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Heart Scan Workshop: Part 1



Heart Scan Workshop Part 2

Heart Scan Workshop Part 3

TRANSCRIPT
(DISCLAIMER: This transcript is auto-generated and may contain errors. It cannot be relied upon for factual accuracy.)

00:00:00
Okay, everyone, welcome to the, uh, Undoctored (now Infinite Health) Inner Circle. Everything you need to know about CT heart scans and coronary calcium scores. This will be a three part workshop. This is the first session, and then two more sessions, and we'll hold these sessions live on this undo inner circle virtual meetup. Uh, uh, now you may not know that the entire Undoctored program had its start with CT heart scans. So I brought a mo, I, I brought a, um, a heart scan device to Milwaukee, Wisconsin about 22, 23 years ago. Something long time ago at a time where there when there were very few of these devices around and, uh, started scanning people left and right and had to fight some battles with my colleagues about what this all meant. But, you know, it led to this, all the findings of this program. But, you know, we haven't talked about that because we've gotten tangled up with things like weight loss, type two diabetes and rheumatoid arthritis, those kinds of things. And the whole notion of what to do with CT heart scans

00:01:01
and cardio calcium scores and cardiovascular risk has kind of just fallen. So I thought we'd resurrect all that. And once again, talk about what is really a very important thing called CT HEART scans. This would be a three part workshop tonight, we'll talk about what exactly is a heart scan. Why do we get this cardio calcium score, and why are we measuring calcium? Why aren't we measuring, uh, inflammatory elements or soft elements or rupture prone elements? It's a common question. We'll talk about why heart scans gauge cardiovascular risk, not blockages. Let's talk about who should have a HEART scan in part two that will conduct another night. We'll talk about why the higher the score you have, the greater the cardiovascular risk and what that risk actually means. Just how much risk is there and when is additional testing necessary after a positive heart scan? And this can sound awfully cynical, but how to avoid being duped by my colleagues when you have a positive score. Then in part three, another evening, again, we'll talk about why.

00:02:07
If you do nothing, if you have a heart scan, you have a score, whatever it might be, 50, a hundred, 150, 700, a thousand. If you do nothing, the score will increase by about 25% per year. And with it, your risk for heart attack and other bad things, and why this notion of optimal medical therapy, that's not my terminology, terminology of my colleagues, uh, does not have any impact on the growth of plaque judged by heart scan scores. It still grow 25% per year. And then let's finally talk about what works and why so that we can stop that 25% per year progression and can your score be reduced. Now, here's a great quote from a colleague John Guyton at Duke, and it kind of sets the stage for what we're gonna talk about today. So he says very nicely, the coronary calcium score is the single best predictor of atherosclerotic cardiovascular risk available today. Not total cholesterol, not LDL cholesterol, not blood pressure, not your framing him score the coronary calcium score. He also adds getting the calcium scores, almost like taking all the risk factors put together

00:03:19
and combining them in a risk calculation. And the calcium score alone is pretty close to being predictive as everything else put together. My emphasis. In other words, you can't do any better to identify potential for the number one killer of hu of men and women in the US and elsewhere. Uh, you can't get any better than a cardiac calcium score. Cholesterol is not better. It's far inferior. LDL bad cholesterol is not better. It's far inferior. Various scoring, uh, uh, schemes like Framingham risk scoring is far inferior. Okay? So we put coronary calcium scores from CT heart scans front and center as a way to gauge your cardiovascular risk. Well, what are we doing in a heart scan? Well, first of all, the heart has three art here. We're looking at somebody's heart, okay? So their right is on your left, right? We're looking at somebody face to face, and this is CT coronary angiogram. The artery to the most left is the right coronary artery. The artery to the right is the left anterior descending, and that left anterior descending. Or we say LAD shares a stem with another artery called the circumflex that winds around the back. Okay? So there are only three arteries

00:04:34
in every human's heart. Now, if we were to visualize plaque, we're trying, we're going to try to quantify, identify, and quantify plaque. If we did an intra coronary ultrasound, which is a very, very precise technique where you pass an ultrasound probe into the artery and you make cross sexual images, these arteries aren't very big in a woman. The average artery is three millimeters in diameter in a male, about four millimeters. We're talking about, uh, uh, teensy, weenie, maybe the size of a, of a noodle. Well, at the upper right hand, uh, graphic, that's the an in an intra ultrasound, cross-sectional image. The circle in the center with a crosshatch, that's the ultrasound probe. The black around it is blood. And then that stuff within the orange circle is all plaque. You can see the plaque is not uniform, right? It's got all kinds of different things in it. The whitest most white stuff is calcium. You can see it's kind of scattered around. The less white stuff is fibrous tissue, the gray stuff and the black stuff. Those are inflammatory cells, nests of inflammatory cells,

