The Utility of Risk Scores in Postcardiotomy Extracorporeal Membrane Oxygenation

Abstract

Background: The use of a venoarterial extracorporeal membrane oxygenation (ECMO) in the postcardiotomy shock setting (PC-ECMO) can be life-saving. Risk stratification for patients under PC-ECMO is currently challenging. The aim of this study was to assess the discriminatory ability of the different available risk scores for mortality in PC-ECMO patients. Methods: Patients aged >18 years undergoing coronary artery bypass, valve surgery, or a combination of these procedures and implanted an ECMO for postcardiotomy shock between January 2017 and June 2022 in a single ELSO registered center were retrospectively included. The STS, Euroscore II, SAVE, modified SAVE, APACHE II, and VIS scores were compared for their discriminatory ability concerning weaning and 30-day survival. Results: During the study period, 7342 patients underwent coronary bypass or valve surgery, of whom 109 patients with PC-ECMO were included in the analysis. The Euroscore II and STS scores were not associated significantly with 30-day mortality, whereas the SAVE, the modified SAVE, APACHE II, and VIS scores significantly predicted 30-day mortality. The SAVE and the modified SAVE scores showed moderate discrimination ability with AUCs of 0.672 and 0.695, while the APACHE and VIS scores had a satisfactory discriminatory ability with AUCs of 0.727 and 0.844, respectively. Conclusion: Currently used risk scores for PC-ECMO patients do not provide satisfactory predictions for weaning and survival. VIS at the 24th hour can be a valuable parameter for risk analysis and prospective studies can investigate novel PC-ECMO risk scoring systems.