Abstract
ABSTRACTBackground and AimsPrevious trials evaluating remote ischaemic preconditioning in children undergoing cardiac surgery showed mixed results. We sought to determine whether adequately delivered bilateral preconditioning is cardioprotective in young children, with or without cyanosis, undergoing surgery.MethodsProspective, double-blind, randomised controlled trial at two UK centres. Children aged 3-36 months undergoing tetralogy of Fallot repair or ventricular septal defect closure were randomised in a 1:1 ratio to receive either bilateral preconditioning or sham intervention. Participants were followed up until hospital discharge or 30 days. The primary outcome was area under the curve for high-sensitivity troponin-T in the first 24 hours after surgery, analysed by intention-to-treat. Right atrial biopsies were obtained in selected patients. Trial registration:ISRCTN12923441.ResultsBetween 24 October 2016 and 8 December 2020, 120 eligible children were randomised to receive either bilateral preconditioning (n=60) or sham intervention (n=60). Participants had a median age of 7 months and 42 (35%) were female. The primary outcome, area under the curve for hs-troponin-T was higher in the preconditioning group (mean: 70.0±50.9µg/L/hr, n=56) than in controls (mean: 55.6±30.1µg/L/hr, n=58), p=0.04. Sub-group analyses did not show a differential treatment effect by oxygen saturations (pinteraction=0.25) but showed evidence of differential treatment effect by underlying defect (pinteraction=0.04). Myocardial metabolism, quantified in atrial biopsies, and secondary outcomes were not different between randomised groups.ConclusionsBilateral remote ischemic preconditioning does not attenuate myocardial injury in children undergoing surgical repair for congenital heart defects, and there was evidence of potential harm in unstented tetralogy of Fallot.
Publisher
Cold Spring Harbor Laboratory