Background

In the early days of December 2019, first pneumonia cases of unknown origin were detected in China, and the causative pathogen was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Patients with SARS-CoV-2 infections, also shortly named as coronavirus disease 2019 (COVID-19), presented in hospitals and in family settings. First COVID-19-infection-cases in Germany were detected at the end of January 2020 in Bavaria and a strong and fast spread from this initial cluster in the German population was observed. Studies have shown that the in-hospital case-fatality rate of hospitalized patients with confirmed COVID-19-infection in Germany during the year 2020 was approximately 18% and increased dramatically if treatment on intensive care units (ICU) and/or mechanical ventilation are needed.

Although a high prevalence of venous thromboembolism (VTE) has been reported as a complication during severe COVID-19 infection in critical ill patients, unselected data of incidence of VTE in ICU patients with COVID-19 and the impact of VTE on their case-fatality are sparse.

Methods

We used the German nationwide inpatient sample to analyze all hospitalized patients with confirmed COVID-19 diagnosis in Germany January-December 2020. Patients were stratified according ICU-treatment. Incidence of VTE events as well as the impact of VTE on ICU admission and on case-fatality rate were analyzed (source: RDC of the Federal Statistical Office and the Statistical Offices of the federal states, DRG Statistics 2020, own calculations).  

Results

Overall, 176,137 hospitalizations of patients with confirmed COVID-19-infection (52.3% males; 53.6% aged ≥70years) were counted in Germany during the year 2020. Among them, 27,053 (15.4%) were treated on ICU. COVID-19-patients treated on ICU were younger (70.0 [59.0 / 79.0] vs. 72.0 [55.0 / 82.0] years, P<0.001), more often males (66.3% vs. 48.8%, P<0.001), had more frequently cardiovascular diseases (CVD) and cardiovascular risk-factors (CVRF) with increased in-hospital case-fatality (38.4% vs. 14.2%, P<0.001). ICU-treatment was independently associated with in-hospital death (OR 5.486 [95%CI 5.299-5.681], P<0.001).

VTE events occurred more often in ICU patients than in those treated on normal wards (2.0% vs. 7.4%, P<0.001). VTE was independently associated with ICU admission (OR 3.78 [95%CI 3.56-4.02, P<0.001). In addition, VTE events were in COVID-19-patients, who were treated on ICU, independently associated with in-hospital case-fatality rate (OR 1.37 [95%CI 1.24-1.51], P<0.001).

Conclusion

During the year 2020, 15.4% of the hospitalized COVID-19-patients were treated on German ICUs with a high VTE rate of 7.4%. VTE vents are independent risk factors for ICU admission and VTE events in ICU patients are independently associated with increased case-fatality.