Effect of cognitive status on exercise performance and quality of life in patients with symptomatic peripheral artery disease

Background We determined whether scores on a cognitive screening measure were associated with the primary outcome measure of peak walking time (PWT) and with secondary outcome measures related to mobility, community-based ambulation, health-related quality of life (QoL), and vascular function in patients with claudication and peripheral artery disease (PAD). Methods Gross cognitive status of 246 PAD patients was assessed with the Mini-Mental State Examination (MMSE) questionnaire. Patients were grouped according to whether they had a perfect MMSE score of 30 points (n = 123) or whether they missed one or more points (n = 123). Patients were characterized on numerous outcomes, including PWT during a treadmill test and QoL. Results Compared with the group with the higher MMSE scores, there was a trend for lower PWT in the group with the lower MMSE scores (P =.06) after adjusting for age, sex, race, and education level (model 1), which became significant (380 ± 250 seconds vs 460 ± 270 seconds; P <.05) after adjusting for model 1 plus coronary artery disease, chronic obstructive pulmonary disease, and arthritis (model 2). Multiple domains of QoL were lower (P <.05) in the group with the lower MMSE scores after adjusting for model 1, but only mental health remained lower (75 ± 20% vs 80 ± 5%; P =.02) after further adjustment with model 2. Conclusions In symptomatic patients with PAD, lower cognitive screening scores were associated with greater ambulatory impairment than in patients with higher MMSE scores. Furthermore, worse cognitive status was associated with lower scores in multiple dimensions of health-related QoL, all of which except mental health were explained by the comorbid conditions of coronary artery disease, chronic obstructive pulmonary disease, and arthritis. The clinical significance is that there is a need for enhanced cognitive and mental health screening as potential indicators of poor outcome among symptomatic patients with PAD. Furthermore, patients identified as having worse cognitive status might be in greatest need of intervention to improve ambulation and QoL related to mental health.