Hearts donated by severely obese donors aren't more risky for recipients than hearts from people who aren't obese, a new study indicates.

"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," said study author Dr. Leora Yarboro. She's an associate professor of surgery at the University of Virginia, in Charlottesville.

Her team analyzed the outcomes of 26,000 heart transplants in the United States from 2003 to 2017. About 3.5% of the donors were severely obese.

There were no significant differences in short-term outcomes, one-year survival rates or long-term death rates between patients who received a heart from a severely obese donor and those who received a heart from a non-obese donor, the findings showed.

The researchers also found that the percentage of heart transplants from donors with severe obesity rose from 2.2% in 2013 to 5.3% in 2017.

Some of the obese donors did have other medical issues: 10% had diabetes versus 3% of non-obese donors, and 33% had high blood pressure versus 15% of donors who weren't severely obese.

The study was published Sept. 16 in the journal Circulation: Heart Failure.

"This study shows that with careful selection, hearts from obese donors can be used without an increased risk to the recipient," Yarboro said in a journal news release. "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 waiting list for a heart transplant in the United States hovers at about 3,000 people. Despite the need to expand the pool of potential heart donors, transplant centers are hesitant to use hearts from obese donors.

Nearly four in 10 adults in the United States are obese, and nearly 8% are severely obese.

"As the prevalence of obesity in the U.S. continues to rise, it directly affects the pool of organ donors," Yarboro noted.