Research toolbox for peripheral arterial disease: Minimally invasive assessment of the vasculature and skeletal muscle

In 2010, more than 200 million people were afflicted with peripheral arterial disease (PAD). Because it is atherosclerotic in etiology, it is not surprising that PAD is a leading cause of cardiovascular morbidity. Cardiovascular disease (CVD) risk can be decreased if ambulatory physical function is improved. However, physical function is limited by a mismatch between oxygen supply and demand in the legs, which results in exertional pain, leg weakness, and balance problems. Therefore, a key factor for improving physical function, and decreasing CVD outcomes, is ensuring oxygen supply meets the oxygen demand. The purpose of this review is to highlight and evaluate practical and minimally invasive tools for assessing PAD etiology, with a specific focus on tools suited to studies focusing on improving physical function and CVD outcomes. Specifically, the macrovascular, microvascular, and skeletal muscle pathology of PAD is briefly outlined. Subsequently, the tools for assessing each of these components is discussed, including, where available, the evidence to contextualize these tools to PAD pathology as well as physical function and CVD outcomes. The goal of this review is to guide researchers to the appropriate tools with respect to their methodological design.