Interview with John McBarron Hodgson MD -- Part One

Dr. Hodgson is an internationally acclaimed cardiologist who, prior to founding Santé Cardiology, was the Chief of Academic Cardiology at St. Joseph Hospital and Medical Center in Phoenix. Previously a faculty member at the Medical College of Virginia and Case Medical School in Cleveland, he has devoted much of his career to training the next generation of physicians. He has served in many administrative positions and developed four Cardiology Departments. Dr. Hodgson is a Past President of the SCAI and a founding member of the SCCT. He has published over 200 peer reviewed articles, 8 books or book chapters, holds two patents and developed the TeachIVUS and TeachFFR online simulation training tools.

Angioplasty recently sat down with Dr. Hodgson to talk about intravascular technologies. This interview is posted in two parts:

Part One discusses intravascular ultrasound (IVUS) and how it can increase the accuracy of stent placement, and the role of IVUS in the era of DES 2.0;
Part Two discusses Fractional Flow Reserve (FFR) with some thoughts on training and recommendations for patients.

John McB. Hodgson, MD
Santé Cardiology
Phoenix, Arizona

Q: Can using intravascular ultrasound (IVUS) for stent placement really improve patient outcome and reduce late stent thrombosis in drug-eluting stents?
Dr. Hodgson: There are nine trials that have compared IVUS-guided bare metal stenting to angiographically-guided stenting. Eight showed IVUS was superior and one was neutral. However, because late stent thrombosis is a very low frequency event (I think Gregg Stone has estimated, it would take upwards of 20,000 patients per arm to try to estimate a difference) there is no randomized, controlled, multi-center trial that proves that IVUS use is better for late stent thrombosis in drug-eluting stents.

Taxus drug-eluting stent

But, in terms of stent restenosis, TLR, acute events, cost-effectiveness -- all of that stuff's been studied for bare metal stents, and all of those studies but one, which was neutral, showed favorable results for routine IVUS use for stenting.

Now a lot of people debated whether that would still be true for drug-eluting stents. But most of us feel there's no magic about drug-eluting stents that makes them somehow mechanically superior, so that you can basically do a sloppy job, or leave unexpanded stents, or leave stent malapposition and get away with it because of the drugs. I don't think anybody believes that now, and it would just be common sense that you would want to implant the device as well as you possibly could in order to prevent any adverse outcome.

You have to look at this in a little bit broader terms. It depends on the tortuosity, the size of the vessel, the type of the stent, the other risk factors that the patient has: renal failure, heart failure or diabetes, etc. If you have a complex lesion (and complex could be small, ostial, bifurcation, calcified) we've learned from the past 15 years that IVUS use will result in a better acute outcome. The minimal lumen diameter, the minimal cross-sectional area, however you want to measure it, it'll be better if you do IVUS guidance than if you don't. And those differences are more pronounced the more difficult the lesion sub-set becomes.

I use it 68% of the time, and the more difficult the lesion, the more complicated the case, the more the patient is at risk for stent thrombosis, or restenosis, the more likely we are to use it. So, the 30 year old with a straight shot, mid-right, 4.5 vessel that's 8 mm long, who's non-diabetic, has no renal failure, no heart failure, nothing else going on, then you could argue that it may not make a difference there. But, that's not usually what we're doing anymore. We're doing much more complicated patients than that.

Q: Would you comment on the S.T.L.L.R. study that showed two-thirds of stents are not optimally placed??
Dr. Hodgson: I use that study all the time. That's an angiographic study, not an IVUS study, but we use that to indicate the importance of the measurements that go into selecting a stent and optimizing its placement. A lot of it had to do with the stent not covering the area they had pre-dilated, or not covering all of the lesion. Those are all things that IVUS could help avoid by properly measuring the length of the stent, and by ensuring that you've had good coverage and good expansion afterwards. And in that trial there were more M.I.s in the ones that had a longitudinal miss, a trend towards more late thrombosis, and all those nasty things.

Another important trial is one that came out of Washington Hospital Center, retrospective, Ron Waksman, looking at over 5,000 stents that they'd put in. One of the important predictors of freedom from late stent thrombosis was use of IVUS. The use of IVUS and larger reference vessel size were the two things that correlated with less stent thrombosis. The other usual predictors came through as well, so people with smaller vessels and renal failure were more likely to have stent thrombosis. So it's retrospective, it's a center that does 78% IVUS use, but the ones who did well had a higher frequency of IVUS use than the ones who had stent thromboses.

Q: So IVUS helps you know you’ve placed the stent optimally?
Dr. Hodgson: I've always been amazed that people are happy to throw $3,000 stents in and not really know for sure whether they've done a good job or not. Would they buy a set of $3,000 wheels for their new Mercedes and not care if the guy put them on backwards, or only used two bolts instead of four? It doesn't make any sense. You would want it done in the best way possible, and yet, in the lab they’ll say “Oh, it looks okay, I've got another case to do. . .”, and the sense that “I don’t have time” to use a tool that's readily available there, is just mind-boggling to me. In my lecture, I grill these people. Some of these studies, there's a 30%, 40% reduction in restenosis rates. So five minutes of your time is not worth a 40% reduction in restenosis for your patient? And that's all it takes, five minutes extra, if you're using IVUS routinely, and have it set up and ready to go. It's not a big deal.

