Diagnostic Approach to Pulmonary Embolism in Patients with COVID-19 Pneumonia: A Single-center Study

Objective: During coronavirus disease-2019 (COVID-19), numerous studies have delineated an increased risk of developing pulmonary embolism (PE). The aim of this study was to determine the prevalence of PE diagnosed on computed tomography (CT) pulmonary angiography (CTPA) in patients with COVID-19 pneumonia. To evaluate the clinical features and outcomes of PE in these individuals. In addition, the use of D-dimer and predictive scores for the diagnosis of PE in COVID-19 were assessed. Methods: All patients with COVID-19 pneumonia who underwent CTPA for suspected PE were retrospectively reviewed. Data of all clinical, laboratory, and CTPA images were obtained from electronic medical records. CTPA images were assessed for PE presence, PE distribution, and extent of lung involvement. The severity of lung involvement was graded by chest CT. D-dimer levels within 24 hours from CTPA were obtained. Clinical characteristics and laboratory data were analyzed and compared between patients with and without PE. Results: PE was detected in 96 of 220 (43.63%) patients who underwent CTPA for suspected PE. Women had a higher rate of PE (p<0.05). D-dimer values were significantly higher (p=0.001) in PE patients, and the median value in the PE group was 5.6 mu g FEU/mL (range 2-5.9). A D-dimer cut-off value of 3.95 mu g FEU/mL provides a sensitivity of 0.64 and specificity of 0.69. Area under the curve of the receiver operating characteristic curve is 0.626 [95% confidence interval (CI) = 0.550-0.703. p=0.001]. PE cases had significantly higher severe CT lung parenchymal involvement compared with non-PE (p<0.05). PE was seen in major vessels in 31.25% (30 cases) and in minor vessels 34.37% (33 cases). Backward logistic regression analysis revealed that female sex and hemoptysis increased the risk of PE by 2.643 and 10.6, respectively (p<0.05 for both). The Wells score three-level model was similar in the PE and non-PE group (p>0.05). However, only 16.7% of patients with PE had a Wells score more than 4 points (p<0.05). Conclusion: We observed that almost half of the COVID-19 pneumonia patients assessed following contrast media administration had PE on CT. The Wells score used in the general population was not helpful in the diagnosis of PE, and the pulmonary embolism severity index score was unreliable in predicting the mortality risk of PE in these patients. Higher D-dimer values may detect COVID-19-related PE. These findings indicate that CTPA could be more widely used when assessing individuals with COVID-19 pneumonia, particularly in those with elevation of D-dimer and presence of hemoptysis.