Advanced risk stratification of intermediate risk group in pulmonary arterial hypertension.

In 301 treatment-naïve patients with pulmonary arterial hypertension stratified by the European Society of Cardiology/European Respiratory Society risk score, further stratification of intermediate-risk patients based on six-minute walk distance and the tricuspid annular plane systolic excursion/systolic pulmonary artery pressure ratio identified a subset with mortality rates comparable to low-risk patients.