Artificial Hearts Are Lasting Longer - Bridging the Gap for Patients on Year-Long Waiting Lists
The following is an excerpt from the new book Beyond Human by Eve Herold (St. Martin's Press, 2016):
When forty-year-old Stacie Sumandig was told by doctors that she had only a few days to live, she had one thought going through her head. So sick that she didn’t have the strength to cry, she thought, “I have four kids to take care of. Death is not an option.” The news that a virus had attacked and destroyed both ventricles of her heart, leading to end-stage heart failure, was a shock that she simply couldn’t process. Even though she had been feeling unwell for months, she was fit and active. In fact, up to two weeks before landing in the hospital, she had been working out three times a week and working full time at a landscaping job. Between a physically demanding job and caring for her young family, Stacie “almost never sat still.”
Stacie’s story proves that, no matter what doctors say, there is no substitute for listening to your body. She first went to her family doctor in July complaining of flu-like symptoms, night sweats, and difficulty breathing. She had a history of frequent bouts with bronchitis, and that is what her doctor diagnosed. She was prescribed antibiotics, which seemed to help for a while, but then the symptoms returned. Between July and September, Stacie had several visits to her doctor, first being diagnosed with bronchitis, then with pneumonia. She was told that her trouble breathing was probably due to asthma. While course after course of antibiotics seemed to temporarily help, the symptoms inevitably came back. Finally, in September, her doctor ordered a chest X-ray. Reading the results early one morning, her doctor picked up the phone and gave her a call she will never forget.
“Your heart is severely enlarged,” the doctor told her, “and it’s surrounded by fluid. You need to go to the hospital immediately.” So began a journey for Stacie that would call for the courage and endurance that few people ever have to draw upon. Doctors at the hospital told her she would likely not live through the weekend. They advised her to get her affairs in order, to notify loved ones, and prepare for the worst. Rather than accepting the news, she could think only of her children, ages eight, nine, thirteen, and fourteen. Who would take care of them? How would her husband manage without her? “I was so sick that the tears wouldn’t come out, but I told them, ‘There has to be something you can do.’”
Soon it was decided that, as a last resort, Stacie should be transferred to the University of Washington Medical Center (UWMC) in Seattle, where there were more resources than at her local hospital in the town of Puyallup, Washington. Luckily, there she met a cardiologist named Dr. Nahush Mokadam, and he offered her last, and only, option. First, he told her that there was no biological heart available for a transplantation that could save her life. However, there was a very new alternative—the Total Artificial Heart (TAH), made by a Tucson-based company called SynCardia. Only a few hundred people had ever been implanted with the artificial heart, but the FDA had recently approved the technology and UWMC had the capacity to offer it to Stacie.
The TAH was not considered a permanent solution, but a bridge technology that would keep Stacie alive until a suitable biological heart became available. Even then, Stacie had a complication that meant that after her natural heart was removed— an irreversible act—she had only a fifty-fifty chance that the TAH could be attached to her aorta, the main trunk of the heart’s arteries that carry blood away from the heart and out to the rest of the body. Stacie had been born with a congenital narrowing of her aorta. Her first heart surgery, a reconstruction of the aorta, was performed when she was only four years old and, at thirty-one, she had had an aortic valve replacement. Due to the damage from the virus, which doctors estimated had been attacking her heart for two years, the only thing holding her aorta in place was an infected, fragile piece of muscle that was attached to the aortic valve. It was entirely possible that once this small piece of flesh was removed, there would be nothing to attach the artificial heart to. Knowing that once she was put to sleep, she had only a 50 percent chance of ever waking up, Stacie was terrified, but the chance that the surgery would be successful was all she had to cling to. It was an enormous amount of information to process within a few days’ time. The idea of having a totally artificial heart was more than a little unsettling, but thinking of her children, she agreed to go through with the operation.
