It’s a tantalizing thought: injecting stem cells isolated from a person’s own blood into an ailing heart in hopes of repairing years of accumulated decay. But so far, human trials testing cell therapies for heart attacks have yielded mixed results, creating controversy over various aspects of the treatment: the types of cells that are used, the way they are delivered, and when in the course of the disease they are given. With the next round of trials, scientists hope to nail down the precise set of conditions needed to effectively heal a sickly heart.
“If it works, it could revolutionize cardiology,” says Amish Raval, a cardiologist at the University of Wisconsin, Madison, who is running a stem-cell trial for heart failure.