Peripheral Artery Disease (PAD)

Introduction

Peripheral artery disease (PAD) affects millions of Americans daily. It can limit your everyday activities and increase risk of experiencing a heart attack or stroke. However, you can take control of PAD by living a heart-healthy lifestyle and following the recommendations of your healthcare professional.

What is it?

Peripheral artery disease is a sub-type of peripheral vascular disease (PVD). PVD is a condition that results in blockage of blood vessels and can result in altered blood flow throughout the body. More specifically, PAD leads to obstruction of blood flow through the arteries (a particular type of blood vessel). PAD is similar to coronary artery disease (CAD), a disease in which the arteries of the heart are obstructed. Although it can affect any artery outside of your heart (which is why it is called ?peripheral?), PAD generally refers to problems with blood flow in your extremities, particularly in your legs. When the flow of blood through your legs is blocked, your muscles do not get enough oxygen. This can lead to symptoms such as pain in your calves or thighs when you walk.

PAD can be a sign of a more serious condition and can lead to decreased blood flow to your heart and brain. Chest pain, or possibly a heart attack, can occur when blood flow is decreased in the vessels of the heart. A stroke can develop if blood flow is decreased in the vessels of the neck or brain.

What causes it?

Atherosclerosis, or the build-up of fatty material (plaque) inside your arteries, is the most common cause of PAD. Plaque is thought to be made up of fat, calcium, and cholesterol, and can collect in any blood vessel.

Less common causes of PAD include injury to a limb, inflammation (swelling) of the blood vessels, abnormalities in the structure of arteries, a serious infection, or blood clots in the arteries.

Who has it?

PAD affects 8 to 12 million people in the United States. An estimated 5 percent of people over age 50 have PAD, and 12 to 20 percent of those older than age 65 may have PAD. Nevertheless, PAD is said to be under diagnosed, mainly because many patients do not experience any symptoms or they mistake the symptoms as ?normal? signs of aging.

Both men and women are affected by PAD, but women are less likely to experience symptoms. Individuals with PAD are 6 to 7 times more likely to develop coronary artery disease or experience a heart attack or stroke.

What are the risk factors?

Many factors can increase your risk of developing PAD. They include:

  • Age - Men and women older than age 40 are at higher risk for developing PAD.
  • Cigarette smoking - Smoking constricts and can damage arteries. Smokers are 3 to 5 times more likely to develop PAD than non-smokers. On average, smokers are diagnosed with PAD 10 years earlier than non-smokers.
  • Diabetes - Having diabetes also greatly increases your risk of developing PAD. One in three individuals over the age of 50 with diabetes has PAD.
  • Kidney disease
  • Overweight
  • Physical inactivity
  • High blood pressure or having a family history of high blood pressure
  • High cholesterol or triglycerides or having a family history of high cholesterol or triglycerides
  • Heart disease or having a family history of heart disease
  • Stroke or having a family history of stroke

      • What are the symptoms?

      Approximately 75% of individuals affected by PAD either have no symptoms or mistake the symptoms for something else, such as arthritis pain. The majority of symptoms of PAD are caused by a decrease in blood flow and oxygen delivery to the limbs.

      Oxygen is brought to the muscles by blood traveling through blood vessels. During exercise, such as walking, running, or climbing stairs, muscles need more oxygen. In PAD, when the blood vessel is partially blocked by plaque, blood flow and therefore oxygen delivery to the muscle is decreased. This reduction of oxygen leads to intermittent claudication, which is a painful or cramping sensation in the legs or hips while exercising. The pain typically goes away with rest because the muscles no longer need extra oxygen. However, people with advanced PAD sometimes do experience pain at rest. This is known as critical limb ischemia and is due to a complete or near complete blockage of the artieries. This resting pain is most often felt in the feet (especially the heels and toes) when lying in bed at night.

