Incidence and predictors of weaning failure from veno-arterial extracorporeal membrane oxygenation therapy in patients with cardiogenic shock

Abstract Background Mortality in cardiogenic shock (CS) remains high even when mechanical circulatory support (MCS) restores adequate circulation. Despite extensive research efforts in recent years, evidence on MCS in this setting is so far neutral. Especially, weaning from MCS is a challenging aspect of daily MCS management and standardized guidance is not yet available. Purpose This study aims to investigate incidence and predictors of weaning failure from venoarterial extracorporeal membrane oxygenation (VA-ECMO) in patients with CS. Methods Patients with CS treated with VA-ECMO at 23 tertiary-care centres in 7 countries were analysed. Weaning failure was defined as death during VA-ECMO support and death within two days after VA-ECMO explantation. To evaluate whether patient or treatment specific characteristics could serve as predictors for weaning success or failure multivariable logistic regressions models were fitted. Results A total of 685 patients with CS treated with VA-ECMO were included in this study. Median age was 57 (49-66) years and 542 (77.1%) were male. More than half of the patients presented with CS due to acute myocardial infarction (AMI) (n=438, 63.9%) and prior cardiac arrest (n=431, 62.9%). Median lactate upon admission was 7.6 mmol/l (4.1-12.7). Of these, 410 patients (59.9%) were successfully weaned from VA-ECMO, whereas in 275 patients (40.1%) weaning failed. Of the successfully weaned patients 162 (39.5%) died before hospital discharge. The mortality of the overall cohort was 63.8%. AMI was slightly less common in patients with failed weaning. Age (Odds ratio (OR) 1.04, 95% confidence interval (CI): 1.02, 1.06; p<0.001) and cardiac arrest before VA-ECMO implantation (OR 1.68, 95%-CI: 1.09, 2.6; p=0.019) where the only baseline parameters associated with weaning failure. Lactate clearance within 24h after VA-ECMO initiation was associated with successful weaning (OR 0.13, 95%-CI: 0.07, 0.26; p<0.001, Figure 1). Conclusion VA-ECMO weaning is common and fails in 40% of patients in whom it is attempted. 60% of patients are discharged alive after a successful VA-ECMO weaning attempt. Older age, cardiac arrest, and slow clearing of lactate are predictors of failed ECMO weaning. These data illustrate the complex factors contributing to successful mechanical circulatory support.Figure 1