Heart attack repair: Cardiac stem cells show promise in trials

It’s long been an article of faith that human heart muscle, once damaged, cannot regenerate. But findings from two clinical trials, presented Monday at the American Heart Assn.'s Scientific Sessions in Orlando, Fla., suggest that isn’t the case.

Two teams of researchers found that stem cells harvested from a patient’s own heart were able to reverse damage from a heart attack. Dr. Roberto Bolli, director of the division of cardiology at the University of Louisville in Louisville, Ky., and colleagues presented initial results from an ongoing clinical trial that treated 16 heart attack patients with infusions of cardiac stem cells that had been harvested from their own hearts during bypass surgery. Their trial was also described in an article published simultaneously by the journal The Lancet.

Dr. Eduardo Marbán, director of the Cedars-Sinai Heart Institute in Los Angeles, discussed final results from another Phase 1 trial in which doctors harvested cardiac tissue using a minimally invasive technique, cultivated stem cells from the tissue and administered them to 17 study subjects.


In the Louisville experiment, 14 patients had improved cardiac function four months after the procedure; eight had further improvements a year after infusion. Heart attack scars shrank.

In an interview with Booster Shots, Marbán said that his team’s cells shrank scars too, but also brought about a “sizable increase” in living heart muscle in the patients -- on the order of about 600 million new heart cells per subject.

The two studies take slightly different approaches to a single question: Are there stem cells in the human heart that can be harnessed to rebuild the heart tissue destroyed during a heart attack? Blocked arteries cause heart attacks by depriving the heart muscle of blood and oxygen, leading to cell death and heart failure. In the U.S. alone, it is estimated that about 6 million people have heart failure. The new results provide hope for such patients, who have been awaiting cellular therapies to mend damaged heart tissue for more than a decade.

Depending on the Food and Drug Administration’s approach to the new therapy, Marbán said, a product based on his team’s work could be available to patients as soon as 2015 or 2016.

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