The process for prioritizing heart and lung transplant candidates and determining the treatments they receive while awaiting donor organs is under review by the International Society for Heart and Lung Transplantation (ISHLT) during its Annual Meeting and Scientific Session this week in Philadelphia.
In the past few years, beta-blockers, ventricular and assist devices, stem cell implants and other advancements have radically changed the landscape of heart and lung transplant medicine and the outlook for patients living with heart or lung disease.
"We urgently need to revisit the current criteria that organ centers are using and provide new, clear guidelines to help these centers update their policies in regard to waiting lists and management of potential transplant recipients," says Mandeep Mehra, M.D., University of Maryland School of Medicine and board member for the ISHLT.
During discussion at the ISHLT Meeting, Mehra explains that several agencies worldwide review and address guidelines for treatment and management of heart and lung failure in patients, but adds that none are comprehensive. "Our Society is in the ideal position to advocate comprehensive guidelines for our constituents," Mehra says.
ISHLT has created several task forces, comprised of a diverse group of its members, all of whom are active in transplant medicine. The task forces are reviewing: criteria for placing patients on a waiting list for a donor organs; pharmacological, surgical and device based intervention to successfully bridge patients to transplant. Highlights from the discussions will be presented on Saturday during the closing session of the Meeting.
Specifically, precise guidelines, without ambiguity, will be presented to the membership. These include guidelines on performance, interpretation and use of stress testing to guide patient listing, as well as when and how to use invasive catheterization. The proposed guidelines also expand the limitations of previously established contraindications to transplant, such as age, diabetes, peripheral vascular disease, renal insufficiency and cancer history.
"There are many issues to consider. A lot has changed just in the past few years," Mehra says. A primary example is that of the growing older population, and with it, a greater number of patients who would benefit from a transplant. "There are now a lot of patients who are viable transplant candidates who probably would not have been considered before because of their age and the therapies we had available in the past."
Jonathan Orens, M.D., Medical Director of the Johns Hopkins Hospital Lung Transplantation Program, explains that logically, the ideal formula is for a patient to be placed on a waiting list when life expectancy and quality of life without transplantation is compromised, but still greater than the expected waiting time for an organ. Simply put, patients should receive donor organs when they will be better with the transplants than without them.
Because the standards for viable organs differ for heart and lung patients, so do the number of available organs. "Demand for donor lungs is much greater – the criteria is much stricter, so fewer lungs are available," says Orens.
The task force groups are also tackling key issues, such as how best to allocate organs to patients, and whether all organ centers should use a "survival score" to determine a patient's prognosis.
"These are guidelines, not governances or mandates," Orens explains. We acknowledge that there are many factors – practical, cultural and medical – that influence how transplant candidates are identified and donor organs are allocated."
Orens says that the Society recognizes the gravity of their decisions. "We have a clear, ethical responsibility to respect the altruistic gift from each organ donor family. Our job is to apply medical principles to find balance between that gift and the needs of potential recipients.
"We do not intend to throw wisdom out the window, rather we want to update widely held beliefs and offer continued support of relevant concepts," Mehra says. "There is a lot of knowledge out there that is robustly worthy of our support."