Pulmonary Embolism at CT Pulmonary Angiography in Patients with COVID-19

PURPOSE: To evaluate pulmonary embolism (PE) prevalence at CT pulmonary angiography in patients testing positive for coronavirus disease 2019 (COVID-19) and factors associated with PE severity. MATERIALS AND METHODS: A retrospective, single-center study evaluated 62 patients who tested positive for COVID-19 who underwent CT pulmonary angiography between March 13 and April 5, 2020. Another 62-patient cohort who underwent CT pulmonary angiography before the first reported local COVID-19 case was retrospectively selected. The relative rate of CT pulmonary angiography positivity was recorded. For the COVID-19 positive cohort, comorbidities, laboratory values, clinical outcome, and venous thrombosis of the patients were recorded. Two thoracic radiologists assessed embolic severity using the Mastora system and evaluated right heart strain. Factors associated with PE and arterial obstruction severity were evaluated by using statistical analysis. A P value < .05 was considered significant. RESULTS: Of the patients testing positive for COVID-19, 37.1% had PE, higher than 14.5% of pre-COVID-19 patients (P = .007). d-dimer levels closest to CT pulmonary angiography date correlated with the Mastora obstruction score. Receiver operating characteristic analysis identified optimal sensitivity (95%) and specificity (71%) for PE diagnosis at 1394 ng/mL d-dimer units. The mean d-dimer level was 1774 ng/mL and 6432 ng/mL d-dimer units in CT pulmonary angiography–negative and CT pulmonary angiography–positive subgroups, respectively (P < .001). One additional patient with negative results at CT pulmonary angiography had deep venous thrombosis, thus resulting in 38.7% with PE or deep venous thrombosis, despite 40% receiving prophylactic anticoagulation. Other factors did not demonstrate significant PE association. CONCLUSION: A total of 37.1% of COVID-19 patients underwent CT pulmonary angiographic examinations diagnosing PE. PE can be a cause of decompensation in patients testing positive for COVID-19, and d-dimer can be used to stratify patients in terms of PE risk and severity. Supplemental material is available for this article. © RSNA, 2020