By the time plaques have formed in the arteries, the process of atherosclerosis, a condition that can lead to heart attacks and strokes, is already underway. Now, by using advanced imaging technology to detect inflammation in the arteries, scientists for the first time have found a way to track the condition before plaques develop.
The finding, which appears in a recent Journal of the American College of Cardiology article, should lead to better diagnosis and earlier treatment of atherosclerosis.
Although scientists now understand that atherosclerosis is a persistent inflammatory disease, it is unclear how much inflammation exists and how it develops in the early stages of the disease.
The recent study addresses this deficit by using an advanced form of positron emission tomography / magnetic resonance imaging (EPT / MRI) to detect the onset of inflammation of the arteries in people who already had some atherosclerotic plaques in some of your arteries.
The study is part of the Progression of Early Subclinical Atherosclerosis (PESA) trial that assesses the stages prior to symptoms of atherosclerosis in more than 4,000 middle-aged employees.
The study author, which is the first to use EPT / MRI techniques in a large number of people. He explains that not long ago all the knowledge of how atherosclerosis developed came from autopsies alone. “Today for the first time,” he adds, “we present, with highly advanced imaging technology, how atherosclerotic disease develops in people.” He notes that while individuals may appear healthy, “we can already see how different aspects of the atherosclerotic process are evolving”.
Arteries and atherosclerosis
Arteries are the vessels that carry blood rich in nutrients and oxygen to the heart and the rest of the body.
Atherosclerosis occurs when fat, calcium, cholesterol, and other materials settle within the artery walls to form plaques. Plaques can build up within any artery, including those that carry blood to the heart, brain, extremities, kidneys, and pelvic area.
As time passes, the plaques harden and the arteries narrow, reducing blood flow and the supply of oxygen and nutrients to cells and tissues.
This process can lead to life-threatening cardiovascular consequences, such as heart disease, heart attack, and stroke.
Potential predictor of atherosclerotic plaques
A doctor and his colleagues showed that inflammation of the arteries “is very prevalent in middle-aged individuals with known subclinical atherosclerosis.” This was particularly evident in arterial regions that had not yet developed plaques.
They suggest that “an arterial inflammatory state” could be a predictor for the later development of plaques and atherosclerotic disease.
The research included analysis of advanced EPT / MRI imaging results for 755 participants in the PESA trial. Their average age was 49 years old, and all had undergone tests that had revealed the presence of calcium buildup or plaques in some arteries.
The first author of the study, who is a cardiologist at the CNIC, says they examined three main types of arteries: the carotid arteries, which supply blood to the head; the aorta, the largest artery in the body, and the iliofemoral arteries, which supply blood to the legs.
Using advanced imaging technology, the team found that inflammation was evident in only about 10 percent of the plaques that had already formed.
Most of the inflammation was in arterial regions without atherosclerotic plaques. More than half of the individuals had this type of inflammation without plaque, and most of them occurred in the femoral arteries.
Where the plaques showed signs of inflammation, they tended to be larger, they contained more cholesterol and were more likely to be in the branches of the femoral arteries.
Inflammation linked to more risk factors
A doctor says they also found that “inflammation was associated with the presence of more risk factors; obesity and smoking, in particular, were independent predictors of the presence of arterial inflammation”.
Doctor explains that the findings show how, due to the power of technology, it is now possible to have “live images” of inflammation that can lead to atherosclerosis as it occurs. This should help diagnose the disease earlier and identify the people who are most likely to benefit from early treatment.
Doctor proposes that future research should “investigate whether inflammation precedes plaque development and assess how quantification of inflammation could contribute to cardiovascular risk assessment.”
He and his team are already taking a closer look at the process of arterial inflammation and how it might contribute to plaque formation. They hope this will result in an improvement in the anti-inflammatory treatment of atherosclerosis.