Direct comparison of the diagnostic accuracy of fifty protein biological markers of pulmonary embolism for use in the emergency department.

OBJECTIVES: Pulmonary embolism (PE) is associated with abnormal concentrations of many proteins involved in inflammation, hemostasis, and vascular injury. The authors quantified the diagnostic accuracy of a battery of protein biological markers for the detection of PE in emergency department (ED) patients.

METHODS: A random and a consecutive sample of ED patients evaluated for PE were prospectively enrolled at two academic EDs between August 2005 and April 2006. A plasma sample was obtained at enrollment, and all patients were followed by telephone and medical record review at 90 days for the development of venous thromboembolism (VTE) defined as PE or deep venous thrombosis (DVT), requiring the consensus of two of three blinded physician reviewers. Measurements of potential biological markers were performed by technicians blinded to the study objectives. The diagnostic accuracy of each biological marker was determined by the area under the receiver operating characteristic (ROC) curve.

RESULTS: Fifty potential biological markers were measured in 304 ED patients, including 22 patients (7%, 95% confidence interval [CI] = 4% to 10%) with VTE. Fourteen biological markers demonstrated an area under the curve (AUC) with the lower limit of the 95% CI > or = 0.5. Of these, three demonstrated an AUC > or = 0.7: D-dimer (0.90), C-reactive protein (CRP; 0.78), and myeloperoxidase (MPO; 0.78).

CONCLUSIONS: From 50 candidate biological markers, only D-dimer, CRP, and MPO demonstrated sufficient diagnostic accuracy to suggest potential utility as biological marker of PE.