Imperial College London thought that said that if Clark's heart was given a time-out, it might be able to recover on its own. So in 1995, Yacoub and others grafted a donor heart from a 5-month-old directly onto Clark's own heart. After four and a half years, both hearts were working fine, so Yacoub and colleagues decided not to take out the extra heart.of
However, the powerful anti-rejection drugs Clark was taking caused cancer, which led to chemotherapy. Even when doctors lowered the doses of drugs to suppress Clark's immune system, the cancer spread, and Clark's body eventually rejected the donor heart.
In February 2006, doctors removed Clark's donor heart. Luckily, by that time, Clark's own heart seemed to have fully recovered. Since then, Clark — now 16 years old — has started playing sports, gotten a part-time job, and plans to go back to school in September.
At the moment, doctors aren't sure how that regeneration happens. Some think there are a small number of stem cells in the heart, which may somehow be triggered in crisis situations to heal damaged tissue.
Granted, Hannah's case is a rare and miraculous one, but it does give us a window of hope for the future!
Side note - even if this were to become an option for treatment in the future, there is a serious shortage of donor organs available for such transplants. Consider becoming an organ donor today, and asking your loved ones to do the same!