Expanding the heart donor pool: Can left ventricular assist devices substitute for marginal donor heart allografts?

BACKGROUND: Generally, heart transplantation with marginal donor allografts is reserved for a subset of high-risk patients. However, given the improved survival rates for patients on left ventricular assist devices, it is worth analyzing if they could potentially substitute for marginal donor allografts. This study aimed to compare survival outcomes of waitlisted patients with left ventricular assist devices who did not undergo heart transplantation to those who underwent heart transplantation with marginal allografts. METHODS: This was a retrospective cohort study of adults (≥18 years) listed for heart transplantation between 2010 and 2022 in the Organ Procurement and Transplantation Network database. A previously validated risk score was used to define marginal donor organs. The primary outcome was death after transplantation or on the waitlist, as appropriate. RESULTS: Of 5,713 patients with left ventricular assist devices, 4,683 (82%) comprised the left ventricular assist devices group and 1,030 (18%) the marginal group. The marginal cohort was older (57 49-64 vs 55 45-62 years, P < .001), similarly female (26 vs 24%, P = .16), and less often White (51 vs 60%, P < .001). Relative to the left ventricular assist devices group, the marginal group demonstrated higher 5-year survival from 2010 to 2014 (81 vs 43%, P < .001) and from 2015 to 2019 (77 vs 66%, P < .001). After adjustment, marginal patients demonstrated a significantly reduced hazard of 5-year mortality for those listed from 2010 to 2014 (hazard ratio 0.25, confidence interval 0.20-0.31; P < .001) and from 2015 to 2019 (hazard ratio 0.46, confidence interval 0.37-0.57; P < .001). CONCLUSION: Our study validates the superiority of transplantation relative to left ventricular assist devices but also underscores the survival benefit of heart transplantation with marginal donor allografts, even in high-risk patients.