One-minute sit-to-stand test cut-offs for risk stratification based on six-minute walk test thresholds in pulmonary...

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.

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).

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.

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.