The state of energy in the right ventricle of patients with pulmonary arterial hypertension

点击翻译按钮获取中文摘要

PROJECT SUMMARY/ABSTRACT Pulmonary arterial hypertension (PAH) is a progressive cardiopulmonary disease with a high mortality rate. In most cases, PAH-induced chronic pressure overload leads to right ventricle (RV) failure. Right heart catheterization (RHC) is currently the gold standard test for PAH diagnosis and follow-up. Furthermore, repeated RHC should be considered in patients who experience unexplained clinical deterioration during their clinical course or for periodic follow-up over time. Yet many centers across the world do not routinely perform RHC during follow-up, for a variety of potential reasons, including its invasive nature, cost, or availability. We have recently developed 3D echocardiographic particle image velocimetry (Echo-PIV), which allows high- temporal volumetric assessment of RV hemodynamics. In combination with standard 3D speckle tracking, 3D Echo-PIV enables a comprehensive assessment of hemodynamics and energy state (ventricular kinetic energy/work and viscous energy dissipation) in the RV. The RV energy state reflects the structural and functional changes in the RV that may occur due to PAH. Thus, it can be used as a load-independent measure to assess RV function and monitor disease progression/regression in PAH patients. The project's global hypothesis is that in PAH patients' follow-up, changes in the RV energy state: (1) reflect changes in RHC-derived pulmonary arterial pressures, and (2) are associated with changes in patients' clinical status such that it can be used to monitor disease progression and regression. Given that in more advanced disease, RV dysfunction is present, we will gather a prospective, ethnically diverse cohort of 210 subjects at Cedars-Sinai Medical Center: 70 PAH patients with normal RV function, 70 PAH patients with RV dysfunction, and 70 healthy control subjects. The following Specific Aims will be accomplished: SPECIFIC AIM 1: Investigate the accuracy of 3D Echo-PIV in characterizing 4D flow hemodynamics in the RV using 4D Flow CMR as a reference standard and assess test/retest reproducibility of 3D Echo-PIV in PAH. SPECIFIC AIM 2: Determine the relationship between the noninvasively derived RV energy state and RHC- derived parameters in following up PAH patients and test whether changes in the RV energy state reflect changes in the RHC-derived pulmonary arterial pressures in PAH patients with and without RV dysfunction. SPECIFIC AIM 3: Investigate the feasibility of noninvasive imaging-derived RV energy state for monitoring disease progression/regression in PAH patients. The success of the proposed studies will establish 3D Echo-PIV as a tool for assessment of PAH patients and will: (1) determine the relationship between noninvasive RV imaging and invasive RHC-based hemodynamics, (2) establish whether changes in noninvasive RV energy state reflect changes in the RHC-derived parameters in PAH patients, and (3) facilitate monitoring of disease progression/regression by noninvasive RV energy state in lieu of invasive RHC (current clinical gold standard).