Microvascular Disease Increases Amputation in Patients With Peripheral Artery Disease.

It is estimated that >2 million patients are living with an amputation in the United States. Peripheral artery disease (PAD) and diabetes mellitus account for the majority of nontraumatic amputations. The standard measurement to diagnose PAD is the ankle-brachial index, which integrates all occlusive disease in the limb to create a summary value of limb artery occlusive disease. Despite its accuracy, ankle-brachial index fails to well predict limb outcomes. There is an emerging body of literature that implicates microvascular disease (MVD; ie, retinopathy, nephropathy, neuropathy) as a systemic phenomenon where diagnosis of MVD in one capillary bed implicates microvascular dysfunction systemically. MVD independently associates with lower limb outcomes, regardless of diabetic or PAD status. The presence of PAD and concomitant MVD phenotype reveal a synergistic, rather than simply additive, effect. The higher risk of amputation in patients with MVD, PAD, and concomitant MVD and PAD should prompt aggressive foot surveillance and diagnosis of both conditions to maintain ambulation and prevent amputation in older patients.