Could showing someone a picture of plaque building up in their arteries be enough to save their life?
That's the question driving latest research by the Baker Heart and Diabetes Institute and University of Tasmania's Menzies Institute for Medical Research into how to prevent the progression of cardiovascular disease.
Many people with inherited heart disease have been told their heart risk score — including cholesterol levels, family history and blood pressure readings — but numbers alone don't always inspire lasting change. Even knowing other family members died of heart disease isn't enough to convince some people that they themselves are at high risk. So our research team showed people images of calcium deposits in their coronary arteries, and that has created lasting change in the way they live their lives.
The study, led by Professor Tom Marwick and PhD candidate and Clinical Nurse, Kristyn Whitmore, have been following 258 Australians with a family history of heart disease for about eight years.
As Ms Whitmore explains, "If someone feels well still, it can be hard to persuade them to take medicine on an ongoing basis, even when we tell them their heart risk score."
"The threat to their health may seem an abstract idea that they can't see and they can't feel but in this study, we also showed them the calcified plaque buildup hardening and narrowing their arteries. They could understand how that would increase the risk of a heart attack and stroke so it convinced them to take cholesterol lowering medication (statins) — to reduce the progression of fatty plaque and prevent more severe heart blockages."
Professor Marwick added, "This study shows that using pictures of calcified plaque (calcium) as well as conventional risk information is helping to bridge a person's knowledge gap and improve adherence to both medication and lifestyle change. This is really important because around 50 per cent of Australians stop taking their statins within a year."
In the study, half received nurse-led care that included repeated viewing of their coronary artery calcium scans during the first three years. The other half received standard care and only saw their scan results at the three-year mark. The people who saw their coronary calcium scans repeatedly in the study were far more likely to start taking statins and keep taking them. After three years, 85 per cent were still on treatment.
At the eight-year follow-up in Hobart and Melbourne, the benefits had persisted, as detailed in the paper in JACC: Cardiovascular Imaging. Those who'd seen their scans repeatedly maintained high medication rates (71%). The standard care group increased remarkably from 5 to 59 per cent of people taking statins — proof that seeing an image once can be enough to spark action. The higher a Coronary Artery Calcium score, the more likely they were to continue taking their statins. Researchers found patients who viewed calcium build-up in their arteries were more likely to have improved levels of risk factors like cholesterol and blood pressure, and overall heart risk reduction.
Study participant 72-year-old Sue shared that seeing her coronary artery calcium images convinced her to start on statins. Her mum died at 55 with her fourth heart attack and her dad died of a heart attack at 72 but Sue thought that was because they were smokers. As she was healthy, exercising and eating well and has a slight build, she thought she didn't have any cause for concern. But Sue explained, "When I saw the CT images showing my coronary artery was around 50 per cent blocked, it shocked me to death. I started on statins straight away and it's kept the plaque in abeyance for almost ten years. It saved my life."
Professor Marwick says when the heart health check or the standard risk calculators indicate the risk is very low or the risk is very high, we can decide on treatment. But there's around 40 or 50 per cent of the population who are at intermediate risk. For those people deemed at intermediate risk who have no prior heart history, these images can help reclassify them into lower or higher risk groups.
"I hope that studies like this may help to justify the wider use of heart imaging like coronary artery calcium scans to enable GPs to strengthen their patients' understanding of their personal risk. It could very well save their lives."
