Selected Podcast
Chronic Total Occlusion Percutaneous Coronary Intervention (CTO PCI)
Calvin Choi, MD, MS, FACC, FSCAI, discusses Chronic Total Occlusion Percutaneous Coronary Intervention (CTO PCI). He reviews pertinent data and shares indications for CTO PCI. He focuses on the factors that play into the decision to pursue CTO PCI and why proper patient selection is critical as he examines contemporary strategy and technique for CTO PCI.
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Learn more about Calvin Choi, MD
Calvin Choi, MD, MS, FACC, FSCAI
Calvin Choi, MD, MS, FACC, FSCAI is an Associate Professor of Medicine in the UF Division of Cardiovascular Medicine and specializes in Interventional Cardiology.Learn more about Calvin Choi, MD
Transcription:
Melanie: Welcome to UF Health Med Ed Cast with UF Health Shands Hospital. I'm Melanie Cole and I invite you to listen as we discuss chronic total occlusion percutaneous coronary intervention or CTO PCI.
Joining me today is Dr. Calvin Choi. He's an Associate Professor of Medicine in the UF Division of Cardiovascular Medicine. Dr. Choi, it's a pleasure to have you join us today. Explain a little bit about chronic total occlusion for us or complete blockages of the coronary arteries. Tell us the prevalence and the pathway of this CTO and when is a blockage considered a CTO?
Dr Calvin Choi: So chronic total occlusion is a fairly common problem. When we perform a coronary angiogram, depending on the patient population, we see this in 10, maybe up to 30% of the time. And, this is a different than acute coronary syndrome or MI or a myocardial infarction. In the setting of acute coronary syndrome or myocardial infarction, the coronary artery blockage is an acute event, namely through a plaque rupture. Chronic total occlusion is different because progression is insidious and it develops over weeks and months. So oftentimes patients may not be acutely aware of the disease process or the symptoms that may come along with it.
But over time, patients often do develop symptoms. So there's different processes involved in chronic total occlusion and acute coronary syndrome. Acute coronary syndrome, as I said, is an acute process, and this is what we typically consider a heart attack. And these are the problems that patients may get acutely ill or even die from. On the other hand, chronic total occlusion is a chronic problem that develops over prolonged period. And the development is insidious and, not necessarily something someone may acutely get sick from or die from, but certainly it can cause a lot of symptoms such as angina, shortness of breath.
Melanie: then what have been the treatment options for CTO? Have they traditionally, Dr. Choi been limited due to the complexity of opening up completely blocked arteries using catheter based techniques? How has the treatment evolved over the years? And how does an understanding of the histopathology of these lesions help provide insight into the development of new revascularization strategies?
Dr Calvin Choi: So as an interventional cardiologists, we do a lot of, angioplasty and stent placement. Chronic total occlusion has been a difficult disease process to manage in the cath lab with angioplasty or stent placement, namely because often these blockages been there for a long period. They do have a lot of calcium involved. So wiring these blockages, or placing a balloon or stent, have been very difficult. Traditionally, these lesions have been treated either with medications for symptom management or if patient has other reasons to have a bypass surgery, they would be referred to our cardiothoracic surgeons for coronary artery bypass grafting.
And that's the traditional way of managing our chronic total occlusion. However, over the past decade or so, we've really made tremendous progress in percutaneous management of chronic total occlusion. Namely because of the technology, advances in technology and also advances in technique in what we do.
In a typical angioplasty, we would wire the artery and use a balloon or stent to open the artery. In a chronic total occlusion setting, just wiring a vessel is extremely difficult using the traditional strategy and technique. So one of the ways we've learned, is that rather than going through the artery, per se, we've learned that we can go all around the blockage, while staying inside the vessel itself, we go through the vessel wall rather than the vessel lumen itself. And that has really tremendously improved our success rate. And today, we're able to have a successful coronary CTO, intervention, up in the ranges of about 90% success rate. Historically, that number has been in the ranges about 50% or even less. So both techniques, as well as equipment, advances in equipment have significantly improved our odds of a successful revascularization involving chronic total occlusion.
