The REVEAL registry risk score calculator in patients newly diagnosed with pulmonary arterial hypertension

Background: 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. Methods: 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. Results: 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). Conclusions: 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. Trial registry: ClinicalTrials.gov; No.: NCT00370214; URL: www.clinicaltrials.gov.