Pulmonary embolism in COVID-19-patients: Diagnostic accuracy of D-dimer

Background : Since the spread of the novel Coronavirus 2(Sarscov2) lately in December 2019, proinflammatory and hypercoagulable states with marked elevation seen in D-Dimer levels have been widely described in COVID-19-patients even in the absence of pulmonary embolism (PE). Aims : We sought to compare D-dimer levels in COVID-19-patients with and without pulmonary embolism and to establish an optimal D-dimer threshold for predicting the incidence of pulmonary embolism which guides the pulmonary computed tomography angiography (CTPA) indications. Methods : We carried out a retrospective analysis of all COVID-19-patients admitted between October 1st and November 22th, 2020, at the University Hospital Center of Mohammed VI, Oujda (Morocco) who were suspected to have PE and underwent a CTPA. Demographic, clinical, characteristics as well as blood test results at the time of PE suspicion, were compared between patients with and without PE. D-dimer levels were compared using the non-parametric test of U-man Whitney. The optimal D-Dimer ' threshold to predict the occurrence of PE was established based on the receiver operating characteristics curve constructed. Results : 84 confirmed-RT-PCR COVID-19-patients with a mean age of 64.93 years (SD14,19) were included in the final analysis. PE was diagnosed on CTPA in 31 (36.9%) patients. Clinical symptoms and inhospital outcomes were similar in both groups except that more men had PE ( P = 0.025). The median value of D-dimer was significantly higher in the PE-positive group compared to the PE-negative group (14680 [IQR 33620-3450] ng/mL vs 2980 [IQR 6870-1600] ng/mL respectively, ( P < 0.001)). (Table1) A D-dimer at 2600 ng/mL was the optimal threshold for predicting PE with a sensitivity of 90.3% and AUC was 0.773 [CI 95%,0.667-0.876). Conclusions : A D-dimer cut-off value of 2600 ng/mL is a significant predictor of PE in COVID-19-patients with a sensitivity of 90.3% and a higher threshold at 3285 ng/mL a with a sensitivity of 83.9%.