Description

Cardiologist Dr. Jason Lui discusses the importance of the coronary artery calcium test used in assessing cardiovascular risk beyond traditional methods.

Dr Liu

Transcript

 


[00:00:08] Matthew DeVane, DO, FACC: Hi, I'm doctor Matt Devane.

[00:00:09] Carolyn Lacey, MD, FACC: And I'm doctor Carolyn Lacey. We are cardiologists at John Muir Health and this is our podcast, Living Heart Smart.

[00:00:16] Matthew DeVane, DO, FACC: Our physician partners and colleagues are going to help guide you through many different and important cardiovascular topics to help keep your heart happy and healthy.

[00:00:24] Carolyn Lacey, MD, FACC: Thank you for listening and we hope you enjoy our show. Hi, everybody. Thanks for being here again with us for another episode of Living Heart Smart. We're here again today with Doctor Jason Liu. He's one of our partners. We've heard him speak before. We're so happy that he's here with us again today. Thanks, Jason, for being here with us.

[00:00:47] Jason Lui, MD: Happy to be here.

[00:00:48] Carolyn Lacey, MD, FACC: Matt, did you notice that as we were preparing for today's talk, that it seems that Doctor Liu doesn't need sleep?

[00:00:57] Matthew DeVane, DO, FACC: I have noticed that before. He's the only person in the group that I get notes from. Like at 1 a.m. 1 a.m.? He's been working all weekend. So you don't need much sleep, do you? We don't.

[00:01:06] Carolyn Lacey, MD, FACC: Understand.

[00:01:07] Matthew DeVane, DO, FACC: That. You are a machine.

[00:01:09] Jason Lui, MD: Yeah. No, I'm a night owl. I'm a night owl. But but I have. I have a little bit of me time once I get home, okay? Somehow ends up with me doing more work in the 12.

[00:01:19] Carolyn Lacey, MD, FACC: Well, we're so happy that you're going to be that. You're here with us again today. Well, I.

[00:01:23] Matthew DeVane, DO, FACC: Know Jason shares a passion for this test that we're going to be talking about today. We're going to be talking about the coronary artery calcium test. It's a test that's been around for at least a decade or so, but it was massively underutilized until recently. Massively. And I can tell you right now, it of all the tests that you can do in cardiology, I've never seen patients respond to lifestyle changes, living healthier and being smarter about the decisions. Then after they've had the coronary artery calcium test. This test is really unbelievable. I find it very useful. It's easy, it's low risk, and it gives you unbelievable data about your heart arteries.

[00:02:03] Carolyn Lacey, MD, FACC: I completely agree with that. I actually saw someone today who has made fantastic changes in their lifestyle over the course of a couple of years with really great exercise routines, trying to be able to eat very healthy with their diet, taking their medications. And this is a test that it's a game changer. And I truly believe that when you show a patient when we're showing our patients their calcium scores and we show them, look, this is what your arteries have in.

[00:02:34] Matthew DeVane, DO, FACC: Them, this is what's happening in your body.

[00:02:35] Carolyn Lacey, MD, FACC: Great. The guessing is gone.

[00:02:37] Matthew DeVane, DO, FACC: Right? So I think before we get into the test itself, Doctor Liu, if you would mind just giving us a. I think in order to understand why this test is so useful and helpful for us is to just kind of give the very basics of what atherosclerosis is, what this test is, looking at, it, and how it's different than other tests that people are more familiar with, like stress testing.

[00:02:56] Jason Lui, MD: Um, so the the idea behind atherosclerosis is, is that, you know, these cholesterol particles, like LDL, they infiltrate the inner lining of the artery, and they they accumulate and it is noxious to the artery. It's causing a lot of inflammation. There's, um, white blood cells that are that are kind of attacking, gobbling and causing more inflammation. And as a part of that process, it eventually heals. And that healing, believe it or not, is the development of calcium in my in my from my point of view, seeing calcium on the arteries is no different than seeing a scar on your skin, right? These are plaques that have gone through inflammation that are starting to heal. And to see calcium on your arteries means that there is plaque there.

