Rapid Adoption of DCD Heart Transplantation Expands Donor Pool

Last fall the transplant team at Cleveland Clinic Weston Hospital became the first in Florida’s southern region to perform modern adult heart transplantation using a donation after circulatory death (DCD) heart, joining a growing number of U.S. centers to adopt this innovative approach.

“Organ procurement and preservation advancements have made it possible to safely use hearts retrieved from donors after circulatory death and achieve good outcomes on par with organs from donors who experience brain death,” says cardiothoracic surgeon Nicolas A. Brozzi, MD, Surgical Director of Mechanical Circulatory Support at Weston Hospital.

Nationally there has been a rapid increase in the use of DCD hearts since the practice was reintroduced in the United States in 2019. According to Organ Procurement and Transplantation Network (OPTN) data, approximately 8% of heart transplants in 2022 involved DCD organs, increasing to 13% in 2023 and reaching nearly 18% in 2024.

“Using DCD hearts has expanded the donor pool for patients on the national waitlist, and in just a few short months we’ve seen a sizeable jump at our center in the volume of potential donor organs being offered and assessed,” Dr. Brozzi reports.

DCD versus DBD

While heart transplants were initially performed with DCD donor hearts, the field shifted to donation after brain death (DBD) organs in the early 1980s following the development of uniform brain death criteria and the increased risk of ischemic injury during organ retrieval associated with DCD hearts.

“Severe ischemic injury can result in loss of pump and electrical function making the heart unsuitable for transplantation,” Dr. Brozzi explains. “The development of machine perfusion for the dynamic preservation of organs, however, has renewed interest in the use of DCD hearts. This advanced technology circulates oxygenated blood or other fluids through the donor organ before transplantation.”

The Transplant Center at Weston Hospital has transplanted machine perfused donor kidneys since its launch in 2013. More recently, the center established a machine perfusion program that has since performed more than 65 adult liver transplants employing a variety of advanced preservation techniques. “We have a very robust machine perfusion program, and now that technology and experience is being applied to heart transplantation,” says Dr. Brozzi.

Heart recovery methods

When a potential organ donor has suffered a severe, irreversible brain injury or devastating illness and is close to death, the donor family may choose to allow a natural death. Once life support is withdrawn and circulatory death is declared, a 5-minute standoff period is observed to monitor for signs of autoresuscitation of the heart before the donor’s heart is recovered.

DCD heart procurement then can be performed either through ex situ normothermic machine perfusion (NMP) or normothermic regional in situ perfusion (NRP) followed by static cold storage (SCS). Both methods allow for heart reanimation and evaluation at the donor site to determine viability for transplantation.

Weston Hospital has transplanted donor organs preserved and transported using the TransMedics Organ Care System (OCS™), currently the only FDA-approved system for ex situ perfusion of DCD hearts.

“Machine perfusion keeps the heart beating and supplied with nutrients while in transport, so that when it reaches our hospital we can then reassess to determine if it's suitable for transplantation,” describes Dr. Brozzi. “Visual inspection, coronary flow and lactate metabolism are used to reassess heart function and viability.”

Alternatively, NRP uses extracorporeal membrane oxygenation (ECMO) technology to restore abdominal/thoracic circulation within an organ donor who has experienced circulatory death. Once viability of the heart is confirmed, it is retrieved and preserved using SCS, the traditional method for organ preservation, and then transported to the recipient site.

The Transplant Center at Weston Hospital has performed adult liver transplants with DCD donor organs retrieved following NRP and plans to adopt this recovery method for DCD hearts as well.

Patient outcomes

Studies have shown that the machine perfusion of DCD hearts can achieve similar patient and graft survival outcomes when compared to DBD organs preserved using SCS.

For example, results from the Donors after Circulatory Death Heart Trial, published in 2023, found that DCD hearts had a 94% survival rate, compared to 90% for DBD hearts. While the U.S.-based multicenter, unblinded, randomized, controlled trial observed a higher incidence of primary graft dysfunction among recipients of DCD hearts, it did not affect patient or graft survival at 30 days or 1 year.

Researchers in another study used the OPTN/United Network for Organ Sharing (UNOS) registry to identify adult heart transplant recipients from 2019 to 2021 and found comparable mortality outcomes between DCD and DBD hearts. The national registry review also noted DCD donors tended to be younger and male while DCD heart recipients were more likely to have a lower UNOS status (3-6), indicating reduced medical urgency.

According to Dr. Brozzi, the last two years have seen an increasing use of DCD hearts in sicker patients higher up on the waitlist. “We are also assessing more hearts from female donors and from individuals who are older than 50, outside the age range of standard criteria organ donors,” he notes.

Looking ahead

Ongoing research continues to focus on improving organ procurement and preservation strategies, reducing ischemic times, and enhancing the viability of DCD hearts. In addition to tracking mid-term and long-term performance and outcomes of NMP and NRP recovery methods, investigators are looking at hypothermic machine perfusion options as an alternative preservation modality for DCD hearts.

“DCD heart procurement and transplantation has evolved quickly this past decade and the increasing demand for donor hearts will continue to drive research in the area of dynamic organ preservation,” says Dr. Brozzi.

He notes that the use of DCD hearts has the potential to significantly expand the donor pool, and that improved organ preservation methods may allow the matching of organ donors and recipients across greater distances.