What is peripheral arterial disease (PAD)?
Peripheral arterial disease (PAD) -- also known as peripheral vascular disease, atherosclerosis or hardening of the arteries -- is a disorder that occurs in the arteries of the circulatory system. Arteries are the blood vessels that carry oxygen and nutrient-rich blood from the heart to all areas of the body. PAD occurs in the arteries that carry blood to the arms and legs.
Healthy arteries have a smooth lining that prevents blood from clotting and promotes steady blood flow. In PAD, the arteries slowly become narrowed or blocked when plaque gradually forms inside the artery walls. Plaque is made of excessive fat, cholesterol and other substances floating through the bloodstream, such as inflammatory cells, proteins and calcium. If the arteries become narrowed or blocked, blood cannot get through to nourish organs and other tissues, causing damage to the tissues and eventually tissue death.
The rate at which PAD progresses varies with each individual and depends on many factors, including where in the body the plaque has formed and the person’s overall health.
What are the symptoms of peripheral arterial disease?
PAD can build up over a lifetime, and the symptoms may not become obvious until later in life. For many people, the outward symptoms will not appear until the artery has narrowed by 60 percent or more.
The first noticeable symptom of PAD may be intermittent claudication -- leg discomfort, pain or cramping that develops with activity, is relieved with rest, and recurs upon resuming activity. The pain is often noticed in the calf, but may also be felt in the buttocks or thighs. Intermittent claudication symptoms may also include numbness, weakness, heaviness or fatigue in the leg muscles when walking that are relieved at rest. The pain can be severe enough to interfere with normal walking. This type of cyclical pain is caused by reduced blood flow to the leg muscles and goes away at rest because the muscles require less blood flow at rest.
Other symptoms of advanced PAD may include:
- A burning or aching pain in the feet and toes while resting, especially at night while lying flat
- Cool skin in the feet
- Redness or other color changes of the skin
- Increased occurrence of infection
- Toe and foot sores that do not heal
Many people with PAD do not have any symptoms.
What are the risk factors for PAD?
An individual is at risk for developing PAD when one or more of these risk factors are present:
- Age: In the United States, people aged 50 and older have an increased risk for PAD
- Race: African Americans have a two-fold higher risk of developing PAD compared to other groups
- History of heart or blood vessel disease: A personal or family history of heart or blood vessel disease may be an indicator for PAD
- High blood pressure (hypertension)
- High cholesterol (hyperlipidemia)
How is PAD detected?
Talk to your doctor if you are having symptoms of PAD so the cause of your symptoms can be identified and treatment can be initiated as soon as possible. Early detection of PAD is important so the right treatments can be provided before the disease becomes severe enough to lead to complications, such as heart attack or stroke.
A physical exam will be performed and your medical history and risk factors will be reviewed. Your doctor may order certain tests to help diagnose PAD and determine the severity of the disease.
- The ankle/brachial index (ABI) is a measurement of the blood pressure in the lower legs compared to the blood pressure in the arms. During this test, blood pressure cuffs are placed on the arms and legs. The cuffs are inflated, while a hand-held device (called a Doppler) is used to listen to the blood flow. The ABI screening helps evaluate the amount of blood flow to the legs and feet, which is decreased in a person with PAD. It is a highly accurate method for detecting PAD.
- A pulse volume recording (PVR) is a noninvasive test that measures the blood volume changes that occur in the legs. During this test, a blood pressure cuff is placed on the arm and multiple cuffs are placed on the legs. The cuffs are inflated slightly while the patient is lying down. As blood pulses through the arteries, the blood vessels expand, causing an increase or decrease in the volume of air within the cuff. A recording device displays these pulse volume changes as a waveform on a monitor. Blood pressures are measured before and after exercise on a treadmill and help define if the pain is due to PAD or other causes. The PVR test also helps locate the area of blockages in the legs.
- A vascular ultrasound is a noninvasive test used to examine blood circulation. During a vascular ultrasound, a transducer (small hand- held device) is placed on the skin over the artery to be examined. The transducer emits sound waves that bounce off the artery. These sound waves are recorded, and an image of the vessel is created and displayed on a monitor. This test may be used to detect a blockage in an artery.
Foot Care Guidelines
Every day, examine your legs as well as the tops and bottoms of your feet and the areas between your toes. Look for any blisters, cuts, cracks, scratches or other sores. Also check for redness, increased warmth, ingrown toenails, corns and calluses. Use a mirror to view the leg or foot if necessary, or have a family member look at the area for you.
Once or twice a day, apply a moisturizing cream or lotion to your legs and soles and top of your feet to prevent dry skin and cracking. Do not apply lotion between your toes or on areas where there is an open sore or cut. If the skin is extremely dry, use the moisturizing cream more often. Care for your toenails regularly. Cut your toenails after bathing, when they are soft. Cut toenails straight across and smooth with a nail file.
If you have diabetes, it is important to see a podiatrist.
