ECMO-CS Trial: VA ECMO in Rapidly Deteriorating or Severe Cardiogenic Shock

Jan Belohlavek, MD, PhD, a cardiologist and intensivist in Prague, Czech Republic, discusses results from the ECMO-CS trial (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock) that he and his colleagues recently published in Circulation. The trial was designed to compare immediate implementation of VA ECMO with an initially conservative therapy that allowed downstream use of VA-ECMO in patients with rapidly deteriorating or severe cardiogenic shock. The 30-day primary endpoint was a composite of death from any cause, resuscitated circulatory arrest, and implementation of another mechanical circulatory support device.

“We presumed 50% benefit of ECMO in cardiogenic shock,” Prof. Belohlavek explains as he describes the study that was designed several years ago. “During the study we actually realized that it might not be true, and the results, as you know, have shown that there was basically no difference in the very early ECMO versus conservative therapy.”

Prof. Belohlavek describes the patients in the study as being in “very, very advanced stages of shock,” corresponding to today’s SCAI stage D and E patients. Patients were categorized as severe cardiogenic shock (defined by hemodynamic criteria) or rapidly deteriorating cardiogenic shock (defined as requiring IV boluses of inotropes or vasopressors to maintain circulation). He reports that patients in the study had lactate levels of 5 mmol/L and were receiving very high norepinephrine doses.

“Extremely surprisingly, even for us as investigators,” Prof. Belohlavek summarizes, “there has not been any major difference and any major benefit of immediate ECMO versus immediate conservative therapy.” He explains that there was very early crossover to ECMO in the conservative/standard arm of the study with about 40% of patients implanted with downstream ECMO in this arm of the study. “So basically we compared, in 40% of patients, very early ECMO versus rescue ECMO.” This, he emphasizes, demonstrates how complex and difficult it is to treat cardiogenic shock. “It’s really not easy to prove that anything might work in such advanced stages of cardiogenic shock.”

“To interpret the study, the study doesn’t say that you shouldn’t use ECMO in cardiogenic shock,” Prof. Belohlavek states. “It just says that if you choose very early, conservative treatment and you try to monitor the patient, to hemodynamically define the status of the patient, and then later you use the ECMO or any advanced hemodynamic support, you might get some benefit.”

With this data in mind, Prof. Belohlavek emphasizes the importance of trying to implement mechanical circulatory support in these patients before they escalate to severe or rapidly deteriorating cardiogenic shock.