Donor Utilization in the Recent Era: Effect of Sex, Drugs and Increased Risk

Abstract

<h3>Purpose</h3> Recently, the number of organ donors has increased as have the number of heart transplants in the United States. However, the percentage of offered donors utilized for transplantation has remained low in prior reports. Whether this has changed in the last 15 years is not known. The effect of donor increased risk status and drug use on donor acceptance is also unclear. <h3>Methods</h3> The UNOS registry was queried for all donors offered for transplantation between 1/1/2007 and 12/31/2017. Donors utilized for heart transplant were compared to rejected hearts including demographics, hepatitis C serology (HCV), Public Health Service Increased Risk (PHSIR) designation as well as history of drug use and positive toxicology. The UNOS Tox Score (UTS) was the sum of positive historical drug use variables in the UNOS registry and the Measured Tox Score (MTS) was the sum of positive donor toxicology categories. Comparisons were made by Pearson Correlation and Chi Square. <h3>Results</h3> Over the 10 years of the study, 87816 donors aged 15 or older were offered for transplantation. In 2007 there were 7504 donors offered, increasing by 28.9 % to 9669 donors in 2017. The median donor age dropped from 45 years (IQR 28-55) in 2007 to 42 (IQR 29-54) in 2017. Heart donor acceptance increased marginally from 26.4 % in 2007 to 30.1 % in 2017 (p<0.0001 across years). Nominal logistic regression analysis revealed the strongest predictors of donor non-use were older donor age, female gender, blood type, HCV, and left ventricular hypertrophy. After excluding demographics and hypertrophy, the strongest predictors were HCV, and positive UTS or MTS, followed by PHSIR status. HCV hearts were utilized less than 1 % until 2017 when 3.5 % of such donors were accepted. The analysis was repeated limiting donor age to 39 or less, and donor age, PHSIR and UTS/MTS were still strong discriminators between the accepted and discarded heart groups. Similar results were obtained with donor age restricted to 15-30 years (n=24347, 53.9 % of hearts accepted), though more donors were accepted. <h3>Conclusion</h3> Even in the last decade, the usage of offered heart donors continues to be very low. Given evidence of safety, factors such as PHSIR, drug use and HCV should not be barriers to utilization of heart donors, particularly at younger ages.