Do not self-treat corns, calluses or other foot problems. Go to a podiatrist to treat these conditions.
Don't wait to treat a minor foot or skin problem. Follow your doctor's guidelines.
Other tests may include angiography, CT scan or MRI.
During angiography (also called arteriography), contrast material (dye) is injected into the blood vessels being examined, and X-ray pictures of the inside of the blood vessels are produced to evaluate blood flow and detect possible blockages.
A CT scan is a technique in which multiple X-rays are taken from different angles in a very short period of time. The images are collected by a computer and cross-sectional “slices” of the blood vessel are shown on the monitor.
MRI uses powerful magnets to create images of internal organs and blood vessels.
How is PAD treated?
Lifestyle changes, medications and interventional procedures are the treatments available for PAD.
Lifestyle Changes. Initial treatment of PAD includes making lifestyle changes to reduce your risk factors. Changes you can make to manage your condition include:
- Quit smoking. Ask your doctor about smoking cessation programs available in your community.
- Eat a balanced diet that is high in fiber and low in cholesterol, fat and sodium. Limit fat to 30 percent of your total daily calories. Saturated fat should account for no more than 7 percent of your total calories. Avoid trans fats including products made with partially-hydrogenated and hydrogenated vegetable oils. If you are overweight, losing weight will help you lower your total cholesterol and raise your HDL (good) cholesterol. A registered dietitian can help you make the right dietary changes.
- Exercise. Begin a regular exercise program, such as walking. Walking is very important and can aid the treatment of PAD. Patients who walk regularly can expect a marked improvement in the distance they are able to walk before experiencing leg pain. (See Walking Program Box)
- Manage other health conditions, such as high blood pressure, diabetes or high cholesterol.
- Practice good foot and skin care to prevent infection and reduce the risk of complications. (See Foot Care Guidelines Box)
Medications may be recommended to treat conditions such as high blood pressure (anti- hypertensive medications) or high cholesterol (statin medications).
An antiplatelet medication such as aspirin or clopidogrel (Plavix) may be prescribed to reduce the risk of heart attack and stroke.
Vascular Medicine and Preventive Cardiology and Rehabilitation offer a structured supervised walking program to help you succeed and maximize your exercise efforts. Please call 216.444.4420 or 800.223.2273 ext. 4420 to make an appointment.
Cilostazol (Pletal) may be prescribed to improve walking distance. This medication has been shown to help people with intermittent claudication exercise longer before they develop leg pain and to walk longer before they must stop because of the pain. However, not all patients are eligible to take this medication. Your doctor will tell you if you are eligible.
Interventional procedures. More advanced PAD can be treated with interventional procedures such as angioplasty (to widen or clear the blocked vessel), angioplasty with stent placement (to support the cleared vessel and keep it open), or atherectomy (to remove the blockage).
In some cases, surgical procedures such as peripheral artery bypass surgery may be performed to reroute blood flow around the blood vessel blockage.
New therapies are currently being researched. Please ask your doctor if any other treatment options are available for you.
If any of these procedures are recommended, your health care team will give you more information about the procedures so you will know what to expect.
What are the conditions associated with PAD?
If left untreated, patients with PAD can develop serious health problems, including:
- Heart attack: permanent damage to the heart muscle caused by a lack of blood supply to the heart for an extended time
- Stroke: interruption of the blood flow to the brain
- Transient ischemic attack (TIA): a temporary interruption in the blood supply to the brain)
- Renal artery disease or stenosis: a narrowing or blockage of the artery that supplies blood to the kidney
- Amputation: the removal of part or all of the foot or leg (rarely the arm), especially in people who also have diabetes
Can PAD be cured?
There is no cure for PAD. Quitting smoking, exercising regularly, limiting fat and following a healthy diet, and managing your risk factors — such as diabetes, high cholesterol and high blood pressure — can help to reduce the progression of the disease.
Development of Peripheral Arterial Disease
Peripheral arterial disease starts when fatty deposits start streaking the blood vessel walls. The fatty matter builds up. This causes slight injury to your blood vessel walls. In an attempt to heal itself, the cells release chemicals that make the walls stickier. Other substances floating through your bloodstream start sticking to the vessel walls, such as inflammatory cells, proteins and calcium. The fat and other substances combine to form a material called plaque or atherosclerosis. The plaque builds up and narrows the artery.
Over time, the inside of the arteries develop plaques of different sizes. Many of the plaque deposits are hard on the outside and soft and mushy on the inside. The hard surface can crack or tear, exposing the soft, fatty inside. When this happens, platelets (disc-shaped particles in the blood that aid clotting) come to the area, and blood clots form around the plaque. The artery narrows further. Symptoms occur.
The artery may become completely blocked by plaque or a blood clot that lodges in a narrowed artery. If this occurs, the tissue below the blockage is permanently damaged and may die (gangrene). This most often occurs in the toes and feet.
Your arteries are shaped like hollow tubes. Inside, they are smooth and elastic, allowing blood to flow freely.