High In-Hospital Mortality Rate in Patients with COVID-19 Receiving Extracorporeal Membrane Oxygenation in Germany: A Critical Analysis

Extracorporeal membrane oxygenation (ECMO) is an established treatment option for severe acute respiratory failure (1). In the context of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic with the occurrence of many severe acute respiratory distress syndrome cases, ECMO is increasingly being used worldwide depending on the available resources. Data from high-volume centers show that ECMO therapy may reduce the in-hospital mortality rate of ventilated patients who would otherwise reach more than 50–80% mortality (2, 3). When 10,021 hospitalized patients being treated in 920 different German hospitals during the first wave of the pandemic were analyzed, ECMO was reportedly used in 119 patients (1.2%) with a mortality rate of 71% (4). In contrast, a recent worldwide meta-analysis revealed a lower in-hospital mortality rate of 37% in 1,896 patients (5). The recent data of the European Extracorporeal Life Support Organization point in the same direction (6). The aim of the current research letter was to determine the in-hospital mortality rate during the first and second coronavirus disease (COVID-19) waves in Germany, a country that maintained quantitively sufficient healthcare resources during the pandemic without major restrictions. We therefore report unbiased and unselected follow-up claims data of the largest German health insurance company, including a total of 768 patients with COVID-19 who underwent ECMO admitted to hospitals between February and December 2020. The largest German health insurance provider, Allgemeine Ortskrankenkasse, provides statutory health insurance for roughly 32% of the German population. All patients included in the study completed the hospital treatment and either died or were discharged from the hospital. Baseline characteristics of the patients are depicted in Table 1. All patients included into the analysis had SARS-CoV-2 infection confirmed by PCR at a time when variants of concern were almost not present in Germany. The mean age of the patients reached 58 years (SD: 11 yr), 78% of whomwere men with a median length of hospital stay of 44 days (SD: 39 d) and a mean length of ventilation time of 31 days (SD: 24 d). Sixty-one percent of patients were tracheotomized and 60% required dialysis. Unfortunately, in-hospital mortality reached 73%. In more detail, in-hospital mortality was 56% for patients 18–49 years of age, 67% for patients 50–59 years of age, 83% for patients 60–69, and 88% for patients.69 years of age (Figure 1A, P, 0.05 for all groups compared with the youngest age group). We found no significant survival difference between men and women (Figure 1B, P=0.47). Regarding the time of initiation of ECMO therapy after onset of mechanical ventilation (either noninvasive or invasive, Figure 1C), we found the lowest mortality in those patients with early onset of ECMO therapy within the first 3 days after initiation of mechanical ventilation. However, no linear relation was observed, although all other groups demonstrated significantly higher mortality rates (Figure 1C, P, 0.05). We also had no information on the time from infection to intubation or ECMO therapy.