Peripheral arterial disease (PAD) encompasses noncardiac systemic atherosclerosis. PAD most commonly manifests in arteries of the lower extremities and may also be present in the carotid, mesenteric, renal, brachiocephalic, and subclavian vasculature. The incidence of PAD increases with age beginning at 40 years. Additional factors identified by the Framingham Heart Study to increase the risk for developing PAD include diabetes, hypercholesterolemia, cigarette smoking, and hypertension (Table 8-1). Patients with PAD have a fourfold increase in coronary artery disease and death compared to individuals without PAD.
TABLE 8-1Factors that Increase Risk for Lower Extremity Peripheral Arterial Disease (PAD) ||Download (.pdf) TABLE 8-1Factors that Increase Risk for Lower Extremity Peripheral Arterial Disease (PAD)
Age <50 y with diabetes plus one additional factor for atherosclerosis (history of smoking, hypertension, hyperlipidemia)
Age 50-64 y plus family history of PAD or personal risk factors for atherosclerosis
Age ≥65 y
Individuals of any age with known atherosclerotic disease (eg, coronary, carotid, subclavian, abdominal, or renal artery disease)
Clinical manifestations of PAD vary based on disease severity and can range from asymptomatic disease to limbs in jeopardy of amputation. Atherosclerotic lesions in the peripheral vessels that impair lower extremity arterial circulation result in intermittent claudication (IC) or symptoms during exercise. IC is characterized by fatigue, pain, discomfort, cramping, or numbness in the buttock, thigh, or calf upon exertion and typically relieved within 10 minutes by rest. Resting pain, limb ischemia, nonhealing wounds, or gangrene can manifest from severe disease. PAD is stratified based on presentation: asymptomatic, atypical leg pain, classic claudication, and critical limb ischemia.
Clinical history and physical examination findings suggestive of PAD warrant diagnostic testing with a resting ankle-brachial index (ABI). An ABI of less than or equal to 0.90 indicates PAD, borderline PAD is recognized by an ABI 0.91-0.99, normal is 1.00-1.40. Additional testing may include exercise treadmill ABI, duplex ultrasound, toe-brachial index, and angiography. Table 8-2 lists key factors associated with the clinical presentation and risk assessment of PAD.
TABLE 8-2Clinical Presentation of Peripheral Arterial Disease ||Download (.pdf) TABLE 8-2Clinical Presentation of Peripheral Arterial Disease
|Signs and Symptoms |
Lack of hair on calves, feet, or toes
Critical limb ischemia (at least 2 wk of ischemic rest pain, nonhealing wound, gangrene)
Abnormal pedal pulses
Femoral artery bruit
Cool skin temperature
Acute limb ischemia (<2 wk with pain, pulselessness, pallor, paresthesias, or paralysis)
None specific to PAD
Other Diagnostic Tests