An Alternative to Heart Transplants
FDA’s Pending Approval Helps Patients Take Heart

Dave Harvison calls his trip to Houston "the trip of a lifetime." By all accounts, he’s right. When the 32-year-old Lubbock resident arrived in Houston three months ago on a LifeFlight helicopter, he was near death, brought down by the effects of end-stage heart failure. Today, he’s back on his feet and looking forward to the future, thanks to a device that takes over the pumping action of his failing heart, and sends life-sustaining blood coursing through his veins.

"Coming to Houston saved my life ... what a gift, to be delivered from death’s door," said the down-to-earth Harvison, who couldn’t wait to trade in his bedroom slippers for cowboy boots upon discharge from the hospital.

Harvison was a seemingly healthy young man with a new wife, a pharmaceutical sales job and hopes for the future until two years ago, when during a routine medical exam he was discovered to have cardiomyopathy, or an enlarged heart. Doctors can’t be sure how he acquired the condition, but most likely Harvison was infected by a virus that attacked his heart 10 to 15 years ago, then gradually took it’s toll.

"I was astonished to learn that at age 30, I had heart disease. I felt fine, with no symptoms at all. For years, my body had been compensating for a malfunctioning heart, and I didn’t even know it," he said.

Harvison began paying regular visits to a Lubbock cardiologist, but his long span of feeling fine would soon come to an end. Within a year, he drastically deteriorated.

"I couldn’t breathe, couldn’t sleep, felt nauseated and tired all the time ... my doctor began using terms like ‘end-stage heart failure.’ It was dismal," he said.

At the recommendation of his doctor, Harvison was airlifted to St. Luke’s Episcopal Hospital in the Texas Medical Center, where on Jan. 19 he was implanted with an artificial heart pump after reaching a terminal state of heart failure in the hospital’s intensive care unit. The two-pound titanium pump, called a HeartMate VE – a vented, electric left-ventricular-assist system – took over the pumping function of Harvison’s failing heart and maintained his circulation, keeping his organs viable and his body alive. Fifteen days after his implant, Harvison was discharged from the hospital. The man who faced imminent death now had a future.

"I’m fortunate to live in an age when devices like the HeartMate have been invented," he said.

Slightly larger than a coffee-cup saucer, the HeartMate is implanted in the abdomen, and is attached to the patient’s own heart with tubes. Once in place, the HeartMate takes over the job of the left ventricle, the heart’s main pumping chamber. Rhythmically, reliably, the HeartMate propels blood through the arteries, keeping patients alive. Lightweight batteries worn in a shoulder- or waist-holster provide power to the pump’s motor through a battery "cable" which enters the body through the skin. Another small hole in the skin allows air to vent to the outside.

"I used to be a little ‘weirded out’ by having something foreign in my body, but I’m used to it now," said Harvison.

"The HeartMate actually replaces the work of the heart," explained Dr. O.H. Frazier, chief of cardiopulmonary transplantation and director of surgical research at the Texas Heart Institute.

Dr. Frazier, who also is chief of cardiopulmonary transplantation at St. Luke’s, has been involved in the development and testing of mechanical devices to support patients with heart failure for 30 years.

The work conducted by Dr. Frazier and his team of researchers has resulted in the invention of several devices over time, the most recent being the HeartMate VE pump, which in 1998 was approved by the Food and Drug Administration as a "bridge" to transplant – a device that "buys time" for end-stage heart failure patients while they wait for a donor heart. To date, nearly 4,000 patients worldwide have been implanted with the HeartMate VE and its slightly more primitive predecessor, the HeartMate IP (implantable pneumatic), a compressed-air-powered pump that gained FDA approval as a bridge-to-transplant device in 1994. Excellent results have been obtained with both the VE and IP models.

"Patients who otherwise faced certain death now had a chance with these heart pumps to hang on until a donor heart became available," said Dr. Frazier who performed the world’s first HeartMate implant.

But there was, and continues to be, a problem.

Less than half the people waiting for heart transplants actually get one, because there simply are not enough donor organs to go around. In the United States, close to 2,200 heart transplants are performed each year, but 4,500 names are on the national patient waiting list. And even if there were no shortage, an estimated 100,000 U.S. patients with congestive heart failure don’t qualify for heart transplants due to advanced age or extenuating health circumstances.

