Myocardial Deformation Imaging by Speckle-Tracking Echocardiography for Assessment of Cardiotoxicity in Children during and after Chemotherapy: A Systematic Review and Meta-Analysis.

BACKGROUND

Children with cancer and childhood cancer survivors (CCS) are at risk for developing chemotherapy-induced cardiomyopathy. Myocardial deformation imaging has shown potential in the early detection of subclinical myocardial damage with implications on therapeutic interventions and improvement of outcomes. The aim of this study was to perform a systemic review and meta-analysis of literature on the assessment of left ventricular and right ventricular myocardial deformation by speckle-tracking echocardiography at rest and during stress in children with cancer during and in survivors after chemotherapy.

METHODS

A systematic review was performed through searching MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature, the Cochrane Central Register of Controlled Trials, and Scopus. Search hedges were created to cover the concepts of childhood cancer, chemotherapy, radiotherapy, anthracycline, cardiotoxicity, speckle-tracking, myocardial strain, and myocardial deformation. Two independent investigators reviewed the eligibility of articles for inclusion. The weighted mean difference in ventricular strain between pre- and postchemotherapy treatment and that between long-term CCS and healthy subjects were estimated using random-effect models with 95% CIs. Heterogeneity and publication bias were assessed using I statistics and the Egger test, respectively.

RESULTS

Of the total of 8,703 records initially identified, 42 studies with a total of 5,430 children with cancer were included. Of these 42 studies that showed heterogeneities, nine assessed early myocardial injury during chemotherapy, 30 assessed late myocardial injury after chemotherapy with no publication bias, and three studied myocardial mechanics during stress. The main findings were as follows: (1) left ventricular systolic deformation is impaired in children with cancer during the initial treatment phase and among long-term CCS, while data on changes in right ventricular deformation are limited and inconclusive; (2) the predictive value of early reduction of myocardial strain imaging in forecasting subsequent development of cardiotoxicity is unknown, as it has not been studied; (3) limited data suggest the possibility of impaired left ventricular contractile mechanics during stress in CCS; and (4) cumulative anthracycline dose and chest-directed radiotherapy are consistently identified as factors associated with impaired myocardial deformation.

CONCLUSIONS

Myocardial strain imaging by speckle-tracking echocardiography unveils early evidence of myocardial injury in children with cancer and long-term CCS. To support its adoption for clinical use, more data are required for the better understating of myocardial deformation parameters in the risk stratification of children with cancer and prediction of development of cardiomyopathy among CCS.