Carl Maronich (Host): Welcome to Flourish, the podcast where we dive into health and healing advice with trusted experts from Prisma Health. I'm Carl Maronich. And with me today is Dr. Moin Syed, an interventional cardiologist and endovascular specialist with Prisma Health. And we're going to be talking about chronic limb-threatening ischemia. We'll explore how to recognize it, treat it and, hopefully, how to prevent it. Doctor, welcome to the podcast.

Dr. Moinuddin Syed: Thank you. Thanks for having me, Carl.

Host: Yeah, glad to. And I appreciate your time. And maybe we could start by having you just describe what chronic limb-threatening ischemia is. I believe it's also referred to as critical limb ischemia.

Dr. Moinuddin Syed: That's correct. So, chronic limb-threatening ischemia is the most severe manifestation of peripheral arterial disease, which affects almost 30% of the population in the U.S. And basically, what chronic limb-threatening ischemia is, it manifests in one of three forms where patients have either gangrenous changes in the toes, which means basically dead toes or ulcers or wounds in the foot, which are not healing because of compromised blood circulation down to the foot. And some patients even can present with what we call ischemic rest pain, which means that they have pain in their foot when they are resting. Usually, that happens because there's not enough blood circulation getting down to the foot because of blockages in the artery supplying blood to the legs.

Host: Those blockages, I'm guessing, could come from a number of things. Trauma could cause that or also just other health issues that close the vessels. Is that correct?

Dr. Moinuddin Syed: Yes and no. Usually, the blockages are caused by what we call atherosclerosis, which is buildup of plaque in the arteries, which can happen as people age or from risk factors that can include smoking, diabetes, high blood pressure, high cholesterol, and sometimes even family history. And when these blockages develop in the artery supplying blood to the legs, we call it peripheral arterial disease, or in the artery supplying blood to the brain, we call it carotid disease. When it affects the artery supplying the heart, it is called coronary artery disease. So, it's kind of the same disease process when patients develop buildup of plaque that kind of compromises the blood circulation to the legs and foot. And when it's more severe and blockage is at multiple levels, that can cause such bad compromise in circulation to the foot that the foot can die essentially. That's what gangrene means.

And sometimes patients with unexpected trauma or from diabetes can develop some ulcers or wounds, which usually in most people should heal if they have good blood circulation to the feet. But when there's compromised blood circulation, the ulcer or the wound doesn't heal, and sometimes when that doesn't heal and progresses, the infection can progress and sometimes people end up with what we call amputation. And that, believe it or not, is a very serious problem currently, especially here in South Carolina where we have a very high burden of amputation and what we call PAD or peripheral arterial disease.

Host: So, chronic limb-threatening ischemia—or CLTI, it could be also called—really can develop from a number of factors, and overall health kind of factors into that. If folks aren't taking care of themselves in a few different ways, maybe you could talk a little bit about the risk factors.

Dr. Moinuddin Syed: Yes, absolutely. You know, the risk factors are similar to people who have blockages in the heart arteries or people who have heart attacks. It's the same disease process that affects a different vascular bed in the legs. And it's something that's kind of really underrecognized and undertreated because no one looks for it or people don't look for it. And even if they find it, they don't refer them to their specialist to get taken care of.

So, the risk factors, as I said, usually it's smoking and diabetes. Those are the major risk factors. And if you have a combination of those two, actually, the U.S. Preventive Services Task Force, which recommends screening for peripheral arterial disease in patients more than 50 if you have both those risk factors. So, the screening tests, we can get a little bit deeper into this a little later, how to recognize it. But the smoking, the diabetes, high blood pressure, high cholesterol, these are the main risk factors, the most important being smoking and diabetes.

Host: Yeah. So as we often talk about in these health podcasts, knowing your body, knowing your health, seeing your primary care provider pretty regularly to be monitoring these things would be an important factor in this as well.

Dr. Moinuddin Syed: Seeing your primary care physician and taking those medications for cholesterol and diabetes and quitting smoking for patients who smoked a lot and getting your blood pressure under the ideal control, that would definitely reduce the risk of developing progression of peripheral arterial disease and progression to CLTI or critical limb ischemia. So, those are definitely important components of care.

Host: Doctor, how prevalent is CLTI in the United States? And are there certain populations that should be more concerned?

Dr. Moinuddin Syed: Yes, definitely. That's a very good question, Carl. So, the burden of PAD is, I would say, around 20-30% of the adult population, especially it's enriched in people who have these risk factors like diabetes and smoking. And it can be way higher in these patients. It's usually the lower socioeconomic status and certain ethnicities, which is mostly in African Americans and Native Americans and Hispanic population. This prevalence is way higher. And for unclear reasons, we are not sure they have more aggressive and more severe manifestation of PAD, which is the chronic limb-threatening ischemia, and their burden of disease is way higher than in some of these other populations. So yes, definitely the African American, native American and the Hispanic population, I would say, has an extremely high burden of peripheral arterial disease.

