PODCAST Coronary Artery Disease with Dr. Ranya N. Sweis

Season 6 | Episode 6

 

 

Joe McIntrye (Host): Welcome to another episode of the Merck Manuals Medical Myths podcast. On this show, we set the record straight on today's most talked about medical topics and questions. I'm your host, Joe McIntyre, and on this episode we welcome Dr. Ranya Sweis, MD, MS and a professor of cardiology at Northwestern University Feinberg School of Medicine. She brings more than 20 years of experience in clinical care, research, and education.

Today we will explore a topic that affects millions worldwide, coronary heart disease and the role of heart stents. Heart disease is the leading cause of death globally, and for many, the first sign of trouble is a heart attack. We will discuss what coronary heart disease really is and why it develops how heart stents work and when they're needed. We will also address common myths surrounding heart health and provide practical advice for maintaining a healthy heart. Dr. Sweis, thanks for joining us.

 

Dr. Sweis: Thanks for having me, Joe.

 

Host: Well, it's great to have you. So maybe you can set the scene for our listeners here a little bit. What is coronary heart or coronary artery disease?

 

Dr. Sweis: So when we say specifically coronary, we're referring to the arteries that supply the heart with its nutrition, which is basically the blood flow that brings oxygen and nutrients to the heart muscle. So coronary arteries are the arteries that supply the heart. When we talk about coronary artery disease or coronary heart disease, we're talking about disease of those arteries, and primarily we're referring to atherosclerotic disease. So disease that's made from an increase in cholesterol that gets deposited in the vessel walls.

 

Host: So which one is cardiovascular heart disease? There are alot of terms,  just want to make sure it's clear for everybody listening.

 

Dr. Sweis: Yeah. Cardiovascular is basically the umbrella term that really covers all the different kinds of heart disease etiologies or causes that we treat. So, we would say that coronary artery disease is a subset of cardiovascular heart disease. Cardiovascular disease will include vessels not just of the heart muscle, so the carotid arteries, the aorta. It can also include valvular heart disease. So it's an all-encompassing term of which one subset is coronary artery disease.

 

Host: Understood. Now let's say you go to the doctors, and the doctor finds that you have higher blood pressure. Does that mean you'll get coronary artery disease?

 

Dr. Sweis: We know that there are risk factors for coronary artery disease. I like to think about the risk factors in a pie chart. So one portion of the pie is hypertension, so high blood pressure. Another portion of the pie is high cholesterol. Another portion of the pie is having diabetes. Another portion of the pie is having a sedentary lifestyle. Another one is being overweight.

A big portion of the pie is genetics. Although we don't know to what extent genetics plays in each separate individual, but genetics definitely plays a big role, particularly in people with family history of early heart disease. So if someone's father died of a heart attack at age 45, that would be a very strong genetic marker. And then there's a part of a pie that's a big question mark. I think that there's probably some factors that we don't fully understand at this point, but yes, hypertension is one of the things that we consider a risk factor for heart disease. It's not a definite that having high blood pressure means you're going to get blockages in your arteries, but it's definitely a reason to want your high blood pressure treated.

 

Host: Good to know. Now, this question probably has multiple answers depending on who you ask, but are younger people such as those age 40 or under less susceptible to coronary heart disease? Is it an issue only for those 40 and above?

 

Dr. Sweis: No, we know that it takes a long time for the initial injury in the vessel wall and accumulation of the cholesterol in the vessel wall to become significant enough to cause whether it's symptoms of stable heart disease, so angina, for example, chest pain whenever you go up and down the stairs or to get to the point of having a heart attack, which is like crushing chest pain, that usually happens kind of suddenly not related to activity. So by definition it will take time to usually develop that kind of disease.

However, I can say unfortunately as an interventional cardiologist, I do see young patients. It's a sad reality that we do have people in their thirties and forties that we do see in the cardiac catheterization lab whether it was just blockages or coming in with a heart attack.

 

Host: Now, for those folks who are coming in when they're younger, is it other factors that people who are listening should be considering or thinking about beyond just weight or high blood pressure, high cholesterol? What other factors, especially as you're younger, should you be looking for maybe differently than older folks or does it not really matter?

 

Dr. Sweis: I think it's important to not ignore chest pain regardless of your age, and that's probably the biggest lesson because I think some people delay their seeking of medical care because they assume that they're young and this can't possibly be something that they're dealing with. It's not really the topic of this conversation, but there are some other reasons why you can have a heart attack related to a problem with your coronary arteries, such as a coronary artery dissection, which actually tend to impact younger and middle-aged women. So the ages that we don't typically think of atherosclerosis, and similar to what I mentioned earlier, if you have a family history of like your father, his father and your uncles all having heart attacks in their forties, then that really significantly increases your risk and it's really worth doing early prevention in that setting to try to change your life course.

