Lower extremity peripheral arterial disease (LEAD) is increasing in prevalence in low with approximately 202 million people affected with LEAD worldwide. Certain subgroups of individuals (cigarette smokers, diabetics) that are particularly high risk for LEAD and major adverse limb events (MALE). Conventionally, the ankle-brachial index (ABI) is the recommended screening test for LEAD. However, the ABI has several limitations, particularly in patients with diabetes. These limitations include increased measurement variability with severity of LEAD, non-compressible calcified arteries inability to detect arterial disease distal to the ankle precludes assessment of disease in the foot where many ulcers can occur, and underestimation of the extent of microvascular occlusive disease. In this systematic review, we discuss methods used for the assessment of microvascular disease and compare outcomes that encompass microvascular flow with the ABI and toe-brachial index (TBI).