Heart transplants from donors with severe obesity provide benefits similar to hearts donated from people with a body mass index of less than 40, according to a study in Circulation: Heart Failure.
A University of Virginia research team pursued the study since a growing list of U.S. patients are waiting for heart transplants. Out of 3,000 people currently waiting for a heart transplant, about half will receive one. Heart transplant centers in the U.S. typically accept size-matched hearts within 30 percent of a recipient’s body weight. These guidelines align with the International Society of Heart and Lung Transplantation, but vary by transplant center.
“As the population becomes increasingly obese, so does the pool of potential organ donors,” the researchers write in the review. They analyzed short- and long-term outcomes associated with 26,532 heart transplants from the United Network for Organ Sharing database between 2003-2017. The data were assessed in 2018 and included 939 hearts from donors with severe obesity.
The primary measure for the heart transplant study was longevity, or life span. Short-term outcomes included incidents while the patient was in the hospital, such as rejection of the heart, or if the patient had a stroke or required dialysis after surgery. Other measures, such as graft failure and the need for a pacemaker, were assessed during follow-up visits. Recipients checked in with their medical team six months after the surgery, and then each year. The researchers limited their analysis to adults receiving a first-time, single-organ heart transplant.
While analyzing these outcomes, the researchers factored in prior comorbidities from hearts donated from people with severe obesity. Obesity-related conditions, like diabetes and high blood pressure, that donors had didn't increase the risk for premature death for heart transplant recipients. However, recipients had an increased risk of death if they had these conditions. The authors note there wasn’t an increased mortality risk for oversized or undersized heart transplants.
“These findings were somewhat surprising because the severely obese donors did tend to have more medical problems,” lead study author Leora T. Yarboro, M.D., explains in a release issued by the American Heart Association. “This study shows that with careful selection, hearts from obese donors can be used without an increased risk to the recipient. Given the continued increase in obesity in the U.S., this research has the potential to expand the critically low donor pool by increasing the number of donors and improving outcomes for the growing list of patients with end-stage heart failure.”
The study was funded by the National Heart, Lung, and Blood Institute.