Functional Decline in Peripheral Arterial Disease: Associations With the Ankle Brachial Index and Leg Symptoms

CONTEXT Among individuals with lower-extremity peripheral arterial disease (PAD), specific leg symptoms and the ankle brachial index (ABI) are cross-sectionally related to the degree of functional impairment. However, relations between these clinical characteristics and objectively measured functional decline are unknown. OBJECTIVE To define whether PAD, ABI, and specific leg symptoms predict functional decline at 2-year follow-up. DESIGN, SETTING, AND PARTICIPANTS Prospective cohort study among 676 consecutively identified individuals (aged ≥55 years) with and without PAD (n = 417 and n = 259, respectively), with baseline functional assessments occurring between October 1, 1998, and January 31, 2000, and follow-up assessments scheduled 1 and 2 years thereafter. PAD was defined as ABI less than 0.90, and participants with PAD were categorized at baseline into 1 of 5 mutually exclusive symptom groups. MAIN OUTCOME MEASURES Mean annual changes in 6-minute walk performance and in usual-paced and fast-paced 4-m walking velocity, adjusted for age, sex, race, prior-year functioning, comorbid diseases, body mass index, pack-years of cigarette smoking, and patterns of missing data. RESULTS Lower baseline ABI values were associated with greater mean (95% confidence interval) annual decline in 6-minute walk performance (−73.0 [−142 to −4.2] ft for ABI