Peripheral artery disease (PAD) refers to diseases of the blood vessels located outside the heart and brain. They are most often caused by a buildup of fatty deposits in the arteries.
PAD is also known as peripheral arterial disease, peripheral vascular disease, and peripheral heart disease.
It affects the blood vessels outside the brain and heart, causing them to narrow, thus restricting the blood flow to the arms, legs, kidneys, or stomach. However, patients with PAD most commonly have symptoms in their legs.
An estimated 8.5 million people in the United States have peripheral vascular disease, affecting approximately 5 percent of Americans over 50 years of age.
Peripheral artery disease is a major risk factor for heart attack and stroke, two of the leading causes of death in the U.S.
PAD is more common in African-Americans than any other ethnic or racial group, and men are slightly more likely than women to develop PAD. Peripheral vascular disease is also more common in smokers; regular smokers with diabetes tend to have the most severe symptoms.
Although the condition is common and can have serious consequences, physical activity alone can substantially improve symptoms.
This article will cover the symptoms, causes, diagnosis, prevention, and treatment of PAD.
Fast facts on peripheral artery disease
Here are some key points about peripheral artery disease. More detail and supporting information is in the main article.
- The best way to prevent PAD is by taking part in physical activities
- The most common cause is a build-up of cholesterol in the arteries
- Peripheral artery disease is a risk factor for more serious cardiac events
Symptoms of peripheral artery disease
The most common cause of PAD is atherosclerosis.
Experts say that around half of all people with PAD do not know they have the condition; this is because many individuals have no symptoms.
If signs and symptoms do occur, they are likely to include:
- Hair loss on the feet and legs
- Intermittent claudication - the thigh or calf muscles may feel pain when walking or climbing stairs; some individuals complain of painful hips
- Leg weakness
- A foot or the lower leg may feel cold
- Numbness in the legs
- Brittle toenails
- Toenails grow slowly
- Ulcers on the legs and feet that take a long time to heal (or never heal)
- The skin on the legs becomes shiny or turns pale or bluish
- Difficulty in finding a pulse in the leg or foot
- Erectile dysfunction (impotence in men, problems achieving or sustaining an erection)
Causes of peripheral artery disease
The most common cause of PAD is atherosclerosis. Atherosclerosis is a gradual process in which a fatty material builds up inside the arteries. The fat may then mix with calcium, scar tissue, and other substances and harden slightly, forming plaques.
These plaques block, narrow, or weaken the walls of the blood vessel. Blood flow through the arteries can be restricted or stopped.
Other, less common causes of peripheral heart disease are blood clots in the arteries, injury to the limbs, and unusual anatomy of the muscles and ligaments.
Risk factors that contribute to PAD are diabetes, smoking, obesity, high blood pressure, increasing age, high cholesterol, family history of heart disease, and excess levels of C-reactive protein or homocysteine.
Diagnosing peripheral artery disease
If peripheral artery disease is suspected, the doctor will initially check the patient's legs. The most common test for PAD is the ankle-brachial index, a test that compares the blood pressure in the ankle with the blood pressure in the arm.
The doctor may also recommend an ultrasound scan, angiography, and blood tests to check levels of cholesterol, homocysteine, and C-reactive protein.
Doppler and ultrasound (Duplex) imaging is a non-invasive method that visualizes the artery with sound waves and measures the blood flow in an artery to indicate the presence of a blockage.
Computed tomographic angiography (CT) is another non-invasive test that images the arteries of a patient's abdomen, pelvis, and legs. This test is particularly useful in patients with pacemakers or stents. Magnetic Resonance Angiography (MRA) gives similar information to that generated by a CT scan, but without the need for X-rays.
Angiography is normally reserved for use in conjunction with vascular treatment procedures. During an angiogram, a contrast agent is injected into the artery and X-rays are taken to show blood flow and to pinpoint any blockages that may be present.
Undiagnosed or untreated PAD can be dangerous; it can lead to painful symptoms, loss of a leg, increased risk of coronary artery disease, and carotid atherosclerosis (a narrowing of the arteries that supply blood to the brain).
Because people with PAD have an increased risk of heart attack and stroke, the American Heart Association encourages people at risk to discuss PAD with their doctor to ensure early diagnosis and treatment.
Treatment options for peripheral artery disease
To lay out the best approach to treating PAD, the American College of Cardiology Foundation and the American Heart Foundation (ACCF/AHA) collaborated to create the "2011 ACCF/AHA Focused Update of the Guideline for the Management of Patients With Peripheral Artery Disease (Updating the 2005 Guideline)." They published the document in the journal Circulation.
The most effective treatment for PAD is regular physical activity. A doctor will often recommend a program of supervised exercise training. The patient may have to start off slowly. Simple walking regimens, leg exercises, and treadmill exercise programs three times a week can result in decreased symptoms in just 4-8 weeks.
Exercise for intermittent claudication must take into account the fact that walking can be painful. The program consists of alternating between activity and resting; this helps build up the amount of time the individual can walk before the pain sets in. Ideally, the patient should do these exercises on a treadmill in a rehabilitation center.
Many individuals with PAD have elevated cholesterol levels. A diet low in saturated fat, trans fat, and cholesterol, as well as plenty of fruit and vegetables can help lower blood cholesterol levels.
Tobacco smoke greatly increases the risk of PAD, heart attack, and stroke. Smokers may have four times the risk of developing PAD than nonsmokers. Stop smoking. It will help to slow the progression of PAD and other heart-related diseases.
The doctor may prescribe antihypertensive drugs as well as statins to lower cholesterol levels. Cilostazol and pentoxifylline may be recommended for patients with intermittent claudication. The ACE inhibitor - ramipril - was shown to improve pain-free walking by 60 percent in a study published in JAMA.
If the treatments mentioned above do not help enough, the doctor may advise angioplasty - the surgical unblocking or repair of a blood vessel.
Preventing peripheral artery disease
Taking action to control risk factors can help prevent or delay peripheral arterial disease and its complications.
Family history - if you or someone in your family has/had periphery artery disease, be sure to tell your doctor.
Smoking - smoking is more closely related to developing heart disease than any other risk factor. Regular smokers are four times as likely to develop PAD than lifetime non-smokers. Talk to a doctor about programs and products that can help you quit smoking.
Diet - follow a healthy eating plan that is low in total fat, saturated fat, trans fat, cholesterol, and sodium. Eat plenty of fruits, vegetables, and low-fat dairy products. Overweight/obese patients should work with a doctor to create a reasonable weight-loss plan.