Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly being used for circulatory support in cardiogenic shock patients, although the evidence supporting its use in this context remains insufficient. The aim of the Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock (ECMO-CS) trial was to compare immediate implementation of VA-ECMO vs. an initially conservative therapy (allowing downstream use of VA-ECMO) in patients with rapidly deteriorating or severe cardiogenic shock.

Methods: This multicenter, randomized, investigator-initiated, academic clinical trial included patients with either rapidly deteriorating or severe cardiogenic shock. Patients were randomly assigned to immediate VA-ECMO or no immediate VA-ECMO. Other diagnostic and therapeutic procedures were performed as per current standard(s) of care. In the early conservative group, VA-ECMO could be used downstream in case of worsening hemodynamic status. The primary endpoint was the composite of death from any cause, resuscitated circulatory arrest, and implementation of another mechanical circulatory support device at 30 days.

Results: A total of 122 patients were randomized; after excluding 5 patients due to the absence of informed consent, 117 subjects were included in the analysis, of whom 58 randomized to immediate VA-ECMO and 59 to no immediate VA-ECMO. The composite primary endpoint occurred in 37 (63.8%) and 42 (71.2%) of patients in the immediate VA-ECMO and the no early VA-ECMO groups, respectively (hazard ratio, 0.72; 95% confidence intervals [CI], 0.46 to 1.12; P=0.21). VA-ECMO was used in 23 (39%) of no early VA-ECMO patients. The 30-day incidence of resuscitated cardiac arrest (10.3. % vs. 13.6%; risk difference [RD], -3.2; 95% CI, -15.0 to 8.5), all-cause mortality (50.0% versus 47.5%; RD, 2.5; 95% CI, -15.6 to 20.7), serious adverse events (60.3% vs. 61.0%; RD, -0.7; 95% CI, -18.4 to 17.0), sepsis, pneumonia, stroke, leg ischemia, and bleeding was not statistically different between the immediate VA-ECMO and the no immediate VA-ECMO groups.

Conclusions: Immediate implementation of VA-ECMO in patients with rapidly deteriorating or severe cardiogenic shock did not improve clinical outcomes compared with an early conservative strategy that permitted downstream use of VA-ECMO in case of worsening hemodynamic status.