Heart Transplant Mortality Worse for Younger Black Adults

By Lisa Rapaport

February 08, 2021

(Reuters Health) - The starkest disparities in heart transplant survival between Black patients and their non-Black counterparts in the U.S. may occur among younger adults, and within the first year posttransplant, a new study suggests.

Researchers examined registry data on 22,997 adult heart recipients from 2005 to 2017. Overall, Black recipients had a 2.05-fold higher risk of mortality compared with non-Black patients.

The mortality risk was higher for Black patients at ages 31-40 (aHR 1.53) and 41-60 (aHR 1.20), but the increased mortality at ages 61-80 (aHR 1.12) wasn't statistically significant, researchers report in Circulation: Heart Failure.

The increased risk in the youngest group was primarily due to deaths within the first year after transplants, when Black patients had an even more pronounced risk of mortality (adjusted hazard ratio 2.30) compared with other heart transplant recipients. The most common causes of death among younger adult transplant recipients were cardiovascular conditions and graft failure.

"The first year after transplant is the highest risk time period for all patients, in part due to a high risk of rejection of the transplanted organ that typically decreases over time," said Dr. Alanna Morris, author of an editorial accompanying the study and director of heart failure research at Emory University School of Medicine in Atlanta.

However, Black patients have many risk factors that may increase mortality, Dr. Morris said by email. Generally, they are younger and sicker at the time they are listed for heart transplant, she said.

In addition, young patients typically have immune systems that are more active, and Black patients also have more diversity of the human leukocyte antigen (HLA) system putting them at higher risk for receiving a mismatched organ," Dr. Morris added.

"Both of these factors put young, Black patients at higher risk for rejection," Dr. Morris said.

Limitations of the analysis include the lack of data on immunosuppression levels or immunosuppression changes after discharge. Researchers also lacked some data for cause of death and rate of graft loss.

"While further investigations to understand factors contributing to the higher first-year mortality need to be performed, we do know that successful outcomes depend on understanding and adjusting for preoperative risk factors, minimizing perioperative complications, appropriate management of immunosuppression and appropriate transplant organ surveillance with optimization," senior study author Dr. Errol Bush, an associate professor of surgery at Johns Hopkins University in Baltimore, said by email.

Clinical decision-making and clinical trials should focus on individualized and unique sets of risk factors that contribute to a higher risk of mortality among young Black recipients especially in the first year post-transplant in order to reduce long-standing disparities in heart transplant outcomes, Dr. Bush said.

"The disparities observed in young Black patients are shocking and sadly similar to what has been reported in heart disease and stroke among young Black patients compared with white patients," said Dr. Sadiya Khan of the Northwestern University Feinberg School of Medicine in Chicago.

"While risk factors may be on the path to these disparities, we have to focus on upstream social determinants of health, such as structural and systemic racism that are likely contributing to both development of risk factor and transplant outcomes," Dr. Khan, who wasn't involved in the study, said by email.

SOURCE: https://bit.ly/2YMLBfh Circulation: Heart Failure, online February 2, 2021.