What Number Are We?

Background In 2007, the United Network for Organ Sharing changed the way centers were notified of possible organ donors. In the new system, a donor sequence number (DSN) was provided signifying the position of a recipient on the list for a particular donor. Whether high DSN donors have equivalent outcomes is unknown. Methods and Results The United Network for Organ Sharing database was queried between May 2007 and March 2014. DSNs were divided into cohorts of 5 (sequence 1-5, 6-10, and so forth). Survival was analyzed by Kaplan-Meier method. In this dataset, 12 363 adult de novo heart transplants were performed, and the median DSN was 3 with 58.3% of donors allocated locally. The distance from donor to transplant hospital was ≤500 miles in 93.8% of cases. With increasing DSN group, recipients were older, with longer ischemic time, and higher distance ( P <0.001 for all comparisons). As well, with increasing DSN, donors were increasingly older, female sex, mismatched gender (female donor with a male recipient), lower ejection fraction, hypertensive, and had a history of smoking, alcohol, or cocaine use. For the whole cohort, the 1-year and 5-year survivals were 89.7% and 74.8%, respectively. Survival based on various cut points of DSN was investigated; there was no difference regardless of DSN. Conclusions Most donors since 2007 were allocated within a close geographic range. DSN functions as a crowdsourced rank with most donors being selected within low numbers. Given the similar survival of donors at higher DSN, this represents an opportunity to increase transplant volumes.