Currently, about 5 million Americans have heart failure, with 550,000 new cases diagnosed every year. Although there are many different methods to treat the condition, heart transplant may be the best treatment for patients with end-stage heart failure, who are able to tolerate immune system suppression medications. Unfortunately, there are less than 3,000 donor organs available worldwide per year. Due to such limiting factors, scientists have developed numerous ways to optimally support failing hearts (with medication and/or devices), so that sufferers' lives may be improved, and in some cases extended.

Search for an optimal circulatory-support device began in 1964, with the National Institutes of Health (NIH) artificial-heart program. In 1994, the Food and Drug Administration (FDA) approved a pneumatically driven LVAD (pronounced "l-vad") as a bridge to transplant (until a matching organ donor is available). Four years later in 1998, the FDA approved a self-contained, vented electric device to replace the pneumatic one that allowed patients to go home while awaiting heart transplant.

Even so, the overall mortality rate due to end-stage heart failure remains high, mainly due to the limited number of donor heart transplant organs. Hence, scientists have carefully studied a possible use of an LVAD as a long-term support destination therapy for patients who are not candidates for heart transplant.

So, how does an LVAD work? It has three parts: an electrically driven mechanical pump, an electronic controller, and a power supply. The pump is about 1.5 pounds, made of titanium with a biological friendly lining. Placed in the abdominal cavity, the LVAD takes blood from the left ventricle and pumps it into the aorta. The LVAD normally pumps at a rate of 60-80 beats per minute, but can increase to 120 beats per minute with exercise.

Two external batteries, via a cable through the abdomen, supply the power for this pump. They are carried in underarm holsters or a waist pack. The electrical controller is a small computer like component that adjusts functions of the pump, such as pumping speed. You can find more details of how an LVAD works at the site www.thermocardio.com

To study the efficacy, safety, and cost-effectiveness of an LVAD for permanent use, compared to optimal medical management through medication therapy, a clinical trial was done, named the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH). This trial was conducted in 129 patients at 22 major hospitals throughout the U.S. and was financially supported by the NIH.

The result of this study showed a 48% decrease in the death rate from all causes with the LVAD over the first 2 years of use. Patients in the LVAD group had a median survival of 408 versus 150 days in the medication therapy group. Only 8% (1 out of 12) survived two years in the optimal medical management group. 23% were alive at 2 years in the LVAD group. The quality of life was improved in the LVAD group, based on the questionnaire completed by patients from both groups at one year. The study was conducted on only the sickest patients, who had no alternative options.

The HeartmateIV is currently FDA approved for bridge to transplant and "destination therapy" in individuals who are not candidates for heart transplant.

Alternative devices for complete heart replacement are also being studied at present.  Click here for more information on other mechanical supports.