James W. Choi, M.D., an interventional cardiologist at Baylor Heart and Vascular Hospital in Dallas, Texas, talks about a newly FDA-approved stent that is giving doctors more life-saving options.
Interview conducted by Ivanhoe Broadcast News in July 2016.
Dr. James Choi
Tell me a little bit about your history, you’re a cardiologist here. What’s your job?
Dr. Choi: I am an Interventional Cardiologists here at Baylor University Medical Center. I’ve been in practice for twelve years now. I did my entire medical school post graduate training in Chicago at Northwestern University and undergraduate education at University of Michigan.
Tell us a little bit of the background and what you encountered, you and your team, your partners. What you encountered with Terry and how you assessed it and decided what to do.
Dr. Choi: Terry’s story is very typical for the American male or the detection in general; he’s a hard-working gentleman who all of a sudden can’t do what he needs to do. He saw one of my partners, Dr. Wong, who is a general cardiologist and upon his questioning heard symptoms that was concerning for angina which is a discomfort one gets when the heart is not getting enough blood. That prompted him to refer him to me, the interventionist, to do an anagram which is looking at specifically the heart arteries. From there we diagnosed the blockages. Now, at the time of the procedure, we’re able in some cases to treat it, which is the situation with Terry.
The angiogram, is that what we were looking at on the screen back there?
Dr. Choi: Exactly, that’s where you go through. Sometimes you can go through a wrist access or a groin access and via catheters. We bring catheters up to the arteries and using contrast we shoot contrast in the arteries to actually look at them with x-ray.
And what did you see or what was alarming about what you saw with Terry?
Dr. Choi: There are three major arteries to the heart and Terry had tight blockages, critical blockages in two of those major arteries. The one in the front called the LAD is the most important of the three, and his right coronary artery was particularly troublesome because it was essentially one hundred percent blocked to the point where he developed his own little natural bypass’s or collaterals to that artery.
So he didn’t know it, but what kind of risk was he experiencing when you met him?
Dr. Choi: It would be nice to make it dramatic but unfortunately no one really knows for sure. We can’t really tease out why some patients show up to the emergency room dying, like in Terry’s case, shows up with more gradual pain. I think a large function of that is because he’s so active with his work that he developed what we call an ischemic preconditioning. He puts his heart under stress and it gets used to it. When that time actually comes, he’s able to tolerate it more.
Specifically what were you seeing there and what were your options? When he came in, he was feeling okay and he said he didn’t even know he was sick.
Dr. Choi: The patient doesn’t know exactly what they’re feeling but clearly Terry knew something was wrong. Because he wasn’t able to do what he was and that’s where you have to give Dr. Wong credit for teasing it out. What he was complaining of was really a classic angina; discomfort you get when your heart doesn’t get enough blood. Based on what we saw after the pictures of his two blockages we really had three options. One was just to continue on, and try to maximize medicines. In his situation that’s not a good option because he was really having symptoms and there are very important arteries that were feeding the heart. The other two options were stinting or bypass surgery. Bypass surgery would be typically where you open the chest and you put arterial or venous detours around those blockages.
How close was he to having something like that?
Dr. Choi: In Terry’s situation it would have been a reasonable option. In some centers where they’re not as apt to take on more challenging cases he may have been recommended bypass surgery. Fortunately we pride ourselves at Bailey University medical center on doing the challenging stuff and his was not extremely difficult. We felt very comfortable treating it percutaneously or with stents.
How many cardiologists would have recommended bypass surgery and what that would have meant in terms of his recovery? I mean that we know the bypass surgery has very good results.
Dr. Choi: If you would have polled it would have been about forty to fifty percent of cardiologist might have recommended bypass surgery in this case. If they go down that road, it’s a great option. I’m not saying it’s the wrong option, they’re all good options. In terms of his recovery and his ability to go back to what he loves, his work on this ranch, his recovery time would’ve been significantly more, probably in the order of months.
