How Big is Too Big? An Analysis of Morbidly Obese Heart Donors in the UNOS Database

Abstract

Purpose As the population becomes increasingly obese, so does the pool of potential organ donors. However, many centers are hesitant to accept hearts from morbidly obese donors, limiting the donor pool. We hypothesized that utilization of hearts from obese donors would not impact recipient outcomes. . Methods Single-organ first-time adult heart transplants from 2003 to 2017 were evaluated from the UNOS database and stratified by donor BMI ≥ 40 (morbid obesity). Univariate analysis compared characteristics and short-term outcomes between groups. Kaplan-Meier analysis evaluated long-term survival. Cox regression assessed the risk-adjusted impact of donor obesity on mortality. Sensitivity analyses evaluated donor BMI cutoffs of 30, 35, and 45. Results A total of 26,532 transplants were evaluated, of which 939 (3.5%) had donors with BMI ≥ 40. Transplants from morbidly obese donors increased over time (2.2% in 2003, 5.3% in 2017). Obese donors were more likely to have diabetes (10.4% vs. 3.1%) and hypertension (33.3% vs. 14.8%, p 130% of recipient). Short-term outcomes were similar, including primary graft dysfunction (1.7% vs. 2.7%, p=0.06), pacemaker need (3.8% vs. 3.3%, p=0.34), dialysis requirement (9.4% vs. 10.0%, p=0.34) and one year survival (10.6% vs. 10.7%, p=0.93). Unadjusted survival was equivalent for those with morbidly obese donors (Log-rank p=0.67), and obesity did not impact survival in risk adjusted analysis (Table). Sensitivity analyses for donor BMI ≥ 30, 35, or 45 and analysis of BMI as a continuous variable demonstrated similar results. Conclusion We demonstrate donor obesity did not impact post-transplant outcomes. Evaluation of hearts from morbidly obese donors has the potential to expand the critically low donor pool.