[00:03:48] Matthew DeVane, DO, FACC: That's a great description of it. And, you know, we tell people about hardening of the arteries. And I'm doing that in quotes is because people kind of heard that term before. But that hardening is calcium. And the unbelievable thing about atherosclerosis is that by the time you see those earliest plaques in a human's arteries aged 15 or 20 years old, by the time you see the calcium, it can be 15 or 20 years later. So this test is looking for calcium in the arteries. But by the time you see calcium, this process is decades old.

[00:04:18] Carolyn Lacey, MD, FACC: Matt, I totally agree. I have so many patients that come into the office to see me and they just want to, quote, get their heart checked out. And to them, that means they're leaving the cardiology office with an order for a stress test. And that's that's actually not the way I think about calculating or estimating someone's risk for having a heart attack or stroke.

[00:04:40] Jason Lui, MD: I absolutely agree, and the way that I counsel my patients regarding stress tests is that, you know, the stress tests we're in, we're looking for clinically significant disease. We're talking about, um, you know, arteries that are potentially 70% blocked that would result in a positive stress test or symptoms, right, going into that, you know, but you can, you know, the benefit of the coronary calcium score is that it? It can detect plaque regardless of the degree of severity, because you can argue you'd rather start treating it before it becomes 70% blocked. Right. Um, and so I think that's the, the benefit when.

[00:05:20] Matthew DeVane, DO, FACC: You, when the, the thing I love about these tests is kind of picking up the very earliest plaque in the arteries that have hardened over time. Well, before you get to the point where stress tests would be abnormal. So the benefit to a patient with no symptoms. Now, if someone comes to you with chest pain or other symptoms of stress test is the preferred test, of course. But in people who just want to know what their risks are and want to know how their arteries are. Want to know how aggressive to be with treating that cholesterol? Should I be starting a medication like a statin drug? This test has really been a game changer to help open people's minds, see their arteries, see what's really happening inside their bodies.

[00:05:55] Carolyn Lacey, MD, FACC: So I think all of us were on a coronary calcium grand rounds talk where where the physician who is presenting, he called the coronary artery calcium score a mammogram for the heart. And that sort of really resonated with me and stuck with me.

[00:06:11] Matthew DeVane, DO, FACC: I think that's so interesting and almost should everybody, everybody should be getting one of these calcium tests. In my opinion.

[00:06:17] Carolyn Lacey, MD, FACC: Prior to ordering calcium scores, we still estimated people's risk. We still made calculations about what your risk is for having a heart attack, and the calcium score really has improved upon that risk calculation. Can you can you tell us more, Jason, about the risk calculation that we used to use and how we've moved into calcium score? Why that seems to be a better test to use overall.

[00:06:41] Jason Lui, MD: Yeah. And so our traditional way of assessing risk is using the pooled cohort equation. And what this equation takes into account is your age, right. Your your blood pressures, your history of smoking diabetes and estimates what your ten year within your ten year risk of heart of a cardiac event. And the issue with this right is that one, it's only a ten year estimate for a problem that is cumulative. Right. Number two, there are many issues that are not addressed by the pooled cohort equation. You know, age features heavily, right. But there are families with young family members are having heart disease. How do you take into account family history? There has to be a way that we can consolidate that image into one picture. And this is exactly where where calcium scoring comes in it. It embodies the concept of pictures, a thousand words. That calcium score represents the sum damage of everything that you've experienced. Of all your risk factors, of all your history, your family history and all.

[00:07:57] Carolyn Lacey, MD, FACC: Throughout the course of your life. Yeah.

[00:07:59] Jason Lui, MD: All compressed into that image. And that is the. That's the advantage of the calcium score.

