The utility and safety of one-minute sit-to-stand test in pulmonary hypertension: A prospective study

Background: Functional exercise capacity in pulmonary hypertension (PH) is routinely assessed using the 6-min walking test (6MWT). However, alternative tests are useful because of resource requirements. This study aimed to evaluate whether the 1-min sit-to-stand test (1STST) is useful and safe in PH and whether it can replace the 6MWT. Methods: Adult patients with PH were recruited from our hospital between September 2023 and April 2024. The correlations between the number of 1STST repetitions (1STSTr) and 6-min walk distance (6MWD), pulmonary hemodynamic parameters, and quadriceps muscle strength; adverse events; and vital sign fluctuations during the tests were evaluated, and a questionnaire with an 11-point Likert scale (-5, 6MWT favor; 5, 1STST favor) was administered. Results: Twenty-one patients with PH were enrolled in this study. The 1STSTr and 6MWD were 23.8 f 7.8/min and 425.8 f 116.8 m, respectively, with a strong correlation (r = 0.771). 1STSTr was significantly correlated with brain natriuretic peptide, but not with other pulmonary hemodynamic markers, respiratory function, or quadriceps muscle strength. No serious adverse events or motor impairments occurred with the 1STST. The minimum SpO2 during the tests was significantly lower with the 6MWT (92.6 f 3.1 vs. 88.0 f 11.0). The questionnaire showed a predominant preference for the 1STST (3.2 f 2.6). Conclusions: To our knowledge, this is the first study in Japan to adapt the 1STST to PH patients. The 1STST is a reliable alternative to the 6MWT for measuring exercise capacity in PH patients. Trial registration: This study was registered with the UMIN-CTR (number UMIN000052010).