Pulmonary Thromboembolism in COVID-19: Venous Thromboembolism or Arterial Thrombosis?

Cavagna, Enrico; Muratore, Francesco; Ferrari, Fabio

BACKGROUND: Coronavirus disease 2019 (COVID-19) in hospitalized patients is frequently complicated by pulmonary thromboembolism (PTE). PURPOSE: To investigate CT pulmonary angiography (CTPA) findings of PTE in COVID-19 and its association with clinical and radiological conditions. MATERIALS AND METHODS: This retrospective study includes 109 hospitalized patients with COVID-19 who underwent CTPA for suspected PTE from March 20 to May 3, 2020. Data were collected from our PACS. CTPA findings of PTE were evaluated. Based on the presence or absence of PTE, patients were divided in two groups and the clinical and radiological conditions were compared using Mann-Whitney U test and χ(2) test. RESULTS: Study population comprised 82M/19F, mean age 64.1±15.0 [95% confidence interval CI:60.4-67.6] years. CTPAs were performed 19.8±6.1 [95% CI:18.1-20.2] days after the symptom onset and 10.5±3.8 [95% CI:10.2-12.9] days after the admission. Patients with PTE were 41/101(40.6%). PTE was mostly bilateral or only right (37/41[90.2%]), mainly involved segmental (37/41[90.2%]) or subsegmental (25/41[61.0%]) arteries, and affected mainly the lower lobes branches (30/41[73.2%]). Parenchymal segments supplied by segmental arteries with PTE showed a prevalent consolidation pattern (25/37[67.6%]). Deep vein thrombosis (DVT) was present only in 5/41(12.2%). Comparing groups with and without PTE, no significant difference was observed in age, gender, onset symptoms, comorbidities, tumor history, use of respiratory supports, activated partial thromboplastin time, prothrombin time and DVT. Conversely, differences were evaluated in CT lesion score (15.7±1.4 [95% CI:15.3-16.1] vs 14.1±1.1 [95% CI:13.8-14.4], p=0.035); d-dimer (p<0.001); lactate dehydrogenase (LDH) (p<0.001), and C-reactive protein (CRP) (p=0.042). CONCLUSION: PTE in COVID-19 involves mainly the segmental and sub-segmental arteries of segments affected by consolidations in patients with more severe lung disease. We hypothesize that the development of PTE in COVID-19 might be a pulmonary artery thrombosis due to severe lung inflammation and hypercoagulability rather than thromboembolism.