Use of a Nonexercise Estimate for Prestroke Peak Vo 2 During the Acute Stroke Hospital Stay

Abstract

For individuals with acute stroke, it is difficult to conduct an exercise test to assess peak oxygen consumption (peak Vo2). Therefore, the purpose of this study was to use a clinically feasible tool for assessing prestroke peak Vo2 using a nonexercise estimation equation to test whether estimated prestroke peak Vo2 was related to the functional outcome measures at discharge from the hospital in individuals after an acute stroke. We hypothesized that the estimated prestroke peak Vo2 would be significantly related to discharge Physical Performance Test (PPT), 6-minute walk test (6MWT), and lower extremity Fugl-Meyer (LEFM) assessment. Estimated prestroke peak Vo2 was calculated using a previously validated prediction equation using the following variables: body mass index, age, sex, resting heart rate, and a self-reported measure of physical activity. Outcome measures were assessed 4 days after enrollment or immediately before discharge (whichever occurred first). Thirty-four participants (mean age = 56.0, SD = 12.6 years; 20 men) with acute stroke were enrolled within 48 hours of admission. For all individuals, mean estimated prestroke peak Vo2 was 27.3 (SD = 7.4) mL·kg-1·min-1 and had a weak, nonsignificant relationship with the PPT (r = 0.19; P = .28), 6MWT (r = 0.10; P = .56), and LEFM (r = 0.32; P = .06). However, when considering sex, women, but not men, had a significant relationship with LEFM (r = 0.73; P = .005) and moderate but nonsignificant relationship with PPT (r = 0.53; P = .06) and 6MWT (r = 0.47; P = .10). Within 48 hours of stroke admission, we were able to administer a nonexercise equation to estimate prestroke peak Vo2. For the entire sample, functional measures conducted at discharge were not related to estimated prestroke peak Vo2. However, when considering sex, the relationship between prestroke Vo2 and the functional measures was strengthened.