New technology to help heart and lung patients awaiting transplants

Apr 6 2005

Promising new technology may extend the life of a failing organ for patients suffering from heart or lung disease while they wait for a donor organ. The use of stem cells may eliminate the need for a transplant and even eradicate heart disease in patients. Research and discussion will be presented today during symposia at the International Society for Heart and Lung Transplantation (ISHLT) Annual Meeting and Scientific Session in Philadelphia.

Presenter Robert Kormos, M.D., University of Pittsburgh (Penn.) Medical Center, advocates the development and use of a pump device that will address, and in some cases eliminate, heart failure. Partnered with stem cell technology, the new pump would be smaller and minimally invasive and would allow a patient's heart to emerge strong enough to accept the implanted stem cells that would improve the heart's function and reduce or eliminate heart disease in the patient.

"We know from successful trials outside the U.S. that implanting stem cells results in myocardial recovery. By changing our way of thinking and addressing heart failure in its earlier states, and by using devices and stem cells together, a patient can enjoy life without heart failure instead of continuing to live with it," says Kormos.

Kormos also suggests that a new approach for ventricular assist devices (VAD) is on the horizon for cardiac patients. While VAD usage gains increasing acceptance, a new way of thinking may change the way doctors use these assistive devices.

Ventricular assist devices stabilize adults with heart disease, and act as a mechanical "bridge" for patients waiting for a donor heart. According to a Columbia University Medical Center study, patients in end-stage heart failure who received a VAD had more than double the one-year survival rate compared with patients who did not receive a device.

However, Kormos challenges that VADs should be incorporated earlier in treatment. "We in the medical community spend a lot of time helping patients live with heart failure until their bodies can't tolerate it any longer. Ironically, by the time we deem the candidate eligible for a heart transplant or a VAD, the patient may be so sick that he is no longer a good candidate for either, " says Kormos.

Pediatric Devices

VADs are designed for adult patients, but recent studies show that they may also help some children suffering from heart disease. "More than 70 percent of children with end-stage heart disease are bridging successfully to transplantation with a VAD. This emphasizes the need to develop a device for smaller patients who cannot be supported with current technology," says James Kirklin, M.D., University of Alabama at Birmingham and participant in this afternoon's Symposium, "The Final Technology Solutions for End Stage Congestive Heart Failure" at the ISHLT Meeting.

Research on implanting cardiac defibrillators in children will also be presented at the Meeting. Defibrillators help prevent sudden cardiac death and have proven effective for adults with heart disease.

"Our research has shown that children who have a higher likelihood of decreased blood flow to tissue or organs may benefit, but in general, children are at a much lower risk of sudden cardiac death," says Kirklin. "Further studies are still needed."

Lung Devices

Several devices are also emerging to help people with lung disease. An estimated 4,000 Americans were on a lung transplant waiting list in 2004 and demand outpaced donor organ availability by approximately 75 percent. Research related to lung devices will be discussed during the afternoon Symposium, "Cardiopulmonary Assist Devices: Looking Beyond the Horizon."

"Unlike the heart, no mechanical device exists for lung patients," says Bart Griffith, M.D., University of Maryland School of Medicine, Baltimore.

Griffith explains that good temporary options have been available for some time, but they are bulky and restrictive for patients. He says there is an urgent need for a better assistive device, and ultimately, a mechanical replacement for failing lungs.

An interventional lung assist (ILA), developed by the German company Novalung GmbH, shows promising results.

"Several hundred patients in Europe have been treated successfully with ILA," Griffith says.

A non-invasive device, the ILA is connected to the patient and simulates lung function by removing carbon dioxide and increasing oxygen levels in the patient's blood, relieving the damaged lung from performing that task.

Griffith's research is focused on a prototype pump lung that could become the first artificial lung in the United States. As small as a CD player, its portability offers patients mobility while it actively mixes blood as it pumps through the device. Griffith estimates the device could be ready for patient use in two years.