Melanie: you for that. And you got to my question about how that radiologic imaging has augmented your therapeutic capabilities for this. So tell us about some widely accepted best practices for CTO PCI. What are the clinical indications Dr. Choi? Give us some indications and what factors the decision to pursue this depends on.
Dr Calvin Choi: So there are a number of reasons why we would pursue or recommend a CTO PCI. One of the reasons is, and probably the most common reason is for symptom management. A lot of patients as mentioned before, have chronic total occlusion, and historically we've offered medical therapy for symptom management and some patients do just fine with medical therapy, some patients, because of other reasons, say they have valve disease or they have multi-vessel coronary artery disease, and they're in need of a coronary artery bypass grafting, so they'll be referred to a surgeon for coronary artery bypass grafting. But those who are not a candidate for bypass surgery because of their comorbidities or other reasons, or patients who are refractory to medical therapy, in other words, medication is just is not enough to control their symptoms and they have debilitating or refractory symptoms despite adequate medical therapy; in that population, CTO PCI is an appropriate treatment option and indicated. But I think the first line therapy would be at least a medical trial of medical therapy. If that fails and patient remains refractory, then CTO PCI is indicated and that will be the primary indication for CTO PCI. That is the symptom management.
Now there are some anecdotal data and also some information that suggest that CTO PCI may improve overall heart function. But I think that's more of select group, not, something that can be applied to a general population with a CTO or chronic total occlusion.
Melanie: Well then since this is such a complex procedure that requires expert care from highly experienced physicians, as you described a little bit about the procedure doctor, do you have any technical considerations you'd like other providers to know, share any contemporary strategy and technique for CTO PCI that you would like other providers to know about?
Dr Calvin Choi: Sure. So, as I've mentioned, we've had a tremendous advance in technique and technology. Regarding technology, to do, to perform CTO PCI successfully, the operator, the physician needs to be fully trained and aware of the use of these equipment. That is critical component of a CTO program. Second is the operator experience. Even with the advances in technique and technology is still a challenging procedure. It takes a lot of experience and time to learn this technique and skill set. If the patient needs a CTO PCI, identifying programs that have a lot of experience in CTO intervention, I think is the first step.
Not every interventional cardiologist is comfortable or facile with CTO PCI, identifying, your experts at an established CTO PCI program, I think is very important. In terms of the skills that's involved for a CTO PCI, one, as I mentioned, rather than trying to go through the blockage itself in the lumen of the vessel, we've learned over the years that you can actually go around the blockage and go through the vessel wall, as opposed to through the lumen of the vessel and in fact, that is a safer and more effective way of opening a chronically occluded, coronary artery. That is one strategy. The other strategy is using collateral vessels. So collateral vessels are these tiny vessels that the heart develops to improve profusion to an area, where the blocked artery is.
And these are small vessels and, may not be big enough to accommodate our traditional balloons and stents, but there are equipments, specialty wires and specialty microcatheters that can be used in this setting to get to the blockage and also use these equipments to successfully open the chronically occluded coronary arteries.
Melanie: Really fascinating, Dr. Choi. So what kind of support do patients need after the procedure? If your program has a focus that engages multidisciplinary teams to best treat the patient, what does that look like for your team? Speak about this approach and why it's so important for these patients.
Dr Calvin Choi: Having a CTO program involves, as you say, multidisciplinary team, surgeons, interventional cardiologists, support staff and nursing technologists. We need to identify first and foremost, who are the patients who are going to benefit from the procedure and what is the best way to treat this patient. And that involves multiple, sub-specialists, cardiac surgeons, interventional cardiologists, imaging specialists. So without that team effort, it will be very difficult to identify that right patient who will benefit from this procedure. And as mentioned before, this is a complex procedure. So I think it's important to identify the patients who will benefit and the best way to do that is to have a multiple sub-specialists engage in a meaningful dialogue and discussion to come up with the best treatment option for the patient. And for that reason, surgeons, imaging specialists, interventional cardiologists, nurses, technologists, and cath lab staff are involved is critical for the success of a CTO program and intervention.
