AUTHOR=Husser Daniela , Hohenstein Sven , Pellissier Vincent , Ueberham Laura , König Sebastian , Hindricks Gerhard , Meier-Hellmann Andreas , Kuhlen Ralf , Bollmann Andreas 

TITLE=Potential Contributors to Increased Pulmonary Embolism Hospitalizations During the COVID-19 Pandemic: Insights From the German-Wide Helios Hospital Network

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2021.715761

DOI=10.3389/fcvm.2021.715761

ISSN=2297-055X

ABSTRACT=Background: After the first Covid-19 infection wave, a constant increase of pulmonary embolism (PE) hospitalizations not linked with active PCR-confirmed Covid-19 has been observed but potential contributors to this observation are unclear. 
Methods: Claims data of Helios hospitals in Germany were used and consecutive cases with a hospital admission between May 6 and December 15, 2020 (PE surplus period) were analyzed and compared to corresponding periods covering the same weeks in 2016–2019. We analyzed the number of PE cases with multivariable Poisson general linear mixed models (GLMM) including (a) cohorts of 2020 versus 2016–2019, (b) the number of cases with pneumonia, (c) CTPA, and (d) volume depletion and adjusted for age and sex. The association between daily number of PE cases in 2020 and the number of preceding SARS-CoV-2 infections in Germany was modelled with Poisson regression.
Results: There were 2,404 PE hospitalizations between May 6 and December 15, 2020 as opposed to 2,112 – 2,236 (total 8,717) in the corresponding 2016 – 2019 control periods. (crude rate ratio [CRR] 1.10, 95% CI 1.05 – 1.15, P<0.01). Using multivariable Poisson GLMM adjusted for age, sex and volume depletion, PE cases were significantly associated with the number of cases with pneumonia (CRR 1.09, 95 % CI 1.07−1.10, P<0.01), and with CTPA (CRR 1.10, 95 % CI 1.09−1.10, P<0.01). The increase of PE cases in 2020 compared with the control period remained significant (CRR 1.07, 95 % CI 1.02−1.12, P<0.01) when controlling for those factors. In the 2020 cohort, number of preceding average daily Covid-19 infections were associated with increased PE case incidence. The best model (log likelihood -576) was with a window size of 4 days, i.e. average Covid-19 infections 14 – 17 days before PE hospitalization had a risk of 1.20 (95 % CI 1.12– 1.29, P<0.01). 
Conclusions: There is an increase in PE cases since early May 2020 compared to corresponding periods in 2016 – 2019. This surplus was significant even when controlling for changes in potential modulators such as demographics, volume depletion, non-Covid-19 pneumonia, CTPA use and preceding Covid-19 infections.