Abstract 19362: Bridging the Gap Between Functional and Biological Phenotypes in Pediatric Pulmonary Hypertension
Introduction: Pediatric Pulmonary Hypertension (PH) is a degenerative disease that ultimately leads to Right Ventricular (RV) dysfunction. RV functional and biological (e.g. N-Terminal proB-type Natriuretic Peptide, NT-proBNP) phenotypes can provide insight into performance and ventricular distress, respectively. Nevertheless, they are normally considered independently, and should be associated to paint a more comprehensive picture of the cardio-pulmonary system. The most utilized prognostic metric of RV performance is Cardiac Output (CO), as it gives a direct measure of the ventricle’s “pumping” ability. CO is only indicative of the immediate functional state and lacks any predictive or stratification value. RV-Pulmonary Artery (PA) axis decoupling (VVC = RV end-systolic elastance/arterial elastance) represents a decrease in the RV functional reserve, and therefore an inability to accommodate an increase in afterload. Therefore, it is more comprehensive of the entire cardio-pulmonary system than CO.
Hypothesis: RV-PA coupling is better associated with NT-proBNP than Cardiac Index (CI = CO/Body Surface Area).
Methods: 26 pediatric PH patients underwent Right Heart Catheterization (RHC), an echocardiograph, and blood composition diagnostics. A 0-D model (Fig. 1a) of the comprehensive cardio-pulmonary system, incorporating extensive patient specificity, was developed to estimate RV pressure-volume curves under baseline and challenged conditions, and approximate the VVC ratio.
Results: CI was not found to be statistically associated with NT-proBNP (Fig. 1b). Nevertheless, VVC was found to be non-linearly related to NT-proBNP expression (Fig. 1c), thus rejecting the null hypothesis.
Conclusion: NT-proBNP is a biomarker of RV-PA functional decoupling. Considering the inter-compartmental interaction of the entire cardio-pulmonary system offers a better picture of PH disease progression then assessing RV “pump” performance.
Author Disclosures: V.O. Kheyfets: None. J. Dunning: None. I. Dunbar: None. K. Hunter: None. U. Troung: None. R. Shandas: None.
- © 2014 by American Heart Association, Inc.