Extracorporeal Membrane Oxygenation Bridge to Heart Transplant: Trends
Following the Allocation Change
Abstract
Background: This study compared outcomes of patients bridged with
extracorporeal membrane oxygenation (ECMO) to orthotopic heart
transplantation (OHT) following the recent heart allocation policy
change. Methods: The United Network of Organ Sharing Registry (UNOS)
database was queried to examine OHT patients between 2010-2020 that were
bridged with ECMO. Waitlist outcomes and one-year posttransplant
survival were compared between patients waitlisted and/or transplanted
before and after the heart allocation policy change. Secondary outcomes
included posttransplant stroke, renal failure, and one-year rejection.
Results: 285 waitlisted patients were included, 173 (60.7%) waitlisted
under the old policy and 112 (39.3%) under the new policy. New policy
patients were more likely to receive OHT (82.2% vs 40.6%), and less
likely to be removed from the waitlist due to death or clinical
deterioration (15.0% vs 41.3%) (both P<0.001). 165 patients
bridged from ECMO to OHT were analyzed, 72 (43.6%) transplanted during
the old policy and 93 (56.3%) under the new. Median waitlist time was
reduced under the new policy (4 days [IQR 2-6] vs 47 days [IQR
10-228]). Postoperative renal failure was higher in the new policy
group (23% vs 6%; P=0.002), but rates of stroke and one-year acute
rejection were equivalent. One-year survival was lower the new policy
but was not significant (79.8% vs 90.3%; P=0.3917). Conclusions: The
UNOS heart allocation policy change has resulted in decreased waitlist
times and higher likelihood of transplant in patients supported with
ECMO. Posttransplant one-year survival has remained comparable although
absolute rates are lower.