00:05:42
collections of dead cells and other sorts of things. You can appreciate that atherosclerotic plaque in a heart artery. Coronary artery is a smorgasbord of things, right? So how do we quantify that kind of plaque through the entire length of all three coronary arteries? So you can imagine not such an easy thing to do be here's what you see at heart catheterization. That is in the cath lab where a a, a catheter is threaded, uh, uh, into your coronary arteries and dye is injected into the lumen, the opening of the artery. This is the kind of thing you see. So here's a blockage of about 50% in the left anterior descend in the LAD. Here's a blockage of about 60, 75% in the circumflex. That's the kind of stuff you see with heart capitalizations blockages. Okay? We're not looking for blockages, but here's what you see. So that's an intra caral ultrasound segment from a relatively normal looking part of the artery. But look what's there. It's still filled with plaque. Okay? So once again, the center, the ultrasound probe, the black around it is blood. And then you see all the, uh, white and gray elements.

00:06:56
That's all plaque. So plaque can occur just about everywhere, and it's not always associated with blockages. So think of a heart scan this way. You've got a length of iron pipe, okay? And there's rust in it. A heart catheterization, the information you obtain from a heart capitalization would be something like this. In this one foot long pipe at the six inch mark is a collection of rust that reduces the diameter of the interior by 35%. That's kind of information get from a heart catheterization. A heart scan would instead say something like this. In this one foot length of pipe, there's 273.3 cubic millimeters of rust. Do you see the difference? It's two different perspectives on coronary atherosclerosis. And it's very important to remember, people who are having heart scans are not going to the emergency room with chest pain or in heart failure, or can't breathe. People who are having heart scans are people like you and me. We're going to work, we're going to school, we're going for walks, riding our bike, going to exercise class with no symptoms of heart disease.

00:08:09
Because when there's symptoms, you look for blockages. Okay? That that's not what we're doing. We are not. Look, this, this simple distinction I'm telling you about has made my colleagues stumble for 20 years. 'cause they didn't understand it. That was a primary criticism. By the way, when I first brought a scan device to Milwaukee, the doc said, what do you do that that test for? It doesn't show blockages. I said, that's right. It doesn't show blockages. It shows cardiovascular risk because it quantifies atherosclerosis. It's taken 20 years for the cardiology community at large to understand that important distinction. Okay? So if symptoms are present, somebody says, Hey, I'm, I am finding that when I climb stairs, I'm getting really breathless. Or when I Ride my bike like I used to, I, I have to stop 'cause my chest, I have pressure, my chest or something like that. When symptoms are present, you don't do a heart scan. You do something like a stress test. This is a nuclear stress test. Those are images, uh, radioactive images of the heart. This is normal. But in an abnormal test, you would see areas that are absent or, or less

00:09:14
or diminished in intensity, okay? That's how you decide where the blockages are. That's not what we're doing. So in heart scanning, we want to get a gauge for cardiovascular risk, not blockages. See, people often think that a heart attack is the gradual accumulation of plaque till one day achieves a hundred percent closure of the art. That is not, the majority of heart attacks are not, that the majority of heart attacks are when you have a relatively minor area of atherosclerotic plaque, maybe only reduce the diameter 20%, like that artery I showed you in cross-section with the ultrasound where it looked normal. It could be something like that. It reduce the diameter, 20%, 10%, 30%, 35, something like that. But it ruptures. 'cause remember in this plaque there's inflammatory elements. There's sometimes hemorrhage within the plaque, and that ruptures through the surface like a little volcano. And when the underlying elements are exposed to flowing blood, it causes blood clots, okay? And that, that's what a heart attack is. So the more plaque you have, the greater there is because there's more length right of plaque,

00:10:30
the greater the potential for plaque rupture or heart. That's what a heart attack is. So we're not looking for blockages in a person with chest pain or equivalent symptoms. We're looking to quantify along the length of three arteries, the entire burden of plaque. Okay? Does that make sense? Now, think how tough that is. The heart's beating, like we said, the arteries are small. In a woman, three millimeters in a male four millimeters, there's heart motion, multiphasic heart motion, there's lung motion. If the person's allow is breathing and there's human motion, we all fidget, right? Pardon me? So the first device to allow imaging of the heart was a very cool device that came out in the 1990s called Electron beam Tomography. This came out at a time where the conventional cat scanners took two to four seconds to image the heart. Well, in two seconds, the heart has beaten twice, right? More or less. And that's a lot of motion. Any photographer will tell you that's too slow and you'll get blurred. And that's what happened. So nobody could image the heart until this device came along. And what this device did, rather than having the, uh,

