Three-Dimensional Speckle Tracking Echocardiography for Assessment of Left Ventricular Function and Myocardial Mechanics after Pediatric Heart Transplantation

Abstract

Three-dimensional (3D) echocardiography for the assessment of LV size, function and myocardial mechanics has been commonly used after heart transplantation (HT) in adults, but not yet in children. We purposed to explore the feasibility of 3D echocardiography for these parameters in children after HT. We analyzed data from 33 pediatric HT recipients with median age 10 yrs at HT (3 mos -17yrs) who had ≥ 2 echocardiograms with 3D LV full volume image within 24 hours of routine biopsy at BCH between March 2013 and December 2015. Rejection was defined by biopsy as acute cellular rejection Grade ≥2R or antibody mediated rejection (ISHLT-2004). We analyzed 3D LV volumes, ejection fraction (EF), mass and mass/volume, global longitudinal, circumferential and radial strains (GLS, GCS and GRS), twist and torsion at first, 6 and 12 months after HT; and compared with corresponding values in 30 age- and BSA-matched controls with median age 7.2 yrs (2 mos-17yrs). During the initial 30 days post HT, all HT recipients had smaller end-diastolic volumes than controls (median EDV: 38 vs. 47 ml/m2) resulting in mild LV hypertrophy (Mass: 50 vs. 43 gr/m2) and impairment in LV systolic function (EF: 56 vs. 65%, GLS: 21 vs. 26%, GCS: 26 vs. 33%, GRS: 39 vs. 48%, for all P<0.001). Among 23 rejection free recipients, EDV, ESV, Mass and GRS gradually increased within 1 year after HT (ANOVA P=0.015, P=0.022, P=0.015, P<0,001, respectively), while stroke volume, EF, GLS and GCS increased within 6 months (for all P≤0.008) and remained steady state through 1 year after HT. The initial mild LV hypertrophy decreased by 6 months after HT (mass/volume: P =0.028) without further changes until 1 year after HT CONCLUSION: 3D echocardiography can assess LV size, function and myocardial mechanics and reflects LV post-transplant recovery in rejection-free pediatric recipients. There were changes in LV size, function and myocardial mechanics associated with rejection and deserve further assessment in larger pediatric heart recipient cohorts.