Leg symptom categories and rates of mobility decline in peripheral arterial disease

OBJECTIVES: To determine whether asymptomatic lower extremity peripheral arterial disease (PAD) and leg symptoms other than intermittent claudication (IC) in PAD are associated with faster functional decline than in people with both PAD and IC. DESIGN: Prospective, observational study. SETTING: Chicago-area medical center. PARTICIPANTS: Four hundred fifteen people with PAD followed annually for up to 7 years. MEASUREMENTS: At baseline, patients with PAD were categorized into symptom categories, including IC; leg pain on exertion and rest; participants who could walk through exertional leg pain (pain/carry on); and participants who never experienced exertional leg pain, even during the 6-minute walk (always asymptomatic). Outcomes included mobility loss (becoming unable to walk one-quarter of a mile or walk up and down one flight of stairs without assistance) and becoming unable to complete the 6-minute walk without stopping. Analyses adjusted for age, sex, comorbidities, ankle brachial index, and other confounders. RESULTS: Always-asymptomatic participants (hazard ratio (HR)=2.94, 95% confidence interval (CI)=1.39-6.19, P=.005) and those with leg pain on exertion and rest (HR=2.89, 95% CI=1.47-5.68, P=.002) had greater mobility loss than participants with IC. Participants with PAD with leg pain/carry on were less likely (P=.047) to become unable to walk for 6 minutes continuously without stopping than participants with IC. CONCLUSION: The ABI identifies patients with asymptomatic PAD and those with atypical leg symptoms who are at risk for greater mobility decline than participants without PAD and participants with PAD with IC.