Diagnosing PAD

Manesh Patel, MD:Tell me a little about diagnosis, or at least what underdiagnosis might mean. What are the things we must have set up to find people? It’s a pulse examination, maybe a blood pressure cuff, some interesting things you need, but the underdiagnosis and misdiagnosis of PAD [peripheral artery disease] can have significant consequences.

Amr Abbas, MD:Whenever I see a patient for the first time, I request my physician assistants or the medical assistants to get them to take off their shoes and socks, and get into a gown. You must fully examine them because if they don’t take off their shoes and socks then you’re going to miss the simplest of all, which is just looking at the foot, feeling the pulses. At every step, we are missing opportunities to diagnose PAD. We don’t take the initiative to ask our patients whether they have claudications, and we aren’t fully examining the patient and giving them the due diligence for that. Once somebody comes and you identify a problem, it’s prudent to see how you can make the diagnosis quickly with the least amount of adverse effects, keeping costs in consideration. At that time, we do a formal vascular exam, where we do the ankle-brachial index [ABI], the toe pressures, and the ultrasound to try to identify locale. And we stage the patients into different classifications, whether you use the Rutherford or the Fontan, to see exactly, is this life-limiting? Is it affecting their quality of life? That is important because when you protect somebody’s heart, you’re saving his life. When you protect his leg, you may be saving his leg and his life, but you’re also improving the quality of his life. That’s really prudent. We are underdiagnosing our patients with PAD, especially women, who sometimes present with atypical symptoms. It is a bit more prominent in the African American population, and those deserve a closer look because of their increased hazard ratio. Once we identify the symptoms, we try to plan whether those patients qualify for interventions and then we decide on further venues.

Christopher Granger, MD:We’ve shifted the role of revascularization, it’s no longer as important for the average patient with coronary disease as simply optimal medical therapy, risk factor modification. Do you think that’s also true in PAD, like for protecting the population against amputation or progressive symptoms, where do you see revascularization versus medical therapy?

Manesh Patel, MD:We will discuss the different types, but it will be dependent on the patient’s syndrome. Marc Bonaca, [MD, MPH,] and I have had this conversation where critical limb ischemia, or acute limb ischemia, is the ACS [acute coronary syndrome] of the limb. There, revascularization will have a large role like we think about patients with ACS, where if you can get blood flow and save tissue, you help that patient. Claudication is what I call the chronic angina of the limb, where many of the same things, risk factor modification, activity, exercise will be extremely beneficial. When we get into trial data where we do revascularization for a variety of reasons, we start to say that just like in the coronary tree, every time I do something there are intended and unintended consequences, and I must be careful about what I’ve been doing there. From a broad perspective what we’ve shown is that it’s extremely common, the risk factor is the same as vascular disease, but it’s not identified. Shoes and socks are critical, don’t get me wrong, I try to take them off and start at the legs in many of my patients, but it’s hard. It’s a systematic thing of which patient you’re doing, and I’ve tried to fundamentally do that. I’m a vascular guy who’s interested in trying to get blood flow to more vessels. That’s not ubiquitous. One of the biggest resources for finding patients is life screening. Patients are willing to give a couple hundred bucks at church in the parking lot to get an ABI, a calcium score, a lipid, blood pressure. Then they show up with these numbers and ask what it all means, and we think, wow, we should probably figure out how we can feed that need for them to want to be healthier.

Larry Allen, MD:Screening is not helpful if you don’t do anything with the information. You might say for a patient with coronary disease, they should be doing Life’s Simple 7, they should be on a statin or an antiplatelet agent, so why does it matter? And for a lot of reasons, it probably does matter. One is, they’re higher risk, so it may be that it’s a greater motivation for the patient to be more proactive about those things that they maybe should’ve been doing but weren’t. It’s greater motivation for the health system and payers to be more aggressive with that population, because the absolute risk reductions are bigger. We will talk a little bit about that in that PAD population, you might want to be a little more aggressive with some of your therapies.

Manesh Patel, MD:We’ll end this area by saying, to fix things like this will take systematic interaction. Our health systems will have to be doing things to get to places. One thing we did in North Carolina is, William Schuyler Jones, [MD,] at our organization published the United States map of amputation. And what you see in North Carolina, and in the United States, is the No. 1 risk factor for amputation was where you live, your creatinine, and your age. Fundamentally, social determinants of health are playing a big role in how our patients get access to our care. So we must identify; the United States Preventive Services Task Force argument, which I know Joshua A. Beckman, [MD, MS,] and others have said, you’re going to do the same things. You don’t have to do something different. That’s fair, although there may be new therapies that we’re going to talk about, you could do something different. The second thing is it may motivate the patient. It’s a price point management issue. People sometimes use a calcium score to say, “Look you have the disease, so you do need to walk, take your blood pressure pill, and take your statin.” Sometimes giving people a reason that their leg is hurting or why they’re not moving as much is helpful.

Christopher Granger, MD:The other thing to mention is the cigarette smoking issue. For those who smoke and have early PAD, stopping smoking might be the single most important thing they could do. If people know they’re going to have an amputation if they don’t stop smoking, it may be an additional motivational factor.

Manesh Patel, MD:It’s a powerful addictive substance. In our PAD clinics we’ve had everything from surgeons who used to say, “I’m not operating on you if you don’t stop smoking”—I thought that was punishing the patient, because it is an addictive thing, and we don’t do that for other parts of medicine—to the other version where, “We wish, despite several interventions, you’re still smoking, and what can we do?” Those are some of the real-world things that are happening.

This transcript has been edited for clarity.