The heart has kept the Central City, Ky., resident alive ten times longer than anybody had expected. Christerson is the only survivor of the six who have received the heart in its early trials.
His surgeons, Dr. Laman Gray and Dr. Robert Dowling, told the The Early Show the progress of Christerson is amazing.
Christerson underwent surgery on Sept.13, 2001, becoming the second person in the world to receive the AbioCor artificial heart, developed by the Danvers, Mass., company, Abiomed Inc.
Christerson is the longest living and only surviving AbioCor heart recipient. He is also the first artificial heart patient to go home. So far, the AbioCor has worked exactly as designed, according to the doctors and manufacturers.
The 71-year-old Christerson was at death's door when he made the decision to let doctors take out his failing heart and put in the AbioCor. Before Christerson's implant surgery at Jewish Hospital, he was so weak that even just a few steps would leave him breathless.
Dr. Gray and Dr. Dowling said he had only days to live. Now, he walks unassisted and was able to lived to see the birth of his first great-grandchild. Next month, he celebrates his 55th wedding anniversary.
The AbioCor artificial heart is a softball-sized titanium and plastic pump. Surgery involves implantation of the artificial heart, an electrical coil used to keep the internal battery charged and a battery and controller that regulates the heart's rate. An external belt has a charger with a coil that transmits electricity to the internal coil through the skin without breaking the skin. The internal battery can operate for about 30 minutes on its own — allowing the wearer to take a shower or walk to the refrigerator.
The candidate has to have a chest cavity large enough to hold the AbioCor heart, which only comes in one size. People with a small chest cavity were ineligible for surgery.
The AbioCor is considered a technological leap from the mechanical hearts used in the 1980s, such as the Jarvik-7. Those devices were attached by wires and tubes to bulky machinery outside the body.
Some heart experts say the clinical trial has already proven that the AbioCor works and can change patients' lives significantly. Most agree it's still an imperfect technology that requires modifications and improvements.
The threat of stroke prompted Abiomed to refine the pump by getting rid of a connecting mesh that could create clots, but it hasn't been able to assess the change yet.
The first patient to receive the altered device died in the operating room at Jewish Hospital in April, the only AbioCor implant this year. The pump wasn't a factor in the death, doctors say.
The threat of stroke has also has become a bigger factor in choosing patients. Doctors are looking more closely in the screening process at factors that might prevent a patient from tolerating anti-clotting medication. Christerson is able to tolerate recommended doses of the anti-clotting drugs. Some heart patients can't tolerate these drugs because of malnourishment and a tendency to bleed.
The FDA has approved eight more AbioCor implants. The company wants to pick up the pace and possibly have the operations done this year. Eventually, the company wants to gain FDA approval to begin selling the AbioCor on a limited basis in 2004. Clinical trials will continue for years to determine safety, effectiveness and the type of patient for whom the heart is appropriate.
However, the artificial heart still raises hope for the future. Up to 100,000 Americans requiring cardiac therapy may one day have an alternative treatment. Only about half of the 4,200 Americans on waiting lists for donor hearts received one last year.