A new, smaller implanted cardiac-assist pump not only helps patients with severe heart failure survive until a transplant becomes available, it can help improve function of the heart and other organs, according to an article in the August 30 issue of the New England Journal of Medicine.

Analysis of data for the HeartMate II R left ventricular assist device, one of four new devices that pump blood continually, showed that it helped 75 percent of patients stay alive for at least six months or until a donor heart became available. In addition, it helped hearts regain intrinsic pumping function and allowed other organs to heal by restoring blood flow. One patient recovered so fully that a transplant was no longer needed. Not unexpectedly, patients reported that their quality of life also improved significantly.

The new assist device is also much smaller than older devices - about the size of a D-cell battery. Thus, it may be useful for more women, teenagers and smaller men with end-stage heart failure who are not big enough for other devices. It is also quieter and has a smaller tube leading into the implanted device from the controller and battery pack that are worn outside the body.

The study was designed and funded by Thoratec Corporation, which makes the HeartMate II and a larger HeartMate device that is already on the market, but the study authors had independent access to data to prepare their analysis.

Although the study did not directly compare the HeartMate II device with any other device, the results give further evidence that the new device is more reliable than previous heart-assisting implants. In fact, 68 percent of the 133 patients in the study were still relying on the device one year after implantation while remaining on the heart transplant list. The same clinical trial included patients who were not eligible to receive a heart transplant and received the devices as a long-term destination therapy.

“As a bridge to transplant, the HeartMate II is showing excellent survival, good recovery potential for the heart, kidneys and liver, and a favorable impact on quality of life,” said Francis Pagani, MD, PhD, co-lead author of the paper and the director of the University of Michigan Cardiovascular Center’s Center for Circulatory Support. “These results suggest it would be a very good addition to the options that physicians have for treating patients who require ventricular assistance while they wait for a new heart, and that it has the potential to last years rather than months.”

Lead author of the analysis was Leslie Miller, MD, a noted cardiologist formerly at the University of Minnesota who is now the director of cardiology programs at Washington Hospital Center.

Currently, according to the United Network for Organ Sharing, American adults who need a heart transplant wait an average of 170 days, but nearly 30 percent are still waiting even after two years on the transplant list. As of August 24, 2007, 2,640 Americans of all ages were waiting for a heart transplant.

The new study included 133 patients and assessed the device’s ability to support patients for six months or until they received a transplant or recovered left ventricular function, whichever came first.

The researchers assessed patients’ functional heart status, as measured by class of heart failure severity and ability to walk for six minutes, as well as kidney and liver function, which are usually diminished by the decreased blood flow characteristic of heart failure. The patients’ quality of life was measured using two standard questionnaires that assess everything from patients’ ability to enjoy social activities to physical day-to-day symptoms and mental health.

Three quarters of participants were men (average age, 50 years). Two thirds had non-ischemic heart failure; all had class IV heart failure. Many had already received other heart-assisting technologies including pacemakers and implanted defibrillators; 41 percent had pre-surgery help from an intraaortic balloon pump.

In all, 100 patients had successful outcomes by the end of six months, with 56 receiving transplants, 43 remaining on the device and one recovering enough to allow the device to be removed. But the 25 deaths in the study before six months, including 18 patients who died before leaving the hospital, show that serious complications do occur even with the newer generation of device due to the severity of illness of these patients. Many patients experienced bleeding related to anticoagulation used with the device.

But nearly all survivors experienced cardiac recovery so significant that by the end of three months they were moved to a less severe stage of heart failure. There were significant improvements in quality of life scores and liver and kidney function.