The Early Stages of Peripheral Artery Disease
Peripheral artery disease (PAD — pronounced P.A.D.) is a narrowing of the peripheral arteries to the legs, stomach, arms and head — most commonly in the arteries of the legs. PAD, like coronary artery disease (CAD), is caused by atherosclerosis — you may have heard it called “hardening of the arteries” — that narrows and blocks arteries in various critical regions of the body.
Sometimes PAD is the first warning of atherosclerosis throughout your arteries, putting your whole circulatory system, including your heart and brain, at risk. Fatty deposits, called plaque, also increase the odds of blood clots that block blood supply and cause tissue death or break off and travel to another part of the body. This is a common cause of heart attack or ischemic stroke.
PAD affects about 8.5 million Americans age 40 and older. It becomes more common as we age. People with PAD have a higher risk of coronary artery disease, heart attack or stroke. The sooner it is diagnosed and treated, the better.
Dr. Antonio Gutierrez
Not everyone with PAD has symptoms. Interventional cardiologist Antonio Gutierrez, assistant professor of medicine at Duke Medical School, estimates as many as half the patients he sees don’t have obvious symptoms, one of the most common being pain in the calves during exertion. “Instead of leg pain, they say, ‘My legs tire out.’ They don’t get pain in their calves or even get any cramping. They just know that they can’t do as much as they could maybe a couple of years ago, and they just chalk it up to getting older and learn to live with it.”
Whether or not a person has symptoms, if they have plaque, technically they have PAD. Gutierrez likens it to coronary artery disease: “If we see any plaques in the coronary arteries, we say the patient has coronary artery disease. The same thing for the legs. If there is any plaque in the legs, you would say that patient has peripheral artery disease. We would just call it nonobstructive. Most of the time, we don’t see the plaque first because patients don’t come in until they have symptoms. Then we do a test.”
Slowing the progression of PAD is key, so if you have any risk factors, it is a good idea to get tested whether or not you have symptoms. “You can definitely slow the progression by quitting smoking, taking cholesterol medication and starting to exercise,” Gutierrez said. “There are some people that that’s all they need. PAD is very hard to reverse, but you can slow it down.”
Gutierrez says PAD does not follow a timeline. “Everybody’s different, but I would presume somebody that’s got all the risk factors for PAD — they have diabetes, they smoke, have a strong family history, and don’t take care of themselves, don’t exercise, don’t watch what they eat, that person will probably progress faster, but the timeframe of that progression is not well studied.”
Another complicating factor is that PAD doesn’t usually happen by itself. “Physicians who take care of PAD know that PAD is a disease of multiple comorbidities,” Gutierrez said. “A lot of times, they’ll have plaque in their coronary arteries or in the arteries of the neck, or they’ll have diabetes, or they’re smokers.”
Atherosclerosis occurs over time, as plaque causes the inner lining of the artery to become increasingly narrow.
“I think it’s perfectly acceptable if you’ve never been diagnosed with PAD and don’t have symptoms to make an appointment and get your pulse taken,” Gutierrez said. “But if you have diabetes, if you have a history of heart disease, carotid blockages, or cerebral vascular disease, or if you smoke or have a family history that includes people with diabetes or peripheral artery disease, it’s a good idea for you to ask your PCP, ‘Can you check the pulses in my feet? I want to make sure I don’t have peripheral artery disease.’”
One of the most common symptoms for early stage PAD is cramping or pain in the calves. This is known as claudication.
“The classic symptom for PAD is claudication, pain or cramping in the calves, or sometimes even in the buttocks, upon exertion, like carrying groceries or going up stairs,” Gutierrez said. “The pain gets better when they rest and then when they go back to exerting themselves, it comes back. That is the classic claudication scenario.”
Gutierrez makes this analogy: “When somebody has blockages in their coronary arteries and they start to exercise, they get chest pain called angina. The legs are a similarly robust muscular group and when someone starts exercising, if not enough blood flow gets down there, the same thing happens. Think of claudication as the angina of the legs.”
The symptoms of PAD may include:
However, many people with PAD don’t have the symptom of leg pain. As Gutierrez mentioned, they describe it as leg fatigue or decreased walking ability. Sometimes people mistake their symptoms for arthritis, a back or muscle problem, or for just “getting old.” By the time many people feel leg pain, it has gone undiagnosed and the disease has gotten worse.
