Is a Simple Biomarker for Peripheral Arterial Disease on the Horizon?

Atherosclerosis is the leading cause of morbidity and mortality in the Western world, and one of the major clinical complications of atherosclerosis is the impairment of blood flow to the lower extremity, which is commonly referred to as peripheral arterial disease (PAD). Although long underrecognized and underdiagnosed in the medical community, the prevalence of PAD in the United States alone is estimated to be 8 to 12 million, and PAD is also quite common in Europe and Asia.1–4 In fact, the prevalence of atherosclerosis primarily, or solely, affecting the lower extremity, cerebral vascular system, renal arteries, and visceral organs is now equal to or greater than the number of individuals afflicted with ischemic heart disease.2,5 The reasons that PAD of the lower extremity has been underdiagnosed are likely multifactorial. Even today, these explanations include but are certainly not limited to (1) an overlap of symptoms of what is perceived to be “normal” aging, (2) a sense that treatment options are limited and that the disease is very stable over time, (3) the attributing of the symptoms of true pain when present to other disease processes such as neuropathy, and (4) the need for busy physicians and healthcare providers to perform additional measures as part of a physical examination in an environment of decreasing time available to each patient. The facts are very clear that PAD imparts an increase in the risk of cardiovascular death and stroke,6 that treatment options for PAD are expanding,7,8 and that even in minimally symptomatic patients over time, evidence points to a decrease in functional capacity.9 Therefore, a pressing need exists for a simple, readily assessable, reliable biomarker to test for PAD.Article p 1396 To that end, the article in this issue of Circulation by Wilson et al10 from …