Association Of D-Dimer/Fibrinogen Ratio With Pulmonary Embolism In COVID-19 Patients

Aim: This study aimed to investigate whether the D-dimer / fibrinogen ratio (DDFR) measured on admission could be used as a diagnostic marker of pulmonary embolism (PE) in coronavirus disease 2019 (COVID-19) patients. Material and Methods: This single-center, retrospective, case-control study was conducted with 204 COVID-19 patients (131 males, 73 females; mean age: 62±15.4 years; range, 28 to 97 years) between October 18, 2020, and December 18, 2020. Patients were followed during the hospital stay and for 30 days after discharge. The primary outcome was the occurrence of radiologically confirmed PE. The DDFR was calculated using the following formula: DDFR=D-dimer (ng/mL) / fibrinogen (mg/dL). Results: Six (2.9%) patients experienced PE during the follow-up. D-dimer had 63.6% sensitivity and 76.2% specificity on admission to predict thromboembolism at a cut-off of 1,375 ng/mL (area under the curve (AUC)=0.687, 95% confidence interval (CI): 0.530-0.845, p<0.05). The DDFR had 75% sensitivity and 90.5% specificity on admission to predict thromboembolism at a cut-off of 5.41 (AUC =0.846, 95% CI: 0.728-0.965, p<0.05). Conclusion: A measurement of DDFR on admission does not provide incremental value over D-dimer to recognize patients who are at risk of developing PE during and early after hospitalization for COVID-19.