DEAR DOCTOR K: I have PAD. It sounds like coronary artery disease of the legs. Is the treatment similar too?
DEAR READER: You’re right: It’s the same disease — atherosclerosis — in different arteries. In atherosclerosis, cholesterol-filled growths, called plaques, grow inside the artery. They block the flow of blood through blood vessels. In coronary artery disease (CAD), atherosclerosis blocks blood flow to the heart. In peripheral artery disease (PAD), plaque builds up in the arteries of the legs and feet, restricting blood flow to those areas. (I’ve put an illustration showing normal and restricted blood flow in the legs on my website, AskDoctorK.com.)
I spoke to my colleague Dr. Marc Bonaca, a cardiologist at Harvard-affiliated Brigham and Women’s Hospital. He cautioned that in addition to narrowing blood vessels, atherosclerosis increases the risk of blood clots.
For example, a blood clot or a piece of a cholesterol-filled plaque can split off from an artery (such as the body’s largest artery, the aorta). Then it travels in the bloodstream to an artery in the leg. If it gets wedged into a part of the leg artery that is narrowed by atherosclerosis, suddenly the blood supply to the leg can stop.
That’s a medical emergency. A blood clot that lodges in the leg can kill off tissue and possibly require amputation.
What’s more, narrowed leg arteries are often a sign of atherosclerosis throughout the body. That means you are at increased risk of heart attack or stroke.
Treatment starts with lifestyle changes:
— Adopt a heart-healthy diet.
— Quit smoking.
— Take medicines to control high blood pressure, cholesterol and diabetes.
You should also exercise regularly. Movement improves circulation in the legs. The more you exercise your legs, the greater the blood supply they need. That gradually causes your leg arteries to widen and provide more blood to the legs. As your increased blood supply develops, the same exercise that may have caused leg pain in the past often no longer does. Regular exercise is key to easing symptoms and regaining mobility.
Before you start any exercise program, check with your doctor. The proper program for you requires knowledge of how severe the atherosclerosis is in your legs. A program that works for many people is to start with a half-hour walk several times a week. Over time, you should be able to walk farther and longer without discomfort.
Your doctor may prescribe new anti-platelet medications, which can help prevent blood clots in the legs.
But sometimes severely narrowed arteries cause extreme pain or threaten the health of your leg or foot. In this case, you may need an angioplasty and stent placement procedure to restore blood flow. The procedure is similar to that done in CAD patients. The doctor will thread a catheter through a blood vessel and into the blocked leg artery. He or she will briefly inflate a small balloon to open the narrowed artery, leaving behind a wire mesh stent to keep the artery open.
Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.