Waitlist Mortality and Extracorporeal Membrane Oxygenation Bridge to Lung Transplant

BACKGROUND Use of extracorporeal membrane oxygenation (ECMO) as bridge to lung transplant has increased. However, little is known about patients placed on ECMO who die while on the waiting list. Using a national lung transplant data set, we investigated variables associated with waitlist mortality of patients bridged to lung transplant. METHODS All patients supported on ECMO at time of listing were identified using the United Network for Organ Sharing database. Univariable analyses were performed using bias-reduced logistic regression. Cause-specific hazard models were used to determine the effect of variables of interest on hazard of outcomes. RESULTS From April 2016 to December 2021, 634 patients met inclusion criteria. Of these, 445 (70%) were successfully bridged to transplant, 148 (23%) died on the waitlist, and 41 (6.5%) were removed for other reasons. Univariable analysis found associations between waitlist mortality and blood group, age, body mass index, serum creatinine, lung allocation score, days on waitlist, United Network for Organ Sharing region, and being listed at a lower-volume center. Cause-specific hazard models demonstrated that patients at high-volume centers were 24% more likely to survive to trans-plant and 44% less likely to die on the waitlist. Among patients who were successfully bridged to transplant, there was no difference in survival between low-and high-volume centers. CONCLUSIONS ECMO is an appropriate strategy to bridge selected high-risk patients to lung transplant. Of those placed on ECMO with intent to transplant, about one quarter may not survive to transplantation. High-risk patients requiring advanced support strategies may be more likely to survive to transplant when bridged at a high-volume center. (Ann Thorac Surg 2023;116:156-63) & COPY; 2023 by The Society of Thoracic Surgeons

Automated summary

This study investigated variables associated with mortality on the waiting list for lung transplant in patients supported on extracorporeal membrane oxygenation (ECMO). The results showed that patients at high-risk centers were more likely to survive to transplantation. This suggests that ECMO is an appropriate strategy to bridge high-risk patients to lung transplant.