Simpson CE, Damico RL, Hassoun PM, et al. - Researchers explored the links between three biomarkers—soluble suppression of tumorigenicity 2 (ST2), galectin 3 (Gal3), and the N-terminal brain natriuretic peptide prohormone (NT-proBNP)—and disease severity and survival among patients with Group I pulmonary arterial hypertension (PAH) constituting a large cohort. They hypothesized that an improved prognostic value of survival models would result from the additive use of biomarkers in combination. This study included 2,017 adults with Group I PAH, from whom, biomarker measurements and clinical data were collected. Findings revealed ST2 and NT-proBNP as strong, noninvasive prognostic biomarkers in PAH. Though Gal3 showed the prognostic value in left heart failure, it was not predictive in PAH. A significantly improved predictive ability of the model was yielded by the addition of ST2 to survival models.