Modeling Right Ventricle Failure After Continuous Flow Left Ventricular Assist Device: A Biventricular Finite-Element and Lumped-Parameter Analysis

Abstract

The risk of right ventricle (RV) failure remains a major contraindication for continuous-flow left ventricular assist device (CF-LVAD) implantation in patients with heart failure. It is therefore critical to identify the patients who will benefit from early intervention to avoid adverse outcomes. We sought to advance the computational modeling description of the mechanisms underlying RV failure in LVAD-supported patients. RV failure was studied by computational modeling of hemodynamic and cardiac mechanics using lumped-parameter and biventricular finite element (FE) analysis. Findings were validated by comparison of bi-dimensional speckletracking echocardiographic strain assessment of the RV free wall vs. patient-specific computational strain estimations, and by non-invasive lumped-based hemodynamic predictions vs. invasive right heart catheterization data. Correlation analysis revealed that lumped-derived RV cardiac output (R = 0.94) and RV stroke work index (R = 0.85) were in good agreement with catheterization data collected from 7 patients with CF-LVAD. Biventricular FE analysis showed abnormal motion of the interventricular septum towards the left ventricular free wall, suggesting impaired right heart mechanics. Good agreement between computationally predicted and echocardiographic measured longitudinal strains was found at basal ( 19.1 ± 3.0% for ECHO, and 16.4 ± 3.2% for FEM), apical ( 20.0 ± 3.7% for ECHO, and 17.4 ± 2.7% for FEM), and mid-level of the RV free wall ( 20.1 ± 5.9% for echo, and 18.0 ± 5.4% for FEM). Simulation approach here presented could serve as a tool for less invasive and early diagnosis of the severity of RV failure in patients with LVAD, although future studies are needed to validate our findings against clinical outcomes.