Everyone knows that chest pain can be a sign of a serious cardiovascular condition. Guess what? So can leg pain.
Atherosclerosis is most often associated with blockages in the blood vessels supplying the heart, which can cause a heart attack. But clogged blood vessels in the legs are a sign of peripheral arterial disease (PAD).
Chances are, if you have atherosclerosis in your legs, you have it everywhere. “PAD is an indicator of widespread atherosclerotic disease and is therefore an indicator of risk for both stroke and coronary heart disease,” explains neurologist Larry B. Goldstein, M.D., Director of the Duke Center for Cerebrovascular Disease at Duke University Medical Center in Durham, NC.
Who is at risk for PAD? Look in the mirror. “PAD is not a disease of old people,” says Alan T. Hirsch, M.D., Adjunct Professor of Epidemiology and Community Health at the University of Minnesota School of Public Health in Minneapolis. “A 38-year-old woman who smokes could have very severe PAD.”
The risk factors for both PAD and heart disease are the same: high blood pressure, diabetes, high cholesterol, smoking and obesity. The more risk factors you have, the higher the odds that you will develop PAD.
The risk of developing coronary artery disease (CAD) or having a stroke among people who have PAD is two to four times higher as compared with those who do not have the condition, and heart attack risk is between 20 and 60 percent higher. When doctors at medical research firm Caro Research Institute in Concord, MA, followed 16,440 patients diagnosed with PAD, they found that within six years, 10 percent suffered a stroke, another 10 percent had a heart attack and half had died of a cardiovascular event.
What To Look Out For
So how do you know if you have PAD? The classic symptom is claudication — leg muscle discomfort, fatigue or pain that occurs in the buttocks, thighs or calf muscles when you're walking or working out. Never had this kind of leg pain? Sorry, but you're not off the hook.
“At least half of the individuals with PAD in the United States are unable to report classic symptoms of PAD, just like people with heart disease don't always have known angina before they have a heart attack,” says Hirsch. Some people may have leg pain without exertion, which can easily be confused with muscle strain, nerve pain, arthritis or other leg conditions. Complicating matters further, some PAD sufferers have no symptoms at all.
Left untreated, circulation in the leg can become compromised enough to require amputation. Hirsch says that hundreds of thousands of preventable amputations every year are attributable to undiagnosed and untreated PAD — equivalent to the number of legs Civil War soldiers lost from battlefield injuries.
So how do doctors detect and diagnose the condition, especially when a patient has not complained of any telltale symptoms? By focusing not only on those who tell them of leg pain, but also on those who have one or more risk factors for the condition, or signs of poor circulation in the legs — particularly, wounds that won't heal, or gangrene.
If you think this is casting a wide net, “there is no diagnostic test for any illness, cardiovascular or otherwise, as accurate, safe and cost-effective as the measurement of ankle pressure to detect [PAD],” says Hirsch. In doctor lingo, the diagnostic test is called an ankle-brachial index. Using a standard blood pressure cuff, the doctor takes the blood pressure in your arm and the blood pressure in your ankle and compares them. The blood pressure in your ankle should be the same or slightly higher than in your arm, so a normal ankle-brachial index is 1 or 1.1. At or below 0.95, you probably have some significant narrowing in one or more blood vessels in your leg.
Figure. ANGIOPLASTY ...Image Tools
Some people may need additional testing, such as an ultrasound or scans of the leg arteries with magnetic resonance imaging (MRI) or computed tomography (CT), but these diagnostic tools are usually used in severe cases that will likely require surgery.
When PAD is caught early, walking is the first line of treatment. “[Whether] you can only walk one block or six blocks, exercise is still likely to be very effective,” says Hirsch. Doctors may also prescribe supervised exercise sessions on a track or a treadmill in a rehab facility three times a week for 12 weeks. Over the course of the supervised program, the intensity of the exercise is slowly ratcheted up to build muscle strength in the legs. Some patients balk at exercise because of leg pain, so they are typically treated with medication to treat claudication by dilating the arteries and inhibiting blood clot formation.
Inactivity can make PAD worse, because the microscopic arteries that supply muscle fibers lose the ability to dilate, adversely affecting the proper function of nerves and ultimately causing the muscles to become progressively weaker. “PAD becomes an illness that affects the whole leg, not just the blood vessels,” says Hirsch. But physical activity can reverse these changes and keep legs strong — even when there is artery blockage.
In severe cases, surgery may be needed to clear blockages in the blood vessels. One such procedure is leg angioplasty. During angioplasty, the doctor threads a balloon-tipped catheter through the arteries right up to the blockage and inflates the balloon, which flattens the cholesterol plaque against the wall of the artery, creating an opening through which blood can flow. The balloon inflation is followed by insertion of a stent, a small mesh device designed to prop the artery open. A blood thinner may also be prescribed to help prevent clots.
Angioplasty “is most effective in the arteries toward the top of the leg and pelvis — between the belly button and the groin — [but] is less effective and less durable as one enters the thigh, and is rarely used below the knee,” explains Hirsch.
Bypass surgery is often recommended when symptoms are severe or the leg is threatened. Typically, a portion of another vein from the same or opposite leg is removed and connected to the clogged artery above and below the obstruction. As with stents and angioplasty, vein grafts are more durable when they are placed toward the top of the leg and less so below the knee.
Effectively treating PAD involves more than dealing with leg pain or clearing blockages. Doctors will also prescribe appropriate lifestyle changes and medications to reduce the risk of heart attack and stroke. “Patients with PAD should be aggressive in their management of general cardiovascular and stroke risk factors,” says Goldstein. “Have [high blood pressure] treated and diabetes controlled. Stop smoking and avoid exposure to second-hand tobacco smoke. Try to reduce weight if [you are] overweight or obese. Ask your doctor about exercise and the use of aspirin or another similar [anti-clotting] medication.”
If you or your doctor suspect PAD, Hirsch urges prompt action: “The clock is ticking. The risk [for heart attack or stroke with PAD] is high within even one year. You can't exactly sit around and think about it.”
In a study published in the peer-reviewed journal Circulation last year, Hirsch and his colleagues conducted a telephone survey of more than 2,500 American adults aged 50 or older and found that only 26 percent had ever heard of PAD or knew that the condition was associated with increased risk of heart attack and stroke, and just 14 percent were aware that it could lead to amputation.
The AHA is one of 14 founding members of The PAD Coalition — an alliance of leading health organizations, vascular health professional societies and government agencies that have united to raise public and health professional awareness about lower extremity PAD. Other members of the coalition include the American College of Cardiology, American College of Physicians, American Diabetes Association and the National Heart, Lung, Blood Institute (NHLBI).
▪ The PAD Coalition offers a national awareness campaign, “Stay in Circulation: Take Steps to Learn About PAD,” with public service announcements, brochures, an educational video and other resources. For more information on the campaign, visit: www.padcoalition.org
▪ The American Heart Association Web site offers additional information about PAD, and includes a message board where patients can share tips and experiences: www.americanheart.org/PAD
▪ You can also register to receive an AHA e-newsletter offering the latest news about PAD: www.americanheart.org/myheartnews
© 2008 American Heart Association, Inc.