New pump effectively backs up failing hearts

Patients with severe heart failure can be bridged to eventual transplant by a new, smaller and lighter implantable heart pump, according to a new study of the device.

Results of this third-generation heart assist device were reported at the annual meeting of the American College of Cardiology March 30.

The device, called a left ventricular assist device (LVAD), is the latest generation of heart assist devices. The LVAD was tested at five main sites: the School of Medicine, the University of Minnesota, Mount Sinai School of Medicine, Inova Fairfax Hospital and the University of Pittsburgh.

“LVADs have allowed us to support patients until they can receive a heart transplant, so they are called a bridge to transplant,” said Gregory Ewald, M.D., associate professor of medicine and director of the Section of Heart Failure and Cardiac Transplantation and medical director of the Total Artificial Heart Program.

“For patients whose hearts are failing and are awaiting transplantation, these devices can be lifesavers. Washington University is the only medical center in the region where patients can receive these devices at this time,” he said.

In addition to Ewald, lead investigators in the trial included Nader Moazami, M.D., associate professor of surgery and surgical director of the Cardiac Transplantation and Total Artificial Heart Programs at WUSTL, and Andrew Boyle, M.D., associate professor of medicine at the University of Minnesota and medical director of Heart Failure, Cardiac Transplantation and Mechanical Circulatory Support.

An LVAD is implanted inside the chest cavity near the heart and is connected to the heart’s left ventricle (pumping chamber). It assists the patient’s weakened or damaged ventricle in pumping blood through the body. By restoring a normal blood flow, the device improves patients’ health. Because it is powered by portable battery packs, patients usually go home while they wait for a heart transplant.

The LVAD used in this study, the VentrAssist, is termed a third-generation heart assist device. Measuring 2.5 inches across and weighing 10 ounces, the pump is considered an improvement over earlier devices because its size and light weight make it suitable for small adults and children. In addition, its pumping mechanism has no contacting parts for improved durability.

Patients who received the LVAD in the study were approved and listed for cardiac transplantation. The study considered the device successful if a patient survived until heart transplantation or survived at least 180 days after the device was implanted and remained qualified for heart transplantation. Eighty-five percent of patients met this measure of success.

Out of 98 patients who received the device, 60 were transplanted, 19 continued to be supported with the device and 19 died. The median time on LVAD support was 131 days. Adverse events reported during the trial included stroke and bleeding, and the number and type of adverse events was similar to other LVADs but better than that of first-generation VAD devices.

Answering standardized questionnaires for patients with heart failure, patients reported a significantly improved quality of life after receiving the device, indicating that their heart failure was less apt to interfere with everyday activities such as housework, hobbies or sleeping or to affect their mood, ability to concentrate or energy level.

“Before implantation of the device, 80 percent of these patients were rated class four on the New York Heart Association scale — they were short of breath at rest,” Ewald said.

“But by six months, 84 percent were in class one or two, meaning their heart failure symptoms were minimal or mild. All of them were able to go home with the device, and that allowed them to rehabilitate themselves — their nutrition improved, and they were in better shape, making them better candidates for heart transplantation,” Ewald said.

The positive results from this clinical study mean the VentrAssist will be submitted to the U.S. Food and Drug Administration for approval for use as a bridge to a heart transplant. In the interim, the School of Medicine will continue to provide the device to patients as part of a clinical trial.

WUSTL doctors are continuing to enroll patients in a trial of the device as a bridge to transplantation, and they are also testing the device as “destination therapy” to see if the device can function as an alternative to heart transplant by permanently assisting failing hearts.

For information about enrolling in the trial, call 454-7687.