Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) provides a temporary support system for patients with cardiogenic shock refractory to conventional medical therapies. It has been reported that levosimendan may facilitate VA-ECMO weaning and improve survival. The primary objective of this review was to examine the effect of levosimendan use on VA-ECMO weaning and mortality in critically ill patients on VA-ECMO.

MEDLINE, EMBASE, and CENTRAL were searched. A pair of reviewers identified eligible clinical trials. Two reviewers extracted data and independently assessed the risk of bias. A random-effect model was used to combine data. The primary outcome was the success of weaning from VA-ECMO.

Seven studies of observational design, including a total of 630 patients, were selected in the final analysis. The sample size ranged from ten-to-240 patients, with a mean age between 53 and 65 years, and more than half of them underwent cardiac surgeries. The VA-ECMO durations varied between four and 11.6 days. Overall, levosimendan use was significantly associated with successful weaning compared with control (odds ratio [OR] 2.89, 95% CI, 1.53-5.46; p_{overall effect} = 0.001); I² = 49%). For survival, six studies (n = 617) were included in the meta-analysis involving 326 patients in the levosimendan group and 291 in the comparator group. Pooled results showed a significantly higher survival rate in the levosimendan group (OR 0.46, 95% CI, 0.30-0.71; p_{overall effect} = 0.0004; I² = 20%).

Levosimendan therapy was significantly associated with successful weaning and survival benefit in patients with cardiogenic or postcardiotomy shock needing VA-ECMO support for severe cardiocirculatory compromise. To date, there is limited literature and absence of evidence from randomized trials addressing the use of levosimendan in VA-ECMO weaning. This study may be considered a hypothesis-generating research for randomized controlled trials to confirm its findings.