Acute pulmonary embolism in non-hospitalized COVID-19 patients referred to CTPA by emergency department

Abstract

Objectives: To evaluate the prevalence of acute pulmonary embolism (APE) in non-hospitalized COVID-19 patients referred to CT pulmonary angiography (CTPA) by the emergency department.

Methods: From March 14 to April 6, 2020, 72 non-hospitalized patients referred by the emergency department to CTPA for COVID-19 pneumonia were retrospectively identified. Relevant clinical and laboratory data and CT scan findings were collected for each patient. CTPA scans were reviewed by two radiologists to determinate the presence or absence of APE. Clinical classification, lung involvement of COVID-19 pneumonia, and CT total severity score were compared between APE group and non-APE group.

Results: APE was identified in 13 (18%) CTPA scans. The mean age and D-dimer of patients from the APE group were higher in comparison with those from the non-APE group (74.4 vs. 59.6 years, p = 0.008, and 7.29 vs. 3.29 μg/ml, p = 0.011). There was no significant difference between APE and non-APE groups concerning clinical type, COVID-19 pneumonia lung lesions (ground-glass opacity: 85% vs. 97%; consolidation: 69% vs. 68%; crazy paving: 38% vs. 37%; linear reticulation: 69% vs. 78%), CT severity score (6.3 vs. 7.1, p = 0.365), quality of CTPA (1.8 vs. 2.0, p = 0.518), and pleural effusion (38% vs. 19%, p = 0.146).

Conclusions: Non-hospitalized patients with COVID-19 pneumonia referred to CT scan by the emergency departments are at risk of APE. The presence of APE was not limited to severe or critical clinical type of COVID-19 pneumonia.

Key points: • Acute pulmonary embolism was found in 18% of non-hospitalized COVID-19 patients referred by the emergency department to CTPA. Two (15%) patients had main, four (30%) lobar, and seven (55%) segmental acute pulmonary embolism. • Five of 13 (38%) patients with acute pulmonary embolism had a moderate clinical type. • Severity and radiological features of COVID-19 pneumonia showed no significant difference between patients with or without acute pulmonary embolism.

Keywords: CT angiography; Coronavirus; Pneumonia; Pulmonary embolism.

Fig. 1

Graph showing the patient selection process for inclusion in our study

Fig. 2

Segmental acute pulmonary embolism in COVID-19 patients: one was a 61-year-old man presenting to the emergency department for fever and myalgia during 9 days with new onset of dyspnea without desaturation. The RT-PCR for SARS-CoV-2 was positive. Unenhanced chest CT scan (a) revealed typical COVID-19 pneumonia with mild lung involvement (TSS of 7). CTPA in axial (b) and coronal reformation (c) showed a segmental acute pulmonary embolism of the right lower lobe (arrows). After 2 days of hospitalization, the patient was discharged at home with a good outcome

Fig. 3

Comparison of lung findings in a COVID-19 patient between unenhanced low-dose chest CT with deep inspiration (a) and CTPA acquisition with breath-hold without deep inspiration (b). The unenhanced series with deep inspiration allows correct analysis of the parenchyma in COVID-19 patients in comparison with CTPA series showing ventilation disturbances which may resemble false GGO images