TY - JOUR T1 - Could a D-dimer/fibrinogen ratio have a role in ruling-out venous thromboembolism? JF - Emergency Medicine Journal JO - Emerg Med J DO - 10.1136/emermed-2020-210688 SP - emermed-2020-210688 AU - Teodoro Marcianò AU - Stefano Franchini Y1 - 2021/09/07 UR - http://emj.bmj.com/content/early/2021/09/07/emermed-2020-210688.abstract N2 - Background Diagnosis of venous thromboembolism (VTE) requires chest CT angiography for pulmonary embolism and venous ultrasound for deep vein thrombosis. To reduce imaging, guidelines recommend D-dimer levels to rule-out VTE in patients with a low pre-test probability. The most widely used D-dimer cut-off is 500 ng/mL. This cut-off has low specificity, meaning many patients without disease require imaging.Methods In this retrospective chart review, we evaluated the diagnostic performance of the D-dimer/fibrinogen ratio (DFR) for identifying thromboembolism and compared it to the performance of two different D-dimer cut-offs (500 ng/mL and 1000 ng/mL) in patients who underwent a chest CT angiography or a venous ultrasound in the ED of San Raffaele Hospital, Italy, in 2017. Patients had a retrospective Wells score calculated after chart review, identifying both high-risk and low-risk pre-test probability patients for this study and low probability patients were further stratified into low-risk of deep vein thrombosis or pulmonary embolism.Results Enrolled patients included 92 with suspected pulmonary embolism and 154 with suspected deep vein thrombosis; of whom 67 (27%) were diagnosed with VTE. The most accurate cut-off for DFR in terms of discriminative power was 2.65. In the whole sample and in low-risk patients, this cut-off had the same sensitivity values of the 500 ng/mL D-dimer cut-off (97% (95% CI: 89.8% to 99.2%)), while slightly lower sensitivity values were found for the 1000 ng/mL D-dimer cut-off (95.5% (95% CI: 87.6% to 98.5%)). Specificity was higher for the 2.65 DFR cut-off (55.3% (95% CI: 48.0% to 62.4%)) in the whole sample compared with both 500 ng/mL D-dimer cut-off (22.9% (95% CI: 17.4% to 29.6%)) and 1000 ng/mL D-dimer cut-off (45.8% (95% CI: 38.7% to 53.1%)). Similar results were found in all subgroups.Conclusion A DFR, with a cut-off of 2.65, may improve the specificity for VTE patients when compared with D-dimer alone in high-risk VTE emergency medicine populations. This is exploratory information only, needing evaluation in prospective, multicentre studies, prior to consideration for use in routine clinical work.Data are available upon reasonable request. ER -