There is discussion evolving around the emergence of different phenotypes of Covid-19-associated thromboembolic disease, i.e. acute pulmonary embolism vs pulmonary thrombosis and different phenotypes of in situ thrombosis. With this study, we wish to provide hospitalization, treatment and in-hospital outcome data for pulmonary embolism during the 2020 Covid-19 pandemic and a corresponding 2016-2019 control period. Methods: We performed a retrospective analysis of claims data of Helios hospitals

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... in Germany. Consecutive cases with a hospital admission between January 1 and December 15, 2020 and pulmonary embolism as primary discharge diagnosis were analyzed and compared to a corresponding period covering the same weeks in 2016-2019. Results: As previously reported for other emergent medical conditions, there was a hospitalization deficit coinciding with the 1st pandemic wave. Beginning with the 12-week interval May 6 - July 28, there was a stable surplus of hospital admissions in 2020. During this surplus period (May 6 - December 15, 2020), there were 2,449 hospitalizations including 45 PCR-confirmed Covid-19 cases (1.8%) as opposed to 8,717 in 2016-2019 (IRR 1.12, 95% CI 1.07-1.18, P<0.01). When excluding Covid-19 cases IRR was 1.10 (95% CI 1.05-1.15, P<0.01). While overall comorbidities expressed as weighted AHRQ Elixhauser Comorbidity Index (14.1+/-10.1 vs. 13.9+/-10.3, P=0.28), the presence of thrombosis (46.1 vs 45.4%, P=0.55) and surgery (3.8 vs. 4.3%, P=0.33) were comparable, coagulopathy (3.3 vs 4.5%, P=0.01) and metastatic cancer (3.0 vs 4.0%, P=0.03) as contributing factors were less frequently observed during the 2020 surplus. Interventional treatments (thrombolytic therapy, thrombectomy or inferior vena cava filter placement) were less frequently used (4.7 vs 6.6%, OR 0.72, 95% CI 0.58-0.89, P< 0.01). Similarly, intensive care (35.1 vs 38.8%, OR 0.83, 95% CI 0.75-0.92, P< 0.01) and mechanical ventilation utilization (7.2 vs 8.1%, OR 0.88, 95% CI 0.74-1.04, P=0.14) as well as in-hospital-mortality rates (7.8 vs 9.8%, OR 0.76, 95% CI 0.64-0.90, P< 0.01) were lower in 2020 compared with 2016-2019. This was associated with a shorter length of hospital stay (6.4+/-5.4 vs. 7.2+/-5.7 days, P< 0.01) during the 2020 surplus period. Conclusions: Only a minority of cases were associated with PCR-confirmed Covid-19 but this does not rule out preceding or undetected SARS-CoV-2 infection. Although there is a shift towards milder disease course, the increased incidence of hospitalizations for pulmonary embolism requires immediate attention, close surveillance and further studies.