Microvascular Reactivity in Peripheral Artery Disease

Peripheral Artery Disease (PAD) is a major risk factor for lower limb amputation. Microvascular reactivity assessed with near-infrared spectrometry has been studied in people with PAD but not in people with limb loss (PLL) who have PAD. The purpose of this research is to explore whether near-infrared spectrometry measures can contribute to identifying people at risk for amputation. Specific aims include: 1) Determine the test-retest reliability of near-infrared spectrometry measures in people with peripheral artery disease with or without major unilateral amputation. 2) Determine construct validity of near-infrared spectrometry measures compared to 6-Minute Walk Test, and time to claudication onset; and self-reported prosthetic mobility in people with transtibial amputation. This methodologic prospective study with repeated assessments and long term phone follow-up every year to identify any subjects that undergo revascularization or amputation will include 2 groups of subjects: a PAD group enrolled from an out-patient walking program, and a PLL+PAD group who receive no care but have their walking step counts monitored.