Published online by Cambridge University Press: 19 May 2010
Peripheral arterial disease (PAD) is a common, age-related, chronic arterial occlusive disease caused by atherosclerosis, resulting in a narrowing of the arteries in the lower extremities and sometimes in the upper extremities. The disease process begins gradually, many years before clinical findings are apparent, and parallels the atherosclerosis of the coronary and cerebral vessels associated with a high mortality rate secondary to cardiovascular and cerebrovascular ischemic events. Cigarette smoking and diabetes are the most common exacerbating factors. Most of the patients with PAD of the lower extremities are asymptomatic. A thorough physical examination is the key to evaluation and treatment. Laboratory tests help confirm the diagnosis and quantify the extent of the disease.
Absence of palpable peripheral arteries and symptomatic intermittent claudication, which are usually present only in the late stages of the disease, are relatively insensitive tools for the diagnosis of atherosclerosis in the peripheral arteries. With the availability of better diagnostic testing, especially the noninvasive methods such as measurement of ankle and brachial blood pressures, and the increasing prevalence in our aging population, PAD is now being identified at an earlier stage. Despite this, there remains a substantial percentage of patients who are not diagnosed with this disorder, especially in the elderly population. These patients continue to have increased morbidity and mortality, largely because of progressive atherosclerosis in multiple vascular beds. The Ankle Brachial Index (ABI) is an important cost-effective, noninvasive tool for assessment of PAD and systemic atherosclerotic disease overall.