Racial and Ethnic Disparities Persist in Pediatric Heart Transplantation

Differences still exist, particularly in waitlist mortality

Over the last two decades, tremendous advances have been made in waitlist and post-transplant outcomes for children undergoing heart transplantation. But whether these advances have benefitted all children in the current era, regardless of racial or ethnic background, was unknown.

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“We didn’t have an answer, because all national studies evaluating disparities in pediatric heart transplantation were conducted prior to 2009. These early studies showed waitlist and post-heart transplant outcomes to be worse among children from racial and ethnic minorities than White children,” says Shahnawaz Amdani, MD, a pediatric heart failure and transplant cardiologist at Cleveland Clinic Children’s.

The impact of VADs

One of the most significant advances of the last 10 to 15 years has been the successful utilization of ventricular assist devices (VADs) to support children with advanced heart failure.

“With approval of the Berlin Heart EXCOR® on December 16, 2011, we started having greater success in bridging younger children to transplant. Additionally, there has been growing comfort using adult devices in adolescents,” says Dr. Amdani. “Other advances include the formation of the Advanced Cardiac Therapies Improving Outcomes Network and the standardization of post-VAD care. Collectively, these have improved our ability to support children with heart failure awaiting heart transplantation.”

The question was whether these developments have had a role in eliminating disparities. Dr. Amdani began exploring this topic scientifically.

“If we are using VADs in all patients eligible to receive this therapy, then they should improve outcomes across the board,” he says.

A diverse group

To conduct their study, Dr. Amdani and colleagues accessed all patients under age 18 listed for primary heart-only transplantation in the Scientific Registry of Transplant Recipients (SRTR) database from December 16, 2011, to February 28, 2019.  

They further stratified the cohort of 4,089 patients into five racial/ethnic groups: White, African American, Hispanic, Asian and other: 2,134 (52.2%) were White, 840 (20.5%) were African American, 808 (19.8%) were Hispanic, 161 (3%) were Asian and 146 (3.6%) were other.  

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African American children listed for heart transplantation had a higher acuity of illness, as evidenced by higher rates of renal dysfunction, hypoalbuminemia and need for higher urgency listing.

A total of 2,865 children— 1,509 White, 563 African American, 570 Hispanic, 125 Asian and 98 other—were transplanted. 

Findings of note

After adjusting for risk factors, only African American children were at increased risk of waitlist mortality compared to White children. No significant difference in post-transplant survival was noted for African American children compared with White children. However, in the first three years after transplantation, African American children were more likely to experience rejection episodes and be hospitalized for rejection than White or Hispanic children.

Their study was published in the Journal of Cardiac Failure.

“These findings raise many questions,” says Dr. Amdani. “Do African American children with advanced heart failure have a different trajectory? Are they more likely to worsen quickly? Are they being referred late? Is organ rejection higher in African American children due to genetic differences? Is it due to differences in the way they metabolize medications? Do they need higher doses of immunosuppressive medication or more frequent dosing or follow-up?”

“The answers are not immediately apparent,” he says.

Getting to the truth

Studies have demonstrated that African American adults with advanced heart failure are less likely to be evaluated by a cardiologist, receive a VAD and get listed for transplantation. Potentially, African American children may be referred for transplantation late, and are therefore sicker, due to racial/ethnic bias. But teasing out the truth may not be simple.

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“It would be easy to say that African American patients are likely to die on the waitlist because they are sicker, but we adjusted for everything we were aware of to see whether race was an independent predictor of mortality and found African American children had a 25% higher risk than White children,” says Dr. Amdani.

“In our study, African American and Hispanic children were most likely to be on Medicaid,” he continues. “It is known that there are barriers to healthcare access for people from racial and ethnic minorities and lower socioeconomic classes. We need to know if this concern affects access to care for children from racial and ethnic minorities with advanced heart failure,” he says.

To understand whether implicit racial and socioeconomic bias exists among pediatric heart transplant providers, Dr. Amdani and a colleague in St. Petersburg, Florida, in conjunction with the Pediatric Heart Transplant Society are currently conducting a research study and have invited national and international caregivers within the heart transplant team to participate. Their findings will be available later this year or early next year.

“When making the decision whether or not to list a pediatric patient for transplantation, many people evaluate the patient independently and then weigh in. If anyone has an unconscious bias, their comments may influence the group’s decision,” Dr. Amdani explains.

“Acknowledging that there is unconscious bias toward children of racial minorities and lower socioeconomic status would be the first step to eliminating it,” he says.

He is also evaluating whether community risk factors — including where the patients live, the availability of local resources, parental education level, access to basic amenities and transportation—impact waitlist and transplant outcomes.

“Despite the advances in medicine and technology, we have not been able to eliminate disparities, and African American children continue to experience higher waitlist mortality and organ rejection,” he says. “Now we have to seek ways to close and, hopefully, eliminate the gap.”