Effect of Evolocumab in Patients With Critical Limb Ischemia (Evol-CLI)

This is a double-blinded, prospective, randomized, pilot, study in thirty-two subjects with clinical CLI on background treatment with a statin. Subjects will be assessed based on their medical history and physical examination. Eligible subjects must meet all inclusion criteria and none of the exclusion criteria. There will be a treatment group and a placebo group, each with equal number of participants (n=16 patients in each group). After consent and enrollment, subjects will have a venous blood sample drawn to perform a lipid profile, serum vascular growth factors such as: vascular endothelial growth factor (VEGF), soluble VEGF receptor-1 (sVEGFR-1), soluble VEGF receptor-2 (sVEGFR-2), fibroblast growth factor (FGF), von Willebrand factor (vWF), tissue plasminogen activator (TPA) and plasminogen activator inhibitor -1 (PAI-1) and endothelial progenitor cells (EPCs). The investigators will then perform lower extremity arterial perfusion assessment of the affected and unaffected limb as rest ankle-brachial index (ABI), toe-brachial index (TBI), bilateral transcutaneous partial pressure of oxygen (TcPO2), spatial frequency domain imaging (SFDI), femoral studies (FMT, compliance, distensibility and stiffness), brachial endothelial function testing (FMD after hyperemia and maximal vasodilation). The study participant subjects will receive monthly subcutaneous injections of evolocumab 420 mg or placebo injections. The LDL cholesterol will be measured at the baseline and a blinded measurement will also be performed at 3 and 12 months. In patients with active wounds, healing will be evaluated at baseline and every month for six months by photographic analysis using planimetry and 2D/3D topographic analysis. The study participants patients will be seen at 3, 6, and 9 months for follow up. After 12 months +/- 2 weeks, all tests will be repeated.