CIMT Testing Vs Carotid Duplex Doppler Ultrasound
Cardiovascular disease is the #1 cause of death for men and women. Many people have significant cardiovascular disease and are high risk for a heart attack yet they have absolutely no idea.
We recommend and perform CIMT Testing in our clinic. All men over the age of 45 and all women over the age of 55 should get CIMT Testing.
Additionally, if you have other risk factors for cardiovascular disease then you should get this testing even younger.
You may have heard of carotid ultrasounds before. However, CIMT testing is NOT the same!
The difference between a Carotid Ultrasound and CIMT?
Just the other day I had a patient tell me that he didn’t need a CIMT test because he had a carotid ultrasound a year ago. Upon further questioning, he had a “conventional” carotid ultrasound and not a CIMT. So what is the difference?
Carotid Doppler Ultrasound
The carotid doppler ultrasound is looking at blood flow through the carotid artery. The idea is that when there is obstruction to blood flow it suggests that there is some plaque build up restricting this blood flow.
Unfortunately, you won’t really see a significant change in blood flow until the stenosis (blockage due to plaque build up) is greater than 50%. The carotid doppler ultrasound does not look at the health of the artery, only if it has plaque and to what degree. Additionally, it is unable to determine the quality of the plaque. Is it a stable or unstable plaque. The difference matters!
Additionally, most physicians do not consider the blockage in the carotid artery to be clinically significant until it is 70% or more. At 70% blockage, most patients will still pass a treadmill stress test (if the blockage were in the coronary artery). 68% of all heart attacks occur in patients with less than 50% blockage and 86% of heart attacks occur in patients with less than 70% blockage.
So, don’t walk away from a carotid doppler ultrasound with a false sense of security.
The carotid doppler ultrasound requires a sonographer trained in vascular ultrasound which will increase the cost of the test. You often need to justify why you want the test to the insurance company in order for them to pay for it.
Carotid IMT Ultrasound
Carotid intima media thickness (CIMT) testing actually measures the blood vessel wall itself. It measures the amount of plaque in the intima & media layers. The plaque buildup in these 2 layers can become significant far before it would show up on a carotid doppler ultrasound.
You don’t wait until your car tires are completely flat to air them up. You usually fill them up the moment you notice they are too low. If you checked your tire pressure every day you’d probably fill them up as soon as the pressure drops too low. So why do we wait until we have a significant problem in our arteries to address it. We shouldn’t!
CIMT also measures the quality of the plaque.
Hard Plaque
Hard plaque is less prone to rupture and tends to be much more stable. These stable plaques can progress to higher grades without rupturing. These are the types of vascular lesions that cause chest pain and shortness of breath when you perform certain activities and resolve when you stop them.
A friend of mine was arguably very healthy. In fact, he ran 5-7 miles almost every day. However, he went for a run one day and started getting chest pain so he stopped and rested. After a few minutes the pain resolved and he got up and started running again. The pain came back again so he stopped and rested again. He was having what is called “stable angina.” He got a heart cath and he had an 85% stenosis in one of his arteries. This is a classic story for a stable plaque.
Soft Plaque
Soft plaques are much more concerning. They have a necrotic ‘lipid rich’ core and a thin fibrous cap. These plaques are prone to rupture.
I see these types of plaques all the time in the Emergency Room. There was a 65 year old man who was having dinner with his wife. He had no known cardiovascular disease. During dinner, he started having a sudden onset of chest pain and shortness of breath. He called 911 and he was brought to my Emergency Room having a heart attack.
This was a soft plaque which ruptured and caused a sudden heart attack. His cardiac catheterization showed 100% blockage of his Right Coronary Artery (RCA). The interventional cardiologist removed the clot and placed a stent in the artery. He walked out of the hospital a few days later.
I had another patient in the ER with a similar issue. The only difference is that he died. He didn’t know that he had cardiovascular disease and he died of a massive heart attack. He also had one of these soft plaques that ruptured. Soft plaques are super scary!
The CIMT report we use gives a relative risk by age and gender. This gives you an indication of your level of risk and can really motivate you to make needed changes to improve your cardiovascular health.
There are no other tests like this that evaluate the cardiovascular system in this way. We have some fantastic tests available to us and we can tell a lot about the cardiovascular system.
The CIMT Test is an excellent tool for evaluating cardiovascular health and is included our Executive Cardiovascular Evaluation Program. I feel very strongly that everyone should have this testing done at least once. I’ve seen cardiovascular disease seriously affect nearly every age of men and women. It never ceases to amaze me just how common cardiovascular disease really is.
Be sure to read Part 1 of CIMT Test in order to understand more about why this test is so important in evaluating your cardiovascular disease risk. Don’t be one of those who has no idea if they are at risk of cardiovascular disease. Schedule your Executive Cardiovascular Evaluation as soon as possible.
Read the post on How to Improve Your CIMT to learn how you can improve your cardiovascular health.
