Pulmonary embolism in COVID-19, risk factors and association with inflammatory biomarkers

The coronavirus disease 2019 (COVID-19) pandemic affected millions of people worldwide resulting in a substantial number of hospitalizations. Venous thromboembolism including pulmonary embolism is a known complication of COVID-19 pneumonia although its incidence in such patients is unclear. In this multicenter retrospective cohort study, we looked at the incidence of pulmonary embolism in COVID-19 patients and its associations with various risk factors including demographics, comorbidities, inflammatory markers and coagulation profiles. We analyzed data from 193 patients of mixed ethnicity with a mean age of 51, mostly South Asians (62%) and Arabs (29%). Diabetes and hypertension were the most prevalent comorbidities accounting for 46% (N = 88) and 36% (N = 71) respectively. Critical COVID-19 illness was diagnosed in 67% of patients. The frequency of COVID-19 related pulmonary embolism was 21.8% (N = 42). We found no association of pulmonary embolism with demographic, comorbid or inflammatory variables. Only a raised D-Dimer was found to be associated with pulmonary embolism. Having a pulmonary embolism had no impact on the length of stay, critical illness, or mortality. Receiving steroids or being on standard thromboprophylaxis or weight/D-Dimer adjusted thromboprophylaxis also had no impact on the frequency of pulmonary embolism. Nine incidents of major bleeding were recorded independent of therapeutic anticoagulation. Patients admitted to the hospital for COVID-19 pneumonia had a relatively high incidence of pulmonary embolism. D-dimer was the only associated laboratory parameter associated with pulmonary embolism. However, further research is needed to evaluate its predictive and prognostic utility, particularly in an older population.