Geographical allocation changes boost heart and lung transplant program at Mayo Clinic in Minnesota

July 29, 2022

Since the U.S. Organ Procurement and Transplantation Network heart and lung transplant allocation changes instituted in 2017 to 2018, the heart and lung transplant program at Mayo Clinic in Rochester, Minnesota, has grown due to an expanded geographical reach. The allocation changes extended the catchment area from each transplant donation center to a range of 250 miles for lungs and 500 miles for hearts — a radius around the hospital designed to keep an organ viable. For Mayo Clinic's Minnesota campus, this region now includes metro areas such as Chicago. Previously, the geographic area for heart and lung allocation for this campus reached only as far as North Dakota and South Dakota.

"The geographical allocation changes have helped Mayo Clinic in Minnesota, as we have the ability to take care of a wider swath of patients, even if they require complex heart and lung transplants," says Philip J. Spencer, M.D., a heart and lung transplant surgeon at Mayo Clinic in Minnesota. "We've had a marked uptick of patients here since these changes: We've gone from 13 to 53 heart transplants a year, and from 10-13 to 36 lung transplants a year."

He also explains that although Mayo Clinic in Minnesota is a state-of-the-art medical center, it is located in a low-population, mostly rural area, unlike similar medical centers located in large metropolitan regions.

Because the previous heart and lung transplant allocation policy kept organs in their regions, a smaller population with a correspondingly lower occurrence of vehicle crashes and violence meant limited availability of hearts and lungs to Mayo Clinic's Minnesota campus, disadvantaging the center for transplants of these organs, according to Dr. Spencer.

At times, patients in an area with fewer organs accessible take the matter into their own hands and move locations. Dr. Spencer knows of patients awaiting transplant who have moved from Massachusetts to Florida or Tennessee, for example, to improve their waitlist status in a region that typically has more hearts and lungs available.

"Florida has always been a state where organs are available," says Dr. Spencer. "It's highly populated, and there are car wrecks and other traumas. Yet transplants turn these tragedies into an opportunity for hope for someone who needs an organ."

However, not all patients can make such a move for financial, family or job-related reasons, hindering these patients in their journeys to obtain new hearts or lungs.

"In the previous allocation system, you'd need a MELD of 25 to get a heart in Massachusetts, but in other states you might only need a 15," he says. "It was very unfair, because if you were not wealthy, in certain geographies you were not going to get a transplant."

What prompted the changes

Dr. Spencer says the following factors led to the national allocation changes:

  • Recognition of fairness in society and equity in transplant organ allocation
  • Technological improvements leading to better perfusion for hearts and lungs — including ex vivo and ex situ perfusion — and ability to transport organs farther and maintain viability

The allocation changes mean that organs are now available beyond the hospital's organ procurement organization.

What allocation changes mean for patients

Dr. Spencer is pleased that now — with the revised allocation system — patients get organ offers earlier. And sicker patients, such as those who are extremely ill on extracorporeal membrane oxygenation (ECMO), rise to the top of the waitlist. Though previously the transplant community thought that patients might not fare well if receiving heart and lung transplants after ECMO, a study by Gabriel Loor, M.D., and colleagues indicated that not to be the case. The study, published in JTCVS Open in 2021, demonstrated that patients bridged to lung transplant with ECMO — if both awake and appropriately selected — experienced posttransplant outcomes similar to those of patients not bridged with ECMO.

"Essentially, the study indicated that if we take care of patients who've been on ECMO well through the transplant process, they do well," says Dr. Spencer. "This is taking people who would surely die and keeping them alive."

The challenge in caring for patients who are ill enough to require ECMO at many hospitals, however, is staffing and having the right expertise to manage these patients, says Dr. Spencer. Mayo Clinic is uniquely privileged to have ICU staff members with specific knowledge, he says, allowing care for patients on ECMO with the appropriate ambulation time necessary to prehabilitate them for transplant.

"Patients who are this ill need to be at a quaternary care center that does what we do — such as four myectomies every day — with ancillary staff members to take care of these patients on the front end, as it leads to better transplant outcomes," he says. "It's the institutional expertise and also the whole support system. These patients need a volume ECMO center to get them in as good a position as possible to have a successful transplant."

A 2021 publication by Nicholas R. Hess, M.D., and colleagues in Clinical Transplantation found that though the geographical allocation changes for heart transplant did increase heart transplantation rates in all regions across the U.S., some geographical disparity persists. Dr. Spencer agrees about the policy's upsides, explaining that it has addressed multiple problems, making it fairer for patients and decreasing waitlist mortality by getting organs to people who are going to die soon.

However, the new system is not perfect and has potential for further improvement, he says, with those in safer, less populated areas of the U.S. still disadvantaged, though not to the degree they were before the allocation changes. Dr. Spencer also indicates that though patients on ventricular assist devices and other mechanical circulatory support devices were highly advantaged with the previous allocation system, the revised system has disadvantaged them.

"We want to help everybody," says Dr. Spencer. "The key questions are: Are they sick enough that doing a heart or lung transplant is the right thing to do? Will they survive the surgery?"

For more information

Loor G, et al. Extracorporeal membrane oxygenation support before lung transplant: A bridge over troubled water. JTCVS Open. 2021;8:147.

Hess NR, et al. Geographic disparities in heart transplantation persist under the new allocation policy. Clinical Transplantation. 2021;35:e14459.

Refer a patient to Mayo Clinic.