New study shows that many adults with no history of heart disease have some degree of atherosclerosis.
More than 40% of adults, who are between 50 and 64 years old and have no history of heart disease, have some degree of atherosclerosis, a new study found.
The findings, led by Dr Göran Bergström, from the Sahlgrenska Academy at the University of Gothenburg, in Sweeden, point towards the need to establish better methods to identify people at risk of developing heart disease.
About the study
Atherosclerosis is the build-up of fatty deposits in blood vessels that supply blood to the heart and is a major cause of heart attacks in Australia and worldwide. Traditionally, levels of atherosclerosis in people with no symptoms of heart disease are measured using a cardiac CT scan, a technique used for coronary artery calcification (CAC) scoring.
The technique creates cross-sectional images of blood vessels going to the heart, allowing the ability to make measurements of calcium-containing plaques present in coronary arteries. Based on these scans, individuals receive a CAC “score” from 0 to over 400, to estimate their risk of coronary artery disease. The higher the score, the greater the risk for having a heart attack, stroke or dying from either one within the next 10 years.
However, this technique can miss a significant percentage of people who are at risk of a heart attack, despite having a zero CAC score.
“Measuring the amount of calcification is important, yet it does not give information about non-calcified atherosclerosis, which also increases heart attack risk,” Dr Bergström said.
Bergström and his team compared CAC scoring results with coronary computed tomography angiography (CCTA) scans in more than 25,000 Swedish men and women, 50 to 64 years old, who had no history of a prior heart attack or cardiac intervention.
CCTA is a radiologic technique that generates a very detailed image of the inside of the arteries that supply the heart with blood. Using this technique, researchers wanted to determine the prevalence of atherosclerosis in the people with no known heart disease and establish the accuracy of CAC scores.
Their key finding was that more than 42% of the study participants had some degree of atherosclerosis. In 5.2% of these participants their arteries were clogged by 50% or more and in 2% of participants, the blood flow to large portions of the heart was severely reduced.
Researchers also found that, in average, atherosclerosis started 10 years later in women, compared to men and was almost two times more common in older adults (60-64 years old) than in younger adults (50-54 years old).
According to the authors, this silent coronary atherosclerosis is common among middle-aged adults, and it increases sharply with sex, age and risk factors. “A high CAC score means there is a high likelihood of having obstruction of the coronary arteries. However, more importantly, a zero CAC score does not exclude adults from having atherosclerosis, especially if they have many traditional risk factors of coronary disease,” he said.