[00:08:06] Matthew DeVane, DO, FACC: And I think the other thing that it does, it is a some picture of all those risks. But the human body is so unique and difficult to evaluate that oftentimes people with many of those risks actually don't have much brewing in their arteries. So especially a lot of people that I see that say they have this terrible family history of heart disease, they're so worried about it, yet they've led a good life. They've been exercising, they've been eating healthier than their father or grandfather, whoever. And so a calcium test in my mind, is another way to help just move that conversation to a different spot. And it really helps a lot of people. Yeah.

[00:08:40] Carolyn Lacey, MD, FACC: And I think that was a great example of how you've taken someone who feels like they have such a rough, hard, bad family history and now you've been able to de-escalate their how much they think they're at risk for having a heart attack or stroke based on having a zero calcium score. And sometimes we even use this to help back off on medications in some patients.

[00:09:06] Matthew DeVane, DO, FACC: Yeah, we'll just say I sometimes use it as a I call it a tie breaker. Someone comes in, their cholesterol is elevated, their physician is recommended a statin medication to lower that. But patient wants to avoid medicines if they can. And so I kind of use this calcium test to help de-escalate for someone that has, you know, normal looking arteries to help say, okay, you need to make lifestyle changes, but maybe we can back off or hold off on the medication at this time. Another great way to use this test. Doctor Lou, if you wouldn't mind, we'd be talking about this test now for a while. But what the heck is it? Let's get into some basics of what someone can expect if their physician orders a coronary artery calcium test.

[00:09:42] Jason Lui, MD: So the CT coronary calcium scan. It's a quick study. You know these things. Ten minutes you're in, you lie down on the scanner bed, you zip in and out and you're done.

[00:09:53] Matthew DeVane, DO, FACC: I tell people also just there's no IV, there's no prep. You just go into the CT scanning area. You lay down in ten minutes. 15 minutes later, you're walking out.

[00:10:03] Carolyn Lacey, MD, FACC: No contrast, no contrast.

[00:10:05] Jason Lui, MD: And the beauty of it is that it is low radiation dose. And so if I were to quantify it's it's roughly around a third to a half of the amount of radiation that you would just get with natural exposure in a year just walking.

[00:10:21] Matthew DeVane, DO, FACC: Around Earth, you get some radiation. Right? Right.

[00:10:23] Jason Lui, MD: Um, and so but the the wealth of information that it provides in terms of preventing, you know, you know, progression of chronic disease is, is, is enormous relative to that risk. And so.

[00:10:37] Matthew DeVane, DO, FACC: So the test is going to give the patient a score, a normal score is zero. And then where does it go from there.

[00:10:44] Jason Lui, MD: Yeah. And so there's a lot of thought in terms of how to quantify risk based off of coronary CT calcium scan. And one there's two approaches to it right. One is percentile right. And the other one is an absolute score. Those young patients like a patient who's 40 years old who has a single spec of calcium, an agatston score of one that's already abnormal. Yeah, right. You should not have any calcium at 40. Right. And so the absolute score is low, but the patient is well over the 75th percentile. And the thought is that patients who are above the 75th percentile are considered higher risk. Um, now the other approach was the score of 300 and above. And when they when they look at data with patients who have a score of 300 or above, they are as likely, um, of having a future cardiovascular event as someone who has already had a heart attack. And so, you know, I use that hard 300 cutoff in my mind. I'm treating you as if you've already had a heart attack. Yeah.

[00:11:48] Matthew DeVane, DO, FACC: Those are the highest risk patients that we have, right? Somebody already had an event. Once a patient gets there, his or her calcium score, is there any other testing that gets triggered by the results.

