EXTRACORPOREAL MEMBRANE OXYGENATION IN THE THERAPY OF CARDIOGENIC SHOCK: ONE-YEAR OUTCOMES OF THE ECMO-CS TRIAL

Introduction: In the Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock (ECMO-CS) trial, immediate initiation of extracorporeal membrane oxygenation (ECMO) did not show any benefit at 30 days in comparison to early conservative strategy. We evaluated clinical outcomes at one year.
Methods: ECMO-CS trial randomized 117 patients with severe or rapidly progressing cardiogenic shock to either immediate initiation of ECMO or early conservative strategy that permitted downstream use of ECMO in case of failure of conservative therapy. Secondary endpoints analyzed at one year included composite of death, resuscitated cardiac arrest or implantation of another mechanical circulatory support, individual components of the composite endpoint, duration of mechanical ventilation, intensive care unit (ICU) stay, and hospital stay. In addition, a post hoc subgroup analysis was performed.
Results: At one year, the composite endpoint occurred in 74.1% of patients in the ECMO group and in 79.7% of patients in the early conservative group (HR 0.83, 95% CI 0.55-1.25, p=0.29). All-cause death occurred in 69.0% of subjects in the ECMO arm in 71.2% of patients in the early conservative arm (HR 1.02, 95% CI, 0.66-1.58, p=0.93). The median durations of mechanical ventilation, ICU stay and hospitalization were comparable. Significant interaction with treatment strategy and one-year mortality was observed in subgroups by baseline mean arterial pressure (≤ 60 mmHg: HR 0.54, 95% CI 0.26 to 0.99, P=0.001) and shock index (˃1.3: HR 0.48, 95% CI 0.24 to 0.96, P=0.02).
Conclusion: Among patients with cardiogenic shock, immediate initiation of ECMO did not improve clinical outcomes at one year in comparison to early conservative strategy. However, immediate ECMO initiation might be beneficial in patients with more severely compromised hemodynamic status.