But you saw when you were assessing the options you solved the possibility of a different option.
Dr. Choi: Exactly. We thought stinting would be the better option or a good option in terms of the recovery time, and also to get the desired result. We were able to treat both blockages with a single stent. In fact, one of the reasons we chose the bio absorbable stent in the artery down the front of the heart is because that gives us the option of future bypass surgery as well. Typically, if you stent an artery it in the place where the surgeon would tie in the graft, it illuminates that chance of bypass surgery. You want, if possible, to preserve always that option for bypass surgery. Using this absorbable stent gives us that option. In the future, should he need it, he has that option as well. The stent over three years should dissolve, and if he develops more blockages and we think bypass surgery is the better option, then that area were we stinted with that absorbable stent can now potentially tie-in a bypass graft by the surgeon. Whereas, if we used the traditional metal stent that wouldn’t be an option at all.
That’s significant because I mean he’s not getting any younger (exactly) and things are going change.
Dr. Choi: When we make these decisions we try to make it for the whole patient over his lifetime. This is just one snapshot in time and we hope Terry lives into his hundreds. We’re mindful of that when we make our decisions.
Let’s talk a little bit about the difference between the traditional stents and these bio absorbable stents. What’s the difference between them and how do they both work?
Dr. Choi: You got to understand a little bit about stent history. Traditionally we went from just ballooning. When we ballooned we would get in trouble during the time of the procedure because the vessel would close abruptly. That’s when we had to add ventives. The only option when you had the balloon was to just do as much balloon inflation and pray that it stayed open. With the advent of stents in the immediate hours, you’re basically ripping open the artery and you have to have that scaffold to protect and preserve that artery. That’s what the role of the stent is.
That’s like shoring up a tunnel, right?
Dr. Choi: Right. And that tunnel has the propensity to close. But, over time, that propensity to close goes away. You don’t really need that scaffolding anymore. But because it’s metal, you’re stuck with it. Another famous interventional cardiologist, Antonio Colombo, says it’s like when you break a bone, you put on a cast. It doesn’t mean you need the cast for the rest your life. That’s the concept of this absorbable stent. So you have the stent that provides its scaffold for the period that you need it, probably in the first few days to three months or so. Beyond that you don’t really need the scaffolding and you would hope it would disappear over time. This is the first commercially available stent that’s able to do that.
Overall what kind of results do you get from stents compared to like bypass?
Dr. Choi: It’s a trade-off on all. I think at one set point in time you have to assess which one of the options are better for the patient, but over the course of a lifetime you have to have all the options available for the patient.
Are these bio absorbable stents the next generation of stents?
Dr. Choi: I think so, but only history will tell. The metals are much easier to use than these polymers. Just to get a polymer to have the physical properties of metal and then also dissolve is extremely challenging. But technology has come to the level where we’re able to do that. Because these are first generation bio absorbable stents they don’t perform necessarily as well as our current metal stents. There’s a hurdle in performance that needs to overcome. That’s why these stents are only used in certain subset of lesions and in certain subsets of patients; it’s not for everybody. But it is the first-generation, so currently we’re using medicated drug-eluding stents that are of the fourth or fifth generation. I suspect as technology advances, and science advances, that we will see fourth or fifth generation absorbable stents that perform as well as our metal stents now but also have the benefit of disappearing.
I guess disappearing is important if you’ve got that metal scaffolding in there that prevents you from doing bypass.
Dr. Choi: Right. In some arteries that is very important. Other arteries, you’re never going to bypass so it’s muter. That’s one theoretical advantage. Two, whether or not they bear out to be in the long-term better than metal stents, it still has to be proven. The data that we have right now is still very early. We don’t have ten, twenty year data to say hey, these dissolving stents are better than the metal stents that really needs to be proven. There’s also a psychological component where patients in general don’t want foreign things in their body forever, and so there is a little bit of that as well. Whether it’s actually better or not in the long term, science will tell.
And that’s what you’re interested in, you want the best result.
