WASHINGTON (AP) - A temporary artificial heart that promises to help keep certain patients alive long enough to receive a heart transplant must pass a key hurdle, as government advisers debate whether the device works well enough to sell.
The CardioWest Total Artificial Heart is essentially the same device that made headlines 22 years ago when Barney Clark became the first recipient of a permanent artificial heart, then called the Jarvik-7. He lived 112 days.
What has changed is how doctors hope to use the device. It's not supposed to be the kind of permanent replacement attempted with Clark so long ago.
"The term 'artificial heart' is a little misleading," cautions Dr. Dan Schultz, the Food and Drug Administration's device evaluation chief. "We're not talking about a permanent artificial heart in the sense that the lay public thinks of an artificial heart."
Instead, the device's new maker, SynCardia Systems Inc., is seeking FDA approval to sell the CardioWest as a temporary "bridge" to keep patients dying of congestive heart failure alive a little longer as they await a donor heart for transplant.
The agency's scientific advisers will weigh SynCardia's attempt Wednesday.
"I think a lot of people are probably dying because they don't have this kind of device available," said Dr. Jack G. Copeland, heart surgery chief at the University of Arizona Health Sciences Center, who helped develop the CardioWest.
Heart failure is an incurable condition where the heart gradually is weakened by age or damaged from a survived heart attack or some other disease and thus can't pump strongly. When medications ultimately fail, sufferers have few options. Heart transplants are scarce, and the wait for a donor heart can be longer than the patient's diseased heart can hold out.
Patients awaiting a transplant already have some FDA-approved options to help their hearts pump a little longer. The ventricles are the heart's pumping chambers, and so-called ventricular assist devices, or VADs, can be attached to a failing ventricle to boost pumping power.
The CardioWest is different. It is for use when both ventricles fail simultaneously. And it doesn't boost patient's existing ventricles - it replaces them. Surgeons must cut off the bottom chambers of the patient's heart and sew the pumping device onto the remaining atria, or top chambers.
Tubes then connect the artificial heart chambers to a washing machine-sized generator that keeps them pumping, making the CardioWest for in-hospital use only.
Of 81 patients implanted with the device in a study, 79 percent survived long enough to get a transplant.
A month after transplant, 69 percent of patients who received the CardioWest device while waiting were considered treatment successes - recovering well - compared with just 37 percent of "control" patients who weren't given the artificial heart before their transplant.
Copeland says the difference is that the artificial heart can pump significantly more blood throughout all the organs, strengthening them before the heart transplant so that other complications like kidney failure are less of a worry.
But FDA scientists argue that the study was done in a way that's impossible to adequately compare CardioWest recipients with transplant recipients who didn't get extra help, making it more difficult to discern the device's impact.
How many people suffer such complete heart failure that they would need more help than from today's standard VAD heart pumps? That's another key question the FDA wants its scientific advisers to answer.
SynCardia, however, estimates that of the 4,000 people usually on the nation's heart-transplant list, between 1,000 and 2,000 have double-chamber failure and wouldn't be candidates for a routine VAD.
