One-minute sit-to-stand test cut-offs for risk stratification based on six-minute walk test thresholds in pulmonary hypertension
Christina Kronberger, Roya Anahita Mousavi, Nikita Ermolaev, Robin Willixhofer, Nima Rassoulpour, Musa Kaya, Michael Poledniczek, Mahshid Eslami, Christoph Krall, Brigitte Litschauer, Mariusz Grzeda, Ian McKenna, Roza Badr Eslam
Abstract
AIMS: We aimed to establish 1-min sit-to-stand test (1-min STST) cut-off values that align with the guideline-recommended 6-min walk test (6MWT) thresholds (165 and 440 m) for 1-year mortality risk stratification in pulmonary hypertension (PH) patients. Furthermore, we aimed to compare clinical characteristics and long-term mortality among patients stratified by these proposed 1-min STST cut-offs. METHODS AND RESULTS: All patients performed the 1-min STST and 6MWT. Receiver operating characteristics analysis was performed to determine 1-min STST cut-offs corresponding to the 6MWT thresholds. Patients were stratified into three groups based on these cut-offs. Among 114 PH patients (mean age 66 ± 14 years, 57% female), the mean number of 1-min STST repetitions was 17 ± 6 and the mean 6MWT distance was 354 ± 133 m. The aligning 1-min STST cut-off for the <165 m 6MWT threshold was 14 repetitions (sensitivity 69%; specificity 100%) with an area under the curve (AUC) of 0.90 [95% confidence interval (CI) 0.84-0.97]. For the >440 m threshold, 20 repetitions (sensitivity 81%; specificity 84%) aligned with an AUC of 0.85 (95% CI 0.75-0.94). Patients performing ≤14 repetitions had worse N-terminal prohormone of brain natriuretic peptide levels (P < 0.001), World Health Organization functional class (P < 0.001), mean pulmonary artery pressure (P = 0.050), and health-related quality of life (P < 0.001) and a higher rate of mortality than those performing ≥20 repetitions (P = 0.020). CONCLUSION: The 1-min STST cut-offs aligning with the 6MWT thresholds of 165 and 440 m are 14 and 20 repetitions, respectively. Patients performing ≤14 repetitions demonstrated worse clinical parameters and higher mortality rates, making the 1-min STST a potential risk stratification tool in PH patients. LAY SUMMARY: This study identified cut-off values for the 1-min sit-to-stand test (1-min STST) that align with the 6-min walk test (6MWT) thresholds used to predict 1-year mortality risk in pulmonary hypertension (PH) patients, proposing the 1-min STST as a practical alternative for risk stratification.