Peripheral artery disease (PAD) remains common among the adult population. Depending on the methods for detection, the estimated prevalence of PAD among U. S. adults ranges from 2.5% in patients < 60 years of age to 18.8% in patients >= 70 years of age (1,2). Using the Rose Claudication Questionnaire, which can underestimate lower extremity PAD (3), the age-specific annual incidence of intermittent claudication in the Framingham Heart Study ranged from 6 per 10,000 men and 3 per 10,000 women for ages 30 to 44 years and increased to 61 per 10,000 men and 54 per 10,000 women for ages 65 to 74 years (4). Overall, an estimated 8 million Americans have PAD, and it remains underdiagnosed. In a large cross-sectional study of patients from 350 large-volume primary care practices in 25 American cities, among patients age 70 years or older, or patients 50 to 69 years of age who smoked or had diabetes mellitus, the prevalence of PAD was 19% (5). Within this group, 16% were observed to have both lower extremity PAD and at least 1 other form of atherosclerotic disease such as coronary artery disease. Despite the high prevalence of PAD in this cohort, the diagnosis of PAD was new in 55% of patients with PAD alone, and new in 33% of patients with both lower extremity PAD and cardiovascular disease.
