In the race to build a better artificial heart, French scientists have turned to technology from satellites and airplanes to create a heart that they say responds better to the human body. So far, the new device, shown at a news conference in Paris on Monday, has only been tested in animals. Its makers hope it might one day help people survive without needing a human heart transplant.
American companies have already produced artificial hearts, and scientists in Japan and South Korea are also working on versions.
But the French artificial heart is the first to be able to determine its patients' needs and respond accordingly. And its maker is a subsidiary of the parent company of Airbus, the European Aeronautic Defense and Space Co., or EADS.
"It's the same principle in the airplane as in the body," said Patrick Coulombier, chief operating officer of Carmat, the manufacturer.
Coulombier said the same tiny sensors that measure air pressure and altitude in an airplane or satellite are also in the artificial heart, detecting things like the heart's pumping speed and the pressure on its walls.
That should allow the device to respond immediately if the patient needs more or less blood. The heart is expected to cost about $192,140. The most advanced U.S. artificial heart, made by the U.S. company Abiomed, sells for up to $250,000.
Abiomed was aware of the French project but declared itself ahead in the race.
"Our artificial heart has already been implanted in patients and is FDA-approved," said Aimee Maillett, a company spokeswoman. On average, Abiomed's heart has extended patients' lives by about five months.
Few details are available about the artificial hearts being developed in Japan and South Korea because the scientists have not published their work widely.
Previous artificial hearts have been unable to automatically vary their pumping speed. The French heart is also the most lifelike, with two pumps to send blood into the lungs and the rest of the body, just like a real heart. Past artificial hearts have only had one pump.
The heart was tested in sheep, in some cases for three to six months to see how the animals' bodies would adjust to the artificial organ. Researchers did not test how long it would keep the animals alive. Laboratory experiments tested the heart in various scenarios, including, for example, when a hypothetical patient was exercising and suddenly needed more blood.
"This could be a bases-loaded home run if it works," said Dr. Douglas Zipes, past president of the American College of Cardiology and professor of cardiology at Indiana University. Zipes was not linked to the French research.
The French model is made from natural materials including polymer and pig tissue, which have already been used in heart valves implanted into people.
Those have not caused any problems like rejection or clotting, commonly seen with artificial hearts or devices. That makes some doctors optimistic that a heart partially constructed from the same tissues could spare patients lifelong anti-rejection and anti-clotting medicines.
The artificial heart would initially be for patients who had suffered a massive heart attack or who had heart failure, but might eventually be used in patients were are not that sick. French doctors hope to start tests in humans in the next two years.
Heart disease is the world's top killer. According to the American Heart Association, about 2,200 heart transplants were performed in the U.S. in 2006, and the waiting list is long.
While previous artificial hearts have mainly acted to buy time until a real heart becomes available, Dr. Ottavio Alfieri, a professor of cardiac surgery at Raffaele University Hospital in Milan and spokesman for the European Society of Cardiology, said the French heart might work in the longer term.
Experts warned that many past attempts to replace the human heart have failed.
"Virtually all devices that have been implanted in humans, no matter how well designed, have been associated with unforeseen complications," said Dr. Tim Gardner, president of the American Heart Association.
"This is a high-risk area with a lot of problems," said Dr. Karl Swedberg, a cardiologist at the University of Gothenburg in Sweden. He doubted the new artificial heart could be used to alleviate the shortage in donors, since it was very expensive and would still require a major operation.
"An artificial heart is an interesting idea, but we should focus on the established treatments we already have," Swedberg said.