Almost everyone has plaque in their arteries

Doctors call clumps of fat deposited on the inside of our artery walls atherosclerosis.

“It may sound scary, but it's very common,” Gunnar Austad says. He is a radiologist and PhD candidate at the University of Oslo.

In a recent study, he and his colleagues found plaque in the blood vessels of as many as 97 per cent of all healthy people they examined.

The participants, 24 women and 36 men, had no known cardiovascular diseases before the study identified the plaque in their arteries. They were on average 59 years old.

Can be dangerous

Too much of this plaque can be life-threatening if it is not detected in time.

Studies have shown that people with a lot of plaque have twice the risk of heart attack and stroke as those with little plaque.

“In the past, it was thought that only a few of us had visible plaque. But ours and other studies in recent years have shown that if you do a thorough examination, you will find plaque in almost everyone,” Austad says. 

This does not mean that everyone has an increased risk of developing cardiovascular diseases, however.

But there has been a lack of a good and objective method that uses ultrasound to assess who can benefit from medications that lower cholesterol. 

Too much cholesterol can lead to atherosclerosis.

Found much more plaque

This is what the researchers are now trying to do something about. They believe that they have found a better method to assess the problem than the one currently in use.

Until now, specialists typically look at a patient’s carotid arteries when they search for plaque.

But this and other studies suggest that this is not enough.

“We discovered that by examining both the arteries in the neck and in the groin, we found much more plaque in many of the study participants,” Austad says. 

Researchers have not been so concerned with the blood vessels in the groin before, he believes. 

“The few studies that exist on this topic, however, suggest that plaque in the groin increases the risk of heart attack more than plaque in the carotid arteries. We also see in our study that the amount of plaque is much greater in the groin. It is consequently important to include this,” he says.

Have built a database

Austad’s study is part of a larger research project. It is financed by the private company Austad Diagnostikk, which the researcher himself owns and runs, in collaboration with Oslo University Hospital.

In this first part of the research project, the researchers have looked at how accurate this method is on a small number of participants.

Now, they will gather information from around 20,000 participants and assess how good the method is at predicting who will be affected by cardiovascular diseases.

But they already have a database of over 20,000 patients, which means they can compare the results of an ultrasound examination on a single patient with the entire database.

“This allows us to calculate how much plaque the patient has compared to others of the same age and gender. As a result, calculating the amount of plaque becomes more objective and accurate,” the researcher says.

Requires experience

“There’s still a lot of work to be done before we can say how well the method can predict who will get sick,” he says.

The ultrasound examination itself only takes five minutes and provides a lot of information about the biological age of the blood vessels of the patient. But it requires a lot of training and experience to conduct the examination adequately, Austad says. 

“The doctors who conducted the examinations in the study used the new method, but both were specialists and had performed thousands of such examinations in the past,” he says.

Getting thicker and thicker

Håkon Ihle-Hansen is a senior physician at Bærum Hospital and has also obtained a doctorate in the use of ultrasound to find plaque in blood vessels.

He also found that a surprising number of people, as many as nine out of ten aged 63 to 65, have visible atherosclerosis.

We are born with thin and slender walls in our blood vessels, but they become thicker and thicker with increasing age and other risk factors for cardiovascular diseases, Ihle-Hansen explains.

“We have known for a long time that patients who have thickened artery walls have an increased risk of developing cardiovascular diseases. But many of the patients over 60 years old don't just have a thickened wall. They also have visible plaque on the inside of the arterial walls. These can grow and make the blood vessel narrower and less elastic,” he says.

Difficult and time-consuming

Studies have shown that the amount of plaque is associated with the risk of cardiovascular diseases. That is why people have become more concerned with measuring the amount of plaque, the researcher explains. 

“But this is difficult and time-consuming. It is therefore not suitable for clinical use today,” he says.

Today, it is recommended that doctors use a scoring tool called NORRISK 2 to calculate the risk of cardiovascular diseases. This is based on blood pressure, cholesterol, smoking habits, age, gender, and family history.

He believes it is unclear whether the use of ultrasound will add value to the tool used today. Doctors need more experience to benefit from this, Ihle-Hansen says.

Still looking for the best method

Ihle-Hansen has read the new study. He says that the researchers are not saying that this method has been shown to be useful in clinical practice, even though it can be a useful way of describing atherosclerosis.

We need more studies, he argues.

“We're still looking for the most effective and simplest method to determine the extent of arteriosclerosis. The future will show whether the researcher's hypothesis that this model can be better and faster than current techniques is correct. This needs to be investigated further in other studies. I welcome all research in this area,” Ihle-Hansen says.

We can do a lot ourselves

If plaque in the blood vessels is detected early, there is a lot we can do ourselves to prevent disease, Gunnar Austad says.

Researchers know that regular exercise and a healthy diet protect against disease.

It is also important to avoid smoking and stress. We should also make sure that our blood pressure and cholesterol levels are fine.

“In the case of a particularly large amount of plaque, it may also be wise to reduce cholesterol to lower levels than normal,” he says.

Information is not enough

Austad refers to a study from Sweden which showed that giving patients information alone does not result in much behavioural change, and that advice on diet and physical activity results in less change than medication.

However, patients who were shown ultrasound images of plaque formation in their own blood vessels had a clearly lower risk of developing cardiovascular diseases one year later than patients who were only informed about their results.

Reference:

Austad et al. Validation and Reproducibility of Total Plaque Thickness in Carotid and Femoral Arteries Using Ultrasound. Ultrasound in medicine and biology, 2023. DOI: 10.1016/j.ultrasmedbio.2023.09.020

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Translated by Nancy Bazilchuk

Read the Norwegian version of this article at forskning.no