Abstract 17209: Impaired Ventricular-Vascular Coupling in Young Adults Born Preterm

Background: Preterm birth affects 10% of live births in the United States, often requiring mechanical ventilation and oxygen supplementation. Although a known risk factor for neonatal and childhood pulmonary vascular disease, little is known regarding the long-term impact on the right ventricle (RV). Here, we utilize novel techniques to investigate RV afterload, contractility, and ventricular-vascular coupling (VVC) in young adults born preterm. Methods: Adults born premature (n=7; 4; current age 26.7±0.4 years; gestational age 28.6±1.1 weeks) born with very low birth weight (≤1500g) were recruited from the Newborn Lung Project. Control subjects (n=7; 2) from the same birth years were recruited from the general population. All subjects had no known cardiopulmonary disease. Right heart catheterization (RHC) and magnetic resonance imaging (MRI) were performed to assess right ventricular hemodynamics. Asynchronously acquired pressure and volume data (from RHC and MRI, respectively) were used to compute effective arterial elastance (Ea), end-systolic elastance (Ees), and VVC as: [ESP/SV], [(P max -ESP)/SV], and [Ees/Ea], respectively, where ESP is the end-systolic pressure, SV is the stroke volume, and P max is the maximum isovolumetric pressure estimated from a novel single-beat approach. Results were analyzed via two-sample t-test; p<0.05 was considered significant. Results: Preterm subjects had significantly increased Ea, a measure of RV afterload (Figure 1A). No difference Ees, a measure of RV contractility, was evident (Figure 1B), resulting in significantly impaired VVC in preterm subjects (Figure 1C). Conclusion: Otherwise healthy young adults born preterm have high resistance-low compliance pulmonary vascular beds with no RV adaptation, resulting in impaired right ventricular-pulmonary vascular coupling. These findings add to the growing literature that preterm birth has profound lifelong consequences that warrant further study.