[00:11:59] Jason Lui, MD: So this is where there's a lot of variety in terms of how we practice. And I can tell you a little bit about how I do it. Um, so a patient, you know, with a high calcium score, let's say, you know, we use that 300 cutoff, this is this gives me an opportunity to really dive into their clinical history. It allows I focus a lot more on their exertional tolerance. You know, the the issue with cardiovascular disease is it's a supply and demand problem, right? The more significant a blockage, the less supply of blood that the the heart gets and the more pain you get. And so that's where I, I really, really, really inquire about their exercise. Because if, if that patient has a calcium score of 300, but he's, he's, he's running marathons, he's hiking up hills and he's not having a single, a single smidge of a symptom. Um, I'm usually okay without any further testing. But for some of those patients who we don't have a reliable story or reliable history, or maybe it it gives me an opportunity to question their, um, symptoms a little bit more. Maybe I do feel a little bit of shoulder pain. Maybe. I feel a little bit of pain in my neck and then that would lead to stress testing.

[00:13:11] Carolyn Lacey, MD, FACC: Six months ago I was able to walk up this hill at such and such a pace. But now, you know, I don't. I just really don't feel like I want to walk up that hill anymore. Those very subtle symptoms. And I think.

[00:13:23] Matthew DeVane, DO, FACC: For a lot of patients we see they're not exercising. And so maybe before you're going to recommend because what we're going to recommend to them is an aggressive exercise program. So for some of those patients I also like to do a stress test just to make sure it's safe for me to start pushing them a little bit.

[00:13:38] Carolyn Lacey, MD, FACC: That's a good.

[00:13:38] Matthew DeVane, DO, FACC: Point. Yeah. Okay. So stress testing for those with potential symptoms for those that are not exercising enough and for those with higher scores makes sense. Yeah, for many reasons. I really think the calcium test is so helpful for us. But it's not a perfect test. Right. So there are some things we miss. What the test is seeing is the hardened plaque inside the arteries, but there's also likely some soft plaque in there too that we can't see.

[00:14:02] Jason Lui, MD: Yeah. Correct. So and I'm going to go back to that example I used earlier about our 40 year old within of a calcium score of one. Right. As you said, the only the only plaque that we see is a plaque that's calcified. But let's look at that score of one. Right. Calcification is not a all or none process. It starts gradually. You get a speck of calcium, and then gradually the rest of the plaque starts to calcify as it heals, right, so to speak, or hardens. So when you see that speck of calcium, it implies that there are is soft plaque that is in the process of scarring. And so, you know, one of my patients, some of my patients ask, oh, should I repeat a CT calcium score to see if there's progression? Right. We start you on therapy. But the idea behind therapy is to stabilize plaque. And honestly those are there's going to have there's going to be progression of calcification because there's soft plaque that we haven't visualized that's still in the process of scarring and becoming calcified.

[00:15:05] Matthew DeVane, DO, FACC: Even with appropriate and aggressive treatment, that soft black will harden over time. Some of it may regress, but most of it's just going to harden. Right.

[00:15:13] Jason Lui, MD: And the idea is if we can get to treatment early enough right. There are there are some studies that have shown, you know, with aggressive management of risk factors, with aggressive lowering of LDL, that we can get some plaque regression. Right. The soft plaque that hasn't completely calcified. We have an opportunity to make inroads in terms of reducing the plaque burden. We won't get rid of it entirely, but you can make some inroads into that. And the other thing you want to prevent is development of new soft plaque elsewhere in the artery. And so this is how this is how identification of of of calcium can help drive therapy. Again we also the question is how aggressive are we with therapy. Right. And so if you think about it our our goals for LDL lowering therapy. Right. If I see a patient with a calcium score of 300 who in retrospective studies have shown that they have the same risk as someone that's already had a heart attack, that tells me that I need to aim for lower LDL goals as opposed to someone, for example, with a with a lower calcium score, or more importantly, especially for the younger patients, like a lower percentile.

[00:16:29] Matthew DeVane, DO, FACC: Yeah. And I think that's what I'm doing now. I think I'm using this test as a way to help set LDL targets. And when we see almost any score, any calcium score that's positive, anything non-zero, I'm taking that LDL and most of my patients at least less than 70, but most less than 55. Now.

[00:16:47] Carolyn Lacey, MD, FACC: Jason, can you describe for us a little bit more? You had a nuanced you had a nuance there between what your score is and your percentile. Can you just tell us a little bit more of how you use the difference between the score and the percentile for age?

