Incidence rate of pulmonary embolism during the covid-19 lockdown period ata southern Italy public hospital

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is manifesting as a multi-dimensional disease. One of its worst complications is interstitial pneumonia with acute respiratory failure (ARF). A severe coagulopathy with poor prognosis is found in 5-10% of cases. Objectives: To investigate changes in the incidence rate of pulmonary embolism (PE) and ARF during the COVID-19 national lockdown (March-April 2020) compared to the same period before the pandemic and reference periods in previous years, with the beginning of the containment measures and public lockdown in our public hospital. Methods: In this single-center study, we explored all International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) Codes for PE (44422, 41519) and pneumonia with ARF (4848, 7889, 51882) between March and April of the years 2019 and 2020. The incidence of PE and ARF was analyzed and matched. Secondary outcomes included a number of deaths for PE and ARF. Results: Compared to March and April 2019, in the two months of 2020 no significant change in the incidence rate of PE cases (312 per 100 person-years vs 252 per 100 person-years, P=NS) and mortality (60 per 100 person-years vs 20 per 100 person-years, P=NS) was observed. On the contrary, comparing the two observation periods, a dramatic increase in pneumonia and ARF (276 per 100 person-years vs 1356 per 100 person-years, P=0,036) and mortality (20 per 100 person-years vs 360 per 100 person-years, P=0.048) was observed. No patient presented a concomitant diagnosis of PE and ARF in either observation period. Furthermore, only the age of subjects with ARF is significantly lower in the two months of 2020 compared to the same period of 2019 (63.2±13.9 vs 77.7±6.8), without sex difference. Likewise, no difference was found regarding age and sex in subjects with PE in both observation periods. Conclusion: Our study shows, with the limitations of a retrospective analysis performed in a single-center, that the COVID-19 pandemic has an impact only on COVID-19-related acute diseases and mortality as shown by the overlapping of the EP incidence rate between the two observation periods. Further studies from other hospitals are needed to verify our findings.