Predicting Survival in Patients With Pulmonary Arterial Hypertension

BACKGROUND: Pulmonary arterial hypertension is a progressive, fatal disease. Published treatment guidelines recommend treatment escalation on the basis of regular patient assessment with the goal of achieving or maintaining low-risk status. Various strategies are available to determine risk status. This analysis describes an update of the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) risk calculator (REVEAL 2.0) and compares it with recently published European Society of Cardiology/Respiratory Society guideline-derived risk assessment strategies. METHODS: A subpopulation from the US-based registry REVEAL that survived ≥ 1 year postenrollment (baseline for this cohort) was analyzed. For REVEAL 2.0, point values and cutpoints were reassessed, and new variables were evaluated. The Kaplan-Meier method was used to estimate survival at 12 months postbaseline; discrimination was quantified using the c-statistic. Mortality estimates and discrimination were compared between REVEAL 2.0 and Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) and French Pulmonary Hypertension Registry (FPHR) risk assessment strategies. For this comparison, a three-category REVEAL 2.0 score was computed in which patients were classified as low-, intermediate-, or high-risk. RESULTS: REVEAL 2.0 demonstrated similar discrimination as the original calculator in this subpopulation (c-statistic = 0.76 vs 0.74), provided excellent separation of risk among the risk categories, and predicted clinical worsening as well as mortality in patients who were followed ≥ 1 year. The REVEAL 2.0 three-category score had greater discrimination (c-statistic = 0.73) than COMPERA (c-statistic = 0.62) or FPHR (c-statistic = 0.64). Compared with REVEAL 2.0, COMPERA and FPHR both underestimated and overestimated risk. CONCLUSIONS: REVEAL 2.0 demonstrates greater risk discrimination than the COMPERA and FPHR risk assessment strategies in patients enrolled in REVEAL. After external validation, the REVEAL 2.0 calculator can assist clinicians and patients in making informed treatment decisions on the basis of individual risk profiles. TRIAL REGISTRY: ClinicalTrials.gov; No. NCT00370214; URL: www.clinicaltrials.gov.