Background: Peak oxygen uptake (VO2peak) established during progressive cardiopulmonary exercise testing (CPET) is the “gold-standard” for cardiorespiratory fitness. However, CPET measurements may be limited in patients with aneurysmal subarachnoid hemorrhage (a-SAH) by disease-related complaints, such as cardiovascular health-risks or anxiety. Furthermore, CPET with gas-exchange analyses require specialized knowledge and infrastructure with limited availability in most rehabilitation facilities. Objectives: To determine whether an easy-to-administer six-minute walk test (6MWT) is a valid clinical alternative to progressive CPET in order to predict VO2peak in individuals with a-SAH. Methods: Twenty-seven patients performed the 6MWT and CPET with gas-exchange analyses on a cycle ergometer. Univariate and multivariate regression models were made to investigate the predictability of VO2peak from the six-minute walk distance (6MWD). Results: Univariate regression showed that the 6MWD was strongly related to VO2peak (r = 0.75, p < 0.001), with an explained variance of 56% and a prediction error of 4.12 ml/kg/min, representing 18% of mean VO2peak. Adding age and sex to an extended multivariate regression model improved this relationship (r = 0.82, p < 0.001), with an explained variance of 67% and a prediction error of 3.67 ml/kg/min corresponding to 16% of mean VO2peak. Conclusions: The 6MWT is an easy-to-administer submaximal exercise test that can be selected to estimate cardiorespiratory fitness at an aggregated level, in groups of patients with a-SAH, which may help to evaluate interventions in a clinical or research setting. However, the relatively large prediction error does not allow for an accurate prediction in individual patients.

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Keywords 6MWT, Cardiopulmonary exercise test, Cardiorespiratory fitness, CPET, Peak oxygen consumption, Rehabilitation, Six-min walk test, Standard error of the estimate, Subarachnoid hemorrhage, VO2peak
Persistent URL dx.doi.org/10.1080/10749357.2016.1260263, hdl.handle.net/1765/99292
Journal Topics in Stroke Rehabilitation
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Citation
Harmsen, W.J, Ribbers, G.M, Slaman, J, Heijenbrok-Kal, M.H, Khajeh, L, van Kooten, F, … van den Berg-Emons, H.J.G. (2017). The six-minute walk test predicts cardiorespiratory fitness in individuals with aneurysmal subarachnoid hemorrhage. Topics in Stroke Rehabilitation, 24(4), 250–255. doi:10.1080/10749357.2016.1260263