Association Between the 6-Min Walk Test and Cardiopulmonary Exercise Testing Parameters in Subacute Cerebral...

Background: Peak oxygen uptake (VO₂peak), as measured by cardiopulmonary exercise testing (CPET), is considered the gold standard for assessing cardiorespiratory fitness (CRF). However, CPET is not always feasible in rehabilitation settings. The 6-min walk test (6MWT) is simple and widely used, yet its relationship with CPET-derived measures in patients with subacute cerebral infarction remains unclear. Methods: A total of 122 patients with subacute cerebral infarction underwent both the 6MWT and CPET. VO₂peak, CPET-derived peak heart rate (CPET HRpeak), 6-min walk distance (6MWD), 6MWTpeak heart rate (6MWT HRpeak), and the ratio of 6MWT HRpeak to age-predicted maximal heart rate were assessed. Results: In multivariate linear regression analysis, 6MWD was independently associated with VO₂peak (unstandardized coefficient B = 0.010, p < 0.001). Partial correlation analyses adjusting for age, sex, and β-blocker use showed that CPET HRpeak was positively correlated with 6MWD (ρ = 0.361, p < 0.001) and 6MWT HRpeak (ρ = 0.217, p = 0.018). The ratio of 6MWT HRpeak to age-predicted maximal heart rate did not mediate the association between 6MWD and VO₂peak. Conclusions: In patients with subacute cerebral infarction, 6MWD was independently associated with VO₂peak, while both 6MWD and 6MWT HRpeak were positively correlated with CPET HRpeak. These findings suggest that the 6MWT may help assess CRF when CPET is not available.