Dr. Choi: Absolutely.
So how do you monitor somebody like Terry over time and decide maybe his body will tell you when it’s time to do something else?
Dr. Choi: Well, the biggest thing first is education. Terry now knows what he thought was okay was actually him having an angina. He had a reliable alarm clock. We’ve got to, one teach Terry that’s his alarm clock; two, better listen to your alarm clock, and then three, periodically Dr. Wong will probably be doing stress tests.
He seemed very healthy. He’s a physical guy, he’s you know outwardly. You would say I wish I looked like that at sixty five. He looks like the picture of health.
Dr. Choi: One hundred percent. I think he could still probably take me right now. I agree with you hundred percent. But that’s coronary artery disease. It is the leading killer of American men and women. It’s ubiquitous, we see it all. It happens, it’s the just the world we live in; largely in part because we’re a well fed country.
Yeah, I know, so much of it has to do with that. And we didn’t even really get into his diet, have you gotten into the diet with Terry.
Dr. Choi: I know he’s a cattle rancher so I’m going to leave that for Dr. Wong.
He likes the steaks.
Dr. Choi: What I typically tell my patients is please enjoy a steak and enjoy a good hamburger. Food is part of what we live for; just don’t call it lunch, which is what most Americans do.
You mean the burgers and the fast food lines.
Dr. Choi: Yep
I just heard the other day that now they’re teaching cooking in medical school. Why? Because of the impact of our diet? And all of these young doctors are like all thumbs and they’re like I didn’t know that. Really, how could you not know?
Dr. Choi: Yeah no, diet, and all that is so important.
It just seems like there wouldn’t be nearly as much coronary artery disease if you ate different.
Dr. Choi: You got it, one hundred percent. I know there’s an initiative to change the diet habits of our young. That’s where it really has to start.
Do you find that interesting that they’re now teaching cooking in med school.
Dr. Choi: Yeah.
They’re doing it like not just in one school. They are doing a lot of them.
Dr. Choi: Well I think they should teach nutrition, but I think there are other things that are probably more important to learn. But I guess that’s why I’m not a Dean of a med school.
Were you going out on a limb to use his bio absorbable stent since it’s so new? I mean, I know you had great results, but were you doing something saying let’s take a shot here and see if this will work for Terry.
Dr. Choi: No, we were fortunate enough, and I was fortunate enough, to be part of before anything gets commercially approved via the FDA. It has to go rigorous testing and we’re part of the initial trials that got to this market. It’s a literally head-to-head comparison of a traditional drug eluding metal stent versus this. In those early trials, in the first two years, the stents functionally worked equivalently. The mystery is not in the short term, it’s in the long term. We don’t know. But in the short term that was enough. The data was compelling enough, which allowed FDA to make this stent commercially available.
So the traditional metal stents in terms of their longevity and their usefulness. It’s really only a couple of days or—
Dr. Choi: No, no. So the real utility is initially in that first scaffolding and providing that support, probably for the first day to three to six months. Beyond that, they have little use in terms of remodeling that plaque.
Would you just reemphasize that again because that is significant. We don’t know what the future is going to be, but it gives you options right?
Dr. Choi: Yeah. I would say one of the advantages of the bio absorbable stent are in one, younger patients who have a potentially a longer lifetime of needing more stents; the less metal you have in your body, in theory, the better. Two, in patients who have disease in the LAD, that’s the artery down the front of the heart much like Terry. That’s the artery were bypass surgery has its greatest benefits. And there are certain patients where you place the stent exactly where the surgeon likes to put in the bypass. In some patients who can’t get bypass at the time, or if you had an option to put in a bio absorbable stent that preserves, that future option of bypass surgery is possible in the future.
And that can very important.
Dr. Choi: Yes. Remember, just like you said, we’re treating these patients over the lifetime. We’ve got to make decisions that are one, best in the situation, but two, don’t eliminate options in the future as well.
END OF INTERVIEW
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