Transcription:
Chronic Total Occlusions

Melanie Cole (Host): Over the last two decades, there's been an increasing interest in new techniques for the treatment of coronary chronic total occlusions, which have a success rate that’s much higher than that of a few years ago. My guest today is Dr. Robert Riley. He’s an interventional cardiologist with the Christ Hospital Health Network. Welcome to the show. Can you define for us what chronic total occlusion is?

Dr. Robert Riley (Guest): Absolutely. Thank you again so much for having me. Chronic total occlusions are where a coronary artery, one of the heart arteries, is 100% blocked and have been so for at least three months. These are often times either found in routine angiographies, meaning pictures we take of the heart arteries, or found on surveillance angiographies.

Melanie: Tell us what's been done in the past when you’ve identified a CTO.

Dr. Riley: Unfortunately, up until the last few years, chronic total occlusions being extremely difficult lesions to treat via traditional routine methods that we have for treating arteries with stents, we’re really left alone, and this is the number one reason patient were actually referred for coronary artery bypass grafting, the surgery where they crack your chest and they sew all the different grafts on. This is a real problem because so many patients couldn’t get treated by using just standard stenting techniques where you can go home the next day and had to go for these very extensive surgeries. Fortunately, over the past few years, we've developed these techniques and skill sets to treat these occlusions percutaneously, meaning through catheters and utilizing stents, relatively easily and with very high success rates.

Melanie: Is there a time frame for CTO development? Give us a little bit about the clinical presentation.

Dr. Riley: Often times, these patients are sent because they’ve been developing either some chest pain or what we've often found of these chronic total occlusions is that actually patient’s angina pain, meaning the symptoms that they're really having issues from, can actually be a shortness of breath, a tiredness, all of these different things. We've actually shown that through large registries that the typical chest pain does not always fit these patients. Their referring cardiologists will often either get a stress test or send them for angiographies, and they will end up seeing them after a chronic total occlusion has been identified.

Melanie: How important is early diagnosis as being crucial to improve the outcome prediction?

Dr. Riley: One of the things that we’re finding is that as mounting studies are coming out, most of the time we do these for symptom benefits. There are times where we will actually reduce someone’s risk of dying from a cardiac cause or having a heart attack from these causes due to the treatment of chronic total occlusions, but the vast majority, 70-80% of these patients are really sent for treatment of symptoms. We really emphasize getting those patients to us as soon as possible because these patients are living with a significant burden of symptoms and the sooner that we can treat them, the sooner that they can start living their lives the way they want to.

Melanie: Tell us about some valuable prognostic tools that can aid you in that early diagnosis.

Dr. Riley: Everything in the normal standard workup that someone would think about in terms of working somebody up for coronary artery disease that would include your basic electrocardiogram. Getting an echocardiogram, we can look at the valvular function along with the ventricular function, then moving onto stress testing, if appropriate, and then the coronary angiography, and really having all that in place so that we can access both the reason for doing and the technical aspects of how we would open these arteries are really key in how we evaluate these patients. Remembering also that patients who have impaired ventricular function where there's a question of whether this area that the chronic obstruction supplies is still alive or not, they can be really important to get viability testing in those patients. Sometimes, providers will have obtained that. Often times, they’ll want us to make that determination, we’re happy to do that in our multidisciplinary collaborative meeting that we have here.

Melanie: While you're doing this diagnosis, are you noticing collaterals? What do we know about collateral circulation cropping up as a result of the CTO?

Dr. Riley: For a long time, there is this idea that if there are good collaterals that these CTOs actually were being fed, that they were doing well, that there wasn't actually an ischemic burden because there was all this extra collateral circulation from these other vessels. Unfortunately, over the last few years, there's been several studies that have confirmed that in fact not once in any of the large studies that have looked at these patients was there ever a patient who had what we would consider adequate filling of a vessel that has a chronic total occlusion from these collateral vessels. There's never one vessel that had an FFR value of above .8, which is our cut off saying that things are okay. That lets us know that in fact, collateral circulation is never a marker of whether CTOs should be treated or not.

Melanie: Do you always treat CTOs? Is there a question of treatment and are some interventionalists reluctant to treat them in the cath lab? Speak about treatment a little bit.