It turned out that one of the effects of Stacie’s long-term heart failure actually improved her chances of a successful implant. According to Dr. Mokadam, when he removed her heart, rather than consisting of the firm, elastic muscle that characterizes a healthy heart, her heart was so soft and mushy that it just slipped through his hands. It was also dramatically enlarged, and as a result, it had enlarged her chest cavity as well. This was one of the only reasons why Stacie, as an average-sized woman, could accommodate the SynCardia 70-cubic-centimeter (cc) heart, which is sized only for men or large-sized women. Fortunately, the TAH, which includes right and left atria, or upper heart chambers, and right and left ventricles, or lower chambers, which carry most of the work of the heart, could be attached to Stacie’s aorta. But by then, Stacie’s vital organs had begun to fail due to the lack of blood flow, and her lungs collapsed during surgery. She was placed in a two-week, medically induced coma, and connected to an ECMO (extracorporeal membrane oxygenation) machine that took over the circulation of her blood while her vital organs came back online and her lungs started to function again.
After two and a half weeks, Stacie woke up from the coma. Her vital organs were steadily improving due to the increased blood flow, and to her relief, the TAH proved to be “better than the heart I was born with.” Even though she had two tubes coming out of her abdomen attached to the Freedom portable driver, a 13.5-pound apparatus, which she carried around with her in a backpack, she was able to go home and live a relatively normal life while she waited for a matching biological heart. The backpack seemed heavy at first, but she soon grew accustomed to it and the tubes attached to it, which were necessary as long as she had the TAH. The battery in the driver, which kept the heart pumping, had to be recharged every day by being plugged into a wall socket. The battery charge lasted for only eight hours, so she had to be ever mindful that an electrical outlet was always within reach. This in itself caused a certain nagging anxiety, but fortunately, she could keep the driver plugged in at night while she slept.
The upside was that the heart pumped 9.5 liters of blood per minute. Her kidneys started to work again and she suddenly had energy. The color came back into her face. Life flowed through her. She walked the dog, took care of her kids, and went shopping at the mall. It felt like a miracle.
Not everyone responded to Stacie’s condition with sensitivity. People tended to stare at her, with the heavy backpack and the tubes that led from her backpack into her abdomen, and some of them asked “rude, obnoxious questions.” The heart had the audible sound of an amplified heartbeat. Stacie quickly got used to it, but not everyone tolerated it. When she was well enough, she and her family went to the church they had attended before her surgery, a church with a sign outside that said “Come as you are.” After attending one service, the pastor told her that the sound of her heart was bothering some of the other parishioners, and he told her not to come back. Stacie and her husband could hardly believe it, but they agreed not to return.
After 196 days of living with the artificial heart, Stacie got the phone call telling her that a donor heart had become available. She had intensely mixed feelings about the news. On the one hand, she was incredibly excited, but on the other hand, she was worried about removing the artificial heart that worked so well that she had been living a virtually normal life. What if her body rejected the biological heart? With the TAH, rejection was not an issue. She had to take medications to avoid blood clots, but having a donor heart would mean having to take lifelong drugs to suppress her immune system, a process that carries serious risks. The immunosuppressant drugs meant that a simple infection could potentially take her life. She went through with the biological heart transplant and today Stacie is an active, healthy, full-time mom. She has to have regular biopsies to monitor for rejection of her new heart, and she was recently surprised to learn that she was actually experiencing mild rejection— surprised because she feels so well. Her cardiologist told her that those who experience mild rejection soon after a heart transplant actually tend to do the best in the long run. But she takes nothing for granted. She has no doubt about her priorities. “I got what I wanted, which was to be here with my family,” she says.
Stacie is one of approximately twelve hundred patients to be implanted with SynCardia’s 70 cc artificial heart. Although the large heart is approved by the FDA as a bridge to transplant, SynCardia has now created a 50 cc heart, suitable for women and adolescents, and has obtained FDA approval to explore the use of the smaller heart as a destination therapy, meaning that the implant would be permanent. No one yet knows how long the TAH can last, but the technology is evolving at an incredible rate. The trend toward miniaturization continues, and a 30 cc artificial heart is now in development that performs just as well as the larger versions. In spite of the overwhelming success of the TAH, there are a few drawbacks. Patients must have an open incision with two tubes the size of small garden hoses extending from their abdomen to the driver. Then there is the need to recharge the driver on a daily basis, plus the inconvenience of carrying the backpack at all times. All of these issues pale in comparison when the alternative is death, but the technology is moving quickly toward a more advanced end product: a small, completely self-enclosed artificial heart with a long-life battery implanted under the skin, which eliminates the portable driver and obviates the need for an open incision.
