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Melanie Cole (Host): Awareness of peripheral arterial disease is very low in both patients and in primary care practice, despite a growing incidence of the disease, secondary to diabetes. Our topic today is Awareness of Peripheral Arterial Disease, and my guest is Dr. Benjamin Pearce. He's the Program Director of the Vascular Training Program at UAB Medicine.

Dr. Pearce, explain a little bit about peripheral arterial disease, and what's going on in this field today, and why you feel that there is not enough awareness.

Dr. Benjamin Pearce, MD (Guest): Thank you so much, Melanie, for the intro and the opportunity to speak today. You know, peripheral arterial disease is something that is exciting to be involved in right now. We're at a real neat point in time as providers because there's a lot that we can actually do for patients, both medically with minimally invasive surgery, and then ultimately we still have good surgical procedures that have excellent results. So there's a lot that we can do to help people.

The interesting thing is how the disease is really changing and becoming more prevalent. Historically only about 5% of the population would be affected by peripheral arterial disease, specifically of the lower extremities we'll speak to today, but as we see with diabetes, the instances of PAD in the diabetic population is more like 25% to 30%. So as we have the increase in diabetic population going forward, we're going to see a lot more peripheral arterial disease in our patients. So I think it's something that the patients and the primary care providers have to be aware of.

There's a lot of problems with legs in diabetic patients. They can have innumerable things regarding neuropathy, changes in gait, obesity obviously causes things like arthritis, low back disease, and it can be quite confusing why a person has leg pain, and I think a lot of times they go for the usual thing, "You have a pinched nerve in your back," when in fact this may actually be something like an arterial obstruction. So that's why it's great.

Melanie: Well also, leg pain can be so non-specific. It could be a pulled tendon, or bad shoes. You know? Women especially get this kind of leg pain, and we all look at our calves and say, "Oh is this a blood clot, or is this peripheral arterial disease?" And so it can be very non-specific. What do you want us to know, and for other providers so that they take seriously these complaints that people have when they do have leg pain?

Dr. Pearce: Sure, great question. So the first thing is, is that peripheral arterial disease is just an extension of cardiovascular disease in general. There's a lot of cross talk between coronary artery disease, carotid artery disease, aneurysm disease, peripheral arterial disease. The risk factors are the same; smoking, hypertension, poor diet, lipid control.

So the first thing's first, leg pain in a patient who doesn't have the usual cardiovascular risk factors, in a healthy patient, leg pain is probably not going to be vascular in nature, and those are patients that you can quickly go down the road of treating for other orthopedic type injuries, neurologic, chronic use syndrome, those sorts of things. But if you have a patient that has those kind of classic cardiovascular risk factors, then that's the first thing that should trigger in your mind as a provider is, "Well maybe this is vascular," and then you can ask some very specific questions.

The kind of classic initial presentation of PAD in patients is a syndrome called claudication, which when you backtrack to the original Latin just means 'to limp.' So these are patients that at rest have adequate profusion, they aren't developing ulcerations, tissue loss on the foot or on the toes. At rest they're getting adequate profusion from collateral flow, but when they need to use their muscles, that's when they notice the pain. It's kind of the leg equivalent to anginal pain in the chest. For whatever reason, heart disease is such a well-known, and well-studied, and well-thought about disease process. Everybody knows what angina is, but very, very few people really know what claudication is, but it's the same sort of principle.

Your body compensates when you're having- when you're chronically developing blockages into an arterial system, and so you can maintain that profusion, but that compensatory mechanism normally would augment flow during exercise. It's no longer there to augment the flow, so when you walk, then you get the pain. So really vascular pain and kind of that initial presentation is usually very specific to muscle groups that are being used. So if you have a patient who's complaining of leg pain, the first question is, "Well when does this bother you?" Just like you learn in med school. "When does this bother you? And what makes it better?" Because if they have pain in a muscle group, we usually describe it, it's almost like a charley horse or a real tightness and discomfort in something like the calf muscle or in the kind of posterior thigh, or buttock region if they have a higher level of occlusive disease.

If they have that pain, and then they stop walking, or swimming, or riding a bike, or whatever it is that brings it on, and as they rest the pain gets better and they're able to go some more, that's classic for PAD related pain. So those are the first things just so you can screen a patient. "Do you have the cardiovascular risk factors? And is this an exertional type pain?" And that's kind of where you start.

