Deep Dive on Cardiac CTs
Empallo Heart-to-Heart
Welcome to the pilot episode of Empallo Heart-to-Heart. This video blog came to life after we realized that many of our patients have similar questions about topics like managing heart conditions and cardiac testing. We thought it’d be helpful to explore these questions in more depth.
In today’s episode, Claire Beskin (CEO, Empallo), Dr. Dana Weisshaar (Medical Director, Empallo), and Joe Lemay (CEO, Longevity Athlete) dive into CT scans. We’ve also included some behind-the-scenes "outtakes" at the end where we chat more casually about Dr. Dana's approach to patient care, education, and some ideas for future episodes.
We hope you find this helpful and engaging! We’d love to hear your thoughts, so feel free to drop us feedback in the contact form on our website.
Check out the episode on Youtube. Enjoy!
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[Transcript]
Claire Beskin: Hey everyone, today we're going to talk about cardiac CT's. Maybe you've been asked by a cardiologist or another healthcare provider to go get a cardiac CT. And today we're going to talk about questions that commonly come up. I'm Claire Beskin, CEO of Empallo, and I'm joined by Dr. Dana Weisshaar, who is an advanced heart failure cardiologist and is also medical director to Empallo. We are kicking off an 'Ask the Expert' series for questions that commonly come up with cardiac testing. And today we're talking about cardiac CTs.
Claire Beskin: Two main types: cardiac CT's for coronary artery calcium scoring, and there's coronary CT angiograms. These two tests are often shortened to CT CACs and CCTAs. Now, that's a lot of similar sounding letters. So, Dr. Dana, could you talk to us a bit about the difference between the two?
Dana Weisshaar, MD: I sure can. Thanks. It is a mouthful, right? C-T-C-A-C and C-C-T-A. What these look at are basically two different types of ways to look at artery disease in the heart. Let me just start by explaining coronary artery disease is the development of plaque in the arteries supplying blood to the heart. We all have some mild soft plaque by the time we're 18-20 years old. And some people are predisposed to developing more plaque faster. And those are people who smoke, who have a family history of atherosclerosis or hardening of the arteries, who have high cholesterol, high blood pressure, or diabetes. As we get older, that plaque can build up. And if the soft plaque narrows to a point where it impinges the blood flow, patients can have symptoms of chest pain when they exert themselves or angina.
Dana Weisshaar, MD: When we have patients who have symptoms suggestive of possible angina, we often times will do imaging to assess the actual outline of the arteries. That's the CCTA, the cardiac CT, computed tomography angiography. So angiography, meaning we inject contrast and look at the outline of the artery to see where it's narrowed. That's different than a CT for calcium because the other way coronary plaque can affect us is if that plaque becomes calcified or hardened. So you've heard of hardening of the arteries. The hardening is the calcium depositing in that plaque. And that can also be seen on CT scan.
Dana Weisshaar, MD: By the way, CT computed tomography is an X-ray imaging of the heart in multiple very quick layers that will give us very fine detail. So we can do a very fast 5-minute quick CT with no contrast and just see if there's bright areas that suggest calcium has been deposited. And we can measure how much calcium has been deposited and in what part of the heart. So that tells us not whether or not you've got enough plaque to impede the blood flow, but whether that plaque has started to harden. That becomes really important because calcium, or hardening of the plaque, risks rupture. Think about breaking of the plaque and that's what can induce heart attacks rather than just a narrowing of the artery that impedes the blood flow. Does that make sense?
Claire Beskin: What might be helpful is to see some images of the two different types of tests. But I'm going to save that for the end because I do have a few other questions. A question that commonly comes up is whether to fast for these tests. So what's the scoop on that?
Dana Weisshaar, MD: Okay. So, if you're having a coronary CTA, the angiogram, we will be injecting dye or contrast through an IV. And we do recommend that people fast before that test for at least 6 hours. If you're having a coronary CT or cardiac CT for coronary artery calcium, you don't need to fast. It doesn't involve any contrast, doesn't involve an IV. We just lay you on the table and take a quick five minute CT scan to look at the calcium score.
