Cardiac dysfunction in children and young adults with heart transplantation: A comprehensive echocardiography study

Abstract

Transplanted heart dysfunction is a serious life-threatening condition in pediatric transplant recipients. Several studies have focused on echocardiographic detection of early signs of cardiac dysfunction in this population. We evaluated advanced echocardiographic indices of cardiac function in a large sample of children and young adults with heart transplants with apparently normal cardiac function. The study included 60 patients with normal ejection fraction with transplantation performed at pediatric age between 1986 and 2014 and 60 healthy control subjects. All patients and control subjects underwent a complete transthoracic echocardiographic examination including tissue Doppler analysis, 2-dimensional speckle tracking, and 3-dimensional echocardiography. Two-dimensional speckle tracking analysis was used to obtain measures of left ventricular (LV) radial, circumferential, and longitudinal strain and to derive LV twist and torsion from basal and apical rotation. Three-dimensional echocardiography was used to measure LV volumes and ejection fraction and to evaluate LV systolic synchrony. No differences were observed between groups in LV volumes, left atrial diameters, LV ejection fraction, or right ventricular fractional area change. However, patients showed lower values of longitudinal systolic excursion of valvular planes at both the mitral and the tricuspid valve level as well as higher mitral E/E' ratio. Cardiac radial strain was similar between groups; a significant net reduction in both global left and right ventricular longitudinal strain and LV global circumferential strain could be observed between the 2 groups (all p < 0.05). In addition, reduced LV twist and torsion was found in patients compared with healthy control subjects (p < 0.01) mainly owing to a significant reduction in basal rotation (-2.4° vs -3.8°; p < 0.05). none of the control subjects demonstrated LV dyssynchrony, whereas systolic dyssynchrony was observed in 20% of heart transplant recipients. Even in the absence of signs of graft failure and in the presence of a normal ejection fraction, transplanted hearts show a significant reduction in biventricular function. Additional prognostic studies are needed to establish whether these abnormalities predict development of overt heart failure.