Outcomes of transplant recipients on ECMO for COVID-19 respiratory failure: an ELSO registry study

ECMO outcomes in COVID-19-related respiratory failure among solid organ transplant (SOT) and hematopoietic stem-cell transplant recipients (HSCT) are poorly described. We investigated: (1) whether transplant patients (SOT/HSCT) with COVID-19 have worse outcomes than non-immunocompromised (IC) COVID-19 patients, and (2) whether among transplant recipients (SOT/HSCT), those with COVID-19 have worse outcomes than those with non-COVID-19-related respiratory failure. Additionally, we aimed to identify factors independently associated with mortality among COVID-19 transplants.

Retrospective analyses of the Extracorporeal Life Support Organization Registry from 1/1/2017 to 31/07/2023. Two comparisons were made: (1) transplant COVID-19 versus non-IC COVID-19, and (2) transplant COVID-19 versus transplant non-COVID-19 patients. Outcomes were analyzed using propensity score (PS)-adjusted, multivariable, and PS-matched analyses, adjusting for a priori identified confounders. Primary outcome was in-hospital mortality.

Among 38,270 runs, 146 transplant COVID-19, 12,552 non-IC-COVID-19 and 886 transplant non-COVID-19 runs were identified. In-hospital mortality in transplant COVID-19 patients was 75.3% and the risk was invariably increased compared to non-IC-COVID-19 (PS-adjusted OR: 2.36 [95%CI:1.61-3.46], p < 0.001, multivariable OR:2.35 [95%CI:1.59-3.49], p < 0.001, and PS-matched analysis OR: 1.89 [95%CI:1.21-2.95], p < 0.005) and transplant non-COVID-19 patients (PS-adjusted OR: 4.20 [95%CI:2.74-6.44], p < 0.001, multivariable OR: 3.79 [95%CI:2.51-5.74], p < 0.001, and PS-matched analyses OR: 3.17 [95%CI:1.90-5.28], p < 0.001). Mortality difference remained stable over time. Older age independently associated with higher mortality. This was accompanied by higher need for renal replacement therapy compared to non-IC-COVID-19 patients. Compared to transplant non-COVID-19 patients, ECMO runs and time-to-live discharge were invariably prolonged. Hemorrhagic, metabolic, pulmonary and infectious complications consistently occurred more frequently.

Mortality was high in COVID-19 transplant ECMO patients, warranting cautious use of ECMO in this population.