Fat in the heart arteries, also known as atherosclerosis, is known to be a major cause of heart attack. People who are at risk for heart disease are generally screened using cardiac computed tomography, commonly known as a cardiac CT scan for coronary artery calcification (CAC). The scan creates cross-sectional images of the vessels that supply blood to the heart muscle to determine the density of calcium-containing plaque in the coronary arteries, finding evidence of coronary artery disease.
However, this scan can often miss a percentage of people who are at risk for heart attack even though they’re not showing a significant amount of plaque.
“Measuring the amount of calcification is important, yet it does not give information about non-calcified atherosclerosis, which also increases heart attack risk,” said study author Göran Bergström, M.D., Ph.D.
For the study, researchers randomly recruited participants aged 50 to 64 years old from the Swedish census register from 2013 to 2018. All participants were part of the Swedish CardioPulmonary BioImage Study (SCAPIS). The information included data from 25,182 participants who had no history of heart attack or cardiac intervention and who had CAC scans and coronary computed tomography angiography (CCTA) scans.
CCTA is a radiologic technique that can provide a detailed image of the inside of the arteries that supply the heart with blood. The researchers used this technique to determine the prevalence of atherosclerosis in the general population.
By the conclusion of the study, researchers found some degree of fat deposits in the heart arteries in more than 42% of the participants. The CCTA scans found that in 5.2% of participants with atherosclerosis, the buildup obstructed blood flow through at least one coronary artery was by 50% or more.
Atherosclerosis Started an average of 10 years later in women compared to men and was 1.8 times more common in people age 60 to 64 versus those aged 50 to 54.
“It is important to know that silent coronary atherosclerosis is common among middle-aged adults, and it increases sharply with sex, age and risk factors,” according to Bergström. “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.”
Limitations of the Study
More research is needed to clarify the limitations of the study, including information on how cardiovascular heart disease can develop in this population. It is also unknown if these findings can help to predict heart disease in people with fatty deposits in their arteries.