 

Host: Is it true that men have coronary artery disease more than women?

 

Dr. Sweis: Women have coronary artery disease similar to men. Women tend to present with symptoms that are less typical. So the textbook will tell you the symptoms of a heart attack or like an elephant sitting on the chest, maybe having shortness of breath, feeling pressure or symptoms kind of up in the throat and the neck or even going to left arm. Often women won't have those typical types of symptoms. And so we used to think long time ago that women had less heart disease. What we found with time is they have similar amounts of heart disease, they just have less typical symptoms or they present later because their symptoms are not identified either by them or their providers.

 

Host: Now let's say you're not showing some of the symptoms you've talked about so far. How in the world do you even know if you have coronary artery? Disease?

 

Dr. Sweis: Symptoms are really what alert us in patients. The gold standard of knowing if there's coronary artery disease as a coronary angiogram, but that's an invasive test and somebody who's feeling well and healthy isn't going to undergo an invasive test that carries albeit small, some risks.

When we think of prevention, we look at patients' risks and we want to address all of them and make sure that they're all optimized in order to make sure that we're decreasing the risk as much as possible. So sort of the pie chart that I mentioned earlier, any of those things we really want to optimize. So that is kind of how we go about it. We're not looking for coronary artery disease per se, but we're trying to prevent it. Now patients may have symptoms and it's hard to know if they're necessarily related to the heart or not, and that will lead to some testing that can help us better determine if they have coronary disease or having symptoms related to the heart.

So sometimes if a patient comes to me and is concerned about chest pain, we might recommend that they have a stress test. That is a test where they would walk on a treadmill with EKG leads on their chest that we're looking at the electricity kind of the heart that can tell us if there's any concern for blockages or not. And then oftentimes the stress test will include some imaging where we look at how the heart muscle is responding to exercise.

One of the newer tests over the last decade or so is a coronary CT angiogram. So this is a CT scan that you inject dye during the scan and it looks at the arteries of the heart, and that is a way to get a sense of what's going on with the coronary arteries without an invasive test. And then the last thing I want to mention that is often used as a screening test is a coronary calcium score.

So instead of injecting the dye in the arteries, it's just a quick CT scan that just picks up any calcium in the arteries. So, when cholesterol builds up in the vessel wall, some of that process involves cholesterol particles that build up as well. And so, there's a scoring, there's a way to score it by radiology and based on the score, we sort of have charts of risk based on gender and age. And so, if somebody has a super high calcium score, even if they're not having symptoms, it might be worth being referred to a cardiologist to talk about the risks and make sure that we're optimizing all of the factors as much as possible.

 

Host: You mentioned a lot of the risk factors, you just said optimizing things, optimizing your body even. How do you prevent heart disease, especially if coronary artery disease runs in your family? What can you do as much as possible to prevent it from affecting you?

 

Dr. Sweis: I'm going to back up and just say that the sad reality is that sometimes the first presentation, and I'll say primarily for men is with their first heart attack in their fifties, for example. Women have a reason to be constantly in touch with the medical system because of reproduction and gynecological exams. So, they're having regular times when their blood pressure and maybe some of their blood work is checked, but there's not a direct reason why men are seeing doctors routinely unless they intentionally do so. So often people will have had a college physical or military physical, and then the next time they have contact with the medical field is when they have their heart attack.

So probably the two most important things that you can do, especially if you know that there's a family history, is know what your cholesterol is and know what your blood pressure is and then live a healthy lifestyle. So have a healthy diet and maintain a healthy weight and exercise. When you're physically active, if there are changes in your arteries where blockages are getting more significant, you're going to start having symptoms and you're going to know, I tell my patients it's like exercise is their barometer. If they're sitting on their couch watching TV all the time, they're never going to know if anything changing, but they're physically active and they notice a change, they'll be able to respond to it and get medical help sooner than later.

 

Host: Now, let's shift gears a little bit to treatment for coronary artery disease. How do you go about treating it? What are some of the ways that you go about doing that? It seems like probably a very scary and very complicated process, especially if you're treating it after a heart attack. So what are some of those methods you use?

