Outcomes of Patients Bridged to Heart Transplantation with ECMO Following the UNOS Allocation Policy Change

Abstract

<h3>Purpose</h3> ECMO utilization has been associated with considerable morbidity and mortality post heart transplant (HT). Heart allocation policy changes prioritize ECMO as highest urgency. Short-term outcomes have improved following this policy change. We sought to assess longer term outcomes in patients bridged with ECMO to HT. <h3>Methods</h3> Patients bridged to HT with ECMO were identified from the UNOS Registry two years before (n=36) and after (n=266) the heart allocation policy change (10/18/2018). Baseline characteristics were compared via standard statistical analysis. Survival analysis was censored at 1-year using Kaplan-Meier analysis. Cox proportional hazard regression analysis (adjusted for age, sex, diabetes, race, ischemic time, dialysis, life support, waiting time, and HLA mismatch) was performed. <h3>Results</h3> Since the policy change, there has been a significant increase in ECMO utilization. Following the policy change, HT recipients bridged with ECMO were more likely to be male (74.8% vs 55.6%, p=0.015) with longer ischemic times (p<0.001). Notably, waitlist time was significantly lower following the policy change (5.0 days vs 13.5 days, p=0.001). Survival at 1 year was significantly improved post-policy change (Figure, p=0.0097). The policy change was associated with decreased mortality with HR 0.39 (0.18-0.82, p=0.013) and HR 0.32 (0.13-0.79, p=0.013) following adjustment. <h3>Conclusion</h3> Following heart allocation policy changes, heart transplant survival has improved in recipients bridged with ECMO with associated reduction in waitlist time. ECMO utilization has significantly increased since policy implementation. Further study is warranted to better understand the contributing factors.