Association of Lower Extremity Performance With Cardiovascular and All‐Cause Mortality in Patients With Peripheral Artery Disease: A Systematic Review and Meta‐Analysis

BACKGROUND: Peripheral artery disease (PAD) is associated with impaired mobility and a high rate of mortality. The aim of this systematic review was to investigate whether reduced lower extremity performance was associated with an increased incidence of cardiovascular and all-cause mortality in people with PAD. METHODS AND RESULTS: A systematic search of the MEDLINE, EMBASE, SCOPUS, Web of Science, and Cochrane Library databases was conducted. Studies assessing the association between measures of lower extremity performance and cardiovascular or all-cause mortality in PAD patients were included. A meta-analysis was conducted combining data from commonly assessed performance tests. The 10 identified studies assessed lower extremity performance by strength tests, treadmill walking performance, 6-minute walk, walking velocity, and walking impairment questionnaire (WIQ). A meta-analysis revealed that shorter maximum walking distance was associated with increased 5-year cardiovascular (unadjusted RR=2.54, 95% CI 1.86 to 3.47, P<10(-5), n=1577, fixed effects) and all-cause mortality (unadjusted RR=2.23 95% CI 1.85 to 2.69, P<10(-5), n=1710, fixed effects). Slower 4-metre walking velocity, a lower WIQ stair-climbing score, and poor hip extension, knee flexion, and plantar flexion strength were also associated with increased mortality. No significant associations were found for hip flexion strength, WIQ distance score, or WIQ speed score with mortality. CONCLUSIONS: A number of lower extremity performance measures are prognostic markers for mortality in PAD and may be useful clinical tools for identifying patients at higher risk of death. Further studies are needed to determine whether interventions that improve measures of lower extremity performance reduce mortality.