Claire Beskin: So no fasting for CAC, but you do need to fast about six hours for the CCTA. What about caffeine?
Dana Weisshaar, MD: Caffeine. So we do recommend that people avoid caffeine before these tests, not because it affects the outcome of the test, but because we gate the X-ray images to the heart signal, electrical signal. So they'll put EKG patches on when you have your CT scan. The reason we've got it gated is if you think about it, the heart's in motion all the time. And so it it can actually swing in the chest and that blurs X-ray images. So by gating it, we can capture the image at the same point in the heart's swing or the same point in the heart's rhythm and so we can catch it in a still moment and get clearer images. So, caffeine is best to be avoided for at least eight hours beforehand to keep the heart rate from spiking.
Claire Beskin: Got to skip that coffee and tea. Another question that comes up is, "What should I wear for the test?"
Dana Weisshaar, MD: For the most part, you they'll have you wear a hospital gown. So, you'll just need to disrobe from the waist up. So, I generally just recommend something that's easy to get in and out of. Also, if you are wearing a a bra, for instance, with an underwire, it'll show up on the X-ray. I usually just recommend you go with just the hospital gown, nothing else underneath, no jewelry, and something comfortable.
Claire Beskin: Okay, that's great. One thing you mentioned is contrast dyes. What are they? When are they used? Why are they used? Could you tell us a bit more about that?
Dana Weisshaar, MD: A contrast dye is injected into a vein in your - usually in your arm and it shows us where the blood flows. So on CT scan, X-rays, we don't see blood. Blood just looks dark. So if we want to see where the blood goes, we have to light it up so that it shows up on the CT scan. So what we do, we inject it. We give it time to circulate and then see where it lights up. Where the blood flows is where it then turns white. And you'll see that when we go over the images of what a CT looks like.
Claire Beskin: Okay, I'm looking forward to that. I have one more question before we move over to the images. A question I'll admit I often have before a medical procedure or a test is, is it going to hurt? So, can you tell us a bit about that?
Dana Weisshaar, MD: That's a great question. I think we all want to know that. The IV will pinch when we put it in. The dye or the contrast agent sometimes will burn a little bit when it's injected. It doesn't hurt though to have a CT scan. I think all of us have had X-rays. There's no pain involved with an X-ray. So, the hardest part I think is getting the IV and then lying still for the test.
Claire Beskin: Okay, that's a relief. And now for the visual learners, I'm wondering if we could see some examples of, you know, what do these medical images look like and what do cardiologists look for in the two different types of imaging?
Dana Weisshaar, MD: Yeah, let me pull up a browser. First, I'm going to share my screen. So, let's just Google it. So, coronary CT angiogram... and you can see the first thing that pops up here is this image of your artery. So, you can see how I mentioned we inject contrast and we can see then where the blood flows through the arteries. So here is a cross-section. So imagine your heart is a gray blob and the aorta is this main blood vessel coming off of the heart where the blood flows and off of that aorta are these blood vessels that carry blood around to the heart muscle. So you can see the outline of those arteries. You can also see these really white patches. Can you see that, or do I need to make it larger? That's the coronary calcium. Remember I said calcium is bright on X-ray. So you can imagine that if we just do the CT scan without the contrast, you can still see how much calcium there is. So I'll show you an image that shows the difference. Also with the ability to use our computers to post-process our imaging, we can lay out the whole artery and see that here and here, there are areas of tight narrowing and this is in the right coronary artery. Whereas this is the left anterior descending artery which is the artery down the front of the heart. And you can see in this image there's a lot of calcium and some narrowing. And then our third major artery is called the circumflex artery which we abbreviate as Cx. And you can see the contrast outlines well here and outlines well here. But then there's this really narrowed area where we don't see any contrast. So those are examples of how we use coronary CCTA.
