Actuarial survival in PAH has been predicted mainly by functional class and echocardiographic evidence of right heart failure. Observing 484 patients with WHO group I PAH for 5 years after diagnosis, Kane et al showed that using their own multivariate model (incorporating clinical data including renal function, BNP, DLCO, BP & HR, etc.) generated better survival predictions than functional class and/or RV function. It also performed slightly better than the REVEAL criteria, a mortality prediction model they validated (and which held up well) in this cohort. CHEST 2011;139:1285-1293.