Take the First Available Heart: Use of Higher-Risk Donors in Recipients with Pre-Transplant Mechanical Circulatory Support

Abstract

Availability of heart transplantation (HTx) is limited by donor supply. We evaluated the post-transplant outcomes of higher-risk organs in recipients supported with pre-HTx mechanical circulatory support (MCS) METHODS: In this retrospective analysis of the UNOS registry, a total of 18,338 adult patients underwent HTx from 1/2010 to 3/2018. Multi-organ transplant patients were excluded. Higher-risk organs were defined as meeting at least one of the following: donor ejection fraction<50%, donor to recipient predicted heart mass ratio<0.86, donor age>55, or ischemic time>240 minutes. The primary outcome was overall 1-year post-transplant survival RESULTS: Among HTx recipients, 4,381 (23.9%) had higher-risk donor hearts, including 3,684 recipients who had donor to recipient predicted heart mass ratio mismatch and 428 recipients with elderly donor age. There were 133 (0.7%) patients supported with pre-HTx extracorporeal membrane oxygenation (ECMO), with 39 and 94 receiving higher-risk and normal-risk organs, respectively. In this subgroup, the higher-risk organ recipients were more likely to be male (82.1 vs. 60.6%; p=0.02) (Figure 1). There was no association between use of higher-risk organs in pre-HTx ECMO patients and overall 1-year survival (71.6% [95% CI: 61.2-79.7] vs. 66.8% [95% CI: 48.8-79.7], p=0.72) (Figure 1). There were 3,776 (20.6%) patients supported with pre-HTx durable left ventricular assist device (LVAD), with 884 and 2,892 receiving higher-risk and normal-risk organs respectively. Similarly, there was no association between use of higher-risk organs in pre-HTx durable LVAD patients and overall 1-year survival (90.6% [95% CI: 88.4-92.4] vs. 90.7% [95% CI: 89.5-91.7], p=0.34) CONCLUSION: In patients supported with pre-HTx ECMO or LVAD, those who received carefully selected higher-risk organs did not have worse overall 1-year post-transplant survival. Utilization of higher-risk organs in HTx may be a feasible option to avoid prolonged MCS.