Melanie: So how important is that early diagnosis as being crucial to improve the outcome prediction and to help improve appropriate and timely referral, and then explain a little bit about the diagnosis, and what tools are you using to aid in this diagnosis?

Dr. Pearce: Yeah, diagnosing it is really important, mostly because the diagnosis of PAD is often then inroad into treating the patient's overall cardiovascular risk. In fact, PAD in its simplest form, in that kind of claudication, problems walking but otherwise intact circulation, itself really isn't going to be even a limb threatening situation. Patients who have chest claudication, if they can get treated appropriately early, often with no intervention, the risk of losing a limb in five years from this disease process is 5% or less. So I think that's one of the big things that's often misunderstood.

Someone hears they have a blockage in the leg artery, and they think, "Oh no, they're going to lose their foot." Someone knows a patient in their family who's had diabetes or has had peripheral arterial disease that's lost a limb. Well that's really not the case if you catch it early. A lot of times even with just medical and exercise treatment, the limb loss risk is very low, but what it allows you to do is actually initiate the conversation with the patient about overall risk factors. Because having PAD does put you at risk - about 20% risk over five years of having some sort of cardiovascular related mortality; a stroke, a heart attack, dissection, or some other pathology in the cardiopulmonary circulation that actually leads to death. It puts you at increased risk for things like heart attacks, and strokes, and so getting the diagnosis is really important.

Because the mainstay is going to be quitting smoking, controlling your diabetes well, lipid management, statin agents have revolutionized cardiovascular care, being on antiplatelet regimen; these are all very important things. So it's critical to get those patients identified, and I think an early referral to a vascular specialist with patients who are symptomatic. It's important too because there's a lot of good data that shows that us doing any oral exams with these patients, getting them in the right therapy, reminding them about their medical management, as well as getting them in an exercise program. All those things lead to less cardiovascular mortality in addition to just helping them to function better in their life. And being able to exercise and walk more is better for your overall health in general.

As far as diagnosis, the simplest thing we can do is what's known as the ABI or ankle brachial index. Quite frankly, anybody with a doppler device and a blood pressure cup can do one at the bedside as a quick screening tool. You just hook the- you get the brachial pressure, you find the best brachial pressure, you put your doppler probe under the dorsalis pedis and tibial arteries and place the cuff on your calf and you get the highest measurement of those two and do a ratio. And anything that's 0.9 to 1.3 ratio is quite frankly considered normal, and most likely means the patient does not have significant symptomatic peripheral arterial disease. If it's less than 0.9 or it's what we call non-compressible or greater than 1.4, then they're probably going to need some more specific testing that can be done in a vascular surgeon's office.

But that's usually where we start is just with an ABI. If the patient's story really sounds like it's vascular in nature but they have a normal ABI at rest, the next thing to do, and any vascular specialist can do this, is you can actually get the patient, do the ABI, and then you can put them on a treadmill and repeat those ABIs after you've walked them, and if you see a significant drop, then that may actually be indicative of kind of that early stage of vascular obstruction.

The hardest thing in this current day in age is with diabetes increasing, diabetes influences some of our how non-invasive tests work. So it's really important to get them into a lab where they can do things like plethysmography, and actually do digital pressures, because digital pressures tend to be preserved in diabetics whereas the ankle pressures may not be. So anybody with diabetes that you suspect has peripheral vascular disease, that's somebody I'd definitely recommend early referral and more specific testing.

A patient who doesn't have diabetes has the other risk factors, and you just want to know if they've got it, then start with an ABI and then you can go from there. But again, I think seeing a vascular specialist is never a problem in patients who have risk factors for cardiovascular disease.

Melanie: Dr. Pearce, what's the first line of defense if you do determine that they have PAD, and what are some of the challenges in adherence and follow-up?

Dr. Pearce: So the first thing is getting those lifestyle modifications done, and it's not easy. I mean, I sympathize with the patients, we're all human, but smoking cessation is an absolute must. That is like the first line of treatment. Excellent diabetic control. There's innumerable research studies that have linked HbA1c control to outcomes with patients with diabetes in regard to limb salvage and improvement in their overall mortality.