Host: So, someone who has peripheral arterial disease, is there a percentage of those patients that might get to the point of amputation?

Dr. Moinuddin Syed: So, a lot of patients have peripheral arterial disease, but I would say probably 3-4% kind of progress to the most severe form, which is the CLTI. And most patients will have what we call asymptomatic PAD, where they do have plaque, but they don't know that they have PAD. And that's where we need to recognize these patients. And I would say, probably 60% of patients with peripheral arterial disease kind of remain asymptomatic, and they never know they have it. And for them, recognizing and preventing progression would be the key.

And of those remaining 40%, probably like quite a few of those, 60% would be asymptomatic and 40% would develop some symptoms. And the most common symptoms would be what we call claudication, where patients develop discomfort or pain in their thighs or calves or hip when they walk or exert themselves. It could even be like tiredness or fatigue in their legs when they walk.

And then, it goes away when they stop and rest, and then they resume walking, they again develop the symptoms. So, that's the most common manifestation of symptomatic PAD. A few percentage of most of those patients will remain stable with claudication. A few percentage of those can progress beyond exertional symptoms to having lifestyle-limiting claudication, what we call advanced claudication, where they can't carry out day-to-day activities or like going to the grocery store or picking up mail from the mailbox. Those kinds of activities can also be difficult for them when they're disease progresses and compromises blood circulation to the legs.

I would say, you know, of those 40% symptomatic, probably 10 or 15% would progress. And given such a huge burden, though it sounds like 10%, 15%, that is still a very high burden of disease. And of those 15%, probably 2% or 3% can, again, progress to more advanced stage where they have pain at rest or ischemic rest pain, or even when they have these other risk factors like diabetes and other things, they can develop ischemic ulcerations or what we call tissue loss, where they have wounds and ulcers in their leg because of compromised blood circulation, which never heal unless we open those blockages, you know, either by surgery or balloons and stents, what we call endovascular therapy.

Host: If someone is having some of these initial symptoms that you talk about, leg pain or extreme fatigue kind of in a sudden onset, if you will, extreme fatigue when walking and such, they're likely going to see their primary care provider first. And if they suspect something, would they then refer to someone like you? Or how would the diagnosis process work?

Dr. Moinuddin Syed: So usually, they could directly refer to a vascular specialist or they can even do some baseline screening tests in their office or send them for a basic screening tests, which we call ABI or ankle brachial index, or even a vascular ultrasound, to assess the blood circulation in the legs. So, this is a pretty basic screening test or they can just directly refer to us and we can order those testing. And there are several layers to testing and when patients have probably claudication, just they can do the testing. But when patients have like ischemic ulcers, wounds or gangrene or dead toe, or someone is considering an amputation, then definitely before progressing to the amputation stage, they should be referred to a vascular specialist.

Host: Yeah. And what would some of the treatment options be at various stages of CLTI?

Dr. Moinuddin Syed: When patients come in with claudication, the first-line therapy would be risk factor modification. If patients are smoking, we would recommend that they quit smoking, get better control of their diabetes, get their cholesterol levels into control with medications. And we prescribe what we call supervised exercise therapy or supervised exercise program where they walk or exercise through their pain—the idea being that the body improves blood circulation by itself to the foot so that they wouldn't need therapy. But that's only for patients who have this claudication, which is the least severe form of manifestation of PAD. And if they continue to have symptoms, then we can offer some more advanced therapies, which could be surgical bypass. And in the past probably couple of decades, our endovascular therapy has advanced so much that has kind of become the first-line treatment for patients with advanced PAD, which could be like ischemic rest pain or patients with CLTI.

Host: Doctor, in what ways is CLTI life-threatening? And how does it impact the patient's quality of life? And you touched on some of those, but maybe you could speak to the life-threatening component of CLTI.

Dr. Moinuddin Syed: Yes. So, it's basically limb-threatening. And when the limbs get threatened, there's a life threat too. So, it's definitely something that has to be recognized. I mean, traditionally, we think of blockages in the heart arteries that need to be taken care of. Otherwise, you know, patients come in with like a heart attack. This is kind of like a limb attack when patients have a wound or ulcer, and they definitely need to be referred to a vascular specialist for evaluation if they have a wound ulcer or gangrene in their toes before they progress to needing an amputation. Because if untreated, the wound never heals.

