After the decision was made to proceed, Chloe became the first person in the world to be transferred between hospitals with her chest open while on a life-supporting extracorporeal membrane oxygenation machine.

With the 50cc total artificial heart successfully installed, doctors waited several weeks for the patient's health to stabilise before transplanting a second donor heart.

Parents Fabienne and Todd Narbonne are now campaigning to change the law on organ donation in England to an opt-out system, such as Wales adopted in 2015, where people must specifically refuse consent for their organs to be retrieved.

Chloe said her experience had been “life-changing”.

“I feel well, like my normal self, but not quite my normal self, not after what I’ve been through,” she told the Guardian.