DESCRIPTION OF THE CLINICAL AND RADIOLOGICAL CHARACTERISTICS OF PULMONARY EMBOLISM IN COVID-19 VERSUS NON COVID-19 PATIENTS: A MULTICENTRIC CROSS-SECTIONAL STUDY OVER A 24-MONTH PERSPECTIVE

Background: COVID-19 is associated with intense systemic inflammation and abnormal coagulation profile leading to an increased incidence of pulmonary embolism (PE). This study investigates whether PE in COVID-19 patients has different clinical, laboratory and radiological characteristics when compared to traditional PE in COVID negative patients.

Methods: We conducted an observational, multicentric, cross-sectional study on consecutive patients diagnosed with PE at admission or during hospital stay from February 21^th 2019 to February 20^th 2021. We compared clinical and laboratory data and Computer Tomography (CT) images between COVID-19 positive and COVID-19 negative patients. The extent of PE was evaluated using the Qanadli Index.

Results: Among 771 enrolled patients with acute PE, 89 were COVID-19 positive. COVID-19 patients were predominantly male (59.6% vs. 41.5%; p=0.001) and exhibited fewer classic VTE risk factors, such as previous VTE (3.5% vs. 11.5%; p=0.02) and active cancer (4.7% vs. 24.2%; p<0.0001). Additionally, these patients showed lower median Troponin-T and NT-proBNP levels (10 vs. 32 ng/L, p=0.0002; and 383 vs. 1448 pg/ml, p=0.004, respectively), a lower median Qanadli Index (4 vs. 7, p=0.0013), more distal PE obstructions (53.5% vs. 32.9%; p<0.001), and less frequent right ventricular dilatation (4.1% vs. 10.9%; p=0.09).

Conclusion: In COVID-19 patients, traditional VTE risk factors were less frequent, a possible role for in situ thrombo-inflammatory processes. The reduced radiological extent and severity of PE observed in COVID-19 patients may riflect an in situ thrombo-inflammatory process rather than classical embolization; however, this hypotesis need to be confirmed by other studies.