Peripheral Arterial Disease (PAD)

Peripheral arterial disease (PAD) occurs when a fatty material called plaque builds up on the inside walls of the arteries that carry blood from the heart to the head, internal organs, and limbs. PAD is also known as atherosclerotic peripheral arterial disease.

• Peripheral arterial disease (PAD) occurs when a fatty material called plaque builds up on the inside walls of the arteries that carry blood to the limbs.
• PAD is a common, yet serious disease.
• PAD affects 8 to 12 million people in the United States. An estimated 5 percent of U.S. adults over age 50 have PAD. Among adults age 65 and older, 12 to 20 percent may have PAD.
• PAD can impair physical health and diminish a person's ability to walk.
• People with PAD have an increased risk for heart attack.
• Early diagnosis and treatment of PAD are important to prevent disability and save lives.
• PAD screening for individuals at high risk is very important.
• PAD can be treated with lifestyle changes, medicines, and/or surgery and special procedures.
• Treatment often includes making long-lasting lifestyle changes, including quitting smoking, lowering high blood pressure, lowering high cholesterol levels, and lowering blood glucose levels if you are diabetic.
• PAD treatment may stop the disease from progressing and reduce the risk of heart attack, heart disease, stroke, and kidney failure.
• Surgery may be necessary to supply more blood flow to the leg if a person has severe symptoms.

Major Risk Factors

Major risk factors for developing PAD include:
• Smoking. Smoking is more closely related to developing PAD than any other risk factor. Smoking increases the risk of developing PAD three to five times. On average, smokers who develop PAD experience symptoms 10 years earlier than nonsmokers who develop PAD. Stopping smoking will slow the progress of PAD. Smoking even one or two cigarettes daily can interfere with the treatment for PAD. Smokers and diabetics have the greatest risk of complications from PAD, including gangrene in the leg from decreased blood flow.
• Chronic or serious illnesses, such as diabetes. One in three people over age 50 with diabetes is likely to have PAD. Anyone over age 50 with diabetes should be screened for PAD.
• Other diseases and conditions, such as:
• Kidney disease
• High blood pressure or a family history of it
• A high cholesterol level or a family history of it
• Heart disease or a family history of it
• A family history of stroke
• Age. Men who are older than age 50 and women who are older than age 55 are at higher risk for PAD.

What Are the Signs and Symptoms of Peripheral Arterial Disease?

At least half of the people who have peripheral arterial disease (PAD) don't have any signs or symptoms of the disease. People who do have signs or symptoms may have pain when walking or climbing stairs, which may be relieved after resting. This pain is called intermittent claudication. Blood brings oxygen to the muscles, but during exercise, muscles need more blood flow. If there is a blockage in the blood vessels, muscles won't get enough blood. If a person has intermittent claudication and exercises while in pain, his or her muscles may be harmed. When resting, the muscles require less blood flow and the pain goes away. Claudication is more likely in people who also have atherosclerosis in other arteries, such as the heart and brain. About 10 percent of people with PAD have intermittent claudication.

Other signs and symptoms of PAD include:
• Pain, numbness, aching, and heaviness in the muscles
• Cramping in the legs, thighs, calves, and feet
• A weak or absent pulse in the legs or feet
• Sores or wounds on toes, feet, or legs that heal slowly, poorly, or not at all
• Color changes in skin, paleness, or blueness (called cyanosis)
• A decreased temperature in one leg compared to the other leg
• Poor nail growth and decreased hair growth on toes and legs
• Erectile dysfunction, especially among people with diabetes

Diagnostic Tests and Procedures

A simple test called an ankle-brachial index (ABI) can be used to diagnose PAD. The ABI compares blood pressure in the ankle with blood pressure in the arm to see how well blood is flowing. A normal ABI is 1.0 or greater (with a range of 0.90 to 1.30). The test takes about 10–15 minutes to measure both arms and both ankles. It can help the doctor find out if PAD is affecting the legs, but it will not identify which blood vessels are blocked. The ABI can be performed yearly if necessary to see if the disease is getting worse.

A Doppler ultrasound is a test that uses sound waves to tell whether a blood vessel is open or blocked. This test uses a blood pressure cuff and special device to measure blood flow in the veins and arteries in the arms and legs. The Doppler ultrasound can help to determine the level and degree of PAD.

