Predicting long-term prognosis in stable peripheral artery disease with baseline functional capacity estimated by the Duke Activity Status Index.

BACKGROUND: The ability of a simple self-assessment tool for estimated functional capacity to predict long-term prognosis in patients with established peripheral artery disease (PAD) is unknown. We investigate whether subjective measurement of functional capacity estimated by using the Duke Activity Status Index (DASI) questionnaire predicts long-term prognosis in patients with established PAD.
METHODS: We administered the DASI questionnaire to 771 stable patients with established PAD who underwent elective diagnostic coronary angiography with 5-year follow-up all-cause mortality.
RESULTS: Two hundred ten patients (27%) died over a 5-year follow-up. The lowest DASI score was associated with a 3.2-fold increased risk of 5-year all-cause mortality (unadjusted hazard ratio 3.23, 95% CI 2.19-4.75, P<.001). After adjustments for traditional risk factors, estimated glomerular filtration rate, high-sensitivity C-reactive protein, and lowest DASI score remained predictive of 5-year all-cause mortality (adjusted hazard ratio 2.09, 95% CI 1.36-3.23, P<.001). Interestingly, the lowest DASI score remained to predict 5-year all-cause mortality regardless of each PAD diagnosis subtype (including lower extremity, non-lower extremity, or carotid artery PAD), although the mortality risk was attenuated when incorporating heart disease severity in the non-lower extremity group.
CONCLUSIONS: A simple self-assessment tool of functional capacity provides an independent and incremental prognosis value for long-term adverse clinical events in stable patients with established PAD beyond each PAD diagnostic subtype.