Performance on the one-minute sit-to-stand test predicts long-term adverse outcomes in pulmonary hypertension

Introduction The one-minute sit-to-stand test (1-min STST) is a simple and reproducible measure of functional capacity. Recently, cut-off values for the 1-min STST equivalent to guideline-recommended six-minute walk test (6MWT) thresholds have been proposed for risk stratification in patients with pulmonary hypertension (PH). However, the prognostic value of the 1-min STST for long-term outcomes remains unclear. Aim To assess the association between the 1-min STST performance and long-term adverse outcomes in patients with PH. Methods Consecutive patients with PH were prospectively enrolled and underwent both the 1-min STST and 6MWT. The primary endpoint was a composite of heart failure hospitalization, heart-lung transplantation or all-cause mortality. Associations between 1-min STST performance and long-term adverse outcomes were assessed using Cox regression. Patients were stratified into three groups based on previously published 1-min STST cut-offs (≤ 14, 15–19, ≥ 20 repetitions), aligned with 6MWT thresholds. Kaplan-Meier curves were used to compare event rates between groups. Results A total of 117 patients (mean age 66 ± 14 years, 56% female) were included. Over a median follow-up of 2.7 years [IQR 1.0–3.9], 60 (51%) patients experienced an adverse event. Lower 1-min STST performance was significantly associated with a higher risk of long-term adverse outcomes (HR per repetition: 0.94, 95% CI: 0.90–0.98, p < 0.001). This association remained significant after adjusting for age, sex, BMI and NT-proBNP levels (adjusted HR = 0.95; 95% CI: 0.91–0.99; p = 0.016) and major comorbidities (adjusted HR = 0.94; 95% CI: 0.90–0.98; p = 0.003). Kaplan-Meier analysis showed significantly worse long-term outcomes in patients performing ≤ 14 repetitions (log-rank p = 0.001). Conclusion The 1-min STST is a predictor for long-term adverse events in PH patients. Performing ≤ 14 repetitions on the 1-min STST indicates a significantly higher risk of long-term adverse outcomes. Therefore, the 1-min STST may be used for risk stratification in clinical practice.