysis found that people with abdominal aortic calcification (AAC) are 2–4 times more at risk of a future cardiovascular event.
Lead author Josh Lewis, an Associate Professor in Cardiometabolic Health at ECU and Heart Foundation Future Leader Fellow, told newsGP the higher the calcium build up that is observed, the worse the prognosis – particularly for patients with chronic kidney disease.
‘What we found was, if there was the presence of AAC in the chronic kidney disease cohort, then it was much worse for cardiovascular events than the general public,’ he said.
‘But even the general public, they were twice more likely to have a cardiovascular event if they had AAC.
‘It’s quite a high relative risk and also a high absolute risk as well for going on to have a cardiovascular event. We looked at cardiovascular events, fatal cardiovascular events, and all-cause mortality, and the results were very consistent.’
A build-up of calcium in the blood vessel wall is known to harden the arteries, resulting in blocked blood supply or causing plaque to rupture, and factors known to contribute include leading a sedentary lifestyle, poor diet, smoking, as well as genetics.
Associate Professor Lewis says AAC can act as an ‘early warning system’.
‘The abdominal aorta is one of the first sites where the build-up of calcium in the arteries can occur – even before the heart,’ he said.
‘If we pick this up early, we can intervene and implement lifestyle and medication changes to help stop the condition progressing.’
As with early coronary artery calcification, AAC is asymptomatic, and according to Associate Professor Lewis, in most cases, is ‘fortuitously’ picked up in routine tests, such as lateral spine scans from bone density machines or x-rays.
But he says it is currently an ‘underappreciated marker’ of structural vascular disease and hopes the research will raise awareness among clinicians.
‘We’re doing quite a lot of work to try and standardise the reporting,’ Associate Professor Lewis said.
‘At the moment, it really is dependent on who reads the scan whether the radiographer will actually mention that AAC is seen. I know there are certain clinicians who will report it to the GPs and patients, but it is not widespread.
‘So we’re really hoping this paper will act as guidance for clinicians for when AAC is seen in their patients.’
Amanda Buttery, head of Clinical Evidence at the Heart Foundation, praised the research.
‘The researchers found that evidence of abdominal aortic calcification in patients with no known cardiovascular disease may indicate that a more comprehensive cardiovascular risk assessment is required, including blood pressure and cholesterol testing or a Heart Health Check,’ she said.
‘The findings are promising, and the Heart Foundation would like to see more research in this area.’
Associate Professor Lewis is focused on doing exactly that.
He is currently running a study to see how much of an impact identifying AAC, and the role of GPs informing patients of lifestyle and dietary changes, including increasing fruit and vegetable intake and increasing physical activity, will make on cardiovascular health outcomes after 12 weeks.
‘We’re going to see whether or not they take more of their cardiovascular medications, or if they’re not on cardiovascular medications and they have aortic calcification whether they’re prescribed more,’ Associate Professor Lewis said.
‘So it’s really working out whether or not this will improve primary prevention of cardiovascular events. That’s what we’ve been focusing on to reduce their future risk of the clinical events.’
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abdominal aortic calcification calcium cardiovascular disease kidney disease stroke