Abstract 16868: Predicted Heart Mass and Organ Offer Turn-Down in Heart Transplant

Abstract

Introduction: Size mismatch is a frequent reason for organ offer turn-down in heart transplantation (HT). While weight is frequently used as the metric for size matching in HT, several recent studies have shown that predicted heart mass (PHM) is a better predictor of mortality. Here, we sought to assess the potential impact of utilizing PHM for size matching. Methods: A data set of all potential transplant recipients from January 1, 2007 to December 31, 2016 was obtained from the United Network for Organ Sharing. For each recipient, offers turned-down for donor size/weight were selected. Donor-recipient ratio of PHM was calculated for each donor-potential recipient pair and a value of 0.85 or higher was considered adequate as determined by previous survival modeling. Distribution of PHM for offers turned-down and accepted according to sex mismatch category was assessed. Mean PHM for each sex mismatch category was compared. Results: There were 18,251 recipients in the study cohort who received 639,247 offers. Of these, 96,043 (15%) were turned down for donor size/weight. Of offers turned down, mean PHM ratio differed significantly between sex-mismatch categories. Mean donor to recipient PHM ratio was 0.75 for female donor/male potential recipient, 0.98 for female donor/female potential recipient, 0.92 for male donor/male potential recipient and 1.36 for male donor/female potential recipient pairs (p < 0.001) The percentage of offers turned-down for donor size/weight (Figure 1) but with an adequate PHM ratio (solid line) ranged from 98% for male donors/female potential recipients to 19% for female donors/male potential recipients. Conclusion: Utilizing PHM for assessment of donor-recipient size match shows that a large number of donors turned down for size would likely be an adequate size match. Thus, the use of PHM has the potential to increase donor heart utilization.