 

Dr. Sweis: So I alluded to this briefly, but I think it's important to understand that there's kind of two pathways that patients will come to me. So over time, as cholesterol builds up in the vessel wall, that causes sort of an impinging of the vessel wall on the vessel opening itself. So it decreases the amount of blood flow that can get through that vessel. As that amount of blood flow is decreasing, at some point you're going to hit a supply demand mismatch point. So perhaps when you're sitting on the couch or laying in bed, you're not requiring a lot of, you're not doing a lot of activity, so your heart doesn't have to beat faster, you don't have any symptoms, but when you forget something upstairs and you have to run up two flights of stairs, all of a sudden you have some discomfort in your chest.

This is what we refer to as angina and most specifically stable angina because if you do the same amount of exertion, you're going to get the same symptoms and when you rest, it goes away. You go up those flights of stairs again and you have the symptoms. If you have an exertion that's slightly less than that, you may not trigger the symptoms because it's not the same level of exertion. This is a progressive process. So as the blockages get narrower, narrower, the same amount of activity that didn't elicit symptoms before will then become more significant. So that's a signal that patients are have a problem, and if they get to their doctor and talk about the fact that they're having this angina, they'll usually wind up with a stress test. Sometimes if the symptoms are so believable, they might even bypass the stress and come directly to me in the catheterization lab to do an angiogram, and then we'll diagnose a blockage and we'll treat it, and I'll get to that in a second.

The other method that people come to me is they're minding their own business feeling fine, and oftentimes they can be super healthy people and exercises, they may even be marathon runners, and then boom, all of a sudden they get this acute chest pain and they feel flushed and sweaty and they can't breathe. They kind of have a sense of doom oftentimes. That's when you're calling 9 1 1, you're coming to the hospital and the EKG may be showing that you have a heart attack. And so that's a medical emergency because we say time is heart muscle, and so if the artery is blocked and that's why you're having chest pain blocked completely, so heart attacks happen, not necessarily because a narrowing became significant enough, but even a mild narrowing can have sort of rupture of the capsule around it. So as it kind of expands in the vessel wall, that can become unstable and rupture, and if it ruptures and it's exposed to the blood, it causes the clot to form there.

The clot forms and completely blocks that artery. So the artery is a hundred percent blocked and that's causing a heart attack. And so that patient went from totally feeling fine to not having blood flow to that area of their heart, and that's what a heart attack is happening, and the faster we get that artery open, the more amount of heart muscle that we're able to save. So those are the two kind of processes or the ways that patients come to me. So if you have stable angina and you have an angiogram and we find a blockage in one of your coronary arteries, then we can treat that potentially with a stent. So the way that I do an angiogram is I put an IV in the radial artery. So usually I use a patient's right arm and in their right wrist where you feel the pulse of your radial artery, we put an IV in there and through that IV we pass the catheters that go all the way to the heart and are able to inject dye in the specific coronary arteries.

And that's how we can see if there's blockages and that's also how we can treat them. So through those same types of catheters, we're able to pass wires and on the wires, the wires become like the train tracks and on the wires we can pass balloons that can help us push that blockage out of the way and open the vessel. We can also bring stents into that area and open the blood vessels that way.

I should clarify what stents are. So stents are basically a wire mesh that is created in the shape of a tube, but it's not a solid metal tube, it's just a mesh. And because it's a mesh, it allows us to sort of fold it kind of like an accordion on itself so that the cylinder is really small and it sits on a balloon. So because a cylinder is really small, we're able to bring it into the body through a small catheter in the wrist that's like hardly two millimeters. And then when we bring it into the area of the blockage and inflate that balloon, that balloon pushes that metal frame open into the area of the blockage, pushes the cholesterol out of the way, opens the blood vessel so that the blood flows again in the area that either was decreased because of the stable coronary disease or even completely blocked because of the clots. And then we remove the equipment, the stent stays in place and stays with the patient and resumes the normal amount of blood flow that the heart muscle needs in those arteries.

 

Host: This is all fascinating science here. So does getting a stent in place, I'm using air quotes here, cure coronary artery disease. What is the reality there?

 

Dr. Sweis: No, we're not curing the disease. Once there's blockages in the arteries, you have coronary arteries disease and there's not really a cure for it. It would be optimal if we can catch people when we know they have early disease, well, it would be optimal if we can prevent it completely, but since we can't at this point prevent it completely, we haven't found that magic pill, then it would be optimal to catch it in the early stages and help prevent it from progressing. And that is really the work of aggressive management of all the risk factors, but especially of cholesterol. So we use the cholesterol medications, statins, and then there are some other categories of medications that I'm not going to completely get into beyond the scope of this, but really aggressively decreasing the cholesterol helps decrease the buildup in the vessel wall and sort of leaches some of the cholesterol out of the blockages so that even though the blockages don't get smaller, they are more stable and less likely to rupture and cause an acute heart attack.

