Physical activity during daily life and mortality in patients with peripheral arterial disease

BACKGROUND - We determined whether patients with lower-extremity peripheral arterial disease (PAD) who are more physically active during daily life have lower mortality rates than PAD patients who are less active. METHODS AND RESULTS - Participants were 460 men and women with PAD (mean age 71.9±8.4 years) followed up for 57 months (interquartile range 36.6 to 61.9 months). At baseline, participants were interviewed about their physical activity. Vertical accelerometers measured physical activity continuously over 7 days in 225 participants. Analyses were adjusted for age, sex, race, body mass index, hypertension, smoking, comorbidities, total cholesterol, HDL cholesterol, leg symptoms, and ankle-brachial index. At 57-month follow-up, 134 participants (29%) had died, including 75 participants (33%) who wore accelerometers. Higher baseline physical activity levels measured by vertical accelerometer were associated with lower all-cause mortality (Ptrend=0.003). Relative to PAD participants in the highest quartile of accelerometer-measured physical activity, those in the lowest quartile had higher total mortality (hazard ratio 3.48, 95% confidence interval 1.23 to 9.87, P=0.019). Similar results were observed for the combined outcome of cardiovascular events or cardiovascular mortality (Ptrend=0.005). Higher numbers of stair flights climbed during 1 week were associated with lower total mortality (Ptrend=0.035). CONCLUSIONS - PAD patients with higher physical activity during daily life have reduced mortality and cardiovascular events compared with PAD patients with the lowest physical activity, independent of confounders. Further study is needed to determine whether interventions that increase physical activity during daily life are associated with improved survival in patients with PAD.