del Nido cardioplegia had not been commercially available in the United Kingdom prior to the DESTINY trial, a multi-centre individually randomised controlled trial to evaluate whether del Nido or St Thomas’ blood cardioplegia provides better myocardial protection in children of all ages. In this sub-study, we explored the experiences of surgeons and perfusionists using del Nido in the trial, to support implementation of del Nido in the United Kingdom and identify any practical or safety concerns.

We conducted qualitative, semi-structured interviews with surgeons and perfusionists who had completed at least three cases with del Nido cardioplegia in the trial. Interviews were conducted face-to-face or via Zoom, digitally audio-recorded, transcribed, and analysed using a hybrid thematic approach, according to the Consolidated Framework for Implementation Research domains. Trial registration: ISRCTN13638147, registered July 2021.

Twelve participants were interviewed, six surgeons and six perfusionists from all four paediatric cardiac surgical centres participating in the trial. Four key themes emerged: (1) attitudes towards the use of del Nido cardioplegia; (2) practical aspects of delivering del Nido cardioplegia; (3) blood conservation techniques; and (4) adopting del Nido cardioplegia into routine clinical use beyond the trial.

Surgeons and perfusionists reported that they found del Nido cardioplegia to have practical benefits over St Thomas’ blood cardioplegia but felt that further research on the optimal cooling temperature, blood conservation, and dosing for paediatric use are required to support the development of a best practice guideline and guide national implementation beyond the trial.