Plaque characteristics in the superficial femoral artery correlate with walking impairment questionnaire scores in peripheral arterial disease: The Walking and leg Circulation Study (WALCS) iii

Purpose: We studied associations of magnetic resonance imaging (MRI)-measured plaque area and relative percent lumen reduction in the proximal superficial femoral artery with Walking Impairment Questionnaire (WIQ) scores and quality of life in people with lower extremity peripheral arterial disease (PAD). Methods: Four-hundred forty-two participants with PAD underwent cross-sectional imaging of the proximal superficial femoral artery with MRI, and completed the WIQ and the Short-Form-12 mental and physical functioning questionnaires. Questionnaires were scored on a 0-100 scale (100=best). Results: adjust for age, sex, race, the ankle brachial index (ABI), comorbidities, and other covariates. Results Adjusting for age, sex, race, ABI, comorbidities, and other covariates, higher mean plaque area was associated with poorer WIQ distance scores (1st quintile (least plaque)-44.8, 2nd quintile-43.3, 3rd quintile-38.9, 4th quintile-34.6, 5th quintile (greatest plaque)-30.6, p trend <0.001) and poorer WIQ speed scores (1st quintile-40.6, 2nd quintile-39.6, 3rd quintile-39.5, 4th quintile-32.8, 5th quintile-33.0, p trend =0.019). Similar associations of higher maximum plaque area, mean lumen reduction, and maximum lumen reduction with poorer WIQ distance and speed scores were observed. Plaque measures were not associated with WIQ stair climbing scores or SF-12 scores. Conclusion: Among participants with PAD, greater plaque burden and smaller lumen area in the proximal superficial femoral artery are associated with poorer walking endurance and slower walking speed as measured by the WIQ, even after adjusting for the ABI.