[00:17:05] Jason Lui, MD: So atherosclerosis is sort of is a long a lifelong process, you know, to see even a speck of calcium in a patient who's 40 years old implies that there's been years IV to decades of soft plaque that has, has accumulated enough to have even a kernel of calcification. And that is when the percentile matters, right? Because otherwise, if you look at the absolute score, it just doesn't seem like very much. Right? But if that if that calcium score of 1 or 3 is puts you in the 99th percentile or above the 75th percentile, um, that is a higher lifelong risk of cardiovascular disease that needs to be addressed sooner early.

[00:17:55] Matthew DeVane, DO, FACC: Right?

[00:17:55] Jason Lui, MD: Right.

[00:17:56] Matthew DeVane, DO, FACC: I think that's so important is is putting your score in perspective. You brought up something earlier. I just wanted to loop back around. We we talked a lot of our patients are concerned about. Getting a repeat scan. And at least for my patients, I'm only getting a repeat coronary artery calcium test for those that get a score of zero. And then I'll potentially repeat that in three, 4 or 5 years. But for someone that's got a positive score, Jason, are you getting repeat scans and if so, why? If not, why not? Yeah.

[00:18:24] Jason Lui, MD: My practice is the same as yours. You know, for my patients who have a positive scan, I'm already on a treatment regimen. I'm already is being as aggressive as possible with managing risk. There is no purpose in repeating the scan because it's, you know, it's already given us an answer. Right. Um, and.

[00:18:41] Carolyn Lacey, MD, FACC: I think just when you say a positive scan, you mean a non-zero score, correct?

[00:18:47] Jason Lui, MD: Yeah. Right. Yeah, yeah. So a patient with a non-zero score, it's already given us an answer. We know that they have coronary artery disease. Um, and in the circumstance, the circumstances where I would repeat, um, a calcium scan in 5 to 10 years, like you, like you said yourself, is in those patients with a calcium score of zero, but choose not to treat or choose not to address, um, their lifestyles, their risk factors.

[00:19:17] Matthew DeVane, DO, FACC: Well, that's a good point, right?

[00:19:18] Carolyn Lacey, MD, FACC: That is a good point. And it also sort of brings things back that atherosclerosis is a lifelong process and that there can be changes as life progresses.

[00:19:29] Matthew DeVane, DO, FACC: Yeah. And I think what you just said, both of you guys said it well, but a zero score doesn't mean no atherosclerosis and doesn't mean don't treat. It means maybe you can put push back the statin drug a little bit depending on what your, you know, overall risk are. But it's important just to remind people that a zero doesn't mean freedom. It means you still need to be sparred if you have other risks.

[00:19:50] Carolyn Lacey, MD, FACC: So it is important to realize that a score of zero is not a free for all. You don't get to just go out and eat whatever you want and eat all the saturated.

[00:20:01] Matthew DeVane, DO, FACC: Fat and take.

[00:20:01] Carolyn Lacey, MD, FACC: Medicine and not take medicines and all those things, but it does change your risk.

[00:20:08] Matthew DeVane, DO, FACC: Yeah, it's a risk identifier for sure. And your risk in the short term may be low if your score is zero. Now there is something there's a concept called the power of zero when it comes to calcium scores. Doctor Lou, can you comment on this power of zero and what that means to you as far as how you treat your patients?

[00:20:24] Jason Lui, MD: And so I want to say there's really two lines of thought in terms of how to interpret the power of zero. The way I look at it, you know, age is a feature in this. Right? And so imagine, you know, a 70 year old patient with a score of zero, that means in seven decades of their life, with all the sum of their risk factors, all their environmental exposures, all their family history, that they didn't even have enough soft plaque to even form a speck of calcium that says something. And I think those patients are truly, truly low risk, you know? But of course, like you look in the younger populations who may not have time to mature coronary calcium, the power of zero and needs to be taken with a little bit of caution. But, you know, in the right age group it says a lot. It really does. And I think.

