We pay much less attention to our arteries than our hearts. But atherosclerosis, the underlying condition in heart disease, is blind when it comes to the cardiovascular system. It strikes with equal belligerence in arteries quite distant from the heart, particularly those of the lower extremities.
Research now indicates that
peripheral artery disease (PAD)
has largely been unrecognized, ignored, or mistakenly thought to be part of the aging process. Men are particularly at risk for the problem. The good news, researchers say, is that increased use of a simple test in the doctor's office could improve detection of this deadly disorder.
PAD occurs when
atherosclerosis
results in a buildup of fatty material called plaques in the arteries of the legs. Because atherosclerosis can affect the entire cardiovascular system, patients with PAD have a risk of
heart attack
or
stroke
that is five to seven times greater than the general population—about the same risk as someone who has
heart disease
.
More rarely, people with arterial plaque in their extremities can also develop life-threatening problems such as ulcers or
gangrene
. More than one-third of patients with these complications eventually have a limb amputation.
Many people are not aware of the dangers of clogged arteries in the legs. According to a recent survey by the National Coalition on Aging, only 32% of people 50 and older are familiar with PAD. Yet the condition is very common, affecting up to 12 million people in the US.
Of those afflicted with PAD, about twice as many are men than are women. The condition increases with age in the general population as follows:
| Age (years) | Proportion affected (%) |
|---|
| 40-59 | 2.5 |
| 60-69 | 8.3 |
| 70-79 | 18.8 |
The other risk factors for PAD are similar to those that increase your chances of getting heart disease. These may include:
So how do you know if you have PAD? The problem is that atherosclerosis is a very gradual process, so early in the disease most people don't have any symptoms. Even later on, only about one-third have classic symptoms of PAD.
The condition's earliest and most characteristic symptom is pain in the calves or thighs while walking, called intermittent claudication. This usually occurs after walking a certain distance and ends after resting for a consistent length of time. Other symptoms may include:
- Numbness, weakness, or a feeling of heaviness in the legs
- Burning or aching in the feet at rest, especially while lying flat
- Coolness or color changes of the legs or feet
- Foot sores that are slow to heal
Since the symptoms of PAD are often absent or unrecognized, many people who have the disease don't even know it. But a recent study in the
Journal of the American Medical Association (JAMA)
found that a simple, non-invasive blood pressure test can be done in the doctor's office to detect PAD.
Called the ankle-brachial index, or ABI, the test involves taking pressures in both arms and ankles using a blood pressure cuff and a simple device to detect blood flow called a Doppler. The resulting blood pressure readings are then used to calculate your ABI. A value less than or equal to 0.9 signals PAD.
Researchers in the
JAMA
study who used the ABI test detected PAD in 29% of 7,000 subjects over the age of 49 who were at risk for the disorder. Over half of these patients had never before been diagnosed with the condition. Of those previously diagnosed with PAD, the patient's current doctor didn't know about it in roughly half the cases. The researchers concluded that PAD is an under-diagnosed condition and that increased use of the ABI test could improve detection.
It remains unclear whether patients who are screened for PAD with an ABI or other test are less likely to have an amputation or die from this disease. Nevertheless, early detection of PAD, particular if the screening test is safe and accurate and could, theoretically, improve your chances of a favorable outcome. Medications and other interventions are available to treat atherosclerosis and reduce some of the complications associated with PAD.
More conclusive evidence, however, suggests that screening for and treating PAD risk factors—particularly high blood pressure, abnormal cholesterol, obesity, and smoking—can have a considerable affect on your risk of cardiovascular disease in general. So whether or not you and your doctor decide to take presymptomatic look for PAD, focusing your efforts on reducing your overall risk of cardiovascular disease makes the most sense of all.
