The US Preventive Services Task Force (USPSTF) recently published recommendations on screening for peripheral artery disease (PAD) and cardiovascular disease (CVD) with ankle-brachial index (ABI) measurement.
What Is Peripheral Artery Disease?
Peripheral artery disease is buildup of plaques that cause blockages inside the arteries (blood vessels) of the legs. Symptoms of PAD include pain in the legs, usually worse with activity such as walking and better with rest. This type of pain is called claudication. In severe cases in which the blood supply is completely blocked off, PAD can lead to tissue death and amputation. Peripheral artery disease is considered to be a type of CVD. Other types of CVD include coronary heart disease and cerebrovascular disease, which can lead to heart attacks, strokes, and death.
Risk factors for PAD include smoking, diabetes, high blood pressure, and high cholesterol. Treatment of PAD includes controlling these risk factors both with lifestyle and with medications as needed. Medications can also help with symptoms of claudication. In severe cases, PAD can be treated with a procedure to open up the blocked blood vessel or surgery to bypass the blocked vessel.
What Is the Ankle-Brachial Index?
The ABI is calculated as systolic blood pressure as measured at the ankle divided by systolic blood pressure as measured at the arm (brachial artery) while lying down. An index of less than 0.9 is considered abnormal and is commonly used to define PAD.
What Is the Patient Population Under Consideration for Using ABI to Screen for PAD?
This USPSTF recommendation applies to adults who do not have any symptoms or diagnosis of PAD, CVD, or kidney disease.
What Are the Potential Benefits and Harms of Using ABI to Screen for PAD?
The potential benefit of using the ABI to screen for PAD is finding and treating the condition earlier to prevent pain, possible leg amputation, and potentially other types of CVD events (heart attacks, strokes, death). Although there is evidence that the ABI is a useful test to diagnose PAD in people with symptoms, there is currently no evidence that it benefits those without symptoms (by finding those who will develop symptoms later and thus benefit from treatment). Potential harms from ABI testing itself are small; however, it may lead to further diagnostic testing, which may have more side effects.
How Strong Is the Recommendation to Use ABI to Screen for PAD?
Based on current evidence, it is unclear whether the potential benefits of using the ABI to screen for PAD in people with no symptoms outweigh the potential harms.
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Source: US Preventive Service Task Force. Screening for peripheral artery disease and cardiovascular disease risk assessment with the ankle-brachial index: US Preventive Services Task Force recommendation statement [published July 10, 2018]. JAMA. doi:10.1001/jama.2018.8357