A treadmill test will provide more information on the severity of the symptoms and the level of exercise that provokes symptoms. For this test, you will walk on a treadmill, which will help identify any difficulties that you may have during normal walking.

A magnetic resonance angiogram (MRA) uses radio wave energy to take pictures of blood vessels inside the body. MRA is a type of magnetic resonance imaging (MRI) scan. An MRA can detect problems that may cause reduced blood flow in the blood vessels. It can determine the location and degree of blockage. A patient with a pacemaker, prosthetic joint, stent, surgical clips, mechanical heart valve, or other metallic devices in his or her body might not be eligible for an MRA depending on the type of metallic device. CT angiography can also be utilized to perform a non-invasive anatomic evaluation of the peripheral vascular arteries.

An arteriogram is a "road map" of the arteries used to pinpoint the exact location of the blockage in a limb. An x ray is taken after injecting dye through a needle or catheter into an artery. When the dye is injected, the patient may feel mildly flushed. The pictures from the x ray can determine the location, type, and extent of the blockage. Some hospitals are using a newer method that uses tiny ultrasound cameras to take pictures inside the blood vessel.

Blood tests may be done to check the patient's blood sugar level to screen for diabetes. Blood tests also may be used to check the patient's cholesterol levels.

How Is Peripheral Arterial Disease Treated?

Goals of Treatment: The overall goals for treating peripheral arterial disease (PAD) are to reduce symptoms, improve quality of life, and prevent complications. Treatment is based on symptoms, risk factors, physical exam results, and diagnostic tests.

Lifestyle Changes:

Treatment often includes making long-lasting lifestyle changes, such as:
• Quitting smoking. Smoking increases the risk of developing PAD three to five times. The risk for coronary artery disease (CAD) decreases rapidly if the smoker quits. The risk for CAD decreases 40 percent within 5 years of stopping smoking.
• Lowering blood pressure. Lowering blood pressure can help to avoid the risk of stroke, heart attack, congestive heart failure, and kidney disease.
• Lowering high cholesterol levels. Lowering cholesterol levels can delay or even reverse the buildup of plaque in the arteries.
• Lowering blood glucose levels if you have diabetes. A hemoglobin A1C test—a test that gives an estimate of how well blood sugar has been controlled over the past 3 months—may be performed.
Talk with your doctor about participating in a supervised exercise therapy program. Follow a low-saturated fat, low-cholesterol diet, and eat foods with less salt, total fat, and saturated fat. Eat more fruits, vegetables, and low-fat dairy products. If you are overweight or obese, work with your doctor to develop a reasonable weight-loss plan. If you are diabetic or at risk for critical limb ischemia, have your feet examined regularly.

Medicines:

Medicines may be prescribed to:
• Lower high cholesterol levels and high blood pressure
• Thin the blood to prevent clots from forming due to low blood flow
• Dissolve blood clots
• Help improve pain in the legs that is the result of walking or climbing stairs (claudication)
Some medicines lower the level of low density lipoprotein (LDL) cholesterol. Blood pressure should be lowered if it is too high. Treatment should aim for a blood pressure lower than 130/80 mmHg. Anticoagulants or blood thinners may be prescribed to prevent clots in the arteries. Thrombolytic therapy involves clot-dissolving drugs inserted into an artery to break up a blood clot.

Surgeries or Special Procedures
:
Surgery may be necessary if blood flow in a limb is completely or almost completely blocked. In bypass grafting surgery, the doctor uses a blood vessel from another part of your body or a tube made of synthetic (man-made) material to make a graft. This graft bypasses the blockage in the artery, allowing blood to flow around it. Surgery does not cure PAD, but it may increase blood flow to the limb.

Angioplasty may be performed to restore blood flow through a narrowed or blocked artery. During the procedure, a thin tube (catheter) is inserted into a blocked artery and a small balloon on the tip of the catheter is inflated. When the balloon is inflated, plaque is pushed against the artery walls. This causes the artery to widen, restoring blood flow. A stent, a tiny mesh tube that looks like a small spring, is now used in most angioplasties. Some stents are coated with medicine to help prevent the artery from closing again.

Written by Dr. Mark Steiner, Cardiologist in Orlando

read Dr. Steiners Overview of Peripheral Arterial Disease