Almost all artificial heart designs have been used as a bridge to human heart transplant. An FDA-approved study later this year will test the most-used artificial heart for permanent use, also called destination therapy. Destination therapy is for patients who do not qualify for a donor heart or do not want a human heart transplant, which is still considered the gold standard of care for treating end-stage heart failure.
Here are seven things you should
know about artificial hearts.
1. Growing Demand for Artificial Hearts
According to the U.S. Department of Health & Human Services, about 4,000 people wait for a donor heart transplant on any given day, while the supply of approximately 2,300 donor hearts annually has been flat in the U.S. for over 20 years.
Among European Union countries, 3,400 patients were on waiting lists for a donor heart in 2012. According to the European Commission’s Department of Health and Consumers, only 2,004 transplants were conducted that year.
2. The Most Used Artificial Heart
There have been 1,413 implants of all artificial heart designs from 1969 to September. 5, 2014. The SynCardia temporary Total Artificial Heart and its direct predecessors account for 1,352 or 96% of all implants. Of that number, nearly 500 SynCardia Hearts have been implanted since 2010.
An artificial heart must fit in the patient’s chest without causing complications. Recent artificial heart designs are significantly heavier and larger than an adult human heart, which averages between 250 and 350 grams. For example, the AbioCor replacement heart ($250,000) weighs 1,090 grams and the Carmat artificial heart ($181,000-$233,000) weighs 900 grams. Only large adult patients can accommodate artificial hearts of that size.
The SynCardia Heart ($124,800, plus Freedom driver service charges) weighs 160 grams, less than half the weight of a human heart, and is similar in size to an average human heart, which makes more patients eligible for implantation.
3. Duration of Support for Patients on Artificial Hearts
Artificial hearts help patients survive and regain their health for transplant. The shortage of donor hearts causes patients to wait longer for heart transplants.
The patient who has been supported the longest was Italian patient Pietro Zorzetto, who had a SynCardia Total Artificial Heart for nearly four years—1,374 days—prior to his successful heart transplant September 11, 2011.
One-third of current SynCardia Artificial Heart patients have been supported for more than a year, including some who have worn the device for two years or more (47% outside of the United States, 21% in the U.S.).
4. Improved Quality of Life
As of September 5, 2014, French resident Frédéric Thiollet, 37, has been living with his SynCardia Total Artificial Heart for 1,122 days. For three years, he has been on the 13.5-pound Freedom® portable driver, which powers the device and is FDA, Health Canada and CE approved. He has lived at home and in his community waiting for a matching donor heart since his discharge from the Thorax Institute at University Hospital of Nantes December 15, 2011.
“I have recuperated all my physical functions,” says Thiollet. “I have enjoyed an effective resurrection, a new birth. Physically I have no limit. I am as strong and powerful as before, even more so than before.”
With the Freedom portable driver, SynCardia Total Artificial Heart patients resume their lives with nearly unlimited mobility.
Christopher Larsen boxes to stay in shape.
Chris Marshall hiked a total of 607 miles before receiving his heart transplant.
Randy Shepherd completed the 4.2-mile Pat’s Run event.
Lexi Henderson, at age 16 years, was the youngest person to be discharged from the hospital with the Freedom portable driver and has since received a donor heart.
5. Highest Bridge to Transplant Rate
According to data published in the 2004 New England Journal of Medicine 2004 New England Journal of Medicine from the 10-year pivotal clinical study which led to FDA approval, 79% of patients who received a CardioWest, an earlier design of the SynCardia Total Artificial Heart, were bridged to transplant.
This is the highest bridge to transplant rate for any approved artificial heart or ventricular assist device in the world.
From June 23, 2006 to September 30, 2012, 82% of patients who had lived one year with a SynCardia Total Artificial Heart implant either received a donor heart transplant (70.3%) or were alive and waiting for a matching donor heart (11.6%), according to the third-quarter 2012 INTERMACS report.
6. Reliability Statistics
Because of the small implantation numbers of nearly all of the artificial heart designs, it is impossible to establish credible data on the reliability of those designs.
The one exception is the SynCardia Total Artificial Heart. It and its predecessors have been implanted 1,352 times over more than 30 years. In those three decades of use
The valves in the Total Artificial Heart have never failed. (after the first implant)
The diaphragm, which is responsible for pumping blood in and out of each ventricle, has a reliability rate exceeding 99.5% for more than 1,350 implants representing 2,700+ diaphragms.
7. Status of 2 Regulatory-Approved Devices and 1 Design Under Study
Only two artificial heart designs are FDA approved: the SynCardia Total Artificial Heart and the AbioCor replacement heart.
The AbioCor replacement heart was implanted 15 times; the last implant was in 2009.
That same year, the Boston Globe published a November 23 story about Abiomed, manufacturer of AbioCor. In the article, Abiomed chief executive Michael Minogue was quoted as saying he considers the self-contained artificial heart “the sports car you watch on television, but you can’t buy from your dealer…It’s a unique product.”
On December 18, 2013, the first implant of the Carmat bioprosthetic heart, which is similar in design to the AbioCor, was conducted under a clinical feasibility study. The patient died after 74 days. A March 16, 2014 article by the Reuters news service said, “The device's inventor, French surgeon Alain Carpentier, told the weekly Journal du Dimanche…that the heart had stopped after a short circuit, although the exact reasons behind the death were still unknown.”