Echocardiographic assessment of pediatric heart transplantation: A single-center experience in China

Abstract

Background: Pediatric heart transplant (HT) has become the standard of care for end-stage heart failure in children worldwide. Serial echocardiographic evaluations of graft anatomy and function during follow-up are crucial for post-HT management. However, evolution of cardiac structure and function after pediatric HT has not been well described, especially during first year post-HT. This study aimed to characterize the evolution of cardiac structure and function after pediatric HT and investigate the correlation between biventricular function with adverse clinical outcomes.

Methods: A single-center retrospective study of echocardiographic data obtained among 99 pediatric HT patients was conducted. Comprehensive echocardiographic examination was performed in all patients at 1-, 3-, 6-, 9- and 12-months post-HT. We obtained structural, functional and hemodynamic parameters from both left- and right-side heart, such as left ventricular stroke volume (LVSV), left ventricular ejection fraction (LVEF), right ventricular fractional area change (RVFAC), etc. The cardiac evolution of pediatric HT patients during first post-HT year was described and compared between different time points. We also explored the correlation between cardiac function and major adverse transplant events (MATEs).

Results: 1) Evolution of left heart parameters: left atrial length, mitral E velocity, E/A ratio, LVSV and LVEF significantly increased while mitral A velocity significantly decreased over the first year after HT (P < .05). Compared with 1 month after HT, interventricular septum (IVS) and left ventricular posterior wall (LVPW) decreased at 3 months but increased afterwards. (2) Evolution of right heart parameters: right ventricular base diameter and mid-diameter; right ventricular length diameter, tricuspid E velocity, E/A ratio, tricuspid annular velocity e' at free wall, and RVFAC increased, while tricuspid A velocity decreased over the first year after HT (P < .05). (3) Univariate logistic regression model suggests that biventricular function parameters at 1-year post-HT (LVEF, RVFAC, tricuspid annular plane systolic excursion and tricuspid lateral annular systolic velocity) were associated with MATEs.

Conclusion: Gradual improvement of LV and RV function was seen in pediatric HT patients within the first year. Biventricular function parameters associated with MATEs. The results of this study pave way for designing larger and longer follow-up of this population, potentially aiming at using multiparameter echocardiographic prediction of adverse events.

Keywords: echocardiography; heart transplantation; pediatric.