Abstract 15746: Statistical Shape Modeling of the Right Ventricle Differentiates Stages of RV Remodeling in Children With Pulmonary Hypertension: An Initial Analysis on 26 Patients
Introduction: Current assessments of right ventricle (RV) dysfunction in pediatric pulmonary hypertension (PH) are limited by the lack of correlative data between RV shape changes and hemodynamic markers. Given the complexity of directly analyzing complete 4D RV image information, statistical shape approaches hold particular promise for defining principal shape features in large patient datasets. The first aim of this study was to identify the principal deformation features or modes of the RV in a small cohort of pediatric patients with varying degrees of PH. A subsequent aim was to evaluate correlations between principal RV deformation modes and hemodynamic markers.
Methods and Results: We selected 26 patients (aged 4 months - 19 years) who had undergone cardiovascular magnetic resonance imaging and right heart catheterization. Indexed pulmonary vascular stiffness (PVSi), indexed pulmonary vascular resistance (PVRi), cardiac index (CI) and ventricular-vascular coupling ratio (VVCR) were measured. Statistical shape analysis was used with principal component analysis (PCA) and a linear regression model to correlate principal RV deformation modes with PVSi and PVRi. The statistical shape analysis revealed four dominant deformation modes. Modes 1 and 2 captured RV basal dilatation and altered RV septal geometry respectively whilst modes 3 and 4 encoded RV apical rounding and wall thickening. Mode 1 and Mode 2 were associated with increasing PVRi: R = 0.42, R=0.51 respectively whilst Mode 3 and Mode 4 correlated to increasing PVSi: R=0.39, R=0.5. Mode 2 and mode 4 negatively correlated with increasing VVCR (R=-0.59, R=-0.47 respectively) whilst decreasing CI (R=-0.39) showed a statistical correlation only to mode 4.
Conclusions: Decreasing RV compliance (PVSi) is more associated with wall thickening (mode 4) than septal motion (mode 2), whilst increasing RV resistance (PVRi) appears more closely related to septal motion (mode 2) than wall thickening (mode 4). Modes 1, 3 and modes 2, 4 could separate different levels of RV remodeling (mild-to-moderate RV remodeling for modes 1, 3; moderate-to-severe RV remodeling for modes 2, 4). This approach may allow differentiation amongst pediatric PH patients undergoing adaptive versus maladaptive RV modeling.
Author Disclosures: F. Agyei-Ntim: None. K. Hunter: None. U. Truong: None. D.D. Ivy: None. R. Shandas: None.
- © 2014 by American Heart Association, Inc.