Melanie: Well it certainly is. As we wrap up, Dr. Choi, looking forward to the next 10 years of the field. Tell us about any promising new therapies. Are there any game changers you'd like to mention for chronic total occlusion? Anything you'd like to talk about? Give us a little blueprint for future research that you know about.
Dr Calvin Choi: So recently they've noticed a very promising treatment option. And if you think about the kidney stones, it shouldn't for long time, urologists have used ultrasound to, break kidney stones with lithotripsy. And that's what it's called and recent application of this technology in coronary artery has revealed some very promising results, particularly because of chronic total occlusion involves arteries that a lot of calcium in it, and that really makes the procedure extremely difficult and challenging. And having an ability to address these challenges with lithotripsy, I think is a very promising treatment option going forward. And, I think that it's very promising, to improve a procedural success and two, to be able to perform procedure safely utilizing the technology.
Melanie: When do you feel it's important for other providers to refer to your team of specialists at UF Health Shands Hospital?
Dr Calvin Choi: I think, a trial of medical therapy is critical. I think patients need a trial medical therapy to see if they'll respond. Because if the patients do respond to medical therapy and they get satisfactory symptom management, then there really is no particular reason for patients to go through an invasive procedure because invasive procedures at the end of the day do carry risks. Patients ought to have a conservative management and if they respond well to that, then really no reason to pursue anything further, or anything invasive per se. There are exceptions, but in general, I think that's the strategy I would hold.
If however, patient is refractory to medical therapy and they're not a good surgical candidate for coronary artery bypass grafting, then that is the patient I think would benefit from having a discussion for possible CTO PCI.
Melanie: Thank you so much, Dr. Choi. What an interesting episode and a fascinating procedure. Thank you so much for joining us today. To refer your patient, please visit ufhealth.org/heart for more information, or to learn more about other healthcare topics at USF Health Shands Hospital, please visit ufhealth.org/medmatters to get connected with one of our providers. That concludes today's episode of UF Health Med Ed Cast with UF Health Shands hospital.
Please remember to subscribe, rate and review this podcast and all the other UF Health Shands Hospital podcasts. I'm Melanie Cole.
Melanie: Welcome to UF Health Med Ed Cast with UF Health Shands Hospital. I'm Melanie Cole and I invite you to listen as we discuss chronic total occlusion percutaneous coronary intervention or CTO PCI.
Joining me today is Dr. Calvin Choi. He's an Associate Professor of Medicine in the UF Division of Cardiovascular Medicine. Dr. Choi, it's a pleasure to have you join us today. Explain a little bit about chronic total occlusion for us or complete blockages of the coronary arteries. Tell us the prevalence and the pathway of this CTO and when is a blockage considered a CTO?
Dr Calvin Choi: So chronic total occlusion is a fairly common problem. When we perform a coronary angiogram, depending on the patient population, we see this in 10, maybe up to 30% of the time. And, this is a different than acute coronary syndrome or MI or a myocardial infarction. In the setting of acute coronary syndrome or myocardial infarction, the coronary artery blockage is an acute event, namely through a plaque rupture. Chronic total occlusion is different because progression is insidious and it develops over weeks and months. So oftentimes patients may not be acutely aware of the disease process or the symptoms that may come along with it.
But over time, patients often do develop symptoms. So there's different processes involved in chronic total occlusion and acute coronary syndrome. Acute coronary syndrome, as I said, is an acute process, and this is what we typically consider a heart attack. And these are the problems that patients may get acutely ill or even die from. On the other hand, chronic total occlusion is a chronic problem that develops over prolonged period. And the development is insidious and, not necessarily something someone may acutely get sick from or die from, but certainly it can cause a lot of symptoms such as angina, shortness of breath.
