Correlation of Transthoracic Echocardiographic Estimates of Right Ventricular Pressure with Right Ventricular Pressure Measurements on Cardiac Catheterization in Children with Pulmonary Hypertension.

Objectives: Evaluate the correlation of non-invasive echocardiographic estimates of right ventricular systolic pressure with measurements on cardiac catheterization in children with pulmonary hypertension.

Design: Retrospective chart review.

Setting: Quaternary academic children's hospital.

Participants: Patients younger than 18 years with a diagnosis of pulmonary hypertension and confirmatory cardiac catheterization from 2015 to 2018.

Measurements and main results: We analyzed the correlation between measures of right ventricular systolic pressure using nonparametric Spearman rho (ρ) with statistical significance set at p < 0.05.

Results: Children (N = 111) with biventricular circulation, strictly defined pulmonary hypertension, and adequate tricuspid regurgitation on echocardiogram to estimate right ventricular systolic pressure using the modified Bernoulli equation. Median age and weight were 4.3 years and 14.4 kg. Median right ventricular systolic pressure estimated by tricuspid regurgitant velocity on echocardiography was 55 mmHg (IQR 45-75 mmHg) plus right atrial pressure. On cardiac catheterization, median right ventricular systolic pressure was 57 mmHg (IQR 46-75 mmHg). Echocardiographic estimates of right ventricular systolic pressure were moderately well correlated with right ventricular systolic pressure directly measured on catheterization (ρ = 0.44, 95% CI 0.27-0.6, p < 0.001) with a median difference of 4 mmHg (IQR -10 to 17). Subgroup analysis revealed that echocardiography and catheterization measurements correlated well in children with suprasystemic right ventricular pressure on cardiac catheterization (ρ = 0.75, 95% CI 0.51-0.99, p < 0.001) although catheterization measurements were a median of 26 mmHg (IQR 12-31) higher than echocardiographic estimates in this subgroup.

Conclusions: In children with pulmonary hypertension, echocardiographic estimates of right ventricular pressure correlated moderately well with gold standard measurements by cardiac catheterization with stronger correlation in children with suprasystemic right ventricular pressures. This is reassuring for clinicians who must rely on echocardiography for risk stratification before anesthetizing children with pulmonary hypertension.