Although cardiac stem cells are harder to get and take longer to prepare than bone marrow cells, Bolli's study suggests they're effective at reversing heart muscle damage even years after a heart attack.
"Even though we cannot treat heart attacks acutely, we still saw this remarkable improvement in patients with heart damage that was on average three and a half years old," said Bolli. "It seems like delivering cardiac stem cells much later still benefits these patients."
Now the quantity of cells needed for the procedure -- one-to-two million -- can be prepared from a heart biopsy, eliminating the need for surgery. The cells are then re-infused back into the heart through a catheter while the patient is awake. And because they're the patient's own, there's no risk of rejection.
Some experts are calling the study a game-changer; one that gives new hope to patients thought to have irreparable heart damage.
"Every once in a while there's a landmark study in medicine," said Hare. "I think this a landmark in medicine. It reaches the level of when the first heart transplant was done."
But it could be five years before the procedure is ready for prime time, said Hare. The results first have to be confirmed in more patients.
Two years after the procedure, Jones said he continues to see improvements. But he still takes medications to keep his heart pumping the best it can.
"There's still damage in my heart so I'm not going to be able to do everything," he said. "I'll never be able to jog, but I can walk pretty quickly now."
But Jones said his personal gains are outweighed by the potential for many more people to benefit from the treatment.
"I try to look at the big picture of it, and the fact that I was able to be a small part of something that's probably going to help hundreds of thousands of people," he said. "That's pretty exciting."