Incidence of acute pulmonary embolism in COVID-19 patients: Systematic review and meta-analysis

Background: Acute pulmonary embolism (PE) has been described as a frequent and prognostically relevant complication of COVID-19 infection. Aim: We performed a systematic review and meta-analysis of the in-hospital incidence of acute PE among COVID-19 patients based on studies published within four months of COVID-19 outbreak. Material and Methods: Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in abstracting data and assessing validity. We searched Medline, Scopus and Web of Science to locate all articles published up to August 1, 2020 reporting the incidence of acute PE (or lung thrombosis) in COVID-19 patients. The pooled in-hospital incidence of acute PE among COVID-19 patients was calculated using a random effects model and presenting the related 95% confidence interval (CI). Statistical heterogeneity was measured using the Higgins I-2 statistic. Results: We analysed data from 7178 COVID-19 patients [mean age 60.4 years] included in twenty-three studies. Among patients hospitalized in general wards and intensive care unit (ICU), the pooled in-hospital incidence of PE (or lung thrombosis) was 14.7% of cases (95% CI: 9.9-21.3%, I2 =95.0%, p < 0.0001) and 23.4% (95% CI:16.7-31.8%, 12 = 88.7%, p < 0.0001), respectively. Segmental/sub-segmental pulmonary arteries were more frequently involved compared to main/lobar arteries (6.8% vs18.8%, p < 0.001). Computer tomography pulmonary angiogram (CTPA) was used only in 35.3% of patients with COVID-19 infection across six studies. Conclusions: The in-hospital incidence of acute PE among COVID-19 patients is higher in ICU patients compared to those hospitalized in general wards. CTPA was rarely used suggesting a potential underestimation of PE cases.