The first recipient of a fully implantable artificial heart has suffered a large stroke, doctors announced yesterday.
Robert L. Tools, 59, developed sudden weakness of his right arm and leg Sunday afternoon and was unable to speak or understand speech, according to his doctors at Jewish Hospital in Louisville. He was subsequently put back on a mechanical ventilator to prevent him from choking.
The doctors say the stroke occurred when a clot traveled to Tools's brain and plugged a large artery. Where the clot formed is uncertain. The best guess, however, is that it arose in the artificial heart.
Blood in contact with metal or plastic surfaces clots readily, but it can be thinned with anticoagulant drugs. Tools has been unable to take blood-thinners for most of the time since he underwent surgery July 2 because of life-threatening episodes of bleeding from his stomach and nose. He has required more than 30 units of transfused blood since.
"We are very disappointed," said Laman Gray, one of the surgeons. "We consider him more as a friend than a patient, and we are sorry to see he has had a problem." He added that Tools's family "is very, very optimistic."
The stroke is considered a major setback for Tools, who had been doing so well that last week he left the hospital for an outing with the Louisville mayor to promote dining out. Buoyed by his progress, doctors had said it was possible he could be home for Christmas. Before he received the heart, Tools was not expected to live more than three months.
Large strokes can be fatal even days after they occur. Damaged brain tissue can swell and put pressure on other regions, such as the areas that regulate breathing and blood pressure. Blood vessels in the dead tissue can also bleed, causing catastrophic brain hemorrhages.
Lynn Simon, a neurologist caring for Tools, said brain images don't show either complication. However, the patient is still at risk for both, and especially for bleeding, as he is now on anticoagulant drugs.
The brain's speech and language center is on the left side of the brain in 90 percent of people. The left side of the brain also controls the limbs on the right side of the body. A large part of that half of the brain is damaged, Simon said, adding that it will take time to determine how many of Tools's current deficits are permanent.
The artificial heart is made by AbioMed, a Massachusetts medical device company. It replaces the heart's two major pumping chambers -- the ventricles -- and is powered by an implanted battery. Unlike previous artificial hearts, however, no wires or tubes pierce the skin. The battery can be recharged with an induction coil that transmits through the skin.
Five patients have received the device since the operation on Tools in July. All are still alive, although some have had rocky recuperations. Another patient at Jewish Hospital, Tom Christerson, 70, recently had a course of fevers as high as 107 degrees. No infection was found, and the physicians now believe the fever was a rare reaction to a drug. Tools's stroke was the first blood clot detected during the total of 278 days that the patients have had the devices.
The recent events were recounted at a news conference at the Louisville hospital yesterday. Robert Kung, an AbioMed engineer, said Tools's complication would not slow clinical research on the artificial heart. The company is awaiting permission from the Food and Drug Administration to put the device in five more patients.
Every person with hardware in the heart must take anticoagulant drugs to prevent clots from forming. (People who receive valves transplanted from pig hearts do not require anticoagulation.) Any clot forming in the heart has a high likelihood of ending up in the brain because the arteries serving that organ are among the first to branch off the aorta, the main vessel carrying blood out of the heart to the rest of the body.
"We never would have intended to put this device in and not anticoagulate him," Gray said.
Tools started to bleed from his stomach two days after his operation. At the time, he was on the blood-thinner heparin and other anti-clotting drugs. The drugs were stopped.
Doctors had inspected his stomach with a fiber optic scope just a few days before surgery, and it was normal, Gray said. They've repeated the procedure about 20 times since to monitor and cauterize small bleeding arteries. For a while, they also reduced the volume of blood the heart pumped per minute, thinking that would cut the bleeding.
That strategy appeared to work. However, when Tools briefly lost the ability to talk for a day earlier in the fall, the doctors restarted the anticoagulants, fearing a stroke was imminent. Tools was stable for a while, but then had a nosebleed requiring a a two-pint transfusion of blood. The anticoagulants were temporarily stopped again.