Dr. Riley: I will tell you I do not treat all chronic total occlusions. There is definitely a certain set of patients that the risk and benefits don’t really work out. The patients that we focus on are those patients who are symptomatic with CCS class three or four symptoms, meaning getting symptoms at less than five meds on optimal medical therapy, meaning at least two antianginal medications. That’s really the largest subset we look at. The other patients are going to be your patients with moderate or high-risk stress testing because we know that we can actually reduce their mortality and risk of myocardial infarctions in the future by treating that. Those are going to be the two big subsets that we think about, but I definitely have referrals where the patient doesn’t really meet those criteria. Not everyone will, and that’s when we really focus on this discussion of benefits versus risks. One of the big things that I'm proponent of is making sure that we have good informed consent because a lot of my research in the past couple of years has been on major adverse cardiovascular events, complications during these procedures, and we spend a lot of time talking about why we would do the procedure, what the potential risks are and really helping patients make this vision.

Melanie: Speak about some of the treatments and how it’s developed over the past few years and speak about PCI and hybrid treatment as well.

Dr. Riley: The development of various stiff wires that can actually drill through plaque was one of the first advancements. We then developed some different techniques and different equipment that can actually allow us to go around the blockage and then actually re-enter the vessel after the blockage and stent it open that way, then there is the development of going backwards through some of these collaterals and actually getting through the vessel from around the backside because the plaque is actually softer on the backside. Those are the three big ways that contribute to this hybrid model about how we go about treating these occlusions and not limiting ourselves to only having one method or strategy in case one of those fails, having other ways of treating that disease. We’re also applying this to patients with multi-vessel disease where they might have CTOs and maybe there's one vessel that would be really well treated by a bypass surgery, but maybe there's a CTO in another vessel that we can actually treat with stents. It’s really allowing us to take the best parts of bypass surgery, meaning CABG surgery, and the best parts of the PCI, and really apply those to these very complex patients with multi-vessel disease.

Melanie: You mentioned consent before. What are some current issues in medical or surgical management, if you do decide to move forward with treatment?

Dr. Riley: We really go over the data and there's no real robust data about here's what the basic complication rates are for this patient group. We break them down into the various components of that and we can really go through those and modify those based on the patient’s condition, based on the way we’re going to treat it, based on their comorbidities, and we can really balance that with here’s the reasons why we would do this and really help patients make decisions based on that.

Melanie: What does current research indicate for future developments and treatment? Give us a little blueprint. Where do you see this going?

Dr. Riley: I think now that we've developed some of the skills, we’re continuing to develop better testing modalities to ensure that we are giving the most appropriate therapy to the patients who would benefit the most, really trying to differentiate patients who have very little benefit, but the same risks, versus those patients who would have the most benefit with those risks, and really trying to continue to pair that down to deliver complex therapy to the patients who would really benefit the most. We’re also continuing to develop various ways of mapping out these lesions in the arteries so that we can continue to refine our techniques and the equipment that allows us to treat these lesions. It's a burgeoning field. It’s at the top of everybody’s agenda at the major meetings and it’s really an exciting time to be an interventional cardiologist in the field.

Melanie: In summary, please tell other physicians what you'd like them to know about chronic total occlusion and when to refer to a specialist.

Dr. Riley: The biggest message that we can have as a take-home would be this: chronic total occlusions are no longer something that can be only treated by surgeons through a big complicated open-heart surgery. This is really something that if there's an indication for PCI, it should not matter if it’s a chronic total occlusion or a non-CTO lesion. If the lesion is appropriate to be treated, we can find a way to treat it. If there's any question, please just send the patient. We’re happy to see them regardless of whether we end up doing the procedure or not.

Melanie: What can a physician expect from your team at the Christ Hospital Health Network after referral in so far as communication with the referring physician and tell us about your team approach?

Dr. Riley: We have a coordinator and a large team where we have a one-stop shop for referrals. One number, get the referral in, they gather all the pertinent data, we then have a weekly meeting where the CTO and chip operators really discuss these patients in detail, whether any further medical therapy is needed, any further testing and talk about the technical approaches to these patients. We then have a second meeting on a different day of the week where we have a heart team approach, including surgeons and interventionalists, heart failure docs, or VAD docs where we really look at these patients from a multidisciplinary perspective and talk about the best ways of treating these patients from a group standpoint.

Melanie: Thank you so much for being with us today. It’s great information. You're listening to Expert Insights Physician Views and News with the Christ Hospital Health Network. More information on Dr. Riley and all of the Christ Hospital physicians is available at tchpconnect.org. That’s tchpconnect.org. This is Melanie Cole. That’s so much for listening.