Dana Weisshaar, MD: Now let me show you just the coronary calcium score. Again, we can see the heart, but we don't see, so this is a heart without coronary calcium. So, coronary calcium score of zero. And you can see where the artery is, but it's not lit up because there's no calcium, nor is there any contrast. Then, if we get a little bit of contrast, our coronary artery score goes above zero but less than 100, we get more calcium and our coronary calcium score higher. And then someone who has extensive coronary calcium might have a score like this of 1,200. You can also see on the CT scan the descending aorta, the part that goes down from the chest to the rest of the body. And in this patient, there's a lot of calcium in that artery as well. So cardiologists use the coronary calcium score to help determine when patients have intermediate risk for coronary disease to determine whether there's coronary disease present or there's no calcium present. And that helps us decide, in someone who's got some elevation of their cholesterol, whether or not we should start them on medications to lower the cholesterol. Because once you start to develop calcium in your arteries, you have that hardened plaque that puts you at risk for heart attacks and we should put you on statin medication to stabilize the plaque and lower the cholesterol.
Joe Lemay: I have a couple questions.
Dana Weisshaar, MD: Please.
Joe Lemay: I can definitely see with my eyes that the zero has no white and the 1,200 has a lot of white, you know, calcium. But how are these scores computed? Are they run through a computer? Is there judgment? How how does that happen?
Dana Weisshaar, MD: That's a great question. It is run through a computer and it's graded based on how much calcium there is. And you can kind of think of it as how many pixels of calcium are there. So this would be mild, this would be moderate, and this is definitely severe.
Claire Beskin: As a cardiologist, when you see a score of 29 versus 250 versus 1,200, what are the typical next steps? It sounds like medication is an option, for example, for a score of 29. How might the options look different for someone who has more severe calcium?
Dana Weisshaar, MD: For all of these patients, they should be on statin medication to try to stabilize the plaque, to reduce the risk of it rupturing, and reduce the risk of having a heart attack. For patients who have mild to moderate coronary disease, we target a LDL cholesterol, low density lipoprotein cholesterol under 100. For patients with more severe disease or patients who've had a prior heart attack or a stent, we drive that number down less than 70. In some cases, even lower, less than 50. So it helps us determine what our target for our LDL should be. Additionally, in someone who has more severe disease, I would be asking more about symptoms because maybe they have angina or limitation to their activity because they don't have enough blood flow through the artery. And so someone with a high coronary calcium score may need a stress test or an angiogram, whether or not it's a CT angiogram or an invasive angiogram where the interventional cardiologist actually takes a catheter up through the artery and injects dye in real time to see where there's narrowing which can be helpful in determining if a stent or a bypass is necessary.
Dana Weisshaar, MD: Let's get a little bit into a conversation for another day about: when does one get a stent, or when does one do bypass surgery? The basic answer is: based on patients' symptoms and the location and the severity of the disease, we'll either choose medical therapy procedural based therapies like stents angioplasty or surgical-based therapies like a bypass surgery.
Joe Lemay: I have a sort of a brewing question. I'm not sure if I know how to articulate it right. you know clearly I can see 1,200 is big and zero is nothing. At what score would a patient start to get concerned and does it depend on their age?
Dana Weisshaar, MD: So I think we have to talk about what concerned means, right? So if concerned means ‘care’, we should all care about our heart health. And so it doesn't matter what your score is. We should be doing things to help preserve our heart health. We should know our numbers. That means know your blood pressure, know your LDL cholesterol, know your blood sugar or your hemoglobin A1C, know your family history. These things are well, we can't change our family history, but the other things are modifiable parameters that we can address in order to lower our risk of heart attack and stroke.
Dana Weisshaar, MD: So if you smoke, stop smoking. If you don't smoke, don't start. If you are diabetic, make sure your blood sugars are well controlled. If you have high blood pressure, we want the blood pressure to be well controlled. If you have high cholesterol, understanding what your cholesterol target should be and then treating that either through diet, exercise, or medications.
Dana Weisshaar, MD: So even if we have a coronary calcium score of zero, we should all be concerned about our heart health.
Dana Weisshaar, MD: If we have a coronary calcium score that shows we have mild disease, we know now that we have coronary disease, we know we should be on a statin and we know we should have an LDL target of less than 100 and we should still be doing all the heart health things. Exercise, diet, don't smoke, control your sugars, control your weight.