It is this dilemma that led Thoratec Corp., the California-based company that manufactures the HeartMate VE, to request FDA approval to allow the device to be used as a permanently implanted heart assist device – a lifelong alternative to transplant for people who have severe heart failure but are not eligible for transplants.

To back up its request, Thoratec cited data from the REMATCH clinical trial, an acronym for "Randomized Evaluation of Mechanical Assistance in Congestive Heart Failure." The study evaluated whether left-ventricular-assist devices that are FDA-approved to temporarily support patients as they wait for transplants (in particular the HeartMate VE), could also be effective as a permanent alternative for patients who are ineligible for heart transplants. Jointly sponsored by the National Institutes of Health, Thoratec, and Columbia University, the study evaluated 129 people who were patients at 21 cardiac transplant centers across the nation, including patients from Texas Heart Institute and its clinical partner, St. Luke’s Episcopal Hospital. The trial enrolled only individuals with Class 4 heart failure – the most severe form – who had been ruled out as candidates for transplantation.

Sixty-eight patients were implanted with a left-ventricular-heart-assist device, while 61 were treated with drug therapy, diet and exercise. After one year, the difference in survival rates was twice as good for those on the pump (52 percent with the pump compared to 25 percent without the pump), and three times as good after two years (23 percent to 8 percent). The difference in survival rates was particularly drastic for patients younger than 60, with a one-year survival rate of 74 percent on the pump, compared to 33 percent without the pump. In addition, patients on the pump reported that their overall quality of life greatly improved.

"This allows us to say that implanted heart pumps can extend life and may be an alternative to transplants in terminally ill heart-failure patients," said Dr. Frazier.

The study’s findings were published in last November’s New England Journal of Medicine, and in January, Thoratec asked the FDA to approve the HeartMate VE as a long-term treatment for heart-failure patients, not just as a bridge to transplant.

On March 4, the FDA’s Circulatory System Devices Advisory Panel recommended that the FDA make the HeartMate VE a permanent alternative to transplant for people with serious heart failure.

"If the FDA approves its panel’s recommendation, the HeartMate VE will become the first heart-assist pump to be used on end-stage heart failure patients who are not eligible for transplantation," Dr. Frazier said.

Historically, the agency usually follows the recommendations of its advisory panels, and approval is expected this summer, he added.

"This is the first really acceptable solution for long-term support of these patients because it allows them to leave the hospital and return to active and productive lives," he said.

And there are also benefits for patients like Harvison who are deemed well enough to receive a donor heart. Now, they can be choosier while waiting for a perfect match.

"In the past, if we had a patient facing certain, imminent death, we’d have to accept a heart from a patient who may be a less-than-desirable match. With this pump, we have some control over nature, and we’re able to more confidently select a donor," Dr. Frazier said.

Some patients’ hearts actually improve on the pump, allowing them to be healthier at the time of transplant, or perhaps avoid a transplant altogether.

"Occasionally, we see patients recover ... their hearts have been resting and strengthening while the pump does all the work. We removed one young man’s pump back in ’98, and he’s doing exceptionally well with no transplant, no pump," said Dr. Frazier.

He predicts that the other three ventricular assist devices in common use today – the Jarvik 2000 (also developed by Dr. Frazier), the MicroMed DeBakey and the Novacor, will soon follow suit and win approval as permanent alternatives to heart transplants.In the meantime, about 30 other assist devices are being developed around the world that are smaller, more efficient, and require less energy. Already, Thoratec has introduced a new-and-improved version of the HeartMate VE. The new HeartMate XVE, which debuted Dec. 17 and is still in the planning stages, will incorporate design changes learned in the REMATCH trial, including quieter operation.

"Good ... someone needs to invent a muffler for this thing," joked Harvison, referring to the subtle, continuous hum emitted by the pump.

One thing is certain, reflected Dr. Frazier.

"These new devices appear to be on the verge of revolutionizing heart care. Each day brings something new, something better."

And for that, Dave Harvison is grateful.

"So many lives have been saved with this technology ... I’m just glad one of those was mine."

---

©2006 Texas Medical Center

---

E-Mail: tmcinfo@texmedctr.tmc.edu
URL: http://www.tmc.edu/tmcnews/04_01_02/page_01.html