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

Abstract

Background Understanding pulmonary embolism (PE) rate and contributing comorbid, clinical, laboratory, and imaging characteristics may aid in management of pro-thombotic events in COVID-19 (COVID+) patients. Purpose To evaluate PE prevalence on computed tomography pulmonary angiogram (CTPA) in COVID+ patients and factors associated with PE severity. Materials and Methods A retrospective, single-center study evaluated 62 COVID+ patients who underwent CTPA between March 13 and April 5, 2020. A 62-patient cohort who underwent CTPA prior to the first reported local COVID-19 case was retrogradely selected. The relative rate of CTPA-positivity was recorded. For the COVID+ cohort, comorbidities, laboratory values, clinical outcome, and venous thrombosis were recorded. Two thoracic radiologists assessed embolic severity using the Mastora system and evaluated right heart strain. Statistical analysis evaluated factors associated with PE and arterial obstruction severity. A P-value<.05 was considered significant. Results 37.1% of COVID+ patients had PE, higher than 14.5% of pre-COVID patients (P=.007). D-dimer levels closest to CTPA date correlated with Mastora obstruction score. ROC analysis identified optimal sensitivity (95%) and specificity (71%) for PE diagnosis at 1394 ng/mL DDU. The mean D-dimer was 1774 ng/mL and 6432 ng/mL DDU in CTPA-negative and CTPA-positive subgroups, respectively (P<.001). One additional CTPA-negative patient had DVT, for a total 38.7% with PE/DVT, despite 40% receiving prophylactic anticoagulation. Other factors did not demonstrate significant PE association. Conclusion 37.1% of COVID+ CTPA exams diagnosed PE. PE can be a cause of decompensation in COVID+, and D-dimer can be used to stratify patients regarding PE risk and severity.