i. a resting ankle/brachial index (ABI) of <0.85, or ii. significant peripheral artery stenosis (>50%) documented by angiography or non-invasive testing by duplex ultrasound, or iii. previous limb or foot amputation for arterial vascular disease (excludes trauma), or iv. previous aorto-femoral bypass surgery, limb bypass surgery or percutaneous transluminal angioplasty of the iliac or infrainguinal arteries, or v. subjects with asymptomatic carotid artery disease ii. amputation, peripheral bypass, or peripheral angioplasty of the extremities secondary to ischemia