Value of the soluble urokinase-type plasminogen activator receptor as a predictor of prognosis in patients attended in hospital emergency departments

Objectives. To determine the value of the soluble urokinase-type plasminogen activator receptor (suPAR) for predicting outcomes in emergency department (ED) patients. Secondary objectives were 1) to measure the predictive value of the usual decision points, 2) to identify patients at low risk for mortality who could be safely discharged from the ED, and 3) to measure the correlation between suPAR and other biomarkers. Methods. Prospective observational cohort study of patients attended in the EDs of participating hospitals. We recorded sociodemographic variables, comorbidity, variables related to the acute episode, prognostic markers commonly used in EDs, and suPAR concentration. Outcome variables were the need for hospital admission during the index episode, ED revisits within 90 days, and 90-day mortality. Results. A total of 990 patients with a median (interquartile range) age of 68 (53-81 years) were studied; 50.8% were men. The median suPAR concentration was 3.8 (2.8-6.0) ng/mL, and 112 patients (11.31%) required admission. At 90 days there were 276 revisits (27.9% of the cohort), and 47 patients (4.74%) had died. Mortality was lower (1%) in patients with suPAR concentrations less than 4 ng/mL (52.5%), and fewer of these patients revisited (24.4%) or required hospitalization (20.6%) than patients with suPAR concentrations higher than 6 ng/mL (mortality, 13.5%; revisits, 39.6%; admissions, 56.3%). A suPAR concentration over 6 ng/mL was associated with 90-day mortality and revisits (adjusted hazard ratios and 95% CIs of 4.61 [1.68-12.67] and 1.59 [1.13-2.10]), respectively. The high suPAR concentration was also associated with hospital admission (odds ratio, 1.62 [0.99-2.62]). Conclusions. A suPAR concentration of less than 4 ng/mL identifies patients at low risk of 90-day mortality and revisits or need for hospitalization, whereas a suPAR concentration higher than 6 ng/mL is associated with higher risk for these outcomes.