Nearly 6 million Americans have heart failure, and another 670-thousand will develop it this year.
It is one of the costliest problems for the nation's health budget.
Today, doctors announced a medical breakthrough, unleashing the power of stem cells from a person's own heart to heal their damaged muscle.
Two years ago, Mike Jones' heart muscle was dying, damaged by a massive heart attack.
He couldn't even climb a flight of stairs.
Now, this 68-year-old is full of life again.
"Ill walk up 2 flights of stairs, instead of taking the elevator. I can pitch with grandkids, play ball with them," says Mike.
He was the first patient to receive a revolutionary treatment. Heart cells were removed from his bypass surgery, then in the lab, stem cells were extracted from them.
Then they were injected back into his heart's blood supply, to grow back into heart muscle.
Mike was one of 16 patients in the small study at the University of Louisville. The goal was to find out if the treatment was safe.
Not only was it safe, it worked amazingly well.
Dr. Roberto Bolli, the study leader, says, "It's remarkable that the very first time we test them, we are seeing such a dramatic effect.
A year after the stem cell treatment, Mike's heart muscle has less damage, and was pumping 40% more blood. Now, it's doing even better, pumping 60% more.
Patients in the trial who didn't get the stem cells showed no improvement.
Dr. Bolli predicts the stem cell treatment will be the biggest advance in heart care in a lifetime.
Mike Jones is still amazed that his body was able to heal itself.