The prognostic utility of the 1-min STST for long-term adverse outcomes in patients with pulmonary hypertension

Background Pulmonary hypertension (PH) reduces functional capacity and is associated with adverse outcomes. Hence, the assessment of functional capacity for risk stratification in PH patients plays an essential role as outlined by current guidelines. Recently, the one-minute sit-to-stand test (1-min STST) has been proposed as a simple, cost-effective method to assess functional capacity. However, its prognostic value in PH patients has not been evaluated yet. Purpose The aim of this study was to assess whether the 1-min STST performance can be used as a predictor for adverse outcome in PH patients. Methods Functional capacity was evaluated in a prospective PH cohort using the 1-min STST. Cox regression was performed with a composite endpoint for adverse outcome of hospitalization, transplantation, and/or death using backward selection. Additionally, Kaplan-Meier survival curves were calculated based on 1-min STST performance tertiles. Results In total 117 PH patients (mean age 66±14 years; 56% female, mean 1-min STST repetitions 17±6) were prospectively included in this study and followed for a median of 2.2 years (IQR 0.9–3.7). During this period, 59 patients (50%) experienced an adverse outcome using the composed endpoint. The 1-min STST performance tertiles were <14, 14-19 and >20 repetitions. In univariate analysis each additional 1-min STST repetition was associated with a 6% reduction in event risk (HR=0.94 per repetition, 95% CI 0.90–0.98, p=0.003). After adjusting for age, sex, BMI and NT-proBNP, the 1-min STST performance remained a significant predictor for adverse outcomes (HR=0.94, 95% CI 0.90–0.98, p=0.002), as shown in Table 1. Furthermore, Kaplan-Meier analysis showed that patients of the lowest tertile had a significantly higher risk of long-term adverse outcomes (log-rank p = 0.001, Figure 1). Conclusion Our study showed that the 1-min STST is an independent predictor of long-term adverse outcomes in patients with PH. Patients performing <14 repetitions are at significantly higher risk for adverse outcomes, highlighting the tests potential as a risk-stratification tool in clinical practice.