David Dow thought he was having back problems, and that his legs were hurting as a result. As it turns out, that pain may have saved his life.
An otherwise healthy 57-year-old, he figured he just needed to learn some back-strengthening exercises, so he found a personal trainer to help him. But despite the workouts, his leg pain got worse - making it hard for him even to walk from the car to the grocery store entrance. He and the trainer suspected something else was wrong and he sought the advice of his doctor.
Soon his doctor's tests revealed the true cause: blockages in the blood vessels of his legs. In fact, the arteries going to his lower extremities were nearly 100 percent blocked. The cause? Years of heavy smoking and high-fat meals, and other factors had caused cholesterol, scar tissue and blood clots to build up inside his blood vessels.
Most people think this kind of clogged artery disease, or arteriosclerosis, only happens in the heart. But as Dow's case shows, it can happen throughout the body. When it does, it's called peripheral arterial disease, or PAD.
And in some people, PAD causes leg pain that acts as an ‘early warning' that someone is at high risk for a heart attack or a stroke, says a University of Michigan Cardiovascular Center expert.
"This is the hallmark of a disease that's all over," says James Stanley, M.D., a director of the U-M CVC and the vascular surgeon who operated on Dow. "It's like gray hair - you don't just get it on one side of your head. So if you've got this kind of blockage in your leg, you're going to have it other places."
In fact, nearly a quarter of people who have leg pain due to PAD will be dead in five years, mostly due to heart attacks and other heart problems, Stanley says. For people like Dow, whose leg pain kept them from walking even short distances, the odds are even worse: as many as half will die by five years.
Fortunately, Dow got diagnosed and treated before that happened to him. Stanley performed a bypass operation to open his blocked leg arteries, similar to the bypasses that heart patients have. A recent checkup showed he's doing well.
"For sure, it's a wake-up call," says Dow, who has quit smoking and changed his eating habits. "You know that old saying, ‘Where there's smoke, there's fire'? I'm sure that I not only have the vascular issues in my lower extremities, but I'm sure I have them in other parts of my body."
Dow isn't alone, says Stanley, who has operated on thousands of patients with severe PAD in his decades as a professor of vascular surgery at the U-M Medical School. Nearly 30 million people in the United States have some form of PAD, though the vast majority are "silent" cases that don't cause symptoms. Among people over age 70, nearly one person in five has PAD.
Who's most at risk for PAD? People over 50, smokers, people with diabetes, people with high blood pressure, people with high cholesterol, and people who are overweight or obese, Stanley explains. In other words, it's the same group of individuals who have a high risk of heart attack and stroke.
So, the advice for preventing PAD, or stopping it before it gets serious, is largely the same as the advice for preventing a heart attack or stroke: Quit smoking, eat healthier, get more exercise, control your blood sugar if you have diabetes, lose weight, and get your blood pressure and cholesterol levels checked. And ask your doctor if you should take a daily aspirin to prevent clots, or drugs to reduce your blood pressure and cholesterol.
Even though PAD makes people's legs hurt or feel tired when they walk or exercise - a symptom that doctors call ‘"claudication" which feels like a "Charlie horse" type cramp - one of the best things to do is to walk more, says Stanley.
"The more a patient walks, the more likely it is that they will develop little ‘detour' blood vessels, called ‘collateral' vessels, around the obstruction," he explains. The large majority of people can develop these vessels that will ease the pain.
But in some people, PAD has already gotten bad enough to cause pain or numbness even when the person is sleeping - something called "rest pain." Stanley says this pain often awakens patients from sleep. It most often occurs in the ball of the feet and may feel like someone has wrapped a bandage around the foot. This level of symptoms is ominous, he says, because it indicates a more severe blockage without adequate collateral vessels.
Another sign of severe PAD is the development of painful sores, or ulcers, on the feet and toes. These occur because the blood flow to the lower leg isn't enough to feed the tissue, and it begins to break down. People with diabetes, whose bodies have an especially hard time healing such ulcers, are most at risk. Left untreated, skin ulcers can get worse and even turn into gangrene - often leading to amputation.
The vast majority of PAD cases are nowhere near this serious. But people who don't get help for symptoms when they first start may find their problem becoming much worse over time.
So, Stanley recommends that anyone who has discomfort in their leg or legs, especially new pain that lasts more than a week, should talk to a doctor. She or he might perform a Doppler examination - a painless, non-invasive ultrasound test that detects blood pressure in the extremity.
The Doppler test can tell whether someone has PAD and how bad the blockage might be. Depending on the result, the doctor might recommend an MRA (magnetic resonance arteriogram) of the leg, or a conventional arteriogram that involves injecting dye into the leg arteries through a device called a catheter.
If a severe blockage is found, like in Dow's case, there are several options. Two are similar to those for heart patients: a minimally invasive procedure like an angioplasty that opens blockages with a tiny balloon, or bypass surgery to place a new graft to carry blood into the blocked area.
There are also promising new options on the horizon, to help the body grow new blood vessels in the blocked area. The U-M CVC the first place in the world where patients with severe PAD can volunteer for an experimental new gene-therapy treatment called MultiGeneAngio.
The MultiGeneAngio trial takes cells from a vein in the patient's arm, adds in new genes that encourage the growth of blood vessels, and then injects the cells into the blocked artery using a minimally invasive technique. Right now, it's still being tested for safety and to find the right dose of cells, says Michael Grossman, M.D., the U-M interventional cardiologist who is leading the study at U-M. But if the study proves successful it may one day become a new treatment option for patients.
Until that day, the best weapon against PAD is better knowledge of the fact that pain in the legs is more than an inconvenience. "If one has PAD there are two issues," says Stanley. "What happens to your leg, and what happens to your life."
Facts about peripheral arterial disease or PAD:
- Peripheral arterial disease, or PAD, is sometimes called peripheral vascular disease. Both names describe the blocking of blood vessels in the peripheral parts of the body, away from the heart.
- The blockages are caused by the buildup of cholesterol, scar tissue and blood clots within the blood vessels - the same thing that happens in the blood vessels that feed the heart.
- PAD interferes with the flow of blood to the legs and feet, which can cause pain or numbness in the legs. When the pain occurs while a person is walking or exercising, it's called claudication. When it occurs as a person is sleeping, it's called rest pain.
- Similar blockages in the heart or brain may cause a heart attack or stroke.
- People with PAD, especially PAD that causes pain, have a much higher than normal risk of having a heart attack or stroke. PAD is considered a warning sign for more serious, life-threatening problems.
- PAD is more likely to develop in people who have an inherited (genetic) tendency to develop blocked arteries, and in people over age 50. It's also much more common in people who smoke, people who have diabetes, high levels of blood fat (for example, cholesterol) and high blood pressure, and in people who are overweight. African-Americans appear to have a higher risk than other groups.
- PAD can be diagnosed using an ultrasound test.
- People who have PAD should quit smoking if they haven't already done so.
- PAD can be treated using exercise, dietary changes, good blood-sugar control, and medications to reduce blood pressure and cholesterol. Severe cases are treated with minimally invasive procedures or surgery.
Written by Kara Gavin