Melanie: then what have been the treatment options for CTO? Have they traditionally, Dr. Choi been limited due to the complexity of opening up completely blocked arteries using catheter based techniques? How has the treatment evolved over the years? And how does an understanding of the histopathology of these lesions help provide insight into the development of new revascularization strategies?
Dr Calvin Choi: So as an interventional cardiologists, we do a lot of, angioplasty and stent placement. Chronic total occlusion has been a difficult disease process to manage in the cath lab with angioplasty or stent placement, namely because often these blockages been there for a long period. They do have a lot of calcium involved. So wiring these blockages, or placing a balloon or stent, have been very difficult. Traditionally, these lesions have been treated either with medications for symptom management or if patient has other reasons to have a bypass surgery, they would be referred to our cardiothoracic surgeons for coronary artery bypass grafting.
And that's the traditional way of managing our chronic total occlusion. However, over the past decade or so, we've really made tremendous progress in percutaneous management of chronic total occlusion. Namely because of the technology, advances in technology and also advances in technique in what we do.
In a typical angioplasty, we would wire the artery and use a balloon or stent to open the artery. In a chronic total occlusion setting, just wiring a vessel is extremely difficult using the traditional strategy and technique. So one of the ways we've learned, is that rather than going through the artery, per se, we've learned that we can go all around the blockage, while staying inside the vessel itself, we go through the vessel wall rather than the vessel lumen itself. And that has really tremendously improved our success rate. And today, we're able to have a successful coronary CTO, intervention, up in the ranges of about 90% success rate. Historically, that number has been in the ranges about 50% or even less. So both techniques, as well as equipment, advances in equipment have significantly improved our odds of a successful revascularization involving chronic total occlusion.
Melanie: you for that. And you got to my question about how that radiologic imaging has augmented your therapeutic capabilities for this. So tell us about some widely accepted best practices for CTO PCI. What are the clinical indications Dr. Choi? Give us some indications and what factors the decision to pursue this depends on.
Dr Calvin Choi: So there are a number of reasons why we would pursue or recommend a CTO PCI. One of the reasons is, and probably the most common reason is for symptom management. A lot of patients as mentioned before, have chronic total occlusion, and historically we've offered medical therapy for symptom management and some patients do just fine with medical therapy, some patients, because of other reasons, say they have valve disease or they have multi-vessel coronary artery disease, and they're in need of a coronary artery bypass grafting, so they'll be referred to a surgeon for coronary artery bypass grafting. But those who are not a candidate for bypass surgery because of their comorbidities or other reasons, or patients who are refractory to medical therapy, in other words, medication is just is not enough to control their symptoms and they have debilitating or refractory symptoms despite adequate medical therapy; in that population, CTO PCI is an appropriate treatment option and indicated. But I think the first line therapy would be at least a medical trial of medical therapy. If that fails and patient remains refractory, then CTO PCI is indicated and that will be the primary indication for CTO PCI. That is the symptom management.
Now there are some anecdotal data and also some information that suggest that CTO PCI may improve overall heart function. But I think that's more of select group, not, something that can be applied to a general population with a CTO or chronic total occlusion.
Melanie: Well then since this is such a complex procedure that requires expert care from highly experienced physicians, as you described a little bit about the procedure doctor, do you have any technical considerations you'd like other providers to know, share any contemporary strategy and technique for CTO PCI that you would like other providers to know about?
Dr Calvin Choi: Sure. So, as I've mentioned, we've had a tremendous advance in technique and technology. Regarding technology, to do, to perform CTO PCI successfully, the operator, the physician needs to be fully trained and aware of the use of these equipment. That is critical component of a CTO program. Second is the operator experience. Even with the advances in technique and technology is still a challenging procedure. It takes a lot of experience and time to learn this technique and skill set. If the patient needs a CTO PCI, identifying programs that have a lot of experience in CTO intervention, I think is the first step.
