The Relation between Obesity and Mortality in Postcardiotomy Veno-arterial Membrane Oxygenation
Abstract
BACKGROUND
Obesity is an important health problem in cardiac surgery and among patients requiring post-cardiotomy veno-arterial extracorporeal membrane oxygenation (V-A ECMO). Still, it remains unclear whether these patients are at risk for unfavorable outcomes after post-cardiotomy V-A ECMO. The current study aimed to evaluate the association between body mass index (BMI and in-hospital outcomes in this setting.
METHODS
The Post-cardiotomy Extracorporeal Life Support (PELS-1)-study is an international, multi-center study. Patients requiring post-cardiotomy V-A ECMO in 36 centers from 16 countries between 2000-2020 were included. Patients were divided in 6 BMI categories (underweight, normal weight, overweight, Class I, Class II, and Class III obesity) according to international recommendations. Primary outcome was in-hospital mortality, secondary outcomes included major adverse events. Mixed logistic regression models were applied to evaluate associations between BMI and mortality.
RESULTS
The study cohort included 2046 patients (median age 65 years, n=838 females (41.0%). In-hospital mortality was 60.3%, without statistically significant differences among BMI classes for in-hospital mortality or major adverse events (p=0.225 and p=0.126). The crude association between BMI and in-hospital mortality was not statistically significant after adjustment for comorbidities and intra-operative variables (Class I odds ratio [OR] 1.21 95% confidence interval [CI] 0.88-1.65, Class II OR 1.45 95%CI 0.86-2.45, Class III OR 1.43 95%CI 0.62-3.33), which was confirmed in multiple sensitivity analyses.
CONCLUSIONS
BMI is not associated to in-hospital outcomes adjustment for confounders in patients undergoing post-cardiotomy V-A ECMO. Therefore, BMI itself should not be incorporated in the risk stratification for PC V-A ECMO.