00:11:43
imaging machine rotate around the body, it focused the x-rays with magnets. And it was very, very rapid. And while the old cat scanners took two seconds to image, to make one image, this took 0.1 seconds, a 10th of a second to make it. That was fast enough to fast enough to image the heart, as well as infants, children, et cetera. General Electric didn't like that. Ge they had a competitive technology called multi detector, uh, CT scans. So they did something odd. They took this wonderful technology called Electron beam Tomography. They bought the patents from the company I matron in South San Francisco, bought the company itself, locked it up and won't let anybody use it. So I don't know why they did that. The only reason I I know of is to pa make the path clearer for the emergence of their technology. And they've done a good job in their defense of promoting and developing and improving this multi detector ct. The original detector had about eight detecting rings. That is X-rays are passed through the body, and they had eight rings to detect the images. They went to

00:12:48
sixteen thirty two, sixty four, a hundred twenty eight, two hundred fifty six, and, and even higher than that. And that accelerated the speed of the scanner and reduced the, uh, radiation exposure and improve the images. So the cur current generations of multi detector CT scanners where the, uh, uh, the entire thing rotates around the human body, not electromagnetic, uh, not not focused by magnets. So this technology, while it was inferior to the original EBT, is now a very good device. This is what you see. So these devices generate 30 to 40 cross sectional images of the chest or of the pelvis and AB or other head. But in this case, we're gonna focus on the chest. And that's what you see, what that, the arrow is pointing to calcium in the, in the LAD, the left anterior descending. And you can see a little bit of the left main stem, the shared stem, between the LAD and the circumflex. Okay? And so that's typically what calcium looks like. Now, why are we quantifying calcium? Well, my friend John Rumberger at Mayo Clinic, now at the Princeton Longevity Center in New Jersey, he did something brilliant. He took the arteries of a bunch of people who had died in car accidents or cancer

00:14:03
or some other cause, not car and heart disease, and then measured the calcium in the arteries, both with, uh, CAT scans and pathologically by looking at it under a microscope. And he determined that calcium occupies 20% of total atherosclerotic plaque volume. So if you had 20 cubic millimeters of calcium, that meant you had 100 cubic millimeters of total atherosclerotic plaque in all its elements. Fibrous tissue, calcium, uh, macrophages, inflammatory cells, dead cells, all this stuff, all the smorgasbord material. It comes in, in, uh, coronary atherosclerosis. You can gauge by this dipstick, this gauge called calcium. And he proved John Rumberger proved that the, uh, calcium area or calcium volume correlated very cleanly with plaque area or plaque volume. So when you do your 30 to 40 cross-sectional slices, you get a whole bunch of slices, and then you determine a score, you score the calcium. Now, the scoring system was developed by Dr. Arthur Agatston. You may know him as the, uh, cardiologist who wrote the South Beach Diet book, but he also in 1990 developed, helped develop a scoring system, uh, that's held till,

00:15:29
till today, 30 years later. That depends on, on a measure of density, a density coefficient multiplied by the area of the calcium, and then summed across all the slices, the 33, 35 whatever slices, cross-sectional slices, and the score can be anywhere from zero to many thousands. The score is accurate to plus or minus 10%. That's a little misleading because think of it, if you have a score of four and you repeat the scan and it's five, that would be defined as 25% inaccuracy, right? But it's really a trivial difference, right? Four to five. What if it was a score of 1,004 and you repeat it at the end and it was 1,005? Well, that's a trivial difference, right? Less than 1%. So we say accurate, the plus or minus 10%. But bear in mind that's very dependent on what the score is, okay? Now, there have been efforts to improve on the STEN score. One of the great criticisms of the score is that it grades density and density is probably not a big player in the behavior of plaque. And so there's, the most popular alternative has been the volumetric score, which only quantifies the volume

00:16:37
of calcium and thereby volume of plaque. But there's never, it's never been shown to be any better than the old fashioned Agatston score. So despite the criticisms of the Agatston score, the car calcium score you get quoted when you have a conventional heart scan, will be the Aden score. So who should have one of these CT heart scans? Well, first of all, we're gonna be people with no symptoms, right? If you have symptoms, no heart scan, go someplace else. Ha, go to ha go have your stress test or other tests, right? To find out why you, uh, have chest pain. Is it some other cause? Is it blockage in the heart? But a heart scan is not the test of choice in general, men, 40 and over, women 50 and over. The difference in age because men tend to have more heart disease as younger people. But those are soft cutoffs because you have to factor in some risk factors. What if you said, uh, what if you're a woman and you said, uh, my mom had a heart attack at age 47. Well, you shouldn't wait till 50, right? You might wanna get it at age 40. Maybe your mom had lipoprotein a had aggressive coronary disease, so you wanna do it earlier.

