Derivation of a Risk Score (REVEAL-ECHO) Based on Echocardiographic Parameters of Patients With Pulmonary Arterial Hypertension

Background: Multiparametric risk assessment tools determine mortality risk in patients with pulmonary arterial hypertension (PAH) by combining invasive and noninvasive variables so management strategies can be tailored to individuals.

Research question: Can a risk score based on common echocardiographic parameters risk-stratify patients with PAH?

Study design and methods: A Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) echocardiographic risk score (REVEAL-ECHO) was derived using retrospective echocardiographic data from 2,400 adult patients with PAH enrolled in the REVEAL registry database. A stepwise Cox regression model identified echocardiographic parameters significantly predictive of survival. Values were assigned to each selected parameter based on survival at 12 months' follow-up (Kaplan-Meier estimates). The REVEAL-ECHO risk score was the sum of individual values. Patients were categorized as having low, intermediate, or high risk based on Kaplan-Meier-predicted 12-month survival.

Results: The risk score included four echocardiographic parameters-right ventricular (RV) chamber enlargement, reduced RV systolic function, tricuspid regurgitation severity, and pericardial effusion-and accounted for PAH etiology. Higher REVEAL-ECHO risk scores signaled lower probability of 12-month survival. Statistically significant separation of mortality risk was observed among the risk strata: intermediate vs low (hazard ratio [HR], 1.43; 95% CI, 1.17-1.75; P = .0004) and high vs low (HR, 2.60; 95% CI, 2.19-3.10; P < .0001). Augmentation of the REVEAL Lite 2 risk calculator with REVEAL-ECHO risk scores achieved separation of REVEAL Lite 2 into four risk groups and identified a subgroup of patients with a low REVEAL Lite 2 risk score who were at higher risk (intermediate-low risk) and a subgroup of patients with an intermediate REVEAL Lite 2 risk score who also were at higher risk (intermediate-high risk).

Interpretation: A REVEAL-ECHO risk score, derived using four echocardiographic parameters, may discriminate risk further when used as an adjunct to current risk assessment scores. Further validation is required.