Echocardiography-derived septal curvature correlated with invasive hemodynamics in pediatric pulmonary hypertension.

BACKGROUND Right ventricular function and afterload are associated with clinical outcomes in pulmonary hypertension (PH). MRI-derived interventricular septal curvature has been associated with invasive hemodynamics in PH patients. This study sought to determine the relationship of echocardiography derived septal curvature with invasive hemodynamics in pediatric PH patients. METHODS A single center chart review identified 56 pediatric patients with PH and 50 control patients with adequate echocardiography to assess septal curvature within one month of initial cardiac catheterization. Echocardiographic indices of septal flattening including end-systolic eccentricity index (EIs), maximum EI (EImax), minimum septal curvature (SCmin), and average SC (SCavg) were determined. RESULTS PH patients had a median right ventricular systolic pressure of 64 mmHg (interquartile range (IQR) 48-81), mean pulmonary artery pressure of 44 mmHg (IQR 32-57), pulmonary vascular resistance of 7.9 iWU (IQR 4.8-12.9), and pulmonary capillary wedge pressure of 10 mmHg (IQR 8-12). Patients with PH had higher EIs and EImax and lower SCmin and SCavg compared to control patients. SCavg demonstrated the strongest association with right ventricular systolic pressure (R2 0.73, p < 0.0001), mean pulmonary artery pressure (R2 0.63, p < 0.0001), and pulmonary vascular resistance (R2 0.47, p < 0.0001). All septal curvature indices were associated with the composite adverse outcome, including Potts shunt, lung transplantation, and death. SCmin (HR 0.29; 95%CI 0.07-0.97) and SCavg (HR 0.15; 95%CI 0.03-0.72) were the only septal flattening indices associated with death. CONCLUSIONS Echocardiography derived septal curvature is a non-invasive marker of ventricular afterload and adverse outcomes.