Not every interventional cardiologist is comfortable or facile with CTO PCI, identifying, your experts at an established CTO PCI program, I think is very important. In terms of the skills that's involved for a CTO PCI, one, as I mentioned, rather than trying to go through the blockage itself in the lumen of the vessel, we've learned over the years that you can actually go around the blockage and go through the vessel wall, as opposed to through the lumen of the vessel and in fact, that is a safer and more effective way of opening a chronically occluded, coronary artery. That is one strategy. The other strategy is using collateral vessels. So collateral vessels are these tiny vessels that the heart develops to improve profusion to an area, where the blocked artery is.
And these are small vessels and, may not be big enough to accommodate our traditional balloons and stents, but there are equipments, specialty wires and specialty microcatheters that can be used in this setting to get to the blockage and also use these equipments to successfully open the chronically occluded coronary arteries.
Melanie: Really fascinating, Dr. Choi. So what kind of support do patients need after the procedure? If your program has a focus that engages multidisciplinary teams to best treat the patient, what does that look like for your team? Speak about this approach and why it's so important for these patients.
Dr Calvin Choi: Having a CTO program involves, as you say, multidisciplinary team, surgeons, interventional cardiologists, support staff and nursing technologists. We need to identify first and foremost, who are the patients who are going to benefit from the procedure and what is the best way to treat this patient. And that involves multiple, sub-specialists, cardiac surgeons, interventional cardiologists, imaging specialists. So without that team effort, it will be very difficult to identify that right patient who will benefit from this procedure. And as mentioned before, this is a complex procedure. So I think it's important to identify the patients who will benefit and the best way to do that is to have a multiple sub-specialists engage in a meaningful dialogue and discussion to come up with the best treatment option for the patient. And for that reason, surgeons, imaging specialists, interventional cardiologists, nurses, technologists, and cath lab staff are involved is critical for the success of a CTO program and intervention.
Melanie: Well it certainly is. As we wrap up, Dr. Choi, looking forward to the next 10 years of the field. Tell us about any promising new therapies. Are there any game changers you'd like to mention for chronic total occlusion? Anything you'd like to talk about? Give us a little blueprint for future research that you know about.
Dr Calvin Choi: So recently they've noticed a very promising treatment option. And if you think about the kidney stones, it shouldn't for long time, urologists have used ultrasound to, break kidney stones with lithotripsy. And that's what it's called and recent application of this technology in coronary artery has revealed some very promising results, particularly because of chronic total occlusion involves arteries that a lot of calcium in it, and that really makes the procedure extremely difficult and challenging. And having an ability to address these challenges with lithotripsy, I think is a very promising treatment option going forward. And, I think that it's very promising, to improve a procedural success and two, to be able to perform procedure safely utilizing the technology.
Melanie: When do you feel it's important for other providers to refer to your team of specialists at UF Health Shands Hospital?
Dr Calvin Choi: I think, a trial of medical therapy is critical. I think patients need a trial medical therapy to see if they'll respond. Because if the patients do respond to medical therapy and they get satisfactory symptom management, then there really is no particular reason for patients to go through an invasive procedure because invasive procedures at the end of the day do carry risks. Patients ought to have a conservative management and if they respond well to that, then really no reason to pursue anything further, or anything invasive per se. There are exceptions, but in general, I think that's the strategy I would hold.
If however, patient is refractory to medical therapy and they're not a good surgical candidate for coronary artery bypass grafting, then that is the patient I think would benefit from having a discussion for possible CTO PCI.
Melanie: Thank you so much, Dr. Choi. What an interesting episode and a fascinating procedure. Thank you so much for joining us today. To refer your patient, please visit ufhealth.org/heart for more information, or to learn more about other healthcare topics at USF Health Shands Hospital, please visit ufhealth.org/medmatters to get connected with one of our providers. That concludes today's episode of UF Health Med Ed Cast with UF Health Shands hospital.
Please remember to subscribe, rate and review this podcast and all the other UF Health Shands Hospital podcasts. I'm Melanie Cole.