The study is aimed at evaluating the role of the activity of the key hemostatic parameters of endothelial dysfunction (nitric oxide II (NO) metabolites, plasmin activator inhibitor-1 (PAI-1), von Willebrand factor (vWF), coagulation factor VIII (FVIII), soluble endothelial protein C receptors (sEPCR)) in the development of disease progression, thrombotic complications and restenosis in subjects with atherosclerotic peripheral artery disease.

The study will involve patients with atherosclerotic peripheral artery disease (Rutherford category 3-5). The subjects are to be divided into three groups:

Group A: patients who undergo bypass surgery with a synthetic graft on aorto-iliac or femoro-popliteal segment; Group B: patients who undergo endovascular balloon angioplasty and stenting on aorto-iliac or femoro-popliteal segment; Group C: patients who undergo standard of care conservative treatment.

Decisions on revascularization or conservative treatment alone is to be made by a team of vascular specialists in accordance with the severity of the disease, previous treatment, anatomy, possible need for repeat procedures in the future, and patient's preferences.

Inclusion Criteria:

1. Males or females older than 40 years of age;
2. Presence of peripheral arterial disease of atherosclerotic origin.

Exclusion Criteria:

1. Males or females younger than 40 years of age;
2. Chronic lower limb ischemia of other ethiology (Buerger's disease, aortoarteritis etc.);
3. Active cancer or remission period less than 5 years;
4. Decompensated diabetes mellitus;
5. Pregnancy or breast-feeding for females.

A prospective study is aimed at enrolling 200 patients with atherosclerotic peripheral arterial disease, Rutherford category 3-5. The patients with PAD are scheduled to undergo either open or endovascular reconstructive procedures on aorto-iliac and femoro-popliteal segment or conservative treatment alone. The subjects of similar age, sex, and ethnicity are to be divided into three groups, respectively.

Basic demographic data, including sex, age, and ethnicity are to be shared if allowed by the privacy policy.