Are Heart Transplants From Severely Obese Donors Safe?
Only about half of the patients on a donor list for a heart transplant receive the needed surgery within a year-long wait. Here’s the latest on whether hearts from severely obese donors should be accepted.
Hearts, like many donor organs are in demand. However, hearts too, are in short supply and typically result in a patient being placed on a wait list until a suitable candidate organ becomes available for transplanting.
But what always qualifies as “suitable” is vague as many transplant centers avoid accepting donor hearts from severely obese individuals. The likely explanation for this is that severely obese donors tend to have more medical problems—such as diabetes and high blood pressure—than the non-obese donors; and therefore, makes transplantation of the donated hearts a questionable practice.
According to a news release from the American Heart Association, in the U.S., almost 40% of the adult population is classified as obese, and nearly 8% have severe obesity, which is defined as a body mass index (BMI) greater than or equal to 40. Couple this with the fact that approximately 3,000 heart transplant patients are wait-listed each year, the growing number of obese is significantly contributing to a decrease in the availability of what are considered suitable hearts for transplanting.
However, a new study published in the journal Circulation: Heart Failure reports that researchers have examined the validity and safety of using donated hearts from seriously obese donors.
“As the prevalence of obesity in the U.S. continues to rise, it directly affects the pool of organ donors,” said Leora T. Yarboro, M.D., lead study author and associate professor of surgery at the University of Virginia in Charlottesville, Virginia. “Since the prevalence of severe obesity has increased significantly over the past 15 years, we wanted to investigate the outcomes of recipients of transplant hearts from donors with severe obesity.”
Analyzing data from the United Network for Organ Sharing (UNOS) database focused on the outcomes of 26,000 heart transplants from 2003-2017, the researchers found that approximately 900, or 3.5%, of the donors had severe obesity categorized within a BMI of ≥40.
What the data showed was that:
• 10% of severely obese donors had diabetes vs. 3% of non-obese donors.
• 33% of obese donors had hypertension vs. 15% of donors with BMI
• 67% of heart transplants from severely obese donors were size mismatched (the donor’s weight was >130% of the recipient’s weight), compared to only 10% of transplants from donors without severe obesity.
• transplants from donors with severe obesity increased over time (from 2.2% in 2013 to 5.3% in 2017).
From this data, the researchers determined that there are no significant differences in post-transplant outcomes for patients who received a heart from a severely obese donor.
In fact, when comparing short-term outcomes such as postoperative stroke, acute rejection of the donor heart, and pacemaker need and dialysis requirement following surgery, incidences were similar for recipients of hearts from both obese and non-obese donors. Nor, were there any differences in one-year survival rates and long-term mortality for patients with transplants from severely obese donors.
“These findings were somewhat surprising because the severely obese donors did tend to have more medical problems, such as diabetes and high blood pressure, than the non-obese donors,” Dr. Yarboro stated for the news release.
“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.”
Timothy Boyer has a Ph.D. in Molecular and Cellular Biology from the University of Arizona. For 20+ years he has been employed as a freelance health and science writer. Today, with an eye on the latest news, Timothy continues writing about science with a focus on what you need to know for healthier living. For continual updates about health, you can also follow Timothy on Twitter at TimBoyerWrites.
Image Source: Courtesy of Gerd Altmann from Pixabay.
“Heart transplants from severely obese donors show comparable outcomes for patients” American Heart Association news release 16 September 2020.
“How Big Is Too Big? Donor Severe Obesity and Heart Transplant Outcomes” Elizabeth D. Krebs et al. Circulation: Heart Failure, originally published16 Sep 2020