A team of surgeons at the National Taiwan University Hospital (NTUH) in Taipei undertook the revolutionary operation, during which the donor heart continues beating between the organ removal and transplantation stages. Traditionally, the donor heart would be removed and preserved in cold storage to reduce its workload – during this stage, it's considered "ischemic time," or the period during which the organ is cut off from blood supply. This comes with the risk of heart damage and rejection once it's transplanted into a recipient.

When the heart is deprived of blood, ischemia – a shortage of oxygen – can damage its muscle tissue, or myocardium, reducing function and health once it is transplanted. While an organ set for transplant rarely endures more than a few hours in ischemic time, it can still lead to myocardial damage.

So the NTUH team skipped this interim, performing the zero-ischemic time transplant that saw the heart continue to beat while between bodies.

"We wanted to perform a heart transplant without any ischemic time so that the heart wouldn't have to stop, and we could also avoid injury that typically occurs after reperfusion," said Chi Nai-hsin, an attending physician from the Cardiovascular Center, during a press conference at the Taipei hospital on Wednesday, April 16.

The operation was able to be performed thanks to a specially designed organ maintenance system that kept the donor heart pumping with oxygenated blood throughout the process. The NTUH organ care system (OCS) was inspired by extracorporeal membrane oxygenation (ECMO), a type of life support system that supplements heart and lung function.

Hooking the heart up to this OCS, the organ was transported from one operating room to another – without skipping a beat.

As for the patient, the 49-year-old woman with dilated cardiomyopathy was discharged from hospital not long after her surgery last August and is doing well. Subsequent post-operative appointments have shown that the woman maintains a low level of cardiac enzyme – something that spikes in typical transplant conditions, indicating heart muscle injury.

"We have demonstrated the safety and feasibility of the surgery," said Chi, who added that a second successful transplant had been conducted earlier this year.

Overall, NTUH has performed around 700 heart transplant surgeries, but the team hopes that, going forward, more will be using the OCS and skipping ischemic time.