Its most common symptom is often dismissed as not worth fretting about: annoying but transient leg pains that kick in when walking, then ease during rest. But peripheral arterial disease (PAD) is a significant cardiovascular condition that deserves serious attention.

Peripheral arterial disease refers to the partial or complete blockage of major vessels outside the heart that supply blood to other important areas of the body, such as the brain, kidneys, arms, and legs.  Caused by the buildup of fatty deposits within the body's blood vessels, a condition known as atherosclerosis, PAD is similar to coronary artery disease; in fact, more than half of all people with PAD also have heart disease. The only difference is that the blood vessel blockages occur in other areas of the body rather than (or in addition to) the heart.

Those blockages can prove lethal. People with PAD are six to seven times more likely to die from a heart attack or stroke.  Severe, untreated PAD can also cause gangrene or kidney damage. Together, PAD, coronary artery disease, and stroke are the principal cause of death and disability among Americans 50 years and older.

Because advancing age increases one’s chances of developing PAD, the condition is becoming much more common as Americans grow older. Anyone over the age of 65 is at high risk for PAD, as are people older than 50 who have ever smoked or who have diabetes mellitus. Yet, while an estimated one out of every eight Americans will be affected by PAD in their lifetimes, most have never heard of the condition, and few primary care physicians routinely screen for it among their high-risk patients. It’s estimated that some 8 million older Americans have PAD and don't know it.   

According to James P. Zidar, MD, of Duke’s Peripheral Arterial Disease program, this widespread lack of awareness translates into tragic outcomes for tens of thousands of PAD sufferers each year. “What makes those figures even sadder is that we do have the tools to manage PAD,” says Zidar. “The earlier PAD can be identified, the more effectively its harmful effects can be minimized--and the more likely it is that patients can realize a longer and more vibrant quality of life.”

PAD of the lower extremities often offers some uncomfortable clues to its presence: pain in the leg, calf, thigh, foot, hip, or buttocks that occurs when walking and is relieved by rest. Other danger signs include leg pains even when at rest; sensations of weakness, heaviness, numbness, or tingling in the legs; and non-healing ulcers and sores on the legs and feet.

Virginia resident Gloria Martin, one of Zidar’s patients, experienced the classic symptoms of PAD’s lower-extremity form. Despite valiant attempts to keep up an active lifestyle that included travel, spending time with her nine grandchildren, and volunteering at her community hospital, "I was terribly fatigued,” she recalls. “My legs hurt when I walked and sometimes would just give out on me. There were times after walking around and visiting with the patients on the units when I thought I would have to crawl to my car.”Gloria is one of the lucky ones: She was diagnosed and treated in time. Most people who experience PAD-related leg pains, however, don’t suspect their true cause. And an estimated 90 percent of people with PAD have no symptoms at all. “That’s why everyone should know not only the symptoms of PAD, but its risk factors,” says Zidar. “Individuals who have those risk factors should be examined by their doctor regularly.”

For such an underdiagnosed disease, lower-extremity PAD is remarkably simple to identify. Using only an electronic stethoscope and a simple office blood-pressure cuff, a physician can measure the ankle-brachial index, or ABI--the relationship between the blood pressures at the ankle and the arm. A blood pressure that is lower in the ankle than the arm implies a PAD-type blockage in the artery between the heart and the leg. Additional diagnostics that may be used to confirm the diagnosis or provide a more detailed evaluation include ultrasound studies to determine how effectively the pulse is being transmitted to the leg, as well as magnetic resonance angiography of leg arteries or conventional lower extremity contrast angiography.

What follows diagnosis varies from patient to patient. Within Duke’s PAD program, the condition is treated collaboratively by vascular surgeons, radiologists, neurologists, and cardiologists, as well as nurses, physician associates, vascular technicians, and pharmacists. “By taking a team approach,” says Zidar, “we can determine the best course of care for each patient.”  

Pharmaceutical therapies are first-line treatment for nearly all PAD patients. Among the many medications that can help control PAD symptoms and effects are drugs that lower cholesterol, dilate blood vessels, reduce high blood pressure, prevent blood clots, reduce plaque buildup in arteries, enhance blood flow, and ease pain. (Duke scientists are also investigating novel therapies for PAD, such as the use of substances called growth factors to stimulate blood vessel development.)

Anyone who’s seeking the solution to PAD in a pill, however, quickly discovers that a lot more effort than filling a prescription is required. Healthy lifestyle changes play a key role in managing the disease. Job number one for any PAD patient who smokes is to quit; if that’s problematic, Zidar urges patients to join a smoking cessation program for the guidance and support they may require.

Then come those omnipresent twins of lifestyle improvement: regular exercise and a healthful, low-fat diet that steers clear of artery-clogging trans-fats (a task that just got easier, thanks to the recent  FDA mandate that trans-fat content be clearly labeled on packaged foods). In addition to stabilizing, even minimizing, symptoms of PAD, these healthful habits help control related conditions such as hypertension and diabetes. Cardiac rehabilitation programs (Duke offers several) can go a long way toward helping PAD patients make these changes.Should more aggressive therapy to clear blocked arteries be required, cardiologists have a growing array of sophisticated tools at their disposal. Many of the latest developments in PAD treatment are in minimally invasive (also known as endovascular--literally, "inside the vessel") procedures. Performed by teams of cardiologists, radiologists, and vascular surgeons, these treatments do not require general anesthesia or large incisions and allow much more rapid recovery than surgery.

One of the most widely used endovascular therapies is called percutaneous transluminal angioplasty (PTA). During PTA, a tiny balloon is inserted into a blood vessel through a small puncture in the skin and then inflated, compressing the plaque that is causing the blockage against the vessel wall. The balloon is then deflated and withdrawn from the vessel.  

Angioplasty therapy for PAD is often done in conjunction with stenting, in which a thin, flexible metal mesh apparatus is introduced into the blood vessel to keep it open after treatment. While stenting to treat PAD is most often performed in the upper legs, it is also now used successfully to treat blood flow blockages to the kidney and in the carotid arteries, where it offers great potential for reducing the incidence of stroke, the leading cause of serious, long-term disability in the U.S.

More than 500 angioplasties are performed each year by Duke interventional cardiologists, who have also developed or designed many of the newer tools now being used in the procedure.

Gloria Martin, who received one of them in 1999, is delighted with the results. “I'm a new person,” she says. “Now I can do the things I like to do again, and my legs give me no problems. As far as I'm concerned, the way I feel now--and the fact that I’m here at all--is like a miracle."

For patients with advanced or extensive PAD, bypass graft operations similar to those performed in coronary artery disease are sometimes performed to create pathways for blood to flow around severely blocked blood vessels. This surgery can also help patients who have been diagnosed with aneurysms (stretching and ballooning) of the aorta or leg vessels. Duke surgeons currently perform between 300 and 400 peripheral bypass graft operations each year. Endartectomy, the surgical removal of plaque from the carotid artery, is another surgical procedure sometimes used to treat PAD.

With the accurate diagnostic techniques and effective treatments now available, says Zidar, what’s really needed to lessen the impact of PAD on American lives is greater awareness. “By combining expert professional care with disciplined self-care, most people with PAD can enjoy more mobile, pain-free, longer lives,” he says. “The stakes are high enough that most people--once they understand the dangers of PAD and what they can do to control it--find that it’s a commitment they’re willing to make.”