Dana Weisshaar, MD: Now, if I have a patient who has plaque, I also make sure I educate them. You have coronary artery disease. If you develop severe crushing or heavy or pressure-like chest discomfort, go to the emergency department and say, "I have coronary disease and I have crushing chest pain." It gets the whole medical apparatus and the whole mechanism moving more quickly toward either confirming or ruling out a heart attack. That risk is lower in someone who's got a score of zero and higher in someone who's got a really high score.
Claire Beskin: What are some of the symptoms for people to look out for to know that they might be having a heart attack? Sometimes people don't realize that they're having a heart attack.
Dana Weisshaar, MD: Yeah. Yeah. The classic heart attack is the crushing substernal. That means midchest discomfort. I have an elephant sitting on my chest. It sometimes will radiate up into the arms or the jaw. It's sometimes associated with shortness of breath, sweating, nausea. That's kind of the classic presentation. In patients who don't have a typical presentation, it can be any of those other things. It can be the: suddenly nauseated and sweating and maybe feeling short of breath, but maybe they just don't feel right. They don't know what it is. So, each patient is a little bit different.
Dana Weisshaar, MD: We know that women tend to have less classic presentation for their heart attacks than men, partly because the classic presentation was described in a mostly male population.
Dana Weisshaar, MD: Diabetics oftentimes don't have the classic chest pain syndrome.
Dana Weisshaar, MD: That said, I see a lot of patients who have chest pain who aren't having a heart attack. So, it really is more about understanding your risk factors, understanding your age group. So, it's unusual for a 30-year-old to have a heart attack. Not unheard of, particularly in patients who are smokers who have high cholesterol and who have a family history of early heart disease.
Joe Lemay: I've sort of heard about some interesting studies that they took some subjects who who were a bit older and they ran them through certain maybe high-intensity cardio programs, or medium-intensity cardio programs, and then they looked at their heart afterward and they said, functionally, looking at the tissues, they were described as being a lot younger. But I don't know what that means. And like we're looking at scans here. If someone went through that, I would imagine calcium is for good, right? Once you have the calcium, it doesn't go away. But maybe in those studies we're talking about like what the muscle tissue looked like, or fat distribution. What do you think they were talking about when they said "looked younger"? Cuz probably not. Or maybe I'll just throw that at you. Maybe you could say what what the heck were they talking about?
Dana Weisshaar, MD: That's a great question. I don't think about hearts looking younger or older. The calcium is there to stay. So, the calcium doesn't go away, which is part of why some people ask me, should I get my coronary calcium score checked on a regular basis to see how it's progressing? And the answer is no. It's really just a one time thing. Once you've got calcium, you've got coronary artery disease, and it's told us what it needs to do. Only in patients who have some risk factors but kind of are in that intermediate risk group might I repeat a coronary calcium score several years later to see if now they've developed it if they had a score of zero before. But once you've got calcium, you've got calcium and it doesn't go away.
Dana Weisshaar, MD: What I do think about in terms of exercise and your heart is when I think about a healthier heart. I think about one that has good function, meaning, you know, our heart's a muscle and it squeezes and it ejects the blood. And so I think about hearts having good strength, good relaxation because relaxation is not just like a balloon that you deflate that's passive. It's actually an active process. So it's called your diastolic function. So people who exercise squeeze and relax well.
Dana Weisshaar, MD: Also our heart rates are sometimes a marker of our heart fitness. So people who exercise tend to have lower resting heart rates and a quicker recovery time. So when we exercise, our heart rate goes up. And when we're in better physical condition, our heart rate comes down more quickly. Recovers back to a baseline more quickly.
Dana Weisshaar, MD: So when you say things like, well, exercise made the heart appear younger, I can think of either that it had a lower resting heart rate, a quicker heart rate recovery, or that they're talking about it had a certain vigor to it on maybe an echocardiogram.
Dana Weisshaar, MD: We do know cardiac rehab is super beneficial and that exercise is great for the heart. So that's the other thing that the American Heart Association, and I, recommend, which is at least 30 minutes of moderate activity at least 5 days a week. Get out, walk, jog, bike, swim, dance. It kind of doesn't matter what activity you do as long as you get your heart rate up and then let it recover. Heart rate up, let it recover.
