Increased walking impairment linked to higher mortality risk in PAD

Patients with peripheral arterial disease (PAD) whose walking ability decreased over a two-year period had a higher risk for death, a new study found.

Researchers asked men and women with PAD to complete the Walking Impairment Questionnaire (WIQ), a self-administered questionnaire specific to PAD, at baseline and again at two-year follow-up. The study aimed to determine whether increased decline in WIQ stair-climbing, distance or speed scores was associated with increased all-cause and cardiovascular disease mortality rates. Data on two-year changes in these variables were examined using Cox proportional hazards models and were adjusted for covariates including age, sex, race, ankle brachial index, body mass index, smoking and comorbid conditions. The study results were published March 5 by the Journal of the American College of Cardiology.

Overall, 442 men and women participated in the study. One hundred twenty-three (27.8%) died during a median of 4.7 years after the two-year follow-up assessment. Of these, 45 (36.6%) died of cardiovascular disease and 11 (8.9%) died of unknown causes. Older age was associated with the greatest decline in the two-year stair-climbing score, while more physical activity at baseline was associated with the greatest decline in distance score. The mean two-year score changes were −0.79, −1.78 and −1.55, respectively, for stair-climbing, distance and speed. Patients were followed for a median of 44.7 months for cardiovascular death.

After the data were adjusted for covariates, all-cause mortality was higher in patients whose WIQ score decreased 20 points or more over two years (hazard ratios, 1.93 [95% CI, 1.01 to 3.68] for stair climbing, 2.34 [95% CI, 1.15 to 4.75] for distance, and 3.55 [95% CI, 1.57 to 8.04] for speed) compared with patients whose score improved by 20 points or more. Patients whose distance score decreased by 20 points or more during the two-year period had higher cardiovascular disease mortality rates than those whose distance scores improved by 20 points or more (hazard ratio, 4.56 [95% CI, 1.30 to 16.01]).

The authors acknowledged that their results may not be generalizable to all patients with PAD and that unidentified characteristics may have affected their findings, among other limitations. However, they concluded that patients whose WIQ scores decrease over time are at greater risk for all-cause mortality. “Further study is needed to determine whether implementing measurement of two-year change in WIQ scores in clinical practice is associated with improved outcomes,” they wrote.