Donor obesity may not affect outcomes in heart transplantation
Transplant recipients of hearts from donors with severe obesity experienced no more adverse events and similar 1-year survival as those who received hearts from donors without severe obesity, according to researchers.
Researchers reported that with the rising prevalence of obesity in the U.S., these findings may support the inclusion of donors with obesity and larger hearts to the already critically low donor pool.
“Transplantation of hearts from obese individuals and utilization of oversized hearts have both been associated with no increase in adverse outcomes and represent a promising, safe way to increase the donor pool,” Elizabeth D. Krebs, MD, MSc, resident physician in general surgery at the University of Virginia Medical Center in Charlottesville, and colleagues wrote in Circulation: Heart Failure. “Furthermore, as the obesity epidemic continues, it is likely that the proportion of obese potential organ donors will continue to grow, necessitating clearer consensus on how to best utilize the organs from these individuals.”
Investigators analyzed 26,532 single-organ first-time heart transplants performed from 2003 to 2017 from the United Network for Organ Sharing database. Of these, 3.5% of transplants were from donors with BMI of at least 40 kg/m2. The researchers assessed the relationship between severe obesity among donors and short-term outcomes and survival at 1 year among recipients.
Among transplants from donors with severe obesity, 67.4% were size mismatched with the recipient, compared with 9.8% of donors without severe obesity (P < .01). Donors who were size mismatched weighed more than 130% of recipient’s weight.
Moreover, donors with severe obesity were more likely to have diabetes (10.4% vs. 3.1%; P < .01) and hypertension (33.3% vs. 14.8%, P < .01) compared with donors without severe obesity.
Impact on short-term, 1-year outcomes
In a univariate analysis of outcomes of heart transplants from donors with severe obesity compared with those without, investigators found no significant differences in the following outcomes between the two groups:
- acute rejection (no severe obesity, 1.8%; severe obesity, 1.5%; P = .54);
- postoperative dialysis (no severe obesity, 10%; severe obesity 9.4%; P = .53);
- pacemaker need (no severe obesity, 3.3%; severe obesity, 3.8%; P = .34);
- postoperative stroke (no severe obesity, 2.4%; severe obesity, 3.4%; P = .07);
- 1-year mortality (no severe obesity, 11.2%; severe obesity, 11.3%; P = .9);
- graft failure at 1 year (no severe obesity, 3.3%, severe obesity, 2.8%; P = .37); and
- graft failure from atherosclerosis (1.7% for both groups; P = .85).
After risk adjustment, donor severe obesity was not associated with worse recipient long-term survival (HR = 0.928; 95% CI, 0.805-1.069).
“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 nonobese donors,” Leora T. Yarboro, MD, associate professor of surgery at the University of Virginia, said in a press 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.”