00:17:44
What if you're a guy who's 35 and you've been smoking two packs of cigarettes since age 14? You should probably go, uh, quit smoking first, of course, but then go maybe earlier than 40. So those age cutoffs are soft factor in things that are clearly risk factors. Uh, now here's where I disagree. A lot of guidelines, they often tell you heart scans are only for people of intermediate risk, not high risk by some measure, like a very high cholesterol or a family history. And you shouldn't have a heart scan if you're low risk, you don't have any. I think that's wrong because one of the things that, one of the great advantages of having a heart scan is that it gives you something to track. What if you're high risk and your score is 900 and you embark in a prevention program to put a stop to it, how are you gonna know you had an effect, right? Unless you have that score. So I think if you are an adult, you should have a heart scan problems. If you had a prior stent in one artery, that artery can no longer be scored. Now, often heart scan centers will tell you you

00:18:49
can't have a scoring at all. Well, that's not true. They can still score the two unstented arteries. The difference being they can't use the total score for prognostication purposes, right? They, you can't use that score to predict your future because the worst arteries has a stent in. You can't score it if you have stents in two arteries. Likewise, you can still score the one artery, but you've really eroded any kind of hope for prognosticating purposes. But you can still use that score of the unstented arteries to track, right? So if you have a stent, let's say in your right coronary artery, but unstented, LAD and circumflex, you can score those two arteries and maybe the score is 300. You can't compare your, you can't develop all these prognosticating uh, predictions about what that means. All you can do is use it to track. So if it's 300 today and 360 a year later, you know, your prevention program is inadequate, right? It gives you a tracking, uh, mechanism. Bypass surge is a problem because you're putting arteries

00:19:48
and veins into your coronary arteries and it changes the flow characteristics both above and below where the, uh, bypass graft is inserted. And so when you have bypass surgery, it really kind of eliminates the usefulness of a heart scan unless you don't have all arteries bypassed. Let's say you had the LAD and circumflex bypassed, but not your right coronary. Just like having stents in those other two arteries, you can still track the plaque in the right coronary. You can't use that score though for prognostic purposes. You can only use it for tracking purposes. What's the radiation exposure? There is radiation. It's about one. We say millisieverts of radiation. It's about 10 chest x-rays of radiation. It's not trivial, but it's not a lot. It's come down over the years too. Also, by the way, the original electron beam tomography device that I brought to Milwaukee was one millisieverts. And then when the early versions, the six eight slice, 16 slice, three two slice multi detector scanners cam, it was much higher. Much higher, tenfold higher. But they've since gotten it back down to the old fashioned level of the electron beam tomography device.

00:20:55
So, but they put this in perspective. If you had a heart catheterization or you had a nuclear stress test or conventional chest ct, a full chest ct or an abdominal and a pelvic CT, you would get more in that range. The five to 12 milli, which is roughly the same as about 300 chest x-rays equivalent. So while there is some radiation involved in getting a heart scan, it's relatively modest, but for the same reason, you don't wanna have one every month, right? We'll talk about how frequently you should have these things, but the radiation exposure is modest. So it does provide useful information, but don't be overly concerned with the radiation exposure. Okay? There is some good and putting radiation good to, to to good purpose. Okay, so we talked about in part one exactly what is a heart scan, right? It's a, it's a, it's a series of cross-sectional images generated on a CT heart scanner. Currently the, uh, third generation multi multi detector scanners. What is a coronary calcium score? And why measure calcium? 'cause calcium, we may not be, uh, uh, concerned per se. With calcium, we're using calcium

00:22:06
as a measuring device, right? Because it occupies 20% of total atherosclerotic plaque volume. So it tells you something about the burden of plaque in the heart's arteries. And it's so important to know this because it tripped up my colleagues for 20 years. Uh, heart scans gauge risk. It is not a good test for block, it's a lousy test for blockage. So, but that's how it's, it was designed to be that way. So you can't criticize for not being a good test for blockage. 'cause remember, we're not looking for blockages. We're looking to gauge risk by quantifying the total burden of atherosclerotic plaque in all three coronary arteries. Now we talk about who should have a heart scan. Now, in the next part, in part two that we'll do next week, we'll talk about how the coronary calcium score is useful for predicting cardiovascular events. Nasty things that no one wants to talk about, like heart attack, angina, sudden cardiac death, those kinds of things. And we'll talk about why the higher the score is, the greater the risk. We'll talk about why it is a test

00:23:13
that predicts risk very accurately, unlike other things like cholesterol values, why it's not a good test for blockage, and when should you go through additional testing? That's a common dilemma. Someone says, I have a, I had a heart scan score of 500. They said I need a nuclear stress test. Maybe a heart catheterization and need to go on Lipitor, all that stuff, right? So when do you know when those sorts of additional tests are necessary? When are they not necessary? And are, and the, and the doctors just using it to twist your arm to generate more revenues for himself and for the system. Okay? Very come. So that's what we'll talk about in part two.