Lisette van Dam

Clinical and CT characteristics of COVID-19 associated PE 12 183 RESULTS A total of 23 patients with proven COVID-19 pneumonia and symptomatic CTPA proven PE were included in the study. Their baseline characteristics are shown in Table 1 . All received pharmacological thromboprophylaxis. The main reason for PE suspicion was lack of clinical improvement in ventilated patients (n=13, 57%), sudden unexpected respiratory deterioration (n=7, 30%), hemodynamic collapse (n=2, 8.7%) and persistent fever of unknown origin (n=1, 4.3%). In the COVID-19 cohort, the most proximal PE was located in the main/lobar pulmonary artery in 4 (17%) patients, and the most proximal PE was in a segmental artery in 16 (70%) ( Figure 1 ). In 3 patients (13%), the PE was limited to subsegmental arteries, and 1 patient had a single subsegmental PE (4.3%). The mean total Qanadli score was 23% (SD 18%). Overall, 426/460 (93%) of the anatomical lung segments in the 23 patients were affected by COVID-19 and the mean percentage of affected lung was 58% (SD 22%). A total of 178/460 (39%) pulmonary artery segments were affected by PE; all pulmonary artery segments with PE were in lung parenchyma with radiological signs of COVID-19 pneumonia. The mean RV/LV ratio was 0.97 (SD 0.15) and the mean pulmonary trunk diameter was 29mm (SD 4.6mm). Six patients had a RV/LV ratio > 1.0 (26%). The control cohort consisted of 100 patients ( Table 1 ). The location of the most proximal PE in the COVID-19 patients was less often the main/lobar pulmonary artery than in the control patients (17% versus 47%; -30%, 95%CI -44 to -8.2%). The Qanadli score was lower in the COVID-19 patients (mean difference -8%, 95%CI -16 to -0.13) as was the mean RV/LV ratio (mean difference -0.23, 95%CI -0.39 to -0.07) and the prevalence of RV/LV ratio > 1.0 (26% versus 49%; -23%, 95%CI -41 to -0.86%). The mean pulmonary trunk diameter was comparable between cases and controls. DISCUSSION Our findings suggest that the PE phenotype in patients with COVID-19 is different from PE patients without COVID-19 pneumonia. Specifically, in COVID-19 patients, the thrombotic lesions were more distributed in the peripheral arteries of the lung, total clot burden was lower and the mean RV/LV ratio and prevalence of RV/ LV ratio > 1 were lower.