      Intermittent claudication is the most common symptom of PAD. Other serious signs and symptoms of PAD include:

      • A weak or absent pulse in the legs or feet
      • Sores or wounds on the legs, feet, or toes that heal poorly or do not heal at all
      • Numbness in the legs or feet
      • Inability to walk normally
      • Changes in the color of skin, such as turning pale or blue
      • One leg that is ?cool to the touch? when compared to the other leg
      • Poor nail growth or decreased hair growth on the legs or feet
      • Erectile dysfunction?the inability to achieve or maintain an erection for sexual intercourse?in men, especially in those with diabetes

      In extreme cases of PAD, gangrene--the death of body tissues--can develop and may require amputation of the affected limb. However, this happens in very severe cases of PAD and is not a common occurrence.

      How is it treated?

      Individuals with risk factors should be screened for PAD, even if they do not have symptoms. Treatments for PAD include lifestyle changes, medications, and surgery.

      Lifestyle changes are an important part of the prevention and treatment of PAD. Lifestyle changes help manage your symptoms and may even help stop progression of the disease. Some risk factors, like your age or a family history of stroke or heart disease, cannot be changed. Other factors, like smoking and physical inactivity, can and should be changed.

      • Smoking - Of all the risk factors for PAD, smoking has been the most closely associated with the development of PAD and is therefore the most important risk factor you can change to decrease the chance of developing PAD. Smoking can even interfere with the treatment of PAD. There are a variety of products available to help you quit smoking. For more information on smoking cessation, please visit our smoking cessation health condition.
      • Exercise - Exercise is also an important aspect to the treatment of PAD. Your doctor may want you to start exercising regularly to help you increase the distance you can walk without pain. Exercise can also help you maintain a healthy weight. Talk to your doctor before starting an exercise program. Your doctor can help you find the exercise program that is right for you.
      • Diet - Eating a healthy diet that is low in fat and cholesterol can help control high blood pressure and cholesterol levels, both of which are risk factors for the development of PAD.
      • Foot care - PAD increases your risk of infection from foot wounds and can also lengthen the time it takes for wounds to heal. Proper foot care is especially important if you also have diabetes. The following is a list of proper foot care techniques:
        • Wash and moisturize your feet daily
        • Wear dry socks and well-fitting shoes
        • Treat any fungal infection of the feet, such as athlete?s foot, quickly
        • Carefully trim your nails
        • Do not walk barefoot
        • See your doctor at the first sign of a sore or injury to your skin

      Medications can also be used to treat PAD. Pentoxifylline (Trental) and cilostazol (Pletal) both help treat the symptoms of intermittent claudication, the pain you may feel when walking or climbing stairs. Some medications can also help lower your risk of developing PAD. In addition, your doctor may prescribe these medications to help manage other health conditions you may have that are associated with PAD. Cholesterol-lowering medications, such as simvastatin, can be used to decrease your cholesterol to a healthy level and help prevent the accumulation of plaque in your blood vessels. Your doctor may also prescribe medication to lower your blood pressure and keep your blood sugar under control. PAD can also increase your risk of developing a blood clot, which can lead to a heart attack or stroke. To help prevent blood clots from forming, your doctor may want you to take a daily dose of aspirin, clopidogrel (Plavix), or other similar medications. For patients with blocked arteries, drugs may be used that dissolve clots. These medications are known as thrombolytics.

      If blood flow is almost or completely blocked, surgery may be necessary to help restore blood flow. Surgery is not a cure for PAD and is only an option for patients who have tried and failed lifestyle changes and medication therapies. Angioplasty is a surgery where a small tube with a deflated balloon attached to the end is inserted into the blocked artery. Once inside, the balloon is inflated, pushing the plaque against the wall of the artery and restoring blood flow through the artery. Often a stent, or a very small cage-like tube similar to the spring inside a ball point pen, is attached to the balloon. When the balloon is inflated, the stent helps push and hold the plaque against the wall of the artery. Some stents, known as drug-eluting stents, are embedded with medications that are released into the blood vessels and help prevent further plaque formation.

