Peripheral Artery Disease Screening in Los Angeles

Leg Discomfort

Generalized leg discomfort should be cause for alarm in diabetics, smokers, and the elderly. Leg pain is certainly not specific to peripheral artery disease, but it may be the first sign that vascular issues are present in a routine check up. Pain patterns can include:

• Heavy or weak legs
• Aching or burning in the lower extremities
• Numbness or tingling

Cold Feet

Weak Pulse

Claudication

Rest Pain

Skin Lesions and Visible Tissue Loss

Tissue loss and ulceration are often viewed as complications of diabetes first and foremost, especially when present on the foot, leaving the vascular component ignored. When managing diabetes, it can be easy to forget that healing is compromised when tissue does not have an adequate blood supply. Tissue loss manifests as visible skin color changes, open wounds, and sores on the leg or foot. Advanced stages of PAD are characterized by open wounds that are slow to heal and can become complicated by infection. Other symptoms may include:

• Redness of the skin or other discolored lesions
• Open sores, ulcers, or wounds on the leg or foot with a foul-smelling discharge. Often, the wound or ulcer starts as a minor traumatic injury and then fails to heal due to insufficient blood supply.
• Gangrene, which occurs when tissue dies and the skin turns black

Major risk factors for PAD are similar to those for cardiovascular diseases. If a patient is suspected of ischemic heart disease, they should also be considered for a PAD screening test. Risk factors include:

Smoking — smokers are 2 to 4 times as likely to develop PAD than non-smokers. Smoking is the most significant risk factor for developing PAD. Nicotine is a vasoconstrictor that exacerbates the narrowing of blood vessels and arteries. Smoking also accelerates stiffening of plaques, which further restricts blood flow.

Diabetes — the risk of diabetics developing PAD is 2 to 3 times the risk for non-diabetics. Diabetics are also 2 to 3 times more likely to develop symptomatic PAD. Patients with diabetes have more advanced and aggressive arterial disease at initial diagnosis and poorer outcomes than nondiabetic patients. In fact, diabetics with lower extremity PAD have amputation rates that are 5 to 10 times higher compared to nondiabetic patients with PAD. The increased amputation rate in diabetics is at least partly attributable to sensory neuropathy and increased likelihood of infection.

High LDL cholesterol and low HDL cholesterol — patients with PAD are more likely to have increased levels of ‘bad’ cholesterol (LDL) and total triglycerides in conjunction with low levels of ‘good,’ protective cholesterol (HDL) compared to patients without PAD.
The atherosclerotic plaques that obstruct arteries and increase the risk of developing PAD are composed of cholesterol, fat, calcium, and other blood substances.

High blood pressure — high blood pressure is extremely common in the United States, with a 30% prevalence rate among adults. Hypertension can double your risk of developing PAD when compared to individuals with healthy blood pressure. High blood pressure also increases the risk of developing symptoms of PAD, such as intermittent claudication. Hypertensive patients also have a higher prevalence of asymptomatic PAD. In one study of 4.2 million adults done by Emdin et al in 2015, a 20 mmHg higher than usual systolic blood pressure was associated with a 63 percent higher risk of PAD.

Known atherosclerosis at other sites or in the family — patients with existing coronary artery disease or atherosclerosis in the carotid or renal arteries are at increased risk of developing PAD. Family history of PAD or cardiovascular disease may also increase the risk of developing PAD. Patients with asymptomatic PAD may still have underlying atherosclerotic occlusive disease present.

Age — according to the American College of Cardiology/American Heart Association, you are at increased risk of developing PAD if you are 65 years or older and should be screened regardless of other risk factors. Beginning after age 40, the prevalence of PAD increases progressively. Individuals over 70 are at a significantly increased risk for PAD due to age alone.

Early peripheral artery disease screening for detection is absolutely critical in the battle against peripheral artery disease and its sequelae. Early identification can lead to lifestyle changes and, if necessary, early intervention that can dramatically lower the likelihood of amputation and other serious complications.

PAD Screening Test Criteria

Even if immediate symptoms are absent, PAD screening tests are now recommended if a patient:

• Is age 65 or older
• Is age 50 to 69 years with a history of diabetes or smoking
• Has a history of diabetes and are less than 50 years old with one additional risk factor such as smoking, dyslipidemia, hypertension, or homocysteinemia
• Has abnormal lower extremity pulses
• Has leg symptoms with exertion
• Has ischemic rest pain
• Has known coronary, carotid, or renal atherosclerosis

PAD screening tests and classifying its severity involves the evaluation of patient symptoms and non-invasive objective tests.

Rutherford & Fontaine Classification Systems

Under the Rutherford and Fontaine classification systems, patients complete a treadmill test or walk a specified distance. Walking impairment is described as mild, moderate, or severe, and advanced stages of PAD include observed tissue loss.

The Rutherford and Fontaine classifications are decades old and were designed to categorize chronic limb ischemia among patients with PAD. However, due to dramatic shifts in patient demographics, particularly in the increasing number of individuals with diabetes, other classification schemes have been created and are widely adopted.

Wound, Ischemia, Foot Infection (WIfI)

Vascular specialist taking an ankle-brachial index reading.

Ankle-Brachial Index & Segmental Limb Pressures

An ankle-brachial index (ABI) measurement alone can be used as a PAD screening test if there is strong clinical suspicion based on symptoms and physical exam findings. ABI is used to assess how well blood is flowing in the legs by measuring blood pressure in the ankles and comparing it to blood pressure in the arms. More than 50% of patients who meet ABI criteria for PAD fail to receive a proper diagnosis, indicating that PAD screening is underutilized.

A diagnosis of PAD is confirmed in patients who have an ankle-brachial index (ABI) of ≤0.9 and who have an appropriate history and physical examination. An ABI is a measurement of the blood pressure in your ankles compared to the blood pressure in your arms. Patients with PAD symptoms such as claudication may have a normal ABI at rest. In these cases, an ABI is obtained following exercise testing. Blood pressures can also be measured at other levels in the legs such as at the calf or the upper thigh to determine the extent of PAD.

Imaging