It has been 50 years since Dr. South African Dr. Christiaan Barnard performed the first human heart transplant.
The main difference between this revolutionary procedure and those performed today has less to do with the surgery itself, and has more to do with the medications that doctors administer to their patients after surgery.
"You must realize that the body sees the new heart as something strange, and so the immune system seeks to destroy it," said Dr. Rhondalyn McLean, medical director of the heart transplant program at the University of Pennsylvania.
As doctors worked more on the development of effective drugs to suppress the immune system, the success rate of heart transplants improved. The first heart transplant patient died 18 days after surgery. Now, most patients live an average of 13 years after receiving a new heart.
But there is a big problem. McLean estimates that about 1 million people have end-stage heart failure in North America, and only about 2,400 heart transplants occur each year due to the lack of viable organs. That number has remained fairly constant over the years.
However, McLean said, advances in cardiac assist devices have been made here.
"Maybe about three years ago, the life expectancy of someone who had a cardiac assist device would be around 18 months, and now it's much longer," he said.
Newer devices provide a survival rate of approximately four years while a patient expects an available heart.
Researchers now focus on how to keep hearts beyond the four-hour window – the organs remain viable once removed from a body.
"If we could find a way to increase that window, then I could potentially take a heart from California, and transplant someone in New York," she says. "At this moment we can not do that, due to time and distance."