Measuring Your CV Risk: CIMT The Importance of Perspective

So I had another patient come to me just yesterday with a carotid artery ultrasound. That really doesn’t help the vast majority of us. All it is it’s what we call a flow study. It’s looking to see if the plaque inside your carotid artery impedes the flow. Well you have to have about 50 to 60% of the lumen covered up in order to impede the flow. Why would be – why would we do that – that test? Well number 1, it’s easy for the radiologist and the ultrasound tech, and number 2 it means a big difference for people that are considering having surgery of the carotid artery. That’s actually very few of us. So even though you can get it everywhere, you can get it because it’s easy. For example in – in Nashville, there were probably about 300 places where you could get a carotid artery ultrasound but only 2 or 3 where you could get an actual CI-MT. We often had people fly CI-MT techs over to – to do a series of CI-MTs. So why not just do the ultrasound and why are we looking at – let’s go back and just take a quick look at a couple of comments here We’re looking at impedance of flow for people that may need surgery, not for risk stratification. What do we mean by risk stratification? This comes out of the CafĂ©’s de Cave study. It’s the ultimate study which demonstrated that, look, if you get CI-MT, in other words, take that ultrasound of the carotid artery. It’s the same ultrasound that all of them are doing. However, it requires that you get a very good technique on the seat and the common artery and look and get averages of the size of the plaque. Now, why is that helpful? Here’s why it’s helpful and here’s what we mean by risk stratification. This is – the group on the left is normal, no risk. The group on the right is the group that you’re looking for with a routine carotid ultrasound Basically you’re saying, these people have so much plaque, it has impeded their flow. This pink group, oranges, pink in the middle, on the right, this third group with atherosclerosis, they have a plaque 1.3 millimeters or more or a high common common media, intima-media thickness. So a very large arterial age. These people, even though they have absolutely no – no impedance of their flow are at 40% risk, over the next 10 years of having an event. Well if you look at it, the standard definition of high risk, high risk is 20%, half of that. So that’s why getting a CI-MT is so important. Now let’s take a look at one of my CI MT’s for from a couple years ago and just focus a little bit on what these means So this is my common carotid artery here This is the carotid bulb. That larger item there is the – that larger fork is the internal carotid and the smaller one is the external carotid. If you’re gonna get discreet plaques, it’s usually gonna be in the ball. Now if you look down here, you see that blue arrow, I have a heterogeneous plaque 1.6 mm there in the bulb. Now, let’s go back and look at arterial age. My arterial age here was 53 and at the time then, I was 60 years old. How did they do that? They basically, basically took a 1 cm section of my common carotid and took 600 slices out of that and measured that distance. The distance between that thin line which is the intima line and the thick white line which is the media line that dark space in between was the – the plaque, the LDL that they were measuring. Remember back from the, from the video views and the

clarification, the drawings, this shows an artery which is normal up here and it gets more and more plaque as we go to the right. What we’re looking to do is measure basically where you are in this progression because as you get too far your immune system starts to attack this plaque If it does, it forms some hot inflamed plaque, that hot inflamed pack plaque. If it breaks out into the flow of the artery causes a clot. Now here’s where the issue about perspective matters. (Let me see if I can move this slide over a little bit. There you go.) Again, as usual I have some image problems but let’s look at the – these couple of arteries. This is an artery cut in cross-section. This is the media, this red area. This is the intima, this little thin area along here That’s hot plaque by the way and that’s that’s stable waxy plaque. So this is what you don’t want to break through into the blood stream. Now back to the question about perspective and some of the difficulties in getting in CI-MT Look at this. In this one you’ve got this much plaque on this side of the artery wall. On this one you, on this side just 180 degrees over, you have very little plaque. So again as we said, that’s really – it’s critical when you’re looking to measure an age or estimate an age that you have the right number; and so as you start looking at this biological gross specimen from somewhere that died due to this plaque breaking out, you begin to realize that if the view comes through here on the ultrasound, they’re going to get a very different perspective than if the ultrasound is coming through here. Let’s go back and look at a different perspective on it. As – as you can see, perspective counts. Using that image, these they obviously had these guys way up in front of the eiffel tower and it looks like they’re as big as it is. The perspective on these arteries counts as well because again, if the ultrasound tech is coming through here, you’re gonna get a measurement of plaque that’s about that thick. However, if he’s coming through here you’re gonna get a much thicker uhm CI-MT level. So again, this is just one of the the reasons that you hear – oh I know how to do CI-MT when maybe you don’t. It takes a lot of effort and practice and training for a CI-MT to learn how to do this correctly and that’s where Todd Eldredge comes in. He does a great job in terms of teaching how to develop reliable, repeatable standards within a – within a difficult subjective, sometimes environment. Now again you go back and you say, well why the old one doesn’t tell us anything except whether or not we – we need surgery What we want to know is – is this patient or are you really at high risk? Are you at 10% risk or 40% risk? Big big difference. Thank you very much for your interest! Thanks and if you hit that subscribe or like button it makes a big difference. An even bigger difference happens when you share. You can share on Facebook, Instagram, LinkedIn, Twitter, Pinterest. When you do that it makes a big difference in terms of the algorithm. It sends this to other people realizing that humans think this is interesting information and helpful Thank you again!