Evaluation of the Stratus® CS Acute Care™ D-dimer assay (DDMR) using the Stratus® CS STAT Fluorometric Analyzer: A prospective multisite study for exclusion of pulmonary embolism and deep vein thrombosis

Background: D-dimer testing is an integral part of the diagnostic algorithm in excluding patients with venous thromboembolism. In this study, we prospectively evaluated the Stratus DDMR D-dimer test in patients suspected of pulmonary embolism (PE) and deep vein thrombosis (DVT). Methods: Patients suspected of venous thromboembolism were prospectively enrolled at four different clinical sites, with sodium citrate and lithium heparin plasma was tested using the DDMR D-dimer test on the Stratus CS analyzer. Results: 1,012 patients were enrolled for analysis, with 85/603 (14.1%) patients with PE and 80/443 (18.1%) with DVT, and four of the patients (0.4%) with PE and DVT. For the samples collected in 3.2% sodium citrate, the DDMR method had a sensitivity, specificity, and negative predictive value for VTE of 98.0%, 38.1%, and 99.1%, respectively. For the samples collected in lithium heparin, the DDMR method had a sensitivity, specificity, and negative predictive value (NPV) for VTE of 98.9%, 28.8%, and 99.4%, respectively. In PE, DDMR testing on citrate plasma had a sensitivity, specificity, and NPV of 98.8%, 39.5%, and 99.6%, respectively, while heparin samples had a sensitivity, specificity, and NPV for PE of 98.0%, 28.4%, and 99.1%, respectively. In DVT, citrate plasma had a sensitivity, specificity, and NPV for DVT of 97.5%, 32.0%, and 98.3%, respectively, while heparin samples had a sensitivity, specificity, and NPV for DVT of 100%, 27.8%, and 100%, respectively. Conclusion: The Stratus CS DDMR D-dimer can be used in those patients with non-high clinical pre-test probability for the exclusion of PE.