 

Host: Got it. So it's not a permanent fix that prevents future heart attacks at all, or it's a permanent fix that helps to prevent future heart attacks?

 

Dr. Sweis: Stents actually don't prevent heart attacks at all. Stents, open blockages so that patients no longer have angina and the heart muscle has the blood flow that it needs. Stents don't prevent heart attacks. In fact, many heart attacks happen at the blockages that aren't significant enough to acquire a stent because of the rupture of the capsule around those less significant lesions. The way to prevent heart attacks is with the medical therapy, so the statin medications that help leach the cholesterol and stabilize the blockages.

When people have coronary artery disease, they need to be on aspirin, and aspirin also helps decrease the chances of blood clotting in those vessels if there were to be a rupture. So those medications together help decrease the chance of having a heart attack. To be fair, what I should mention is about the treatment is that sometimes people may have blockages that are too complex to get stented or maybe too extensive and to be stented. And then the other treatment option is coronary artery bypass grafting. So this is open heart surgery where the surgeon will take arterial vein from the chest wall or veins, veins from the legs and use that to sort of create a bypass or a detour of blood so that the areas that need the blood are getting it even though the blockages are still there. So I just wanted to make sure that people didn't think that the only treatment was stent.

 

Host: Let's say someone gets a stent on a Tuesday. Are they back to normal life living as they were before on Wednesday? How quick is that recovery process and how much does their life change after having a stent?

 

Dr. Sweis: Yeah, so I like to say that stents are part of the miracle of modern medicine because before we had stents, the only treatment for blockages like this was open heart surgery, and that's a big surgery to recover from. If you come to me with stable angina and I do an angiogram, like I mentioned, I'm going with a tiny little hole in your radial artery. If I find a blockage and I'm able to put a stent in it, depending on how everything goes and how you're feeling, you could theoretically go home that day or maybe the next morning. I ask you, I ask my patients to take it a little bit easy for the next week with their wrist. I don't want a lot of crazy lifting with that arm. Just let things heal. But they can walk, they can do all their activities that they want to do, and if they were having that significant angina that they were having before the procedure that got them to the procedure and they try to do that same activity the next day, they should notice that those symptoms or the chest pain is now gone.

 

Host: Dr. Sweis, as we kind of close up here, what is one thing or one factor or one myth you want to bust? What's something about coronary artery disease that you wish more people understood?

 

Dr. Sweis: I think it's important for people to understand that just because you exercise and you live a healthy lifestyle doesn't necessarily mean you're going to be spared. You need to know the data, and by the data, I mean you need to know your blood pressure and you need to know what your cholesterol is. Because if you know that in your thirties and forties and it's elevated and you're able to treat it, you can prevent a lot of pain down the road. If you don't know those things, then you're destined to have things like a heart attack, which will have irreversible damage, and then you've lost ground. So I'd like people to remember that knowledge is power. Knowing what your risks are so that you can treat them and address them is the best way to prevent more pain and suffering down the road and probably even save some lives.

 

Host: Are there any other myths that you find yourself dispelling for patients or their families regarding coronary artery disease or overall health? Beyond that, I'm sure there are tons of questions you, we've gotten, we've gone through maybe a dozen or so here. Any that you, beyond what we've talked about that you find yourself dispelling?

 

Dr. Sweis: I think one of the questions people often ask is, can stents be taken out and specifically about the stents themselves? No, they can't. The wires of the mesh are almost like the hairs on your head. They're very thin and they kind of become integrated in your vessel wall and the vessel wall grows around them. So there's no way that those can be taken out. They kind of become part of you.

 

Host: Okay. Dr. Sweis, thank you so much for joining us on this podcast. It's been super insightful to learn about coronary artery disease, some of the risk factors, how to avoid it, how it's treated. If our listeners are looking for more information about this topic, where should they go?

 

Dr. Sweis: The American Heart Association is a really great resource for patient education about coronary artery disease and a lot of other heart disease factors as well. Of course, Merck Manuals.com is one of the places, and I can tell you because I have edited the chapter on coronary artery disease, but that is full of valuable information.

 

Host: Love to hear it. Thanks again for joining us, and as we close out, I'll let you leave our listeners with the final word.

 

Dr. Sweis: Well, I'd like to say that medical knowledge is power and pass it on.

 

Host: Thank you so much.