The potential market for artificial hearts is huge. Heart disease is the number one killer of both men and women, and biological hearts are extremely scarce. Many people today die of heart disease when they are otherwise healthy. With a durable, dependable artificial heart, who knows how long their lives could be extended?
To obtain a physician’s perspective on the artificial heart, I spoke with the pioneering heart-lung transplant surgeon Mark Plunkett, MD, who implanted three TAHs as chief of cardiothoracic surgery at the University of Kentucky (UK) College of Medicine. To speak with Dr. Plunkett is to hear the passion he has for artificial hearts and the incredible lifesaving alternative they offer to the “sickest of the sick” patients who would otherwise die waiting for a donor heart. While at UK, Dr. Plunkett pushed to have the medical center invest nearly $1 million to become equipped to offer the TAH to patients. A specialist in pediatric transplants, he has since accepted a position at the University of Florida and the Congenital Heart Center at Shands Children’s Hospital in Gainesville, Florida.
Dr. Plunkett knew from earliest childhood what he wanted to do with his life. Growing up in a small town on Maryland’s eastern shore, he was only seven or eight years old when he started telling people that he wanted to be a surgeon. He remembers vividly how, in 1967, when he was only seven years old, the world’s first human-to-human heart transplant was performed by South African doctor Christiaan Barnard. The recipient, fifty-three-year-old Louis Washkansky, lived for only eighteen days until complications took his life. The transplant, however, was successful, and from that moment forward Plunkett knew that he wanted to be a transplant surgeon. He was already fascinated by medicine, and hearing about the transplant was “just over the top.” He consumed medical information wherever he could find it and dedicated himself to clearing all the academic hurdles to becoming a surgeon. The farther along he got in his studies, the better he felt about his choice, and after an internship at Duke University Medical Center and a fellowship at UCLA Medical Center, he began performing heart and lung transplants on people of all ages, including children.
Plunkett was attracted to artificial organ transplant surgery in part because of the extreme shortage of biological organs, a problem that continues to plague patients with end-stage organ failure. There are over 119,000 people currently on waiting lists for donor organs, and about 7,000 of them die each year still waiting. The problem is that, for various reasons, too few people opt to become organ donors. Meanwhile, with the growth and aging of the U.S. population, the need for organ transplants is growing. Additionally, the average heart transplant only lasts twelve to fifteen years before rejection and heart failure necessitate another transplant. This may not be such a problem in elderly people who may die of other causes before their heart fails, but for pediatric patients, it means that children must go through multiple heart transplants in a lifetime, and each time their transplant gives out, they are faced with the dire shortage of compatible hearts.
Several different artificial organs are now being created and tested, but the technology behind the artificial heart has long been in development. In 1963, Paul Winchell created the first artificial heart, which became the prototype for the Jarvik heart, first implanted in a human in 1983. Over the next few decades, artificial hearts became more sophisticated and patients who received them were living longer and longer. In Dr. Plunkett’s words, the biotech industry is “exploding with gadgets,” and doctors have to look carefully for the ones that prove safe and effective. He is excited about the SynCardia Total Artificial Heart, especially about the future prospects of smaller, totally enclosed hearts that could be a lifetime therapy for children and adolescents, a prospect that he believes is just around the corner. He is especially impressed by the TAH because it doesn’t require drugs that suppress the immune system. The transplantation of a biological organ always requires immune system suppression, which only works for a while; in every case, the body will eventually reject the heart. He sees the next breakthrough in artificial hearts to be a miniaturized version with all the pumping power of the SynCardia heart, but only requiring the patient to wear a belt with a battery pack that continuously recharges the battery rather than the heavy backpack. The next version, a completely self-enclosed heart with a subcutaneous battery, is all but inevitable.
BEYOND HUMAN. Copyright © 2016 by Eve Herold. All rights reserved. Printed in the United States of America. For information, address St. Martin’s Press, 175 Fifth Avenue, New York, N.Y. 10010.