So getting those things in line are- those are the most difficult ones for patients, right? Smoking cessation and diet. So those are the kind of first things you've got to harp on, and the great news is, like I said, as vascular specialists we really- as we've started to treat the patients with multi-modality therapy, we're really understanding how important it is that even though we're surgeons, that we get involved with things like smoking cessation. So in our clinic, we've dramatically increased our interventions to help with smoking, and I think it's important patients understand sometimes they have pain and they want a procedure. It's kind of the American way. It's important to explain to them just because we're not necessarily recommending a bypass or a stint for this problem, by doing things like targeted smoking cessation, statin therapy, exercise therapy, we're treating your disease. We're actually doing something proactive for you to make you better. And I think when you can get them to buy into the idea that we're doing something about your disease process, that gives you a lot more success. So that's the first line is getting on those kind of lifestyle risks, and then doing a real assessment of their overall medication list and making sure they're getting a statin agent, and they're getting some sort of anti-inflammatory agent, either Aspirin or Plavix, and sometimes both depending on their other cardiovascular comorbidities.

Melanie: So now as you sort of wrap it up for us, Dr. Pearce, what do you want other physicians to know about doing a patient level explanation from their whole team so that the whole team is on board, and understands how to work with this patient on adherence, on medication adherence - because that's a problem as well - and really what you want them to know about early referral and explaining all of this to their patients?

Dr. Pearce: Well I appreciate the opportunity, because I do think there's still a lot of confusion out there. And so what I want the referring docs, and the referring nurse practitioners, and mid-level providers, and the people who are seeing these patients on the ground floor to really remember is that this is about treating their overall well-being. So it's about lowering their overall mortality, dying from cardiovascular disease, but that the leg itself in the early stages of PAD, the leg is not at risk, and they shouldn't die from this. They can be treated early and this will help them to live better overall.

So getting them in early for a referral and getting on those programs, like I said the smoking cessation, diabetic control, diet, and exercise can really help. In fact, getting a patient in and getting them to buy into the fact that when this person evaluates you, they send you to a specialist. When the specialist evaluates you, they're going to look at your whole picture, they're going to look at the medicines you're on, how you function, what is it you do in your life? Because what we recommend for someone who's dependent upon their limbs for their well-being may be a slightly different recommendation for someone who's retired and just wants to enjoy going to their grandchildren's basketball games. So they're going to look at you as an individual and they're going to determine what's the right thing for you. That may be exercise therapy, targeted drug intervention, lifestyle modification. It may be a recommendation for some sort of an interventional type procedure that's minimally invasive, or it may be surgery depending on you as an individual. I think that's the important thing, is making sure the patients understand that whichever modality ends up being the right one for them to treat, we're doing something to help them.

I think the other thing I want the practitioners to take away from is there's a lot of confusion right now about what should be done for patients with this kind of early PAD claudication type thing, because the milieu is to send patients to some sort of a specialist, and there's a lot of people that offer intervention. There's interventional cardiology, there's interventional radiology, vascular surgeons, interventional nephrology. There's a big mixed bag of people who are treating these disease processes, and there are great people doing it in all those different specialties, there's no doubt that they're really good practitioners in all of them, but I think that there's probably an over-abundance of interventions being done without appropriate modification or risk factors in attempts at non-operative therapy first.

And the other thing I think that confuses the works is there's a difference between someone who has a wound, or tissue loss, or their disease has progressed to the point where they're having constant pain from the blockages. Patients in a more advanced stage, what we call chronic limb threatening ischemia, that's a different modality. Those are patients needing to be treated with some sort of intervention albeit surgical or minimally invasive on a much sooner basis. So getting the patients in early, you can prevent them from getting down the road to that point, and having them see a specialist on a regular basis can do that, but not everybody needs an intervention. At that early stage, a lot of the things they need is exercise therapy, physical training, and like I said, appropriate medical management and appropriate lifestyle management. So get them in early and get them to understand that we're being proactive about helping them to live better and live longer.

Melanie: Absolutely fantastic information, Dr. Pearce, and so important for other providers to hear. You've laid it out so very well. Thank you for being with us today. A community physician can refer a patient to UAB Medicine by calling the MIST line at 1(800) UAB-MIST. That's 1(800) 822-6478. You're listening to UAB MedCast. For more information on resources available at UAB Medicine, you can go to www.UABMedicine.org/physician. That's www.UABMedicine.org/physician. This is Melanie Cole, thanks so much for listening.