The Impact of Donor Obesity on Outcomes of Donation After Circulatory Death Heart Transplantation

Objectives: In the setting of the obesity epidemic and donor organ shortage in the United States, there's a growing need to expand the donor organ eligibility criteria for orthotopic heart transplantation (OHT). Donation after circulatory death (DCD) has emerged as a promising solution, but the outcomes with obese donor hearts in DCD remains unknown.

Methods: Using the UNOS registry between 2019 and 2024, recipients of DCD OHT were stratified into three donor obesity categories by body mass index (BMI): underweight/normal (BMI <25kg/m²), overweight (BMI 25-30kg/m²), and obese (BMI >30kg/m²). These cohorts were sub-grouped by organ procurement strategies: direct procurement and preservation (DPP) and normothermic regional perfusion (NRP). Recipient and donor characteristics, and risk factors for mortality were analyzed using Cox regression hazard models. Survival at 30-days, 1-, and 5-years were analyzed using the Kaplan-Meier method.

Results: We found no significant differences in patient and graft survival between donor BMI categories at all time points. Among recipients of overweight (HR 0.38; p=0.0371) and obese (HR 0.24; p=0.0493) donor hearts, NRP was associated with decreased risk of mortality. Donor-recipient predicted heart-mass (PHM) undermatching (defined as <86%) was associated with increased risk of mortality among underweight/normal weight (HR 1.28; p=0.0323) and overweight (HR 1.08; p=0.0382) donors.

Conclusions: Donor obesity does not confer increased risk of recipient mortality in DCD OHT, particularly when utilizing NRP. PHM undermatching continues to be associated with adverse outcomes in DCD OHT.