Chronic subcritical limb ischemia: a poorly recognized stage of critical limb ischemia.

It is well-known that critical limb ischemia is associated with high mortality and amputation risk. Chronic subcritical limb ischemia, however, represents a subgroup of patients with critical limb ischemia in whom severely reduced circulation to the foot does not manifest as rest pain, ischemic ulceration, or ischemic gangrene. Admittedly, there is a paucity of data describing the fate of this patient subset, and little evidence to support appropriate treatment. To better understand the distinctive characteristics and clinical outcomes of this population, a cohort of 20 patients was examined. During the mean follow-up of 1.9 years, there were no deaths or major amputations, and only one patient progressed to surgical intervention. This review describes the characteristics and outcomes of this patient cohort and discusses the clinical implications. These findings suggest that attentive medical care and risk-reduction strategies may reduce mortality and alter progression of limb ischemia to amputation in patients with chronic subcritical limb ischemia.