Despite the rave reviews thus far, the world's first implantable mechanical heart has raised questions from some critics who wonder about its high costs and long-term public health benefits.
Indeed, Robert Jarvik, M.D., whose ultimately failed Jarvik-7 artificial heart triggered those same concerns in the early to mid-1980s, says he believes far too much money is being spent on a device that will help too few patients to ever be worthwhile.
Jarvik, for one, suggests that ventricular-assist devices, which don't require the removal of the heart and often serve as a "bridge" to traditional transplants, are a preferred medical route in all but a relative handful of the most severe cases. Through his New York-based company, Jarvik Heart, he has developed a miniaturized ventricular-assist device called the "Jarvik 2000," which he believes is more effective than the AbioCor replacement heart.
"In my view, it's an obsolete approach," he says of the AbioCor, which Abiomed Corp., Danvers, Mass., spent at least $60 million to develop, with $20 million of that coming from the National Heart, Lung and Blood Institute.
Jarvik believes the pool of potential recipients is too small for the AbioCor mechanical heart to provide a widespread benefit to the general public. His device, which has been undergoing clinical trials in the U.S. since April 2000, could benefit "tens of thousands" of patients each year, he says.
So far, the AbioCor device has proven to be a qualified clinical success since being implanted July 2 in the chest of a deathly ill patient at Jewish Hospital in Louisville, Ky., which took the lead in the first stage of a national clinical trial that will eventually involve four more patients. A second trial is expected to include about 30 patients.
Officials at Abiomed have estimated that there will be as many as 100,000 potential recipients for replacement hearts once the technology wins acceptance. A recent review by the national heart institute says from 5,000 to 10,000 patients per year might be helped by the implantable mechanical heart, which is now priced at about $75,000 for the hardware alone.
Jarvik suggests that the AbioCor, a two-pound device made of titanium and plastic, is so large that it will fit "perhaps 10% of adult Americans." Of that population, he estimates, only about 10% will ever need a fully implantable mechanical heart as opposed to the support provided by a ventricular-assist device or some other variation. Jarvik is confident that his miniaturized heart pump, now being tested in the U.S. only as a bridge to transplants, will eventually be used to permanently assist in the flow of blood.
"You come down to a situation where there really are very few patients who will be candidates for this device-500 to 1,000 a year, maybe," Jarvik says. "I think the key issue is whether this will have an impact on public health. It's very unlikely to have an impact."