[00:21:15] Carolyn Lacey, MD, FACC: That brings up the concept of serial testing in a zero score patient who is on the younger side in their 40s. 50s can you may continue to do further repeat calcium scoring because their score was zero. We expect to start seeing some calcium.

[00:21:32] Matthew DeVane, DO, FACC: At some point. Yeah, at some point. Well, I think we all agree that this is a fantastic test that many of our patients would benefit from. But I got to imagine there are some patients out there that shouldn't be getting a coronary calcium test. Doctor Lou, can you comment on who those people are?

[00:21:45] Jason Lui, MD: Yeah. So there are patients who have known, um, cardiac disease, people who've already had a history of a heart attack at stents implanted, um, you know, and those patients, those the question's already answered. Right. We already know. Needed to address them, um, aggressively.

[00:22:04] Matthew DeVane, DO, FACC: I think the only other patient population would be the very young. Right. Do you have a lower limit set?

[00:22:10] Jason Lui, MD: Yeah, I use I use 40 as my cutoff. And really the 40 are those patients with a family history of MI in their 40s and 50s, um, where I absolutely need to, to know what their risk factors, how aggressive do I need to be right off the bat? I don't have a I don't have an upper limit. Right. But that's that's because yeah.

[00:22:31] Carolyn Lacey, MD, FACC: 40 is my lower limit. Yeah.

[00:22:32] Jason Lui, MD: Yeah yeah.

[00:22:33] Carolyn Lacey, MD, FACC: Age as well. Perfect. I think the other patients too, if you've had stroke, if you've had uh, peripheral arterial disease, if you've had aneurysm like abdominal aortic aneurysm or things like that. Those are also patients that I'm not getting calcium scores in. We're already treating them. They've already shown us that they have severe atherosclerotic disease, even if it's not in their heart, they have it in other areas of their bodies. And that will put them at risk for having disease in their heart as well.

[00:23:00] Jason Lui, MD: That's absolutely right. Yeah.

[00:23:01] Matthew DeVane, DO, FACC: Because atherosclerosis is usually not one body part. It goes everywhere, everywhere. Once the diagnosis has been made somewhere then calcium testing is really no longer needed. Okay. So please everybody out there 40 years and above, talk to your doctors, see if a coronary artery calcium test may be right for you. I think I've just we've all seen it be a major game changer in how we treat people and how people can change their lives around this one test.

[00:23:25] Carolyn Lacey, MD, FACC: This is a regular test that I'm ordering. We do this test here at John Muir Health. It's a Cat scan. One of the things that we found, though, that insurance companies really haven't paid for this test very well, and hopefully that will change over the years. But as of right now, most insurance companies are not covering it as part of their plans. So there is a cash price that covers the equipment fees, the technician fees. And that's $250 right now at John Muir Health warned.

[00:23:55] Matthew DeVane, DO, FACC: My patients there's going to be out of pocket expense. But I also talked to them about the potential benefit. And it's money well spent when it comes to your health, right.

[00:24:03] Jason Lui, MD: Small cost for a wealth of information.

[00:24:05] Matthew DeVane, DO, FACC: Doctor Lou, thank you so much. This was a fantastic discussion. I really appreciate you being here and discussing it with us tonight.

[00:24:12] Jason Lui, MD: Thanks again for having me. I love talking about this stuff with you guys.

[00:24:15] Matthew DeVane, DO, FACC: You'll be back.

[00:24:16] Carolyn Lacey, MD, FACC: We'd love to hear from our listeners out there. What do you want to listen to? What can we do better? Please feel free to drop us a line.


[00:24:25] Matthew DeVane, DO, FACC: Please let us know we're here for you. Thank you. This is Doctor Matt Devane and on behalf of my co-host, Doctor Carolyn Lacey and our partners at John Muir Health, we hope that you enjoyed this show and we really hope that you keep living heart smart.

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