The prognostic value of impaired walking distance on long-term outcome in patients with known or suspected peripheral arterial disease.

Abstract

To assess the predictive value of walking distance after an exercise test on long-term outcome in patients with normal and impaired ankle-brachial index (ABI). A total of 2191 patients with known or suspected peripheral arterial disease (PAD), who were referred for a single-stage treadmill exercise test to diagnose or evaluate their PAD, were enrolled in an observational study between 1993 and 2006. They were divided into two groups: normal ABI (>or=0.90) and impaired ABI (<0.90). Walking distance was divided into quartiles (no (reference), mild, moderate or severe impairment). In patients with normal ABI, severe walking distance was, after adjustment, associated with higher mortality risk (hazard ratio (HR): 2.60 (range: 1.16-5.78)). In patients with impaired ABI, all walking distance impairment quartiles were associated with higher mortality (mild HR: 1.26 (range: 0.95-1.67), moderate HR: 1.52 (range: 1.13-2.05) and severe HR: 1.69 (range: 1.26-2.27)). Furthermore, comparable associations were observed between all walking distance quartiles, cardiac death or major adverse cerebrovascular and cardiac events. Our study illustrated that walking impairment is a strong prognostic indicator of long-term outcome in patients with impaired and normal ABI, which should be a warning sign to physicians to monitor these patients carefully and to provide them optimal treatment.