Outcomes by Severity of Obesity During Extracorporeal Membrane Oxygenation Support for COVID-19

PURPOSE: Obesity adversely impacts outcomes during COVID-19 but its relation to mortality in those receiving extracorporeal membrane oxygenation (ECMO) is uncertain. METHODS: A retrospective multicenter study was conducted. Adult patients (≥18 years old) with severe COVID-19 infection placed on ECMO between March 1, 2020 to April 30, 2021, across the United States were included. A web-based database application, REDCap, was utilized to capture clinical characteristics and outcomes. Patients were grouped into tertiles of body mass index (BMI). The primary outcome was in-hospital mortality after ECMO placement assessed by a time-to-event analysis. RESULTS: Overall 444 patients (age 49, IQR: 38-57 years, 29% female, BMI: 33, IQR: 29-39 kg/m2) from 17 centers comprised the study cohort. Patients that expired during hospitalization had a similar BMI in comparison to those that were discharged (33, IQR: 29-38 vs. 34, IQR: 30-40 kg/m2, p=0.13). BMI across groups was 27, IQR: 25-29 (lowest tertile), 33, IQR: 32-34 (middle tertile), 41, IQR: 38-45 kg/m2 (highest tertile). At 90 days, in-hospital mortality between BMI tertiles was 53%, 59%, and 53%, p=0.99 (figure). After adjustment for clinical covariates including age, sex, presence of preexisting co-morbidities, cardiopulmonary arrest prior to ECMO, serum creatinine and arterial partial pressure of oxygen (PaO2) to inspired oxygen concentration (FiO2) ratio, there was no difference in hospital mortality in the middle (aHR:1.13, CI: 0.79-1.63, p=0.5) and highest (aHR: 1.38, CI: 0.95-2.01, p=0.09) tertiles in comparison to the lowest BMI tertile. CONCLUSION: Severity of obesity is not associated with death during hospitalization in patients placed on ECMO for COVID-19