Studies: Stem cells reverse heart damage

A new study says heart damage may be reversible with stem cell therapy without dangerous side effects.

Story highlights

  • In a study by Dr. Robert Bolli, 16 patients with heart failure received stem cell therapy
  • Within a year, the heart function of the patients in the study markedly improved
  • "We were surprised by the magnitude of improvement," says Bolli
  • "We would possibly be curing heart failure. It would be a revolution," says Bolli
On a June day in 2009, a 39-year-old man named Ken Milles lay on an exam table at Cedars-Sinai Medical Center in Los Angeles. A month earlier, he'd suffered a massive heart attack that destroyed nearly a third of his heart.
"The most difficult part was the uncertainty," he recalls. "Your heart is 30% damaged, and they tell you this could affect you the rest of your life." He was about to receive an infusion of stem cells, grown from cells taken from his own heart a few weeks earlier. No one had ever tried this before.
About three weeks later, in Kentucky, a patient named Mike Jones underwent a similar procedure at the University of Louisville's Jewish Hospital. Jones suffered from advanced heart failure, the result of a heart attack years earlier. Like Milles, he received an infusion of stem cells, grown from his own heart tissue.
"Once you reach this stage of heart disease, you don't get better," says Dr. Robert Bolli, who oversaw Jones' procedure, explaining what doctors have always believed and taught. "You can go down slowly, or go down quickly, but you're going to go down."
Conventional wisdom took a hit Monday, as Bolli's group and a team from Cedars-Sinai each reported that stem cell therapies were able to reverse heart damage, without dangerous side effects, at least in a small group of patients.
In Bolli's study, published in The Lancet, 16 patients with severe heart failure received a purified batch of cardiac stem cells. Within a year, their heart function markedly improved. The heart's pumping ability can be quantified through the "Left Ventricle Ejection Fraction," a measure of how much blood the heart pumps with each contraction. A patient with an LVEF of less than 40% is considered to suffer severe heart failure. When the study began, Bolli's patients had an average LVEF of 30.3%. Four months after receiving stem cells, it was 38.5%. Among seven patients who were followed for a full year, it improved to an astounding 42.5%. A control group of seven patients, given nothing but standard maintenance medications, showed no improvement at all.
"We were surprised by the magnitude of improvement," says Bolli, who says traditional therapies, such as placing a stent to physically widen the patient's artery, typically make a smaller difference. Prior to treatment, Mike Jones couldn't walk to the restroom without stopping for breath, says Bolli. "Now he can drive a tractor on his farm, even play basketball with his grandchildren. His life was transformed."
At Cedars-Sinai, 17 patients, including Milles, were given stem cells approximately six weeks after suffering a moderate to major heart attack. All had lost enough tissue to put them "at big risk" of future heart failure, according to Dr. Eduardo Marban, the director of the Cedars-Sinai Heart Institute, who developed the stem cell procedure used there.
The results were striking. Not only did scar tissue retreat -- shrinking 40% in Ken Milles, and between 30% and 47% in other test subjects -- but the patients actually generated new heart tissue. On average, the stem cell recipients grew the equivalent of 600 million new heart cells, according to Marban, who used MRI imaging to measure changes. By way of perspective, a major heart attack might kill off a billion cells.
"This is unprecedented, the first time anyone has grown living heart muscle," says Marban. "No one else has demonstrated that. It's very gratifying, especially when the conventional teaching has been that the damage is irreversible."
Perhaps even more important, no treated patient in either study suffered a significant health setback.