Treatment time limit for successful weaning from veno-arterial extracorporeal membrane oxygenation in cardiogenic shock

Knowing the upper time limit for successful weaning from temporary mechanical circulatory support in cardiogenic shock will help with decision-making regarding advanced heart failure (HF) therapy or considering withdrawal of care. The aim of this study was to investigate the association between the support duration and successful weaning from veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in patients with cardiogenic shock.

A retrospective single-centre cohort study was conducted between January 2013 and June 2023. It included 100 consecutive patients with cardiogenic shock who were treated with VA-ECMO. Patients with out-of-hospital cardiac arrest were excluded. The primary outcome was successful weaning from VA-ECMO (i.e., VA-ECMO decannulation and survival to discharge). The association between the length of support duration and the weaning success rate was analysed. Patients were divided into three groups according to ECMO support duration: Group A (≤7 days), Group B (8-14 days), and Group C (≥15 days). Multivariable logistic regression analysis was used to evaluate the impact of the length of support duration on successful weaning of VA-ECMO. The median age was 67 years, and 73% of study participants were male. The underlying aetiologies of cardiogenic shock were as follows: acute myocardial infarction, 50; fulminant myocarditis, 19; cardiomyopathy, 15; valvular heart disease, 8; and other, 8. Seventy-five patients (75%) were attempted to wean VA-ECMO, and 67 moved on to decannulation. In total, 43 (43%) patients were successfully weaned from VA-ECMO. The median length of ECMO support duration was 8 [3-15] days. Compared with those who underwent successful ECMO decannulation, those who did not had a significantly longer support duration of VA-ECMO (5 [3-9] days vs. 12 [3-22] days, P = 0.004). The weaning success rate was significantly higher in patients with short support duration; 58% (29/50), 40% (10/25), 16% (4/25) in Groups A, B, and C, respectively (P = 0.002). Overall, none of the patients supported for over 24 days (0/11) were successfully weaned from VA-ECMO. On multivariable logistic regression analysis, the length of support duration was independently associated with successful weaning after adjusting for age, sex, underlying aetiology, and left ventricular ejection fraction (odds ratio, 0.813 [per 3 days]; 95% confidence interval, 0.679-0.914; P = 0.025).

Long support duration of VA-ECMO was significantly associated with a low rate of successful weaning in patients with cardiogenic shock. Patients who require VA-ECMO for over 1 week should start considering advanced HF therapy or withdrawal of care.