The Artery Test Doctors Don't Do
Leg blockage often goes undiagnosed
TUESDAY, Sept. 18, 2001 (HealthDayNews) -- Too many doctors aren't testing high-risk patients for peripheral arterial disease (PAD), a condition that is a strong signal of impending heart attack or stroke, a study finds.
PAD is atherosclerosis of the arteries in the arms and legs, a buildup of fatty deposits that narrow the blood vessels and can eventually block them. Studies have shown that "PAD of any severity indicates a major future risk of heart attack or stroke, comparable to that of someone who has already had a heart attack or stroke," says Dr. Alan T. Hirsch, associate professor of medicine at the University of Minnesota Medical School. People with PAD have a 5 percent to 15 percent greater chance of having a heart attack or stroke, he says.
Yet a nationwide study led by Hirsch and his colleagues found that PAD had previously been diagnosed in fewer than half of patients with the condition. "The impression of most of us in the study is that physicians in general don't perform this test. We hope this study will help change that," says Hirsch.
The study, reported in the latest Journal of the American Medical Association, focused on patients with the risk factors that indicate both PAD and general cardiovascular disease -- people 70 and older (because age can be a risk factor) and those 50 and older with a history of smoking or diabetes. The researchers say they expected to find a 15 percent incidence of PAD and of cardiovascular disease in that group. Originally, they had intended to enroll 10,000 patients, expecting to find 1,500 with PAD and 1,500 with cardiovascular disease.
However, by the time they enrolled fewer than 7,000 patients, they found 1,865, or 29 percent of subjects, had PAD, many of them with cardiovascular disease, as well. And half of those with PAD had not been diagnosed previously because their doctors had not been doing the questioning and the test required to detect it, the researchers say.
The first step was to ask about pain in the leg, most notably about the acute calf pain caused by intermittent claudication, a blockage of blood flow in leg arteries that occurs during physical activity. The researchers then did the standard test to detect PAD.
It's "a very simple test that can be performed in the physician's office" and requires only moderately sophisticated equipment, Hirsch says. In addition to using an ordinary blood-pressure cuff at the usual place on the arm, doctors also used the cuffs on the ankle and at two places on a leg, then, using an electronic stethoscope (which costs about $500), they determined something called the ankle-brachial index, an indicator of PAD.
Why aren't more doctors doing the test, which takes about 15 minutes? Some answers are starting to come from a separate study in which doctors are being polled, Hirsch says.
"There is a lack of appreciation of the value of the test in preventing heart attack and stroke," he says. In addition, many doctors don't have the electronic stethoscope. And insurance coverage often is not available. "Health insurers haven't appreciated the value of the test. This study demonstrates that it does have value," Hirsch says.
"The most important thing about the study is that it can increase awareness of PAD in both doctors and patients," says Dr. Kenneth Ouriel, chairman of the Department of Vascular Surgery at the Cleveland Clinic Foundation.
Ouriel says one noteworthy finding of the study is that even when PAD is diagnosed, it is not treated as vigorously as atherosclerosis of the heart and brain arteries. PAD patients were less likely to be prescribed cholesterol-lowering and anti-clotting medications, the study found.
"We're very good at treating atherosclerosis of the heart and getting good at treating atherosclerosis of the brain, but we have a ways to go when it comes to atherosclerosis of the lower extremities, which is closely linked to the other two," Ouriel says.
What To Do
Which patients should ask their doctors about testing for PAD? "Data from our research suggest it is certainly worthwhile for individuals of age 70 and older and for persons over 50 with a history of smoking, diabetes and perhaps other risk factors," Hirsch says. "Clinical experience also suggests that anyone with claudication should have this test, and anyone with an unhealing wound of a leg."