Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis resulting in progressive blood flow obstruction in arteries excluding coronary and intracranial vessels. Although PAD can occur in multiple arterial beds, it often manifests in the arteries of the lower extremities. Lower extremity PAD is diagnosed using the ankle-brachial index, by measuring lower blood pressures in the ankles due to stenosis. PAD can be either asymptomatic or symptomatic, and symptoms are classified by the Fontaine and Rutherford classifications. Two main groups of patients can be identified within PAD populations, being patients with intermittent claudication (Fontaine II) and patients with acute or chronic limb ischemia (Fontaine III and IV).

Both groups are at increased risk of nonfatal cardiovascular events, amputation and mortality. Cardiovascular events are, in most cases, caused by a process called atherothrombosis, which is defined as atherosclerosis with superimposed thrombus formation. It has yet to be elucidated why certain patients develop atherothrombotic events and other patients, within the same PAD population, never experience any events. An interplay between inflammation and coagulation might play a key role in the pathophysiology of atherothrombosis.

To date, there is no functional test to identify patients at risk of cardiovascular events. By developing such test, treatment can be optimized for high-risk patients in order to decrease the mortality risk as well as the number of cardiovascular events.