The 50-year ‘Grail Quest’ to develop an artificial heart has as much drama as a telenovela. Learn how scientists, entrepreneurs and a blues musician are fighting to bring this dream to life.
Dr. Billy Cohn, leader at the Center for Device Innovation at the Texas Medical Center for J&J, in his workspace
The heart is an incredible muscle. The fist-sized pump circulates 2,000 gallons of blood per day through 60,000 miles of blood vessels. It beats 5 million times a year, every year for a lifetime. We have yet to invent an artificial replacement that can demonstrate the necessary robustness to withstand that level of effort for a few years, let alone a few decades. In fact, success typically has been measured in survival increments of months rather than years.
Unfortunately, heart disease affects 5 million Americans, who face a five-year mortality rate of 50 percent. Only 2,000 patients per year receive a heart transplant, compared to the 350,000 that die from heart failure. Creating a mechanical system that can keep up with a healthy heart is of vital importance if we are to reduce these numbers.
This topic is of much interest in the healthcare community, which is why a standing-room-only crowd turned out when Dr. Billy Cohn spoke last month at JLABS Houston on the “Past, Present, and Future of the Total Artificial Heart.”.
Dr. Cohn recently joined J&J to lead the Center for Device Innovation at the Texas Medical Center, where he will apply his breadth of experience as an inventor, scientist, financier, and blues musician. Prior to joining J&J he was a professor of surgery at Baylor, and director of the legendary Cullen Cardiovascular Research Laboratory at the Texas Heart Institute in Houston.
At the outset of Dr. Cohn’s talk, I was struck by the fact that the ‘Grail Quest’ of artificial heart development spans almost 50 years with the first implantation being conducted in 1969.
The history of the artificial heart has as much interpersonal drama as any telenovela. The infancy of the field was fueled by the long-time rivalry of Dr. Michael Debakey and his protégé, Dr. Denton Cooley. Cooley completed the first artificial heart implant with the assistance of Dr.Domingo Liotta, whilst Debakey was back in Washington D.C. lobbying for funds to support furthering the ground breaking research effort.
This rivalry is well described in a NY Times article and ultimately graced the cover of LIFE magazine. The first patient implanted, whose heart had completely failed at the time of implant, lived only 64 hours. Regardless, a giant step forward had been made.
The next major leap was in the 1980’s when Dr. Rob Jarvik pioneered the Jarvik-7 device which was implanted by William DeVries into retired dentist, Barney Clark, at the University of Utah on December 2, 1982. While he only survived 112 days, that technology eventually made its way into the SynCardia device, a technology that would eventually be implanted in over 1,600 patients, of which 60 percent survived to one year. Also, in the early 1980’s, David Lederman partnered with the Texas Heart Institute and Cohn’s mentor, Dr. O. H. “Bud” Frazier developed the AbioCor device that eliminated the need for patients to be tethered to pneumatic hoses. About $250 million was invested in the AbioCor effort which resulted in 14 patients being implanted- only four survived more than nine months.
A notable sidelight to implantable heart technologies are left ventricular assist devices. A brilliant ER doctor turned technologist, Dr. Richard Wampler, conceived a device based on an Archimedes screw. His collaboration with Bud Frazier at the Texas Heart Institute led to a pencil sized rotor that induced very limited damage to red blood cells. Wampler liked to describe the atraumatic nature of blood cell (RBC) to rotor interaction being that the force applied to the RBC’s was so brief, and transit time so long between exposure to the impeller, that it was like passing one’s hand briefly over a candle flame—an effect that was felt but so briefly that no damage occurred. This technology would eventually make its way into the Thoratec Heartmate II, a left ventricular assist device (LVAD). Over 50,000 patients have benefited from the technology, and more than 100 have survived more than 10 years.
While there is a robust set of LVAD options available currently, no one has line-of-sight on being the first long term artificial heart implant. There are however three teams that are making a run for it.
Cleveland SMART Heart
The SmartHeart TAH is based on the design of the SmartHeart LVAD. In 2012, a Korean private equity firm invested $30 million to develop the technology that features a single moving part - the rotor, supported in a blood-lubricated fluid film bearing. The technology is described on the Cleveland Heart website as a device featuring a single motor driving two centrifugal pumps on both ends of the same shaft. One might expect that the integrated pressure regulating valve that automatically balances left and right circulations without the need for a second motor, reduces energy consumption.
Two of the world's leaders in cardiovascular technology, Dr. Richard Wampler and Dr. Albert Starr are involved in the Portland based OregonHeart. The company is 100 percent owned by OHSU’s Knight Cardiovascular Institute. Clyde Taylor, OregonHeart’s CEO has said the genius of the design is that the pump mechanism shuttles back and forth, instead of staying in one position, or using valves. Wampler heads the research and development team and has a collaborative relationship with the Texas Heart Institute.
The OergonHeart system features a pump mechanism that shuttles back and forth, instead of staying in one position, or using valves
The BiVacor double sided, bearingless, brushless DC motor was originally conceived of by Daniel Timms, Ph.D., and Australian researcher whose father was diagnosed with heart failure. Timms’ concept was seen by Dr. Cohn and Dr. Frazier at the Texas Heart Institute and was recruited to Houston to advance his idea from concept to working device. Jim "Mattress Mack" McIngvale was a key financial supporter of this effort. Research and development was able to advance quickly leveraging plastic, and eventually metal, 3D printing technologies. The current device iteration being evaluated in animals provides 23L/min of peak flow, and a nominal power consumption of 10W for 10L of flow. The convergence of emerging capabilities of 3D printing, microsensor, and microprocessor technologies are enabling the creation of a device that will likely be compact enough to be used not only in small adults, but in pediatric patients (10- or 11-year-olds) as well.
As a final note, when the session at JLABS Houston turned to Q&A, one audience member asked, “How can you raise money for ambitious projects like these?” Dr. Cohn responded that no Grail quest ever gets funded without a passionate leader. “You better be excited if you are going to get others excited.”
He extolled elbow grease and perseverance, “Try harder, and don’t give up.” If you look at the history of the total artificial heart from Dr. Debakey and Dr. Cooley in the 1970’s to Dr. Cohn, Dr.Timms and Dr. Frazier in the present, to use an often invoked sports phrase, the Texas Heart Institute ‘doesn’t have any quit in them.’ My sense is that someday tens of thousands of patients a year will be grateful for the clinicians, donors, entrepreneurs, investors and industry partners that persevered through all set-backs and obstacles to deliver the first life-sustaining total artificial heart.
Note, a more scholarly look at the total artificial heart can be found here: “Total artificial hearts; past, present, and future”, Nature Reviews Cardiology 12, 2015, June 2; 609-617