Because the consequences of untreated PAD can be dire — including gangrene and sometimes even amputation — it’s something people need to be proactive about. A person is at increased risk of PAD if they:
- Are age 65 or over
- Are age 50-64 and have any risk factors for atherosclerosis, such as:
- Smoke, or used to
- High cholesterol
- Family history of PAD
- High blood pressure
- Are under 50 with diabetes and have one of the other risk factors listed above
- Regardless of age, have known atherosclerotic disease
In Gutierrez’s clinic, he sees many patients with these risk factors, but he emphasizes diabetes and smoking as being particularly telling. “The prevalence of PAD in patients with diabetes is pretty high, at least 25 percent of patients with diabetes have peripheral artery disease,” he said. “We always measure their pulses. And smokers, too. These are patients who, statistically, epidemiologic studies have shown that they’re at higher risk of PAD.”
Age and obesity also add to that risk. “Obviously, PAD is a disease that you see in older folks, 50, 60, 70, 80,” he said. “If they’re saying they can’t get up and go, we’re always going to check for pulses because it gives you a quick answer.
“Patients with diabetes, and those that have had prior atherosclerotic disease in the coronary or carotid arteries, those are groups that I’m not surprised to find lower extremity disease, because atherosclerosis is systemic,” Gutierrez said.
Gutierrez’s biggest concern for patients with PAD is their increased risk for adverse cardiac events like a heart attack or stroke. “Because of that, we really emphasize prevention, prevention, prevention,” he said. “We put them on aspirin and on a statin. If they are diabetic, we emphasize the importance of sugar control in their diet. We want them on evidence-based therapies that are going to prevent these adverse events that could shorten their lives. That’s just keeping them alive.”
Next, they work on regaining function. “We tell our patients to get more exercise, specifically to walk more. If they start having claudication, stop and rest, but then push through, go a little farther,” he said.
According to the American Heart Association, structured exercise therapy is an important component of care for individuals with PAD. Walking and regular leg exercises can ease symptoms and improve walking distance.
This exercise prescription takes into account the fact that walking is uncomfortable. Structured treadmill exercise programs, whether in supervised exercise therapy or a cardiac rehab program, consist of alternating periods of walking and rest.
With practice, this walking regimen improves muscle fitness and increases the time you can walk before the discomfort sets in. Ideally, the training is done for 30 to 45 minutes at least three times a week. Once the program is completed, it is recommended that individuals with PAD continue walking exercise on their own.
If you can’t participate in a supervised exercise program, ask your healthcare provider to help you plan a communityor home-based program best suited to your situation.
Medicare now covers supervised exercise therapy for patients with PAD who experience pain, cramping, or fatigue in the leg muscles when walking or exercising, and that diminishes or goes away when standing still.
“We always tell our patients, ‘use it or lose it.’ You need to start exercising and practicing other lifestyle changes. And if you’re smoking, quit,” Gutierrez said.
PAD patients with diabetes present a peculiarly vexing challenge. “Those patients have a kind of double whammy,” he said. “For example, they have an ulcer on their foot that is not healing, or they’re in danger of losing a leg. Not only are they not healing because of the lack of blood flow from the PAD, but they also have issues healing just because of the nature of diabetes and its pathology. That’s one of the most concerning things when you’re dealing with a diabetic patient.”
As for whether PAD gets better, Gutierrez likens the prognosis to diabetes: “I think it’s something that most patients learn to live with. You can improve symptoms, and some patients get a very good result when you intervene invasively by removing a clot or placing a stent,” he said. “But the question is how long it lasts? It’s also up to them — Are they not smoking, taking their preventative medications, exercising? And some people are also fighting their genes. Every patient is unique. But I can tell you that if you compare two patients with peripheral artery disease, one with diabetes and one without, the patient with diabetes almost always will have a harder time. They are definitely a higher-risk population for PAD.”
In addition to a supervised exercise program, a comprehensive treatment program for PAD can include a variety of medications, treatments and lifestyle modifications to improve function and protect against cardiovascular ischemic events, such as a heart attack or stroke. Important lifestyle changes include following a heart-healthy diet, avoiding tobacco smoke, regular exercise and losing weight if you are overweight or obese. Additionally, treatment and control of other risk factors, such as diabetes and hypertension, is necessary.
It’s important to learn the facts about PAD. The more you know, the more likely you’ll be able to work with your healthcare provider to make an early diagnosis and start treatment. In the next installment of this series, we’ll discuss the more advanced stages of PAD and how it’s treated. Be sure not to miss it in our Winter 2018 issue.