Potential participants will be identified and screened prior to discharge or at the time of the first out-patient visit (within 2 weeks after discharge) after a percutaneous lower extremity arterial angiography with arterial intervention (stent or balloon angioplasty) for the presence of lower extremity vascular insufficiency. Participants will be classified as Rutherford Class IV - VI (with or without ulcerations). A total of 60 patients will be randomized into 2 treatment groups in a 1:1 ratio (ticagrelor to clopidogrel). Patients are placed on clopidogrel after their arterial intervention per standard of care. They will remain on clopidogrel up to the time that randomization occurs. For patients that are randomized to ticagrelor, the clopidogrel will be stopped.