Joe Lemay: What's your activity that you like to do about 30 minutes a day? I love to swim, but frankly, it's harder for me to get to the pool, so I was on the treadmill this morning.
Claire Beskin: Dr. Dana, once someone gets a CT CAC done, then they can figure out if they have calcium and what to do about it. But for whom is it appropriate to go get a CT CAC done? Do a lot of people have calcium and not realize it?
Dana Weisshaar, MD: Yeah, the calcium causes no symptoms. It's not until you have enough narrowing of the arteries to impede the blood flow that you might get symptoms. So we order coronary artery calcium scores specifically for patients who are in an intermediate risk group and patients - the guidelines from the American Heart Association and American College of Cardiology from I believe 2019 are specifically targeted for an age group between 40 and 70. So if you as a cardiologist have someone in that age group who you calculate their coronary risk and they're in an intermediate range and you're trying to determine whether or not to treat their cholesterol, get a coronary calcium score. And if it's zero, it lends us to thinking maybe we can pass on treating the cholesterol at this point. Whereas if it's more than zero, we make the diagnosis of coronary artery disease and we recommend controlling the LDL to less than 100.
Dana Weisshaar, MD: Now coronary calcium score is not the only variable in that conversation. If it was, it wouldn't be so challenging to be a cardiologist, right? So we have to take into account additional risks. And in fact, I can show you another table if you think it might be helpful that's from the ACC. Oh, it's 2018, from the ACC and AHA guideline and primary prevention just means for any patient who is not already known to have coronary disease, has not had a heart attack...
Joe Lemay: I don't see your sharing yet. Are you sharing?
Dana Weisshaar, MD: Oh, you don't see me sharing? Okay. Okay. Let me share. Boy, I didn't want to do that. All right. Let me share.
Joe Lemay: The internet has collapsed upon itself.
Dana Weisshaar, MD: Okay. So, let me share this image from the 2018 American Heart Association & American College of Cardiology guidelines on the treatment of cholesterol. And so it says here primary prevention which means someone who does not yet have a diagnosis of coronary artery disease. So who among the patients who have elevated cholesterol should get treated?
Dana Weisshaar, MD: And so you can see in the upper right corner, if your LDL is over 190, don't pass go. Don't collect $200. Just go get a statin, a high intensity statin, because you're at high risk of developing premature coronary artery disease.
Dana Weisshaar, MD: And if you're diabetic and between the ages of 40 and 75, you should absolutely be on a moderate intensity statin. Don't pass go, don't collect $200, just get treated.
Dana Weisshaar, MD: If you're under the age of 40, then we really just, like I said, want to know what your risk factors are. Do you have a family history of familial hypercholesterolemia, in which case you should be on a statin. Otherwise what you do is you just focus on: don't smoke, get plenty of exercise, control your weight, control your blood sugar, control your blood pressure. Just a generally healthy, hearthealthy lifestyle.
Dana Weisshaar, MD: If you're between the ages of 20 and 39, we have risk calculators where we can estimate the lifetime risk that's based again on some of those risk factors including kidney function into that equation.
Dana Weisshaar, MD: Or if you've got an intermediately elevated LDL and a family history of premature coronary disease, we would have a discussion about treating you. It's in this group of patients between 40, oh I think I said 40 to 70 earlier but I misspoke. It's 40 to 75. And you've got this intermediate LDL without diabetes that we really then calculate your 10-year risk. And if you're in this intermediate risk, this is where we do the coronary artery calcium score potentially to determine that you have coronary artery disease or don't have hardened plaque.
Dana Weisshaar, MD: Now there are a lot of additional risk factors. So Southeast Asian heritage, chronic kidney disease, persistently elevated LDL, metabolic syndrome, and if you're a woman and you've been pregnant in the past, you had preeclampsia or premature menopause, your risk increases. So there are also some additional lab values we can do.
Dana Weisshaar, MD: So cardiologists use this schemata to help each patient find the right therapy for them.
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(And now, a peek behind the scenes with some outtakes!)
