More studies are needed to determine whether the procedure reduces the incidence of congestive heart failure and death, Botker said. "To be honest, we need these clinical endpoints," he said. "To show that the therapy translates into clinical benefit, that is the next step."
Most of the work on induced ischemia is being done in Europe. In the United States, a group led by Jacob Vinten-Johansen, a professor of cardiothoracic surgery at Emory University in Atlanta, has been trying a variation on the theme, in which blood flow is interrupted by inflating the balloon on a catheter, the thin wire inserted for the artery-opening procedure called angioplasty.
"We were the first to try it, in 2003," Vinten-Johansen said. "We did a series of pilot studies simulating models of myocardial infarction. We did find it beneficial and went through the litany of what would be rational and effective. Essentially, in a nutshell, a little bit of ischemia can be helpful and a little bit of reperfusion can be helpful."
The beauty of the technique is its simplicity, Vinten-Johansen said, but there are complexities within the simplicity. While one small human trial is under way at Emory, "we still are looking at preclinical work, what makes it tick, what are the mechanisms," he said. "We want to answer some questions about why this thing is doing what it is doing."
So far, there have been only small human trials of induced ischemia, generally in single medical centers in Europe, Vinten-Johansen said. "The U.S. cardiology community is a bit slower to embrace these things, and the regulatory situation is better in Europe," he explained.
U.S. regulations require signing of a consent form for such an experimental procedure, "and that is difficult when the patient is in an ambulance coming into the hospital," said Dr. Ajay J. Kirtane, an interventional cardiologist at
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