Cardiac MR-derived indices are stronger predictors of resource use and risk than jugular venous pressure, in paediatric patients with functionally single ventricles, prior to completion of total cavopulmonary connection (TCPC)

Methods Outcome data for all patients undergoing inter-stage pre-TCPC CMR between 2007-2014 was analysed. Predetermined outcome measures included survival, duration of peri-TCPC hospitalisation and TCPC fenestration. MRI was performed under general anaesthetic with simultaneous transduction of jugular venous pressure (JVP), as per our Unit protocol. CMR-derived data included volumes and function of single ventricle, through-plane phase contrast flow volumes, contrast-enhanced angiography and 3D SSFP images. Flow was measured in ascending aorta, SVC, IVC, pulmonary arteries and pulmonary veins bilaterally. Thus systemic to pulmonary (S-P) collateral flow, net PA flow and SVC:IVC flow was quantified. 3D images allowed quantitative scoring of systemic veins off-loading the SVC system into IVC : 0= no SVC-IVC offloading veins seen, 1= few, small, low calibre veins, 2= large, obvious veins.