Human stem cells reverse heart failure in monkeys

Human stem cells helped restore left ventricular ejection fraction (LVEF) in monkeys induced with experimental heart failure, giving scientists hope that a similar treatment could work in humans following myocardial infarction.

"Our findings show that human embryonic stem cell-derived cardiomyocytes can re-muscularize infarcts in macaque monkey hearts and, in doing so, reduce scar size and restore a significant amount of heart function," senior investigator Charles Murry, MD, PhD, with the University of Washington School of Medicine, said in a press release. "This should give hope to people with heart disease."

The induced heart attacks reduced LVEFs from about 65 to 40 percent. Two weeks later, roughly 750 million embryonic stem cells were implanted into some of the monkeys while others were left untreated as a control group.

The stem-cell treated monkeys’ average ejection fraction rose to 49.7 percent four weeks after treatment, while the untreated animals’ remained near 40 percent. Murry and colleagues published these findings in Nature Biotechnology.

Long-living cardiomyocytes like those introduced in this study could permanently replace the muscle cells lost from myocardial infarction, Murry said. The researchers followed two animals for three months after treatment and found LVEFs further increased to 61 and 66 percent, near normal levels.

“What we hope to do is create a ‘one-and-done’ treatment with frozen ‘off-the-shelf’ cells that, like O-negative blood, can go into any recipient with only moderate immune suppression,” Murry said.

The group plans to begin clinical trials of this technique in 2020, according to the release.