      Other procedures for PAD treatment include endarectomies and by-pass grafts. These are more invasive procedures that some doctors use to restore blood flow through or around blocked vessels. Endarterectomy is a procedure in which the plaque inside the blood vessel is removed surgically to allow blood to carry oxygen to the muscles. A bypass graft is another option for some patients. Doctors can use a blood vessel from another part of your body or one that has been man-made and ?bypass,? or go around, the blocked artery. This restores blood flow to the legs.

      What is on the horizon?

      Investigators are currently researching the potential advantages to cell and gene therapies in patients with PAD. These new therapies could improve blood flow in the legs and may even promote the growth of new blood vessels. However, cell and gene therapies would only treat the symptoms of PAD, such as intermittent claudication, and would not stop the progression of PAD.

      In addition to gene therapies, researchers are also investigating genetic factors that may be responsible for the development of atherosclerosis, as well as genetic factors that increase or decrease the likelihood of developing PAD. Research in this area may help us find better ways to prevent the development of atherosclerosis and PAD.

      Investigators are also researching a new surgical technique called photoangioplasty. This procedure involves the injection of a drug called texaphyrin into the blood vessels. Texaphyrin attaches to the plaques in the blood vessels, and a laser is used to activate the drug and cause the plaque to dissolve.

      While some researchers are investigating new ways to prevent and treat PAD, others are currently developing new and improved techniques to diagnose PAD. One such technique uses an ultrasound machine to examine the calf muscles, which may provide an easier and more effective way to diagnose PAD.

      References

      Atherosclerosis of the Extremities. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000170.htm. Accessed October 2007.

      Gey, D et al. Management of Peripheral Artery Disease. American Family Physician 2004; 69(3): 525-32. Available at: http://www.aafp.org/afp/20040201/525.pdf Accessed October 2007.

      Heart Health. Available at: http://heart.health.ivillage.com/index.cfm Accessed October 2007

      Hirsh, AT; Haskal ZJ et al. ACC/AHA Guidelines for the management of patients with peripheral artery disease (lower extremity, renal, mesenteric, and abdominal aortic): Executive Summary. JACC 2006: 1-75. Available at: http://www.americanheart.org/downloadable/heart/1137607531918PAD_ES_MASTER.pdf Accessed October 2007.

      Hirsch, A; Criqui, M et al. Peripheral Artery Disease Detection, Awareness, and Treatment in Primary Care. JAMA 2001; 286: 1317-24. Accessed February 2007.

      Peripheral Artery Disease Coalition. Available at: http://www.padcoalition.org/wp/ Accessed October 2007.

      Peripheral Vascular Disease, Self-Care at Home. Available at: http://www.emedicinehealth.com/peripheral_vascular_disease/page7_em.htm Accessed October 2007.

      Peripheral Artery Disease (PAD). Available at: http://www.americanheart.org/presenter.jhtml?identifier=3020242 Accessed October 2007.

      Peripheral Artery Disease (PAD). Available at: http://www.mayoclinic.com/health/peripheral-artery-disease/DS00537 Accessed October 2007.

      Peripheral Artery Disease. Available at: http://www.nhlbi.nih.gov/health/dci/Diseases/pad/pad_what.html Accessed October 2007.

      Peripheral Artery Disease. Available at: http://www.vascularweb.org/_Contribution_Pages/Patient_Information/NorthPoint/Leg_Artery_Disease.html. Accessed October 2007.

      Understanding PAD. Available at: http://www.understandingpad.com/ Accessed October 2007.

      Vascular Disease Foundation. Available at: http://www.vdf.org/ Accessed October 2007.

      Peripheral Artery Disease (PAD) Health Condition Last Updated: October 2007

      Note: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It is not intended to diagnose a health condition, but it can be used as a guide to help you decide if you should seek professional treatment or to help you learn more about your condition once it has been diagnosed.

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