Study finds resuscitated hearts are also effective for transplants, potentially making more organs available to patients in need

CNN
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The researchers say they were able to open up a new pool of organ donors for heart preservation and transplantation. These are people whose hearts stop beating, leading to so-called circulatory death.

Traditionally, only people who were declared brain dead but whose hearts and other organs continued to function were considered suitable organ donors.

There is another group that is willing to donate if survival is not possible. These are people who may have severe brain damage but are not brain dead. In such cases, if the heart stops beating after the life support machine is removed, the person is considered dead, also called circulatory death.

Circulatory post-death donations (DCD) are also popular in countries such as the UK and Spain. It has become somewhat common in organs such as the kidney in the United States. But US transplant teams were reluctant to accept hearts that stopped beating even briefly, fearing that lack of oxygen to the heart would damage organs and affect lifespan.

Shortly after death, before the heart recovers, “there is a period of both reduced blood flow and cessation of blood flow during which the heart is very sensitive. That’s why people didn’t think this was always possible.” said Jacob Schroeder, Ph.D., chief of surgery at Duke University’s heart transplant program and author of a new study on the subject published Wednesday in The News. British Journal of Medicine.

Schroeder and his team found that it was not only possible, but actually worked just like using organs from brain-dead donors.

In the first clinical trial of the new technology, the research team randomly selected 180 patients with heart failure to transplant either resuscitated donor organs or hearts from brain-dead donors.

Six months later, it was found that patients who received a resuscitated heart after a cardiovascular death were just as likely to be alive as those who received a new heart from someone who had been declared brain dead.

Additionally, the team was able to use 90% of hearts from donors who experienced cardiovascular death, with very few hearts wasted.

“Honestly, this should be the standard of care, and every transplant center in the country should consider using it,” Schroeder said.

Once a donor has been identified, a transplant team will be on standby after life support is turned off. When the heart stops beating, it can take minutes to hours, and doctors wait at least 5 minutes before declaring death.

After that, they work quickly, first removing the heart from a deceased patient by cooling it, then placing it in a special machine that fills the heart with warm blood. A small shock from the pacemaker can help activate the pacemaker and get the heart beating again. It will be stored in the machine until the recipient is ready to pick it up.

Schroeder says that moment when the heart comes alive again and starts beating again never gets old.

“Every time I do this, it’s like the best thing ever,” he said.

Survival rates were high in both groups, with about 94% of patients receiving resuscitated hearts still alive after 6 months, compared with 90% of those receiving hearts from brain-dead donors.

Researchers say the number of hearts available for transplantation in the United States could increase by up to 30% if more transplant centers adopted the new method.

A donated heart after dying of cardiovascular disease saved the life of 45-year-old Jason Banner. A native of Fayetteville, Georgia, Banner became a single father to a 5-year-old daughter and a 9-year-old son after his wife died in 2019.

For a while he feared that they too might lose him.

Banner was born with a genetic condition that caused her heart to begin deteriorating in her late 30s.

Surgery to replace two heart valves in 2015 bought him some time, but by December 2021 his condition was rapidly going downhill. Doctors in Atlanta put him on drugs to extend the life of his heart and evaluated whether he could be placed on a transplant list.

Doctors also encouraged him to participate in a clinical trial testing new transplant options at Duke University.

Time was running out and research felt like a lifeline. Banner said it “really gave us more options” for finding the heart.

Transplant candidates are ranked according to disease severity on a scale of 1 to 6, with 1 being the most urgent case. Banner made the list at 3, but deteriorated rapidly. The sack around his heart filled with fluid, which he said was one of the most painful he had ever felt. Doctors told him to stay near the Duke University hospital until his heart was found.

“Well then, June 15th^th The phone rang at 5:58 in the morning and they said they had found my heart,” Banner said.

Doctors said it was probably from a donor whose heart had stopped beating.

“I would love to have you,” said Mr. Banner. “Yes. I didn’t mind. I wanted to be here I wanted to see my children’s graduation ceremony. I would like to see my children get married or hopefully have a family of their own,” he said. “I wanted to give myself a chance.”

After doctors examined the heart to make sure it was healthy enough for a transplant, surgery began. Banner said he was under anesthesia by noon. He woke up early in the morning and started singing along to the TV.

Four hours later he was circling around the nurses station. He said he was discharged nine days later with “zero rejection.”

Expansion of the donor pool

Banner knows he’s one of the lucky ones. 17 people die every day in the United States while waiting for an organ transplant. according to Federal Office of Health Resources Services.

Schroeder said that number could be reduced if more hearts were transplanted from donors who died of cardiovascular disease.

“By expanding the donor pool, we are also expanding the list of recipients, making transplants available to more people who need them,” Schroeder said.

Getting 30% more organs from cardiac arrest donors would be a significant increase.

The number of cases has steadily increased since post-cardiovascular donations began to be studied in the United States in 2019 for heart and cardiopulmonary transplants. Last year, 345 such surgeries were performed, which is only about 8% of the total of 4,162 heart and cardiopulmonary transplants performed in 2022. According to statistics From United Network for Organ Sharing (UNOS).

“I think it’s safe to say that the number of these heart transplants is increasing, and we expect that trend to continue, especially now that the outcome data for this study are now available.” UNOS spokeswoman Anne Pashke said.

The new study found some differences between the participant groups. Hearts transplanted after circulatory death were likely to suffer from a complication called severe graft failure, in which the transplanted organ fails to pump enough blood to meet the circulatory needs of the recipient. This occurred in about 15% of people who received resuscitated hearts, compared with 5% of those who received hearts from brain-dead donors.

However, this complication did not appear to affect overall survival and was considered manageable.

Experts also say the study was good, but it wasn’t blind, meaning doctors knew which participants would get each type of organ. The study authors say this was necessary to prevent the most critically ill patients from being placed on waiting lists and always qualify to receive the next available organ regardless of source.

However, this precaution created an imbalance in the study. The sickest patients were more likely to receive a heart donation from a post-brain dead person, whereas the more stable candidates were more likely to be selected to receive resuscitated heart donations.

Nancy Switzer, M.D., medical director of the Department of Clinical Research at the Department of Cardiology, Washington University School of Medicine in St. Louis, said studies have shown worse outcomes when high-risk organs are transplanted into sick patients.

Sweitzer, who wrote an editorial alongside the study but was not involved in the study, said the doctors who participated in the study were not willing to risk weakening the organs of their sickest patients. thinking.

That means the study leaves some open questions about who this method works for.

“It is not clear whether heart transplantation from a circulatory deceased donor is truly safe for patients with the most severe heart failure,” she wrote. “As the number of organs transplanted from deceased cardiovascular donors increases, the impact of usage patterns and the expansion of the donor pool needs to be carefully evaluated.”

She says more research is needed to understand who is the best candidate for this surgery.

“I think a lot of programs… have been waiting for this data to see if transplants would increase significantly if they invested in all the necessary infrastructure,” Sweitzer told CNN.

“From now on, people will start pushing the envelope, and I think it will be years before we know when it works and when it doesn’t,” she said. The publication of this paper will change what is happening in our field pretty quickly. ”