ID:58 FC-D05-3 Association Between Thoracic and Abdominal Subcutaneous Fat and Prognosis in Severe ARDS Cases Requiring VV-ECMO: A Secondary Analysis of the J-CARVE Study

Background and Purpose: Reports exist suggesting that obesity does not affect mortality in ARDS cases requiring VV-ECMO (the obesity paradox), and we also report on our own cases. One proposed reason is the impact of body fat on respiratory mechanics, but reports on body fat distribution are scarce. Therefore, we aimed to examine the impact of body fat distribution on prognosis in cases of severe respiratory failure. Methods: This is a secondary analysis of the multicenter, retrospective J-CARVE study evaluated patients with severe ARDS treated with VV-ECMO at 24 institutions in Japan between 2012 and 2022. Subcutaneous fat area was calculated from CT images of the abdomen (at the umbilical level) and chest (just above the diaphragm). Patients were grouped using quartiles of subcutaneous fat area, and the primary outcome was survival discharge. Results: 194 cases were included. Of all cases, 147 (76%) were male. The median age was 62 years, BMI was 25, SOFA score was 12, Murray score was 13, RESP score was 1. The ECMO survival rate was 83%, and the survival discharge rate was 66%. Subgroup analyses showed no significant association between thoracic or abdominal subcutaneous fat and survival at discharge in female patients (p = 0.263 and p = 0.910, respectively). In male patients, thoracic subcutaneous fat was not associated with survival at discharge (p = 0.282); however, survival at discharge was significantly higher in the group with the largest abdominal subcutaneous fat area (p = 0.013). Multivariate analysis demonstrated that males in the largest abdominal subcutaneous fat group had a significantly higher likelihood of survival at discharge compared with the smallest group (odds ratio [95% confidence interval], 3.93 [1.03–15.0]). Conclusion: These findings suggest that abdominal fat may have an influence on discharge survival than thoracic fat in severe ARDS.