Artificial heart pump funded

By Charlotte Crystal

Heart disease is America's top killer, claiming more than 400,000 lives each year. The most severely affected patients could be saved by new hearts, but only 3,000 or so heart transplants are performed each year. That leaves a number of seriously ill patients -- estimates range from 17,000 to 240,000 annually -- who could live long, productive lives if reliable artificial hearts were available.

Paul Allaire, a U.Va. professor of mechanical engineering, and his colleagues here and in Utah are working to develop such an artificial heart.

Allaire and his associates have received a grant of nearly $4.2 million from the National Institutes of Health to continue development of an artificial heart pump. This new grant provides funding after an earlier, $3 million research grant from InterMountain Health Care, a not-for-profit corporation that runs a hospital system in Utah, ended last month.

The new grant will be split between Allaire's group at U.Va., which is refining the mechanical aspects of the pump, and the Utah Artificial Heart Institute, an independent research center in Salt Lake City whose researchers include cardiologists formerly associated with the University of Utah. The U.Va. Patent Foundation has patents pending for the technology.

Utah's researchers are internationally known for their work in artificial heart development and cardiac surgery. It was at the University of Utah in 1982 that the Jarvik-7 artificial heart was implanted in Barney Clark, the world's first recipient of a "permanent" artificial heart.

In 1991, the Utah artificial heart researchers sought Allaire's expertise at the Engineering School's Center for Magnetic Bearings. Researchers wanted to reduce the number of moving parts thereby minimizing the chances for mechanical failure. Current pulsating heart pumps have more than 100 moving parts and associated reliability problems. They typically last one to two years before malfunctioning, according to Allaire. In contrast, the U.Va.-Utah prototype has only one moving part -- the pump impeller -- boosting the device's expected lifetime to more than 10 years, he said.

The simple, circular design of the inside of the pump and a single moving part, the impeller, also minimize the chance of thrombosis, or potentially fatal blood clotting, according to Allaire.

The U.Va.-Utah team's current prototype, the CF-4 or "HeartQuest," will probably be made of some type of plastic, to make it as lightweight as possible, and operated by eight electromagnets, Allaire said. U.Va. engineers have yet another experimental version of the heart pump on the drawing board, the CF-5, which will use permanent magnets instead of electromagnets and require even less power to operate.

The U.Va. team includes biomedical engineering professor Milton Adams, mechanical engineering professor Ronald D. Flack Jr., mechanical engineering professor James C. McDaniel Jr., Gang Tao, associate professor of electrical engineering, and Houston Wood, associate professor of mechanical engineering. U.Va. will devote its share of the grant to covering the costs of testing the model now under development and building new, smaller and more sophisticated prototypes of the heart-assist devices.

Currently, some patients receive artificial, "bridge-to-transplant," hearts. These grapefruit-sized devices enable patients to survive, in bed, for six months to a year, waiting for a compatible human heart to be found. But these artificial hearts are only a temporary solution. No "permanent" (that is, offering a life of 10 to 20 years) artificial hearts have been approved for routine use by the U.S. Food and Drug Administration, which regulates medical devices.