Exercise capacity is the strongest predictor of mortality in patients with peripheral arterial disease

Abstract

Objective The objective of this study was to assess the predictive value of clinical and exercise test variables in patients with peripheral arterial disease (PAD). Methods 725 PAD patients referred for exercise testing at the Palo Alto Veterans Hospital between 1997 and 2011 were subjected to a customized symptom-limited ramp treadmill protocol. Detailed clinical and exercise test data were collected at baseline and patients were followed for a mean of 11.3±6.3 years. Results During follow up, there were 364 deaths. Baseline exercise capacity was 7.0±2.6 Metabolic equivalents (METs) among survivors and 5.5±2.4 METs in those who died (P<.001). Although several physiologic parameters differed between survivors and non-survivors, age-adjusted Cox regression revealed that exercise capacity was the strongest independent predictor of mortality. Each additional MET achieved was associated with age-adjusted 18% and 20% reductions in all-cause and cardiovascular mortality, respectively (P<.001 for both). This variable surpassed all classical risk factors (including smoking and history of congestive heart failure) as well as all measured exercise test responses (including symptoms and ECG abnormalities). Conclusions Amongst PAD patients, reduced exercise capacity is the most powerful harbinger of long term mortality. This factor has predictive power beyond traditional risk factors and confirms the critical importance of fitness in this cohort.

Toe Pressure and Toe Brachial Index are Predictive of Cardiovascular Mortality, Overall Mortality, and Amputation Free Survival in Patients with Peripheral Artery Disease

“…30,31 Non-invasive limb pressure measurements were not assessed by these analyses. The prognostic value of combined exercise capacity and distal non-invasive pressure measurements on mortality is a tempting target for further studies.…”

Physical Activity and Vascular Events and Mortality in Patients with Vascular Disease

“…However, before an elective operation for AAA, a lower exercise capacity, which is presumably associated with less physical activity, was associated with higher mortality (12). These same associations have been observed in patients with CAD and PAD (18,21).…”

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

“…Consequently, the more rapid occurrence of exercise-limiting, maximal claudication pain not only resulted in a shorter PWT, but it indicates that the lower MMSE group is not capable of sustaining ambulation at an intensity of approximately 4 metabolic equivalents (MET’s). The shorter PWT of the lower MMSE group is clinically relevant given that exercise capacity of patients with PAD, as measured by MET’s calculated from the duration of walking on a graded treadmill test, is the strongest predictor of mortality 35 . Furthermore, we have previously found that sedentary symptomatic patients with PAD who do not perform ambulatory activity above light intensities have a higher rate of mortality 36 .…”