And if they develop an infection, it can progress and be a threat to their limb, which would require an amputation. And as you can imagine, when someone gets an amputation, that could be very disabling. They can't move around and amputation itself carries a very high mortality. I mean, two amputations are okay. But when patients start getting below-the-knee or above-the-knee amputations, it's a very morbid procedure. And we do know that the survival of these patients gets down to almost 50% over a year or two. So, almost sort of out of two, four patients can die if they get an amputation. And the death may be from like cardiovascular causes or stroke or those kind of things. But still, these patients are extremely sick and need to be cared for with appropriate medications and therapy before they progress to needing an amputation.

Host: Doctor, maybe a brief moment to talk about people hear cardiologists and they may not think of extended limbs in their feet and things. But really, it's because of circulation and your expertise in endovascular surgery that you're involved in CLTI. Is that right?

Dr. Moinuddin Syed: Yes. Just generally, this is a multidisciplinary care that our patients need when they have PAD, that traditionally they would need care from a vascular surgeon or even like—I'm a vascular specialist. And I have specialized training in endovascular and vascular medicine.

So, patients need care from multiple different specialties, who should be coordinating care because sometimes surgery might be a better option when they have extremely complex disease. And when patients have these kind of wounds and ulcers or gangrenous changes in the toes, we do advanced evaluation with an invasive angiogram. And then, we classify their disease based on what we call a task classification. And when, it's extremely severe, some disease may not be amenable to endovascular therapy, then they would require surgical therapy, which would include an open bypass.

But currently, some of our patients are so sick that they're too sick to go through a surgery, And then, those patients will still be candidates for endovascular therapy. So, I would say they require multidisciplinary care with vascular surgery or interventional cardiologists with specialized training in endovascular therapy and podiatrists and primary care and endocrinology, infectious disease, and all these specialties definitely—and wound care, that's another thing, you know, sometimes we restore blood circulation of the foot, but the wound needs to be taken care of, making sure it heals completely, and that would prevent an amputation. So, I would say, yes, they do require a multidisciplinary approach.

Host: Like, with many things in healthcare, it takes a village truly. Doctor, if listeners have a loved one who's going through this, how can they support someone who is having these vascular health issues?

Dr. Moinuddin Syed: My message would be that the burden of amputation currently is so high that, when patients develop wounds or ulcers that have not been healing for some time, and then you're following up with a podiatrist or your doctor. And so when someone recommends an amputation, you have to get them to see a vascular specialist before someone gets an amputation.

Unfortunately, there's a lot of patients out there who have progressed to an amputation without getting their vasculature evaluated and seeing a specialist who can potentially salvage their limb and prevent an amputation by revascularizing them with either endovascular therapy or open surgery.

So, that would be my key message. And if you have any symptoms, where you have tiredness, fatigue in your legs when you're walking, then you have to be referred to a vascular specialist, or if you develop changes in your feet that you have some ulcers or wounds that are not healing, those kind of things, they have to be evaluated by a vascular specialist and take it from there.

Host: Doctor, as you mentioned earlier, a lot of lifestyle components to staying healthy and keeping good circulation. And certainly, one of those is eating healthy. And, Doctor, I know you like to cook, so I'm sure you mentioned to your patients and give them some healthy options when they're cooking to make sure their vascular health is maintained. Is that right?

Dr. Moinuddin Syed: Yes, absolutely. The diet obviously, currently with the burden of obesity and diabetes going hand in hand, and calorie restriction is a key component. And we have excellent therapy for even weight loss and those kind of things, and eating healthy, incorporating more fruits, vegetables, and more Mediterranean diet. And less saturated fats and fast foods and those kind of things would help a lot go a long way, mainly in preventing diabetes and obesity, which kind of play into developing this atherosclerosis, which is the underlying disease process for patients with PAD and CLTI.

Host: As an accomplished chef, do you offer to go to the homes of patients and cook them healthy meals?

Dr. Moinuddin Syed: I don't usually do that. I do advocate that patients. You know, currently, in our society, we don't have that. Everyone's busy and, you know, no one has the time to make a meal or we rely more on fast foods, but definitely trying to be cognizant of planning your meals and calorie restriction, eating healthy, those would definitely help in preventing diabetes and obesity, that is underlying risk factors for PAD and progression to chronic limb-threatening ischemia.

Host: Well, even if you're not going to cook us a meal, you were very helpful today with all this great information, Doctor. We greatly appreciate it.

Dr. Moinuddin Syed: Thank you so much, Carl, for having me.

Host: Yes. And for more information, visit prismahealth.org/flourish. If you enjoyed this podcast, please share it on your social channels and explore our full podcast library for topics of interest to you. I'm Carl Maronich, and this is Flourish from Prisma Health. Thanks for listening.