Q: But we now have a new second generation of drug-eluting stents – which I call DES 2.0. Won’t they be better? Do you see the role of IVUS changing with these newer devices?
Dr. Hodgson: I don't really. I think that the attention to drug-eluting stents has been largely focused on polymers, and different drugs, and whether you do or don't get in-growth of tissue. But the bottom line that hasn't changed is that this is a balloon-expandable metal scaffolding device, and the mechanics of putting that in and getting it there, has nothing to do with the drug. And I've preached for years about vessel compliance. You have to understand that the resistance to expanding a stent has nothing to do with the stent, and has everything to do with the vessel. So, I don't care what stent you've got, what balloon it’s on, what name you want to call it, what drug is there -- if you can't get it in and get it inflated and expanded in the right spot, it doesn't really matter! And that hasn't changed. And again, it doesn't make any difference what the drug is. The drug is going to help you later, but what you need to do up front, is deliver this thing properly. Put it in the right lesion, get it to the right size, get it implanted as best as possible, and then you'll let the drug do its work.

Now, some of the stents are a little more flexible, so maybe they’ll be better in terms of getting them there, but there is nothing magic about these stents in terms of implanting them -- it has not changed. What we do, in terms of blowing up vessels, has not changed since the first procedure that Andreas Gruentzig did. We have to go in and mechanically push the plaque out the way, and you either do a good job at that, or you don't. If you can get the vessel wide open, the patients do well. So that's the fundamental issue here, and Andreas understood it, and many of us have understood it for years.

All these tools, every one of them we use, are designed to make the narrow part of the pipe look like the not-so-narrow part. That's all we do. We don't make atherosclerosis go away, we don't dissolve plaque -- all we do is make the narrow spot look like the not-so-narrow spot. And if you can do a good job at that, then you relieve ischemia. And that's all angioplasty does: it relieves ischemia. It doesn't make you live longer, any of that stuff.

I don't care if you've got a balloon, a cutter, a zapper, a laser, whatever, that's your ultimate outcome. Whether you want to call the stent a Xience, or put it on a Vision, it doesn't make any difference, you still have to make sure that you've got a good opening, and the only way that you can do that effectively is with IVUS.

So, I don't care what they develop in the future, we need a way to ensure that we have mechanically opened that vessel in the best way possible, and it depends on the plaque distribution, the plaque burden, the plaque calcification, etc., and the only way you can reliably look at that is with intravascular ultrasound.

IVUS at top shows under-expanded stent; at bottom the stent has been post-dilated with a balloon for a better fit. Both frames look identical on the angiogram.

Q: OK. You and others feel that intravascular ultrasound is critical in proper stent placement, but how many interventional cardiologists in the U.S. are able to interpret IVUS images, how many use it, and do you think that can increase?
Dr. Hodgson: Well, that's a constant source of frustration. I don't think there's an interventionalist practicing today who isn't aware of IVUS, and hasn’t at least heard of or seen it. I would say that there are far fewer, maybe 20%, who actually feel comfortable interpreting it.

I think the bulk of the people are able to be trained, certainly have the skill set to do it, but for whatever reason haven’t. This may change when somebody says, “Wait a second, I want documentation that you've done a good job here.” But nobody's even asking for a follow-up on outcomes; nobody asks what percentage of your patients has restenosis.

Q: How could this change?
Dr. Hodgson: I think we need to continue to work on educating people to the ease of use of IVUS. A lot of the things have been done lately with automatic border detection. And training sessions are important but they don't drive utilization. They help the people who want to do it, but they don't really drive new people to utilize it, not until individual hospitals or insurers start saying “we would like to see 100% documentation at one year of your patient follow up.”

Now there are centers that do that. Duke’s got a great database, Cleveland Clinic’s has a good database, Washington Hospital Center has a good database, Columbia-Presbyterian has a good database. We've been offering guaranteed angioplasties. We tell the insurers, “Listen, we’ll guarantee your angioplasty. If anything happens in the next year we'll do it for free.” Because we know we do a good job, and we attend to the details. But until the insurers are willing to either pay for a difference or require follow-up information, it's not going to change.

Also IVUS and FFR have to be a full member of the family. My folks set it up on every case. The IVUS and the FFR are turned on, patients' names are input, they are ready to go on every case. We don't open the disposables, but the machinery is ready to go. So you say “let's do FFR” -- it’s fine, it's simple. You throw the wire on the table and we're up and running. They prefer that. At 2:00am they don't mind doing this, because they know that we're gonna get the right answer and be done faster, and they also recognize that we're doing the right thing for the patient. And actually all the nurses and techs in their hearts, that's what they want. They want the right thing for the patient.

(Continue to Part Two)

This interview was conducted in February 2008 by Burt Cohen of Angioplasty.Org.