In pulmonary arterial hypertension (PAH), survival predictions can be important for optimization of therapeutic strategies. The present study aimed to validate a quantitative algorithm for predicting survival derived from the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL Registry) and develop a simplified calculator for everyday clinical use.
Prospectively collected data from patients with newly diagnosed (< 3 months) World Health Organization group I pulmonary hypertension enrolled in the REVEAL Registry were used to validate a predictive algorithm for 1-year survival. Model calibration was evaluated by comparing algorithm-predicted survival with observed Kaplan-Meier estimates for the overall validation cohort and for five risk groups. Similarly, the risk discriminators for the simplified calculator were compared with those of the quantitative algorithm.
The validation cohort comprised 504 individuals with mean ± SD 6-min walk distance 308 ± 128 m, and 61.5% were functional class III. The proportion of patients surviving 1 year fell within the range predicted by the model (95.1%, 91.5%, 84.6%, 76.3%, and 58.2%, respectively) among patients in the low (predicted survival ≥ 95%), average (90% to < 95%), moderate (85% to < 90%), high (70% to < 85%), and very high (< 70%) risk strata. Predicted and observed 1-year survival were similar across risk stratum, and the c-index indicated good discrimination for both the full equation (0.726) and the simplified risk calculator (0.724).
The REVEAL Registry predictive algorithm and simplified risk score calculator are well calibrated and demonstrate good discriminatory ability in patients with newly or previously diagnosed PAH.
ClinicalTrials.gov; No.: NCT00370214; URL: www.clinicaltrials.gov