“In the previous five years, the program has grown in both talent and innovation,” says Jeffrey Teuteberg, MD, section chief of Heart Failure, Cardiac Transplantation, and Mechanical Circulatory Support. “The resulting larger volumes and improved transplant outcomes have led to our ranking at the top in the country according to expected survival and decreased wait times.”
Driving innovation to optimize transplant outcomes
These achievements rest on a foundation of innovations that continue to improve care for patients receiving either heart or heart-lung transplants. Stanford Health Care’s Heart Transplant Program has benefitted from three transformative innovations in particular.
Noninvasive assessment of transplant status
Utilizing a simple blood test targeting cell-free DNA (cfDNA) has largely replace traditional biopsies of the transplanted heart. As cells from the transplant heart die and break apart, the DNA from those cells can be detected in the circulating blood. There is usually a low level of cfDNA in the blood, but the level of cfDNA increases in the setting of injury to the transplanted heart, such as during rejection.
In the context of heart transplants, Teuteberg explains that traditional biopsies tend to offer information exclusive to the biopsy site, which precludes overall evaluation of heart function. “Clearly cfDNA is non-invasive, but also a more sensitive marker of what is currently happening across the entire heart.”
The ability to establish baseline cfDNA levels specifically related to the transplanted heart enables identification of adverse events based on changes in those levels. This has also altered how routine surveillance post-transplant is being performed. “We are beginning to look at analyzing cfDNA as a way to predict long-term outcomes,” states Teuteberg. “Aside from simply replacing a biopsy, cfDNA has provided a different perspective on how to monitor patients over time.”
Personalization of immunosuppressive therapies
Introducing allografted tissue to the host immune system inevitably elicits a strong immune response that can result in graft rejection. Suppressing this response is a critical step in any transplant procedure, with the goal being to avoid adverse systemic side effects while also preventing transplant failure.
Currently, immunosuppressive regimens tend to be applied broadly according to patient stratification as either high or low risk of rejection. However, this represents another area where post-transplant evaluation of overall graft health via cfDNA levels is transforming post-transplant patient care.
“The ability to accurately assess how both the patient and graft are responding to therapy allows us to optimize treatment for that patient,” explains Teuteberg. “This type of personalization involves tailoring the medication according to what works best for the patient to avoid downstream side effects, such as hypertension and renal insufficiency.”
Capitalizing on improved methods to obtain and transport donor hearts
Efforts to reduce transplant wait times tend to focus on addressing issues related to organ procurement and transport. Stanford Health Care utilizes an innovative device that has revolutionized organ transport by supplying a stable environment capable of maintaining the tissue within a narrow temperature range.
Teuteberg says that this effectively addressed the limiting factor of travel distance in obtaining donor organs and allowed their team to be more confident and aggressive in procuring organs further away from Stanford. “In addition to increased availability to patients, both local and national data suggest decreases in the incidence of failure in grafts transported using this equipment.”
Another pathway to organ availability is donation after cardiac death (DCD). In these cases, a donor who has suffered irreversible brain injury experiences natural death according to the wishes of the family. After the heart stops beating, the recovered organs can be donated; however, DCD hearts need to be revived, stabilized, and evaluated prior to transplant.
The use of a heart perfusion system allows the resuscitation, preservation, and possible reconditioning of heart function prior to transplantation. These systems enable the successful transplant of a heart after long-distance transport in a machine that allows the heart to beat and circulate oxygenated blood and nutrients. Teuteberg emphasizes the benefits of this device to patients awaiting transplants. “The use of DCD donors significantly increases the donor pool, which shortens wait times while promoting improved transplant outcomes.”
Saving lives through teamwork and collaboration
Significant contributors to improved transplant outcomes involve hiring highly qualified surgeons and focusing on research, both of which translate to expanding criteria for patient eligibility, including acceptance of those requiring multiorgan transplants.
Teuteberg specifically acknowledges Joseph Woo, MD, chair of the Cardiothoracic Surgery Department, and the growth of his surgical team as keys to the numerous transformative innovations realized within the transplant arena. In addition, he emphasized the critical contributions of Hannah Valentine, MD, and Kiran Kaur Khush, MD, both Stanford Health Care cardiologists, in driving cfDNA research and its successful application in heart transplantation.
“As an interdisciplinary team, our continuous efforts to improve patient outreach and standardize intake and follow-up procedures have helped the program grow in numbers and outcomes,” explains Teuteberg. “Stanford’s receptiveness to new techniques and embracing innovation allowed us to expand our program, which has translated into lifesaving transplants.”
Learn more about Stanford Health Care’s Heart Transplant Program.
Top image of William Hiesinger, MD (left) and Patpilai Kasinpila, MD (right), courtesy of Winston L. Trope.