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Joe Lemay: Yeah, I think that's great. I think all that detail is excellent because, you know, I think one thing that these videos can do for people is help out with the reality that, you know, when they meet with their doctor, their time is is precious and everything. Sometimes they might just want to put on a video and consume plenty of information. They've got these tests coming up and not all of it they're going to absorb, but they want to just like kind of listen, you know, and I don't know about you guys, but I often listen to like hour-long podcasts where most of it goes over my head and like I like that, you know.
Claire Beskin: Dr. Dana, you had heard - I think seen Joe's Shark Tank before?
Dana Weisshaar, MD: I did. Yeah, exactly.
Joe Lemay: Cool.
Dana Weisshaar, MD: Yeah. Yeah.
Joe Lemay: Well, one thing I didn't do when I built that company [Rocketbook] is I made like videos and stuff for Kickstarter products and did a little bit of podcasts, but I didn't really build my own personal documentation of what I was doing like some people do a good job of. And so when I look back on it, I kind of was like I should have made more content. So now I'm interested in, even though like a lot of it is just like my personal interests, like fitness and longevity and stuff like that. So, I'm doing different things on Instagram and YouTube and so when Claire was talking, I was like, "Let's do this. Let's just jump on and we'll record it." I thought it'd be really fun.
Dana Weisshaar, MD: So, well, I just love to teach. So, I'll teach anyone anywhere anytime. And this has always kind of been, I don't know about a dream of mine, but I've always thought, wouldn't it be great just to get these lessons that I give to patients every day out in a recorded format? So, it's great. Thanks for doing this.
Joe Lemay: I think that's awesome. Yeah, I love teaching so much that I drive two hours up to the medical school each week to teach. So, the classes I teach are med skills. So, we teach students how to interview patients and how to examine patients and then write up the medical report and present to their attending the skills that they're going to take into their clinical rotations. So, how do you talk to a patient? How do you translate that into medicine for your attending? And then the other part that I love is how do you turn that back around and speak English back to the patient? And so, I'm teaching kind of these these doctoring skills. And then the other class that I teach is the problem-solving and the critical thinking as a clinician. So, how do you take the history and the physical exam findings and solve the problem? Right? So the detective work and how do you come up with what we call a differential diagnosis and a plan to try to work it out like I think this might be going on or I think that might be going on. And so that's another thing I get really passionate about is then how do you tell a patient because it's one thing to be a really smart doctor.
Dana Weisshaar, MD: So, you can be a really smart doctor and really know what's going on and figure it out. But patients don't care how much you know until they know how much you care. And so, you've got to be able to to say, "Hey, Joe, I think you've got coronary artery disease and here's why, right? And here are the symptoms and here are the risk factors and I need to explain to you why I came to that conclusion so that you can believe it, understand it, and trust it rather than me just saying, "Hey, you've had coronary disease." Right? And if you believe it and own it and trust it and and then I can talk to you about what you can do about it. And if I make that make sense to you about what you can do about it, then you're more likely to do it. But if I just say you've got coronary disease, take this medicine to control your blood pressure and control your cholesterol. You have less buy-in and less commitment to the treatment. And heaven forbid you get a side effect, you're just going to stop it. Or it's not going to make you feel any better, so why bother? I don't want to take a pill. I don't want to have this. It's easier to dismiss it. We as physicians can do a better job by explaining to patients why we think they have what they have and helping them understand how we came to that conclusion and then teaching them what they have control over and helping them be a part of their own solution rather than just somebody we expect to follow our advice because because "I said so". Right. Who likes to hear that from their parents? "Because I said so." You don't want to hear it from your doctor, either.
Joe Lemay: Yeah, that's great. Well, this is awesome, guys. I got to get going, but I think this is a great first episode. Let's keep thinking of other ones. I think even if we go down different avenues, I think having one question to focus on and give that question some something that you introduce at the beginning and it can go down other places too. But I think really each episode being like one big thing that we introduce and have a discussion around, I think that it could be a great series.
Dana Weisshaar, MD: I love it.
Claire Beskin: Awesome.
This content is for general informational purposes only and is not medical advice. Talk with your healthcare provider before making any decisions about your health.
